Michiel de Boer | University Medical Center Groningen (original) (raw)

Papers by Michiel de Boer

Physiotherapy, 2021

Background A 2019 review concluded that spinal manipulative therapy (SMT) results in similar bene... more Background A 2019 review concluded that spinal manipulative therapy (SMT) results in similar benefit compared to other interventions for chronic low back pain (LBP). Compared to traditional aggregate analyses individual participant data (IPD) meta-analyses allows for a more precise estimate of the treatment effect. Purpose To assess the effect of SMT on pain and function for chronic LBP in a IPD meta-analysis. Data sources Electronic databases from 2000 until April 2016, and reference lists of eligible trials and related reviews. Study selection Randomized controlled trials (RCT) examining the effect of SMT in adults with chronic LBP compared to any comparator. Data extraction and data synthesis We contacted authors from eligible trials. Two review authors independently conducted the study selection and risk of bias. We used GRADE to assess the quality of the evidence. A one-stage mixed model analysis was conducted. Negative point estimates of the mean difference (MD) or standardized mean difference (SMD) favors SMT.

Nutrients, 2020

We developed an implementation plan including several components to support implementation of the... more We developed an implementation plan including several components to support implementation of the “Guidelines for Healthier Canteens” in Dutch secondary schools. This study evaluated the effect of this plan on changes in the school canteen and on food and drink purchases of students. In a 6 month quasi-experimental study, ten intervention schools (IS) received support implementing the guidelines, and ten control schools (CS) received only the guidelines. Changes in the health level of the cafeteria and vending machines were assessed and described. Effects on self-reported purchase behaviour of students were analysed using mixed logistic regression analyses. IS scored higher on healthier availability in the cafeteria (77.2%) and accessibility (59.0%) compared to CS (60.1%, resp. 50.0%) after the intervention. IS also showed more changes in healthier offers in the cafeteria (range −3 to 57%, mean change 31.4%) and accessibility (range 0 to 50%, mean change 15%) compared to CS (range −...

Journal of physiotherapy, 2017

Is referral for early rehabilitation after lumbar disc surgery effective and cost-effective compa... more Is referral for early rehabilitation after lumbar disc surgery effective and cost-effective compared to no referral? Multicentre, randomised, controlled trial, and economic evaluation with concealed allocation and intention-to-treat-analysis. Adults who underwent discectomy for a herniated lumbar disc, confirmed by magnetic resonance imaging, and signs of nerve root compression corresponding to the herniation level. Early rehabilitation (exercise therapy) for 6 to 8 weeks, versus no referral, immediately after discharge. In line with the recommended core outcome set, the co-primary outcomes were: functional status (Oswestry Disability Index); leg and back pain (numerical rating scale 0 to 10); global perceived recovery (7-point Likert scale); and general physical and mental health (SF12), assessed 3, 6, 9, 12 and 26 weeks after surgery. The outcomes for the economic evaluation were quality of life and costs, measured at 6, 12 and 26 weeks after surgery. There were no clinically rele...

BMC musculoskeletal disorders, Jan 25, 2017

Transforaminal epidural injections with steroids (TESI) are used increasingly for patients with s... more Transforaminal epidural injections with steroids (TESI) are used increasingly for patients with sciatica. However there is much debate about their safety and effectiveness. It is important to identify patients that benefit most from TESI and only few trials have yet evaluated the effects in patients with acute sciatica. We describe a prospective, randomized controlled trial (RCT), with the aim to evaluate the hypothesis that TESI plus Levobupivacaine (TESI-plus) added to oral pain medication is more effective compared to pain medication alone or compared to transforaminal injection with a local anesthetic of short duration among patients with acute sciatica. We will recruit a total of 264 patients with sciatica (<8 weeks) caused by a herniated disc, from two clinical sites. Participants are randomly assigned one of three study groups: 1) oral pain medication (control group), 2) oral pain medication and TESI-plus (intervention group one), 3) oral pain medication and transforaminal...

Journal of occupational rehabilitation, Jan 30, 2016

Objective To evaluate the implementation process of a workers' health surveillance (WHS) prog... more Objective To evaluate the implementation process of a workers' health surveillance (WHS) program in a Dutch meat processing company. Methods Workers from five plants were eligible to participate in the WHS program. The program consisted of four evaluative components and an intervention component. Qualitative and quantitative methods were used to evaluate seven process aspects. Data were gathered by interviews with stakeholders, participant questionnaires, and from registries of the company and occupational health service. Results Two recruitment strategies were used: open invitation or automatic participation. Of the 986 eligible workers, 305 participated in the program. Average reach was 53 %. Two out of five program components could not be assessed on dose delivered, dose received and fidelity. If components were assessable, 85-100 % of the components was delivered, 66-100 % of the components was received by participants, and fidelity was 100 %. Participants were satisfied wit...

PloS one, 2016

Little is known regarding incidence and recurrence of sickness absence in self-employed. The prim... more Little is known regarding incidence and recurrence of sickness absence in self-employed. The primary aim of this study was to evaluate the influence of the number of prior episodes of sickness absence on the risk of subsequent periods of sickness absence in higher educated self-employed. In a historic register study based on the files of a Dutch private disability insurance company all sickness absence periods of 30 days or more were analysed. A total of 15,868 insured persons contributed 141,188 person years to the study. In total, 5608 periods of sickness absence occurred during follow-up. The hazard of experiencing a new period of sickness absence increased with every previous period, ranging from a hazard ratio of 2.83 in case of one previous period of sickness absence to a hazard ratio of 6.72 in case of four previous periods. This effect was found for both men and women and for all diagnostic categories of the first period of sickness absence. Our study shows that for all diag...

