irene jensen | Karolinska Institutet (original) (raw)

Papers by irene jensen

Pain, 2009

The cost effectiveness of work-oriented rehabilitation for persons on long-term sick leave needs ... more The cost effectiveness of work-oriented rehabilitation for persons on long-term sick leave needs to be assessed. This prospective observational study presents a follow-up seven years after rehabilitation using two different evidence-based work-oriented regimens. Individuals on sick leave for neck and back pain were referred to two rehabilitation programmes in Sweden. The first programme was a relatively lowintensity programme based on orthopaedic manual therapy and exercise programme (OMTP). The second programme was a full-time multidisciplinary programme (MDP). The primary outcome was sickness absence seven years after intervention. Cost effectiveness was calculated on the basis of loss of production due to sickness absence. The results show that participants referred to MDP and with less than 60 sick days before rehabilitation have reduced sickness absence after intervention as compared to matched controls. This corresponds to a cost reduction of about 94,494 EUR per referred individual. Further, the results indicate that participants of the OMTP who have more than 60 sick days before rehabilitation have a statistically significant increased risk of disability pension. This means increased cost in terms of loss of production of 44,593 EUR per referred individual. The results of this study show that MPD but not OMTP achieves the goal of working life-oriented rehabilitation. A direct comparison between the rehabilitation programmes strengthened the assumption that long-term sickness absence prior to rehabilitation is associated with more days on sick leave after rehabilitation. This analysis also indicated the importance of participants' pain self-efficacy beliefs and recovery beliefs on rehabilitation outcome. Ó

Annals of Epidemiology, 2003

Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant- and crash-rela... more Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant- and crash-related factors, such as age, gender, seating position and type of MVC are associated with the risk of whiplash injury. A study of occupants in cars covered by motor insurance at one of the largest insurance companies in Sweden, was undertaken during a one-year period. The study population comprised all occupants in cars exposed to an MVC in which at least one occupant was injured (n = 7120). Adjusted estimates of the relative risk of whiplash injury, associated with the different factors, were calculated by means of binomial regression analysis. Considering different MVCs, rear-end collisions were associated with the highest relative risk of whiplash injury when compared with side impacts (1.82; 95% CI 1.68-1.96), while drivers showed the strongest association with respect to seating position when compared with passengers in the rear seat (1.78; 95% CI 1.60-1.97). Females had a somewhat higher relative risk of whiplash injury than males (1.20; 95% CI 1.16-1.25). Regarding age, the relative risk was moderately increased across the different age groups when compared with the oldest age group. No interaction was observed on the additive scale. Given that an MVC had occurred, subjects exposed to a rear-end collision and drivers had a substantial increased risk of whiplash injury, while age and gender were of minor importance.

Pain, 2006

The influence of potential prognostic factors (occupant- and crash-related factors, initial neck ... more The influence of potential prognostic factors (occupant- and crash-related factors, initial neck pain intensity and headache, whiplash injury severity, helplessness, locus of control, socioeconomic status) on neck pain intensity (VAS), disability (DRI), anxiety and depression (HADS) was estimated in a cohort of 3704 subjects with whiplash injury following a motor vehicle crash. Questionnaires were administered (baseline, 1-, 6-, 12-, 24-month follow-ups). VAS was trichotomized; "low" (0-30), "moderate" (31-54), "severe" (55-100). A cumulative logit model with a proportional odds assumption was applied. Results regarding depression differed somewhat from the other outcomes. Overall, initial neck pain intensity was an important prognostic factor, but acted also as an evident effect modifier. Females had slightly increased odds for all outcomes but depression, for which no gender differences were shown. Injury severity was associated with all outcomes, but was most pronounced regarding disability among those who perceived numbness/pain in arms/hands and also had severe initial neck pain (proportional odds ratio [OR] 6.5; 95% confidence interval [CI] 2.5-17.0). Initial headache influenced all outcomes. Income was not related to any of the outcomes, whereas a lower level of education was associated with all outcomes but depression. Locus of control was not a factor of importance. In contrast, helplessness was related to all outcomes, but was most pronounced regarding neck pain intensity and depression for subjects with severe initial neck pain (OR 4.8; 95% CI 2.9-7.8; OR 6.6; 95% CI 2.6-17.0). Associations seem to be established early, and then to be relatively constant over time.