PLOS ONE, 2016

Background The impact of tobacco control policies on measures of smoking cessation behaviour has ... more Background The impact of tobacco control policies on measures of smoking cessation behaviour has often been studied, yet there is little information on their precise magnitude and duration. This study aims to measure the magnitude and timing of the impact of Dutch tobacco control policies on the rate of searching for information on smoking cessation, using Google Trends search query data. Methods An interrupted time series analysis was used to examine the effect of two types of policies (smoke-free legislation and reimbursement of smoking cessation support (SCS)) on Google searches for 'quit smoking'. Google Trends data were seasonally adjusted and analysed using autoregressive integrated moving average (ARIMA) modelling. Multiple effect periods were modelled as dummy variables and analysed simultaneously to examine the magnitude and duration of the effect of each intervention. The same analysis was repeated with Belgian search query data as a control group, since Belgium is the country most comparable to the Netherlands in terms of geography, language, history and culture. Results A significant increase in relative search volume (RSV) was found from one to four weeks (21-41%) after the introduction of the smoking ban in restaurants and bars in the Netherlands in 2008. The introduction of SCS reimbursement in 2011 was associated with a significant increase of RSV (16-22%) in the Netherlands after 3 to 52 weeks. The reintroduction of SCS in 2013 was associated with a significant increase of RSV (9-21%) in the Netherlands from 3 to 32 weeks after the intervention. No effects were found in the Belgian control group for the smoking ban and the reintroduction of SCS in 2013, but there was a significant increase in RSV shortly before and after the introduction of SCS in 2011.

PloS one, 2015

In present-day life-insurance medical underwriting practice the risk assessment starts with a sta... more In present-day life-insurance medical underwriting practice the risk assessment starts with a standard health declaration (SHD). Indication for additional medical screening depends predominantly on age and amount of insured capital. From a medical perspective it is questionable whether there is an association between the level of insured capital and medical risk in terms of mortality. The aim of the study is to examine the prognostic value of parameters from the health declaration and application form on extra mortality based on results from additional medical testing. A history register-based cohort study was conducted including about 15.000 application files accepted between 2007 and 2010. Blood pressure, lipids, cotinine and glucose levels were used as dependent variables in logistic regression models. Resampling validation was applied using 250 bootstrap samples to calculate area under the curves (AUC's). The AUC was used to discriminate between persons with and without at l...

PloS one, 2016

Fortification of staple foods is considered an effective and safe strategy to combat micronutrien... more Fortification of staple foods is considered an effective and safe strategy to combat micronutrient deficiencies, thereby improving health. While improving micronutrient status might be expected to have positive effects on immunity, some studies have reported increases in infections or inflammation after iron supplementation. To study effects of micronutrient-fortified rice on hookworm infection in Cambodian schoolchildren. A double-blinded, cluster-randomized trial was conducted in 16 Cambodian primary schools partaking in the World Food Program school meal program. Three types of multi-micronutrient fortified rice were tested against placebo rice within the school meal program: UltraRice_original, UltraRice_improved and NutriRice. Four schools were randomly assigned to each study group (placebo n = 492, UltraRice_original n = 479, UltraRice_improved n = 500, NutriRice n = 506). Intestinal parasite infection was measured in fecal samples by Kato-Katz method at baseline and after thr...

PLOS ONE, 2015

The aim of the current study was to evaluate the effects of and adherence to an active video game... more The aim of the current study was to evaluate the effects of and adherence to an active video game promotion intervention on anthropometrics, sedentary screen time and consumption of sugar-sweetened beverages and snacks among non-active video gaming adolescents who primarily were of healthy weight. Methods We assigned 270 gaming (i.e. !2 hours/week non-active video game time) adolescents randomly to an intervention group (n = 140) (receiving active video games and encouragement to play) or a waiting-list control group (n = 130). BMI-SDS (SDS = adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds were measured at baseline, at four and ten months follow-up (primary outcomes). Sedentary screen time, physical activity, consumption of sugar-sweetened beverages and snacks, and process measures (not at baseline) were assessed with self-reports at baseline, one, four and ten months follow-up. Multi-level-intention to treat-regression analyses were conducted. Results The control group decreased significantly more than the intervention group on BMI-SDS (β = 0.074, 95%CI: 0.008;0.14), and sum of skinfolds (β = 3.22, 95%CI: 0.27;6.17) (overall effects). The intervention group had a significantly higher decrease in self-reported nonactive video game time (β =-1.76, 95%CI:-3.20;-0.32) and total sedentary screen time (Exp PLOS ONE |

International Archives of Occupational and Environmental Health, 2014

Objective: To investigate the effectiveness of occupational health interventions in the meat proc... more Objective: To investigate the effectiveness of occupational health interventions in the meat processing industry on work and health-related outcomes. Methods: A systematic literature review was performed. PubMed, Embase, and The Cochrane Library were searched. Studies were included when they reported on an intervention among employees in the meat processing industry and with outcomes related to work or health. Studies were assessed on risk of bias and data were synthesized by type of intervention. Results: A total of 13 articles reporting on two randomized controlled trials and nine nonrandomized intervention studies were retrieved. Studies were categorized into three topics: ergonomics programs, skin protection, and Q fever vaccination. All studies had high risk of bias. Based on four studies, there was limited evidence for workplace health and safety programs showing reductions in musculoskeletal injury severity, reduction of lost work days, and reduction of costs and claims for several musculoskeletal disorders. There was limited evidence for added rest breaks resulting in improved productivity at the end of a workday and in reductions of perceived discomfort in various body regions at the end of the workday. One study on skin protection showed reductions of eczema prevalence, although evidence was moderate. Based on four studies, there was high quality evidence for strong effectiveness of Q fever vaccination. Conclusion: This review presents evidence for the effectiveness of a variety of workplace interventions. There was limited evidence for effectiveness of ergonomic interventions, moderate evidence of a skin protection intervention, and strong evidence for Q fever vaccination.

Journal of Occupational Rehabilitation, 2015

Background Workers' health surveillance (WHS) programs commonly measure a large number of indicat... more Background Workers' health surveillance (WHS) programs commonly measure a large number of indicators addressing health habits and health risks. Recently, work ability and functional capacity have been included as important risk measures in WHS. In order to address work ability appropriately, knowledge of associations with work and health measures is necessary. The objective of this study was to evaluate which of the factors measured in a WHS are independently associated with work ability in a group of meat processing workers. Methods A cross-sectional study was performed in a large meat processing company in The Netherlands. Data were collected during a WHS between February 2012 and March 2014. Personal characteristics, health habits and health-risk indicators, functional capacity, and work-related factors were measured. Work ability was measured with the Work Ability Index and was used as dependent variable. Univariable and multivariable logistic regression analyses were conducted, a receiver operating characteristic curve was constructed and the area under the curve (AUC) was calculated. Results Data sets from 230 employees were used for analyses. The average age was 53 years and the average work ability index score was 39.3. In the final multivariable model age (OR 0.94), systolic blood pressure (OR 1.03), need for recovery (OR 0.56), and overhead work capacity (OR 3.95) contributed significantly. The AUC for this model was 0.81 (95 % CI 0.75-0.86). Conclusion Findings from the current study indicate that multifactorial outcomes (age, systolic blood pressure, need for recovery, and overhead work capacity) from a WHS were independently associated with work ability. These factors can be used to assess employees at risk for low work ability and might provide directions for interventions. Keywords Occupational health Á Health risk appraisal Á Work ability Á Functional capacity evaluation Á Meat-packing industry Electronic supplementary material The online version of this article (

BMC public health, Jan 4, 2015

BackgroundAn ageing workforce combined with increasing health problems in ageing workers implies ... more BackgroundAn ageing workforce combined with increasing health problems in ageing workers implies the importance of evidence-based interventions to enhance sustainable employability. The aim of this study is to evaluate the effectiveness of the `Staying healthy at work¿ problem-solving based intervention compared to business as usual.MethodsThis study was designed as a quasi-experimental trial with a one-year follow-up. Measurements were performed at baseline, three and twelve months. The problem-solving based intervention provides a strategy for increasing the awareness of ageing workers of their role and responsibility in living sustainable, healthy working lives. The primary outcomes were work ability, vitality and productivity. Secondary outcomes were perceived fatigue, psychosocial work characteristics, work attitude, self-efficacy and work engagement.ResultsAnalyses were performed on the 64 workers in the intervention and 61 workers from the business as usual group. No effects ...

Annals of Behavioral Medicine, 2014

Background Food portion sizes influence energy intake. Purpose The purpose of this paper is to de... more Background Food portion sizes influence energy intake. Purpose The purpose of this paper is to determine effectiveness of the "PortionControl@HOME" intervention on body mass index and portion control behavior. Methods A randomized controlled trial among 278 overweight and obese participants was conducted. PortionControl@HOME aimed to increase: portion size awareness, portion control behavior, portion control cooking skills, and to create a home environment favoring portion control. Results Intention-to-treat multi-level regression analysis indicated statistically significant effects of the intervention on portion control behavior at 3, 6, and 12 months follow-up. The effect on body mass index was significant only at 3 months follow-up and when outliers (n=3) were excluded (B=−0.45; 95 %CI=−0.88 to −0.04). The intervention effect on body mass index was mediated by portion control behavior. Conclusions The intervention improves portion control behavior, which in turn influence body mass index. Once the intervention ceased, sustained effects on body mass index were no longer evident. (Current-Controlled-Trials ISRCT N12363482).

Spine, 2011

Study Design. Systematic review of interventions. Objective. To assess the effects of spinal mani... more Study Design. Systematic review of interventions. Objective. To assess the effects of spinal manipulative therapy (SMT) for chronic low-back pain. Summary of Background Data. SMT is one of the many therapies for the treatment of low-back pain, which is a worldwide, extensively practiced intervention. Methods. Search methods. An experienced librarian searched for randomized controlled trials (RCTs) in multiple databases up to June 2009. Selection criteria. RCTs that examined manipulation or mobilization in adults with chronic low-back pain were included. L ow-back pain is a common and disabling disorder in western society, which represents a great fi nancial burden in the form of direct costs resulting from loss of work and medical expenses, as well as indirect costs. 1 Therefore, adequate treatment of low-back pain is an important issue for patients, treating clinicians, and healthcare policy makers. Spinal manipulative therapy (SMT) is widely used for acute and chronic low-back pain, which has been examined in many randomized controlled trials (RCTs). These trials have been summarized in numerous recent systematic reviews, 2-5 which have formed the basis for recommendations in clinical guidelines. 6-11 Most notably, these guidelines are largely dependent on an earlier version of this Cochrane review. 12 That review concluded that SMT was moderately

Spine, 2013

Background Many therapies exist for the treatment of low-back pain including spinal manipulative ... more Background Many therapies exist for the treatment of low-back pain including spinal manipulative therapy (SMT), which is a worldwide, extensively practised intervention. This report is an update of the earlier Cochrane review, first published in January 2004 with the last search for studies up to January 2000. Objectives To examine the effects of SMT for acute low-back pain, which is defined as pain of less than six weeks duration. Search methods A comprehensive search was conducted on 31 March 2011 in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, PEDro, and the Index to Chiropractic Literature. Other search strategies were employed for completeness. No limitations were placed on language or publication status. Selection criteria Randomized controlled trials (RCTs) which examined the effectiveness of spinal manipulation or mobilization in adults with acute low-back pain were included. In addition, studies were included if the pain was predominantly in the lower back but the study allowed mixed populations, including participants with radiation of pain into the buttocks and legs. Studies which exclusively evaluated sciatica were excluded. No other restrictions were placed on the setting nor the type of pain. The primary outcomes were back pain, backpain specific functional status, and perceived recovery. Secondary outcomes were return-to-work and quality of life. SMT was defined as any hands-on therapy directed towards the spine, which includes both manipulation and mobilization, and includes studies from chiropractors, manual therapists, and osteopaths. Data collection and analysis Two review authors independently conducted the study selection and risk of bias (RoB) assessment. Data extraction was checked by the second review author. The effects were examined in the following comparisons: SMT versus 1) inert interventions, 2) sham SMT, 3) other interventions, and 4) SMT as an additional therapy. In addition, we examined the effects of different SMT techniques 1 Spinal manipulative therapy for acute low-back pain (Review)

Scandinavian Journal of Work, Environment & Health, 2013

A broad range of possible predictors of recurrent sickness absence (SA) among workers with common... more A broad range of possible predictors of recurrent sickness absence (SA) among workers with common mental disorders (CMD) is investigated over 12 months follow-up. The results show that work-related factors, especially conflicts with supervisor and company size >100 employees, rather than disease-related factors predict recurrent SA among workers who returned to work after SA due to CMD.