Journal of occupational …, Jan 1, 2006

Study Design: Prospective cohort study with 18-month follow-up. Objective: To investigate if long... more Study Design: Prospective cohort study with 18-month follow-up. Objective: To investigate if long-term sick listed persons' own predictions of their future return to work (RTW) have an impact on their RTW when controlling for other established factors. Method: Postal questionnaires at baseline were sent to persons who had been on sick leave for more than 90 days, and were employed in five municipalities and four county councils in Sweden. A follow-up regarding their RTW was performed 18 months later. Results: After 18 months 135 out of 508 persons (27%) had returned to work, full or part-time. In a multivariate logistic regression, the sick listed persons' own prediction of their RTW proved to be highly significant (OR = 8.28, 95% CI: 3.31-20.69). Only six out of 132 persons with a negative view of their RTW did return to wok. Other predictive factors that were found for RTW were: being on sick leave for a period of less than 1 year (OR = 2.09, 95% CI: 1.19-3.67), having less pain than persons in the quartile with most pain (OR = 2.65, 95% CI: 1.21-5.81), perceiving that one was welcome back to work (OR = 1.98, 95% CI: 1.10-3.58), and being under 55 years of age (OR = 2.37, 95% CI: 1.07-5.23 for age between 45 and 54 years and the same trend for age below 45 years OR = 1.85, 95% CI: 0.82-4.20). Conclusion: Persons with a positive prediction should get help to realise their potential for RTW. Offering traditional rehabilitation measures to a person with a negative prediction of his/her RTW, could be a waste of resources if done ahead of improving self-confidence and view of what is possible. The problems in this group might decrease or be easier to handle if decisions about the future are taken within a year.

Pain, Jan 1, 2001

A better knowledge of differential treatment outcomes for subgroups of chronic spinal pain patien... more A better knowledge of differential treatment outcomes for subgroups of chronic spinal pain patients may, for instance, help clinicians in treatment planning or pain researchers in treatment outcome research. The purpose of this prospective study was to evaluate the predictive validity of a subgroup classi®cation based on the Swedish version of the (West Haven Yale) Multidimensional Pain Inventory, the MPI-S. Patients referred to a vocational rehabilitation program were classi®ed into one of three groups, labeled`adaptive copers',`dysfunctional' patients, and`interpersonally distressed' patients, and followed over an 18-month follow-up period. The outcome variables were absence from work (de®ned as sick listing plus early retirement), general health status, and utilization of health care resources. To our knowledge, the predictive validity of the MPI subgroups has not been evaluated regarding sick listing and early retirement after rehabilitation. As hypothesized, the results showed that the`dysfunctional' patient group had signi®cantly more registered absences from work and reported higher utilization of health care, over the follow-up period compared to the`adaptive copers'. Furthermore, as hypothesized, the`interpersonally distressed' and`dysfunctional' patient groups report a poorer general health status than the`adaptive copers' over the whole follow-up period. However, contrary to our hypothesis, the proportion of improved patients did not differ signi®cantly between the subgroups. Altogether, the predictive validity of the MPI-S subgroup classi®cation was mainly con®rmed. The clinical implications of this study suggest that the matching of treatment to patient needs may enhance treatment outcome, reduce pain and suffering among chronic spinal pain patients and facilitate a better health economic allocation of treatment resources.