Scandinavian Journal of Work, Environment & Health, 2012

Noordik E, van der Klink JJ, Geskus RB, de Boer MR, van Dijk FJH, Nieuwenhuijsen K. Effectiveness... more Noordik E, van der Klink JJ, Geskus RB, de Boer MR, van Dijk FJH, Nieuwenhuijsen K. Effectiveness of an exposure-based return-to-work program for workers on sick leave due to common mental disorders: a clusterrandomized controlled trial.

Preventive Medicine, 2012

Objective. Fiscal policies may form a solution in improving dietary intake. This study aimed to e... more Objective. Fiscal policies may form a solution in improving dietary intake. This study aimed to examine the effectiveness of varying taxing and subsiding schemes to stimulate healthier food purchases. Methods. A randomized controlled trial with three levels of price reduction on healthy foods (no; 25%; 50%) × three levels of price increase on unhealthy foods (5%; 10%; 25%) factorial design was used. 150 participants were randomized into one of nine conditions and were asked to purchase groceries at a web-based supermarket. Data were collected in the Netherlands in January-February 2010 and analyzed using analysis of covariance. Results. Subjects receiving 50% discount purchased significantly more healthy foods than subjects receiving no (mean difference = 6.62 items, p b 0.01) or 25% discount (mean difference = 4.87 items, p b 0.05). Moreover, these subjects purchased more vegetables (mean difference = 821 g; p b 0.05 compared to no discount). However, participants with the highest discount also purchased significantly more calories. No significant effects of the price increases on unhealthy foods were found. Conclusion. Price decreases are effective in stimulating healthy food purchases, but the proportion of healthy foods remains unaffected. Price increases up to 25% on unhealthier products do not significantly affect food purchases. Future studies are important to validate these results in real supermarkets and across different countries.

Occupational and Environmental Medicine, 2013

General introduction | Chapter 1 13 process. The SHARP-at work intervention is provided by OPs to... more General introduction | Chapter 1 13 process. The SHARP-at work intervention is provided by OPs to align with the Dutch OP guideline on the management of mental health problems of workers, and because OPs are closely connected to the work environment. OPs guide workers through the fivestep problem solving process to find and implement solutions for problems/ opportunities experienced when back at work. OPs monitor that all steps are taken and activate and support the worker when needed. Furthermore, OPs empower the worker to define the problems and design solutions. Two to five consultations are recommended to the OPs, and assignments are available for each step of the intervention. The first assignment is the key element of the intervention. In this assignment, workers have to make an inventory of problems and opportunities at work and, subsequently, to define if help is needed to solve the problems or realise the opportunities. THESIS OBJECTIVE AND RESEARCH QUESTIONS The objective of this thesis is to generate knowledge on the prevention of recurrent sickness absence in workers who returned to work after sickness absence due to CMDs. The main focus is on the evaluation of the effectiveness of the SHARP-at work intervention in preventing recurrent sickness absence in workers who returned to work after sickness absence due to CMD. Alongside this effect evaluation, a process evaluation and an economic evaluation are presented. The process evaluation is helpful in explaining the results of the effect evaluation and whether these results are attributable to the SHARP-at work intervention. As part of the process evaluation, an indepth exploration of challenges with recruiting research participants by OPs is described. The economic evaluation provides information on the cost-effectiveness and cost-benefit of the intervention. Next to the evaluation of the SHARP-at work intervention, a systematic literature review is presented on interventions to facilitate return to work in adults with adjustment disorders. A specific focus on adjustment disorders as a subgroup of CMDs is chosen as this group has often been investigated in relation to RTW. Also, predictors for recurrent sickness absence among workers with CMDs are investigated. The following research questions form the basis of this thesis: Research question 1: Which interventions are effective in facilitating return to work in workers with adjustment disorders? Research question 2: Is the SHARP-at work intervention effective in preventing recurrent sickness absence and improving mental health, work functioning and problem solving coping in workers who returned to work after sickness absence due to CMDs compared to care as usual? Chapter 1 | General introduction 14 Research question 3: Is the SHARP-at work intervention conducted according to the protocol, does it differ from care as usual, and how are the key elements of the intervention related to the effect outcome (i.e. recurrent sickness absence)? Research question 4: What are barriers and facilitators for participant recruitment by occupational physicians? Research question 5: Is the SHARP-at work intervention cost-effective and costbeneficial compared to care as usual? Research question 6: Which factors predict recurrent sickness absence in workers who returned to work after sickness absence due to CMDs? THESIS OUTLINE This first chapter provides an overall introduction to the topic of the thesis to address the importance of the topic, explain the context and describe relevant constructs. In Chapter 2, the results of a systematic literature review are presented on the effectiveness of interventions to enhance return to work in workers with adjustment disorders. Chapter 3 describes the study design of the cluster-RCT with an effect evaluation, process evaluation and economic evaluation of the SHARP-at work intervention compared to care as usual. Chapter 4 presents the effect of the SHARP-at work intervention on preventing recurrent sickness absence in workers who returned to work after sickness absence due to CMDs. Moreover, the effects on mental health complaints, work functioning and coping behaviour are evaluated. In Chapter 5, the process evaluation of the SHARP-at work intervention is described. The chapter focuses on: 1) evaluating whether the SHARP-at work intervention was conducted according to the protocol and differed from care as usual, and 2) investigating the relationship between the key elements of the intervention and the primary outcome of the effect evaluation (i.e. recurrent sickness absence). Chapter 6 focuses on problems with participant recruitment by OPs. Barriers and facilitators for recruitment as experienced by OPs are reported, and the relationship between OP's personal and work characteristics and the recruitment of participants is evaluated. Chapter 7 addresses the economic evaluation of the SHARP-at work intervention and presents the costeffectiveness and cost-benefit evaluations. In Chapter 8, predictors for recurrent sickness absence in workers who returned to work after sickness absence due to CMDs are investigated. In Chapter 9, a general discussion is provided. The main research results are summarized and discussed, methodological considerations are addressed and the implications of this thesis for future research and practice are presented. 16 23. van der Klink JJ, Blonk RW, Schene AH, van Dijk FJ. Reducing long term sickness absence by an activating intervention in adjustment disorders: A cluster randomised controlled design.