Occupational and …, Jan 1, 2007

ObjectivesTo identify risk factors for new episodes of sick leave due to neck or back pain.Method... more ObjectivesTo identify risk factors for new episodes of sick leave due to neck or back pain.MethodsThis prospective study comprised an industrial population of 2187 employees who were followed up at 18 months and 3 years after a comprehensive baseline measurement. The potential risk factors comprised physical and psychosocial work factors, health‐related and pain‐related characteristics and lifestyle and demographic factors. The response rate at both follow‐ups was close to 73%.ResultsAt the 18‐month follow‐up, 151 participants reported at least one episode of sick‐listing due to neck or back pain during the previous year. Risk factors assessed at baseline for sick leave due to neck or back pain at the follow‐up were blue‐collar work, back pain one or several times during the previous year, 1–99 days of cumulative sickness absence during the previous year (all causes except neck or back pain), uncertainty of one's own working ability in 2 years' time and the experience of few positive challenges at work. After 3 years, 127 participants reported at least one episode of sick leave due to back or neck pain during the year previous to follow‐up. The risk factors for this pain‐related sick leave were blue‐collar work, several earlier episodes of neck pain, no everyday physical activities during leisure time (cleaning, gardening and so on), lower physical functioning and, for blue‐collar workers separately, repetitive work procedures.ConclusionThe most consistent risk factors for new episodes of sick leave due to neck or back pain found during both the follow‐ups were blue‐collar work and several earlier episodes of neck or back pain assessed at baseline. Preventive efforts to decrease sick leave due to neck or back pain may include measures to increase the occurrence of positive challenges at work and to minimise repetitive work procedures. An evidence‐based secondary prevention of neck and back pain including advice to stay active is also warranted.

Physiotherapy …, Jan 1, 1999

Background and Purpose. The intra-and inter-rater reliability of 11 tests assembled by physiother... more Background and Purpose. The intra-and inter-rater reliability of 11 tests assembled by physiotherapists for clinical purposes was investigated. Forty-five patients and 23 healthy volunteers participated in the study. Method. Twenty-one patients were tested simultaneously and independently by two physiotherapists to determine inter-rater reliability for two raters. Twenty-four patients and 11 healthy volunteers were tested by one physiotherapist three times in a week to determine intra-rater reliability over time. Twelve healthy volunteers were tested by three different physiotherapists in a week to determine inter-rater reliability for three raters. Results. Inter-rater agreement for two simultaneous raters was clinically acceptable. Repeatability on three test occasions was clinically acceptable in six of the 11 tests. There were no systematic differences between occasions. Conclusions. Intraand inter-rater reliability was acceptable for six of the 11 tests in the form described here: three gait tests, two functional lifting tests and a functional muscular endurance test in the right leg. If these tests are to be used as outcome measures, account must be taken of the size of the typical fluctuation in measurements shown. The repeatability figures given may be used as guidelines for interpreting the clinical value of possible changes in test values.

Behaviour research and …, Jan 1, 2001

The aim of this study was to identify reliable and valid subgroups of spinal pain patients, using... more The aim of this study was to identify reliable and valid subgroups of spinal pain patients, using data from the Swedish version of the Multidimensional Pain Inventory (MPI-S). A second aim was to test the generalisability of the three patient profiles described in earlier studies on the MPI ("adaptive coper", "dysfunctional" and "interpersonally distressed" patients). The study base consisted of two samples of individuals suffering from long-term, non-specific spinal pain and the results were validated across these samples. Cluster analysis was used to detect distinct groups of patients and the validity of these subgroups was evaluated on variables not used to generate the cluster solution. One subgroup was characterised by lower pain severity, lower interference with everyday activities, lower affective distress and higher life control than the other two subgroups. This patient profile was similar to the MPI adaptive coper patients. A second subgroup resembled the dysfunctional patient profile, thus displaying a worse adjustment to chronic pain than the AC patients. The third patient group reported significantly lower levels of social support from "significant others" than the other subgroups. This patient profile was similar to that of the interpersonally distressed patient group. Taken together, the results support the reliability, validity and generalisability of three subgroups of chronic pain patients derived from the MPI-S. : S 0 0 0 5 -7 9 6 7 ( 9 9 ) 0 0 1 7 5 -8

Spine, Jan 1, 2000

A prospective cohort study including patients with nonspecific spinal pain was performed. To inve... more A prospective cohort study including patients with nonspecific spinal pain was performed. To investigate whether the use of expert judgment in routine practice can provide a basis for reliable decision making concerning the need for intervention in patients with spinal pain and their ability to benefit from treatment. A wide range of instruments and techniques are used to assess and treat patients with spinal pain. Many instruments are used without being clinimetrically tested. A questionnaire concerning the patients' need of treatment and their potential to assimilate it was sent to experts in the health care arena: physicians, physical therapists, social insurance officers. The experts included were those connected with patients participating in a larger outcome study. Two cohorts of patients (sample 1, n = 217; sample 2, n = 257) were followed for 6 and 12 months, during which time the patients' health and work status were mapped. No acceptable agreement was found between any of the experts' ratings of patients' needs and potential for rehabilitation. Logistic regression showed that the experts' judgments were based almost solely on the age of the patient. The prediction analyses showed that the most consistent predictor of the patients' status at the 6-month follow-up assessment was the patients' own belief in the existence of effective treatments and their perceived ability for learning to cope with the condition. Expert judgment as exercised in routine practice cannot be used as basis for reliable decision making concerning the need of the patient with spinal pain for intervention and the patient's ability to benefit from treatment.

Annals of …, Jan 1, 2003

Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant-and crash-relat... more Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant-and crash-related factors, such as age, gender, seating position and type of MVC are associated with the risk of whiplash injury. METHODS: A study of occupants in cars covered by motor insurance at one of the largest insurance companies in Sweden, was undertaken during a one-year period. The study population comprised all occupants in cars exposed to an MVC in which at least one occupant was injured (n ϭ 7120). Adjusted estimates of the relative risk of whiplash injury, associated with the different factors, were calculated by means of binomial regression analysis. RESULTS: Considering different MVCs, rear-end collisions were associated with the highest relative risk of whiplash injury when compared with side impacts (1.82; 95% CI 1.68-1.96), while drivers showed the strongest association with respect to seating position when compared with passengers in the rear seat (1.78; 95% CI 1.60-1.97). Females had a somewhat higher relative risk of whiplash injury than males (1.20; 95% CI 1.16-1.25). Regarding age, the relative risk was moderately increased across the different age groups when compared with the oldest age group. No interaction was observed on the additive scale. CONCLUSIONS: Given that an MVC had occurred, subjects exposed to a rear-end collision and drivers had a substantial increased risk of whiplash injury, while age and gender were of minor importance. Ann Epidemiol 2003;13:66-72.

Occupational …, Jan 1, 2006

This thesis presents the results from a prospective industrial population cohort study on epidemi... more This thesis presents the results from a prospective industrial population cohort study on epidemiology and risk factors for low back pain (LBP) in Iran. The four papers in the thesis were based on a cross-sectional survey and one-year follow-up of 18,000 employees in the automotive industry. The main goals of this thesis were: 1) to identify prevalence and incidence of LBP, and 2) to identify work-related exposures and lifestyle factors related to LBP.

Pain, Jan 1, 2006

The influence of potential prognostic factors (occupant- and crash-related factors, initial neck ... more The influence of potential prognostic factors (occupant- and crash-related factors, initial neck pain intensity and headache, whiplash injury severity, helplessness, locus of control, socioeconomic status) on neck pain intensity (VAS), disability (DRI), anxiety and depression (HADS) was estimated in a cohort of 3704 subjects with whiplash injury following a motor vehicle crash. Questionnaires were administered (baseline, 1-, 6-, 12-, 24-month follow-ups). VAS was trichotomized; "low" (0-30), "moderate" (31-54), "severe" (55-100). A cumulative logit model with a proportional odds assumption was applied. Results regarding depression differed somewhat from the other outcomes. Overall, initial neck pain intensity was an important prognostic factor, but acted also as an evident effect modifier. Females had slightly increased odds for all outcomes but depression, for which no gender differences were shown. Injury severity was associated with all outcomes, but was most pronounced regarding disability among those who perceived numbness/pain in arms/hands and also had severe initial neck pain (proportional odds ratio [OR] 6.5; 95% confidence interval [CI] 2.5-17.0). Initial headache influenced all outcomes. Income was not related to any of the outcomes, whereas a lower level of education was associated with all outcomes but depression. Locus of control was not a factor of importance. In contrast, helplessness was related to all outcomes, but was most pronounced regarding neck pain intensity and depression for subjects with severe initial neck pain (OR 4.8; 95% CI 2.9-7.8; OR 6.6; 95% CI 2.6-17.0). Associations seem to be established early, and then to be relatively constant over time.