Physiotherapy, 2021

Background A 2019 review concluded that spinal manipulative therapy (SMT) results in similar bene... more Background A 2019 review concluded that spinal manipulative therapy (SMT) results in similar benefit compared to other interventions for chronic low back pain (LBP). Compared to traditional aggregate analyses individual participant data (IPD) meta-analyses allows for a more precise estimate of the treatment effect. Purpose To assess the effect of SMT on pain and function for chronic LBP in a IPD meta-analysis. Data sources Electronic databases from 2000 until April 2016, and reference lists of eligible trials and related reviews. Study selection Randomized controlled trials (RCT) examining the effect of SMT in adults with chronic LBP compared to any comparator. Data extraction and data synthesis We contacted authors from eligible trials. Two review authors independently conducted the study selection and risk of bias. We used GRADE to assess the quality of the evidence. A one-stage mixed model analysis was conducted. Negative point estimates of the mean difference (MD) or standardized mean difference (SMD) favors SMT.

Nutrients, 2020

We developed an implementation plan including several components to support implementation of the... more We developed an implementation plan including several components to support implementation of the “Guidelines for Healthier Canteens” in Dutch secondary schools. This study evaluated the effect of this plan on changes in the school canteen and on food and drink purchases of students. In a 6 month quasi-experimental study, ten intervention schools (IS) received support implementing the guidelines, and ten control schools (CS) received only the guidelines. Changes in the health level of the cafeteria and vending machines were assessed and described. Effects on self-reported purchase behaviour of students were analysed using mixed logistic regression analyses. IS scored higher on healthier availability in the cafeteria (77.2%) and accessibility (59.0%) compared to CS (60.1%, resp. 50.0%) after the intervention. IS also showed more changes in healthier offers in the cafeteria (range −3 to 57%, mean change 31.4%) and accessibility (range 0 to 50%, mean change 15%) compared to CS (range −...

Journal of physiotherapy, 2017

Is referral for early rehabilitation after lumbar disc surgery effective and cost-effective compa... more Is referral for early rehabilitation after lumbar disc surgery effective and cost-effective compared to no referral? Multicentre, randomised, controlled trial, and economic evaluation with concealed allocation and intention-to-treat-analysis. Adults who underwent discectomy for a herniated lumbar disc, confirmed by magnetic resonance imaging, and signs of nerve root compression corresponding to the herniation level. Early rehabilitation (exercise therapy) for 6 to 8 weeks, versus no referral, immediately after discharge. In line with the recommended core outcome set, the co-primary outcomes were: functional status (Oswestry Disability Index); leg and back pain (numerical rating scale 0 to 10); global perceived recovery (7-point Likert scale); and general physical and mental health (SF12), assessed 3, 6, 9, 12 and 26 weeks after surgery. The outcomes for the economic evaluation were quality of life and costs, measured at 6, 12 and 26 weeks after surgery. There were no clinically rele...

BMC musculoskeletal disorders, Jan 25, 2017

Transforaminal epidural injections with steroids (TESI) are used increasingly for patients with s... more Transforaminal epidural injections with steroids (TESI) are used increasingly for patients with sciatica. However there is much debate about their safety and effectiveness. It is important to identify patients that benefit most from TESI and only few trials have yet evaluated the effects in patients with acute sciatica. We describe a prospective, randomized controlled trial (RCT), with the aim to evaluate the hypothesis that TESI plus Levobupivacaine (TESI-plus) added to oral pain medication is more effective compared to pain medication alone or compared to transforaminal injection with a local anesthetic of short duration among patients with acute sciatica. We will recruit a total of 264 patients with sciatica (<8 weeks) caused by a herniated disc, from two clinical sites. Participants are randomly assigned one of three study groups: 1) oral pain medication (control group), 2) oral pain medication and TESI-plus (intervention group one), 3) oral pain medication and transforaminal...

Journal of occupational rehabilitation, Jan 30, 2016

Objective To evaluate the implementation process of a workers' health surveillance (WHS) prog... more Objective To evaluate the implementation process of a workers' health surveillance (WHS) program in a Dutch meat processing company. Methods Workers from five plants were eligible to participate in the WHS program. The program consisted of four evaluative components and an intervention component. Qualitative and quantitative methods were used to evaluate seven process aspects. Data were gathered by interviews with stakeholders, participant questionnaires, and from registries of the company and occupational health service. Results Two recruitment strategies were used: open invitation or automatic participation. Of the 986 eligible workers, 305 participated in the program. Average reach was 53 %. Two out of five program components could not be assessed on dose delivered, dose received and fidelity. If components were assessable, 85-100 % of the components was delivered, 66-100 % of the components was received by participants, and fidelity was 100 %. Participants were satisfied wit...

PloS one, 2016

Little is known regarding incidence and recurrence of sickness absence in self-employed. The prim... more Little is known regarding incidence and recurrence of sickness absence in self-employed. The primary aim of this study was to evaluate the influence of the number of prior episodes of sickness absence on the risk of subsequent periods of sickness absence in higher educated self-employed. In a historic register study based on the files of a Dutch private disability insurance company all sickness absence periods of 30 days or more were analysed. A total of 15,868 insured persons contributed 141,188 person years to the study. In total, 5608 periods of sickness absence occurred during follow-up. The hazard of experiencing a new period of sickness absence increased with every previous period, ranging from a hazard ratio of 2.83 in case of one previous period of sickness absence to a hazard ratio of 6.72 in case of four previous periods. This effect was found for both men and women and for all diagnostic categories of the first period of sickness absence. Our study shows that for all diag...

PLOS ONE, 2016

Background The impact of tobacco control policies on measures of smoking cessation behaviour has ... more Background The impact of tobacco control policies on measures of smoking cessation behaviour has often been studied, yet there is little information on their precise magnitude and duration. This study aims to measure the magnitude and timing of the impact of Dutch tobacco control policies on the rate of searching for information on smoking cessation, using Google Trends search query data. Methods An interrupted time series analysis was used to examine the effect of two types of policies (smoke-free legislation and reimbursement of smoking cessation support (SCS)) on Google searches for 'quit smoking'. Google Trends data were seasonally adjusted and analysed using autoregressive integrated moving average (ARIMA) modelling. Multiple effect periods were modelled as dummy variables and analysed simultaneously to examine the magnitude and duration of the effect of each intervention. The same analysis was repeated with Belgian search query data as a control group, since Belgium is the country most comparable to the Netherlands in terms of geography, language, history and culture. Results A significant increase in relative search volume (RSV) was found from one to four weeks (21-41%) after the introduction of the smoking ban in restaurants and bars in the Netherlands in 2008. The introduction of SCS reimbursement in 2011 was associated with a significant increase of RSV (16-22%) in the Netherlands after 3 to 52 weeks. The reintroduction of SCS in 2013 was associated with a significant increase of RSV (9-21%) in the Netherlands from 3 to 32 weeks after the intervention. No effects were found in the Belgian control group for the smoking ban and the reintroduction of SCS in 2013, but there was a significant increase in RSV shortly before and after the introduction of SCS in 2011.

PloS one, 2015

In present-day life-insurance medical underwriting practice the risk assessment starts with a sta... more In present-day life-insurance medical underwriting practice the risk assessment starts with a standard health declaration (SHD). Indication for additional medical screening depends predominantly on age and amount of insured capital. From a medical perspective it is questionable whether there is an association between the level of insured capital and medical risk in terms of mortality. The aim of the study is to examine the prognostic value of parameters from the health declaration and application form on extra mortality based on results from additional medical testing. A history register-based cohort study was conducted including about 15.000 application files accepted between 2007 and 2010. Blood pressure, lipids, cotinine and glucose levels were used as dependent variables in logistic regression models. Resampling validation was applied using 250 bootstrap samples to calculate area under the curves (AUC's). The AUC was used to discriminate between persons with and without at l...

PloS one, 2016

Fortification of staple foods is considered an effective and safe strategy to combat micronutrien... more Fortification of staple foods is considered an effective and safe strategy to combat micronutrient deficiencies, thereby improving health. While improving micronutrient status might be expected to have positive effects on immunity, some studies have reported increases in infections or inflammation after iron supplementation. To study effects of micronutrient-fortified rice on hookworm infection in Cambodian schoolchildren. A double-blinded, cluster-randomized trial was conducted in 16 Cambodian primary schools partaking in the World Food Program school meal program. Three types of multi-micronutrient fortified rice were tested against placebo rice within the school meal program: UltraRice_original, UltraRice_improved and NutriRice. Four schools were randomly assigned to each study group (placebo n = 492, UltraRice_original n = 479, UltraRice_improved n = 500, NutriRice n = 506). Intestinal parasite infection was measured in fecal samples by Kato-Katz method at baseline and after thr...

PLOS ONE, 2015

The aim of the current study was to evaluate the effects of and adherence to an active video game... more The aim of the current study was to evaluate the effects of and adherence to an active video game promotion intervention on anthropometrics, sedentary screen time and consumption of sugar-sweetened beverages and snacks among non-active video gaming adolescents who primarily were of healthy weight. Methods We assigned 270 gaming (i.e. !2 hours/week non-active video game time) adolescents randomly to an intervention group (n = 140) (receiving active video games and encouragement to play) or a waiting-list control group (n = 130). BMI-SDS (SDS = adjusted for mean standard deviation score), waist circumference-SDS, hip circumference and sum of skinfolds were measured at baseline, at four and ten months follow-up (primary outcomes). Sedentary screen time, physical activity, consumption of sugar-sweetened beverages and snacks, and process measures (not at baseline) were assessed with self-reports at baseline, one, four and ten months follow-up. Multi-level-intention to treat-regression analyses were conducted. Results The control group decreased significantly more than the intervention group on BMI-SDS (β = 0.074, 95%CI: 0.008;0.14), and sum of skinfolds (β = 3.22, 95%CI: 0.27;6.17) (overall effects). The intervention group had a significantly higher decrease in self-reported nonactive video game time (β =-1.76, 95%CI:-3.20;-0.32) and total sedentary screen time (Exp PLOS ONE |

International Archives of Occupational and Environmental Health, 2014

Objective: To investigate the effectiveness of occupational health interventions in the meat proc... more Objective: To investigate the effectiveness of occupational health interventions in the meat processing industry on work and health-related outcomes. Methods: A systematic literature review was performed. PubMed, Embase, and The Cochrane Library were searched. Studies were included when they reported on an intervention among employees in the meat processing industry and with outcomes related to work or health. Studies were assessed on risk of bias and data were synthesized by type of intervention. Results: A total of 13 articles reporting on two randomized controlled trials and nine nonrandomized intervention studies were retrieved. Studies were categorized into three topics: ergonomics programs, skin protection, and Q fever vaccination. All studies had high risk of bias. Based on four studies, there was limited evidence for workplace health and safety programs showing reductions in musculoskeletal injury severity, reduction of lost work days, and reduction of costs and claims for several musculoskeletal disorders. There was limited evidence for added rest breaks resulting in improved productivity at the end of a workday and in reductions of perceived discomfort in various body regions at the end of the workday. One study on skin protection showed reductions of eczema prevalence, although evidence was moderate. Based on four studies, there was high quality evidence for strong effectiveness of Q fever vaccination. Conclusion: This review presents evidence for the effectiveness of a variety of workplace interventions. There was limited evidence for effectiveness of ergonomic interventions, moderate evidence of a skin protection intervention, and strong evidence for Q fever vaccination.