Journal of clinical …, Jan 1, 2001

Journal of clinical …, Jan 1, 2000

Neck pain is the most frequently reported feature in connection with whiplash injury, but it is a... more Neck pain is the most frequently reported feature in connection with whiplash injury, but it is also a common complaint in the general population. Therefore it is crucial to include an unexposed comparison group when evaluating the association between neck pain and a previous motor vehicle crash (MVC). To determine whether exposure to a rear-end collision, without or with whiplash injury, is associated with future neck or shoulder pain, a cohort study was conducted. The study population consisted of persons covered by traffic insurance at one of the largest insurance companies in Sweden. Claim reports were collected from the period November 1987 to April 1988. Drivers exposed to a rear-end collision were divided into two subgroups, without reported whiplash injury ( n ϭ 204) and with reported whiplash injury ( n ϭ 232). Two comparison groups, unexposed to MVCs, consisting of 1599 and 2089 persons, were selected with consideration taken to the age and gender distribution in the exposed subgroups. A questionnaire concerning neck or shoulder pain and other subjective health complaints was mailed to all the study subjects at follow-up in 1994, 7 years after the rear-end collision. The relative risk of neck or shoulder pain at follow-up was 1.3 (95% CI 0.8-2.0) in the exposed subjects without whiplash injury compared with the unexposed. The corresponding relative risk in subjects with whiplash injury was 2.7 (95% CI 2.1-3.5). We conclude that there is no increased risk of future neck or shoulder pain in drivers who did not report whiplash injury in connection with a rear-end collision 7 years earlier. In drivers with reported whiplash injury, the risk of neck or shoulder pain 7 years after the collision was increased nearly three-fold compared with that in unexposed subjects.

Journal of rehabilitation …, Jan 1, 2001

The effects of two different prevention programmes on: (1) reported neck, shoulder and back pain,... more The effects of two different prevention programmes on: (1) reported neck, shoulder and back pain, (2) perceived physical exertion at work and perceived work-related psychosocial factors, were evaluated by questionnaires after 12 and 18 months. Female nursing aides and assistant nurses (n = 282) working in the home-care services, were randomly assigned to one of three groups for: (1) individually designed physical training programme, (2) work-place stress management, (3) control group. Results revealed no signi cant differences between the three groups. However, improvements in low back pain were registered within both intervention groups for up to 18 months. Perceived physical exertion at work was reduced in the physical training group. Improvements in neck and shoulder pain did not differ within the three groups. Dissatisfaction with work-related, psychosocial factors was generally increased in all groups. As the aetiology of neck, shoulder and back disorders is multifactorial, a combination of the two intervention programmes might be preferable and should be further studied.

Scandinavian journal of public health, Jan 1, 2004

The scientific evidence on the causes for sick leave attributed to back and neck disorders was re... more The scientific evidence on the causes for sick leave attributed to back and neck disorders was reviewed. Categories were established for acute, recurring, and chronic problems based on the duration of the sick leave period. Forty-eight articles were found to be relevant, ...