Journal of Occupational Rehabilitation, 2015

Background Workers' health surveillance (WHS) programs commonly measure a large number of indicat... more Background Workers' health surveillance (WHS) programs commonly measure a large number of indicators addressing health habits and health risks. Recently, work ability and functional capacity have been included as important risk measures in WHS. In order to address work ability appropriately, knowledge of associations with work and health measures is necessary. The objective of this study was to evaluate which of the factors measured in a WHS are independently associated with work ability in a group of meat processing workers. Methods A cross-sectional study was performed in a large meat processing company in The Netherlands. Data were collected during a WHS between February 2012 and March 2014. Personal characteristics, health habits and health-risk indicators, functional capacity, and work-related factors were measured. Work ability was measured with the Work Ability Index and was used as dependent variable. Univariable and multivariable logistic regression analyses were conducted, a receiver operating characteristic curve was constructed and the area under the curve (AUC) was calculated. Results Data sets from 230 employees were used for analyses. The average age was 53 years and the average work ability index score was 39.3. In the final multivariable model age (OR 0.94), systolic blood pressure (OR 1.03), need for recovery (OR 0.56), and overhead work capacity (OR 3.95) contributed significantly. The AUC for this model was 0.81 (95 % CI 0.75-0.86). Conclusion Findings from the current study indicate that multifactorial outcomes (age, systolic blood pressure, need for recovery, and overhead work capacity) from a WHS were independently associated with work ability. These factors can be used to assess employees at risk for low work ability and might provide directions for interventions. Keywords Occupational health Á Health risk appraisal Á Work ability Á Functional capacity evaluation Á Meat-packing industry Electronic supplementary material The online version of this article (

BMC public health, Jan 4, 2015

BackgroundAn ageing workforce combined with increasing health problems in ageing workers implies ... more BackgroundAn ageing workforce combined with increasing health problems in ageing workers implies the importance of evidence-based interventions to enhance sustainable employability. The aim of this study is to evaluate the effectiveness of the `Staying healthy at work¿ problem-solving based intervention compared to business as usual.MethodsThis study was designed as a quasi-experimental trial with a one-year follow-up. Measurements were performed at baseline, three and twelve months. The problem-solving based intervention provides a strategy for increasing the awareness of ageing workers of their role and responsibility in living sustainable, healthy working lives. The primary outcomes were work ability, vitality and productivity. Secondary outcomes were perceived fatigue, psychosocial work characteristics, work attitude, self-efficacy and work engagement.ResultsAnalyses were performed on the 64 workers in the intervention and 61 workers from the business as usual group. No effects ...

Annals of Behavioral Medicine, 2014

Background Food portion sizes influence energy intake. Purpose The purpose of this paper is to de... more Background Food portion sizes influence energy intake. Purpose The purpose of this paper is to determine effectiveness of the "PortionControl@HOME" intervention on body mass index and portion control behavior. Methods A randomized controlled trial among 278 overweight and obese participants was conducted. PortionControl@HOME aimed to increase: portion size awareness, portion control behavior, portion control cooking skills, and to create a home environment favoring portion control. Results Intention-to-treat multi-level regression analysis indicated statistically significant effects of the intervention on portion control behavior at 3, 6, and 12 months follow-up. The effect on body mass index was significant only at 3 months follow-up and when outliers (n=3) were excluded (B=−0.45; 95 %CI=−0.88 to −0.04). The intervention effect on body mass index was mediated by portion control behavior. Conclusions The intervention improves portion control behavior, which in turn influence body mass index. Once the intervention ceased, sustained effects on body mass index were no longer evident. (Current-Controlled-Trials ISRCT N12363482).

Spine, 2011

Study Design. Systematic review of interventions. Objective. To assess the effects of spinal mani... more Study Design. Systematic review of interventions. Objective. To assess the effects of spinal manipulative therapy (SMT) for chronic low-back pain. Summary of Background Data. SMT is one of the many therapies for the treatment of low-back pain, which is a worldwide, extensively practiced intervention. Methods. Search methods. An experienced librarian searched for randomized controlled trials (RCTs) in multiple databases up to June 2009. Selection criteria. RCTs that examined manipulation or mobilization in adults with chronic low-back pain were included. L ow-back pain is a common and disabling disorder in western society, which represents a great fi nancial burden in the form of direct costs resulting from loss of work and medical expenses, as well as indirect costs. 1 Therefore, adequate treatment of low-back pain is an important issue for patients, treating clinicians, and healthcare policy makers. Spinal manipulative therapy (SMT) is widely used for acute and chronic low-back pain, which has been examined in many randomized controlled trials (RCTs). These trials have been summarized in numerous recent systematic reviews, 2-5 which have formed the basis for recommendations in clinical guidelines. 6-11 Most notably, these guidelines are largely dependent on an earlier version of this Cochrane review. 12 That review concluded that SMT was moderately

Spine, 2013

Background Many therapies exist for the treatment of low-back pain including spinal manipulative ... more Background Many therapies exist for the treatment of low-back pain including spinal manipulative therapy (SMT), which is a worldwide, extensively practised intervention. This report is an update of the earlier Cochrane review, first published in January 2004 with the last search for studies up to January 2000. Objectives To examine the effects of SMT for acute low-back pain, which is defined as pain of less than six weeks duration. Search methods A comprehensive search was conducted on 31 March 2011 in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, PEDro, and the Index to Chiropractic Literature. Other search strategies were employed for completeness. No limitations were placed on language or publication status. Selection criteria Randomized controlled trials (RCTs) which examined the effectiveness of spinal manipulation or mobilization in adults with acute low-back pain were included. In addition, studies were included if the pain was predominantly in the lower back but the study allowed mixed populations, including participants with radiation of pain into the buttocks and legs. Studies which exclusively evaluated sciatica were excluded. No other restrictions were placed on the setting nor the type of pain. The primary outcomes were back pain, backpain specific functional status, and perceived recovery. Secondary outcomes were return-to-work and quality of life. SMT was defined as any hands-on therapy directed towards the spine, which includes both manipulation and mobilization, and includes studies from chiropractors, manual therapists, and osteopaths. Data collection and analysis Two review authors independently conducted the study selection and risk of bias (RoB) assessment. Data extraction was checked by the second review author. The effects were examined in the following comparisons: SMT versus 1) inert interventions, 2) sham SMT, 3) other interventions, and 4) SMT as an additional therapy. In addition, we examined the effects of different SMT techniques 1 Spinal manipulative therapy for acute low-back pain (Review)

Scandinavian Journal of Work, Environment & Health, 2013

A broad range of possible predictors of recurrent sickness absence (SA) among workers with common... more A broad range of possible predictors of recurrent sickness absence (SA) among workers with common mental disorders (CMD) is investigated over 12 months follow-up. The results show that work-related factors, especially conflicts with supervisor and company size >100 employees, rather than disease-related factors predict recurrent SA among workers who returned to work after SA due to CMD.

Scandinavian Journal of Work, Environment & Health, 2012

Noordik E, van der Klink JJ, Geskus RB, de Boer MR, van Dijk FJH, Nieuwenhuijsen K. Effectiveness... more Noordik E, van der Klink JJ, Geskus RB, de Boer MR, van Dijk FJH, Nieuwenhuijsen K. Effectiveness of an exposure-based return-to-work program for workers on sick leave due to common mental disorders: a clusterrandomized controlled trial.

Preventive Medicine, 2012

Objective. Fiscal policies may form a solution in improving dietary intake. This study aimed to e... more Objective. Fiscal policies may form a solution in improving dietary intake. This study aimed to examine the effectiveness of varying taxing and subsiding schemes to stimulate healthier food purchases. Methods. A randomized controlled trial with three levels of price reduction on healthy foods (no; 25%; 50%) × three levels of price increase on unhealthy foods (5%; 10%; 25%) factorial design was used. 150 participants were randomized into one of nine conditions and were asked to purchase groceries at a web-based supermarket. Data were collected in the Netherlands in January-February 2010 and analyzed using analysis of covariance. Results. Subjects receiving 50% discount purchased significantly more healthy foods than subjects receiving no (mean difference = 6.62 items, p b 0.01) or 25% discount (mean difference = 4.87 items, p b 0.05). Moreover, these subjects purchased more vegetables (mean difference = 821 g; p b 0.05 compared to no discount). However, participants with the highest discount also purchased significantly more calories. No significant effects of the price increases on unhealthy foods were found. Conclusion. Price decreases are effective in stimulating healthy food purchases, but the proportion of healthy foods remains unaffected. Price increases up to 25% on unhealthier products do not significantly affect food purchases. Future studies are important to validate these results in real supermarkets and across different countries.

Occupational and Environmental Medicine, 2013

General introduction | Chapter 1 13 process. The SHARP-at work intervention is provided by OPs to... more General introduction | Chapter 1 13 process. The SHARP-at work intervention is provided by OPs to align with the Dutch OP guideline on the management of mental health problems of workers, and because OPs are closely connected to the work environment. OPs guide workers through the fivestep problem solving process to find and implement solutions for problems/ opportunities experienced when back at work. OPs monitor that all steps are taken and activate and support the worker when needed. Furthermore, OPs empower the worker to define the problems and design solutions. Two to five consultations are recommended to the OPs, and assignments are available for each step of the intervention. The first assignment is the key element of the intervention. In this assignment, workers have to make an inventory of problems and opportunities at work and, subsequently, to define if help is needed to solve the problems or realise the opportunities. THESIS OBJECTIVE AND RESEARCH QUESTIONS The objective of this thesis is to generate knowledge on the prevention of recurrent sickness absence in workers who returned to work after sickness absence due to CMDs. The main focus is on the evaluation of the effectiveness of the SHARP-at work intervention in preventing recurrent sickness absence in workers who returned to work after sickness absence due to CMD. Alongside this effect evaluation, a process evaluation and an economic evaluation are presented. The process evaluation is helpful in explaining the results of the effect evaluation and whether these results are attributable to the SHARP-at work intervention. As part of the process evaluation, an indepth exploration of challenges with recruiting research participants by OPs is described. The economic evaluation provides information on the cost-effectiveness and cost-benefit of the intervention. Next to the evaluation of the SHARP-at work intervention, a systematic literature review is presented on interventions to facilitate return to work in adults with adjustment disorders. A specific focus on adjustment disorders as a subgroup of CMDs is chosen as this group has often been investigated in relation to RTW. Also, predictors for recurrent sickness absence among workers with CMDs are investigated. The following research questions form the basis of this thesis: Research question 1: Which interventions are effective in facilitating return to work in workers with adjustment disorders? Research question 2: Is the SHARP-at work intervention effective in preventing recurrent sickness absence and improving mental health, work functioning and problem solving coping in workers who returned to work after sickness absence due to CMDs compared to care as usual? Chapter 1 | General introduction 14 Research question 3: Is the SHARP-at work intervention conducted according to the protocol, does it differ from care as usual, and how are the key elements of the intervention related to the effect outcome (i.e. recurrent sickness absence)? Research question 4: What are barriers and facilitators for participant recruitment by occupational physicians? Research question 5: Is the SHARP-at work intervention cost-effective and costbeneficial compared to care as usual? Research question 6: Which factors predict recurrent sickness absence in workers who returned to work after sickness absence due to CMDs? THESIS OUTLINE This first chapter provides an overall introduction to the topic of the thesis to address the importance of the topic, explain the context and describe relevant constructs. In Chapter 2, the results of a systematic literature review are presented on the effectiveness of interventions to enhance return to work in workers with adjustment disorders. Chapter 3 describes the study design of the cluster-RCT with an effect evaluation, process evaluation and economic evaluation of the SHARP-at work intervention compared to care as usual. Chapter 4 presents the effect of the SHARP-at work intervention on preventing recurrent sickness absence in workers who returned to work after sickness absence due to CMDs. Moreover, the effects on mental health complaints, work functioning and coping behaviour are evaluated. In Chapter 5, the process evaluation of the SHARP-at work intervention is described. The chapter focuses on: 1) evaluating whether the SHARP-at work intervention was conducted according to the protocol and differed from care as usual, and 2) investigating the relationship between the key elements of the intervention and the primary outcome of the effect evaluation (i.e. recurrent sickness absence). Chapter 6 focuses on problems with participant recruitment by OPs. Barriers and facilitators for recruitment as experienced by OPs are reported, and the relationship between OP's personal and work characteristics and the recruitment of participants is evaluated. Chapter 7 addresses the economic evaluation of the SHARP-at work intervention and presents the costeffectiveness and cost-benefit evaluations. In Chapter 8, predictors for recurrent sickness absence in workers who returned to work after sickness absence due to CMDs are investigated. In Chapter 9, a general discussion is provided. The main research results are summarized and discussed, methodological considerations are addressed and the implications of this thesis for future research and practice are presented. 16 23. van der Klink JJ, Blonk RW, Schene AH, van Dijk FJ. Reducing long term sickness absence by an activating intervention in adjustment disorders: A cluster randomised controlled design.