Pain, Jan 1, 1998

The psychological assessment of chronic pain is often accomplished using questionnaires such as t... more The psychological assessment of chronic pain is often accomplished using questionnaires such as the (West Haven-Yale) Multidimensional Pain Inventory ((WHY)MPI) which is constructed to capture the multidimensionality of chronic pain. The (WHY)MPI theoretically originates from behavioural and cognitive behavioural theories of pain. It is divided into three parts and measures psychosocial and behavioural consequences of pain. This questionnaire has displayed satisfactory psychometric properties and translations of the original English version into German and Dutch have been demonstrated to be reliable and valid. The aim of this study was to test the reliability and factor structure of a Swedish translation of the (WHY)MPI, the MPI-S, and also to test the generalisability of the factor structure found for the (WHY)MPI. We performed analyses of internal consistency using Cronbach's alpha, and carried out a confirmatory factor analysis (CFA) employing LISREL-8 on a population of 682 patients suffering from chronic musculoskeletal pain. Test-retest analysis was accomplished on a sub-sample of 54 individuals taken from the aforementioned population. For sections 1 and 2 of the MPI-S the overall reliability and stability were good, and after the exclusion of four items, the factor structure was similar to other versions of the MPI. For section 3, despite removal of five questions, the proposed factor structure could not be replicated. This part of the inventory is designed to measure the extent of different types of activities, and our results suggest that this section may only be used for assessing general activity level. We conclude that, with a few adjustments, the analyses yielded satisfactory results for sections 1 and 2 of the MPI-S regarding its factor structure, reliability and generalisability. For section 3 the hypothesised factor structure could not be confirmed.

Pain, Jan 1, 2005

The aim of the present study was to evaluate the long-term outcome of a behavioural medicine reha... more The aim of the present study was to evaluate the long-term outcome of a behavioural medicine rehabilitation programme and the outcome of its two main components, compared to a 'treatment-as-usual' control group. The study employed a 4!5 repeated-measures design with four groups and five assessment periods during a 3-year follow-up. The group studied consisted of blue-collar and service/care workers on sick leave, identified in a nationwide health insurance scheme in Sweden. After inclusion, the subjects were randomised to one of the four conditions: behaviour-oriented physiotherapy (PT), cognitive behavioural therapy (CBT), behavioural medicine rehabilitation consisting of PTCCBT (BM) and a 'treatment-as-usual' control group (CG). Outcome variables were sick leave, early retirement and health-related quality of life. A cost-effectiveness analysis, comparing the programmes, was made. The results showed, consistently, the full-time behavioural medicine programme being superior to the three other conditions. The strongest effect was found on females. Regarding sick leave, the mean difference in the per-protocol analysis between the BM programme and the control group was 201 days, thus reducing sick leave by about two-thirds of a working year. Rehabilitating women has a substantial impact on costs for production losses, whereas rehabilitating men seem to be effortless with no significant effect on either health or costs. In conclusion, a full-time behavioural medicine programme is a cost-effective method for improving health and increasing return to work in women working in blue-collar or service/care occupations and suffering from back/neck pain. q

Pain, Jan 1, 1994

PfCI. 57 (1994) lh7-172 ,cm IYY4 Elsevier Science B.V. All rights resewed 0304-395Y/94/$07.0!) lh... more PfCI. 57 (1994) lh7-172 ,cm IYY4 Elsevier Science B.V. All rights resewed 0304-395Y/94/$07.0!) lh7 PAIN 74x1

Pain, 2009

The cost effectiveness of work-oriented rehabilitation for persons on long-term sick leave needs ... more The cost effectiveness of work-oriented rehabilitation for persons on long-term sick leave needs to be assessed. This prospective observational study presents a follow-up seven years after rehabilitation using two different evidence-based work-oriented regimens. Individuals on sick leave for neck and back pain were referred to two rehabilitation programmes in Sweden. The first programme was a relatively lowintensity programme based on orthopaedic manual therapy and exercise programme (OMTP). The second programme was a full-time multidisciplinary programme (MDP). The primary outcome was sickness absence seven years after intervention. Cost effectiveness was calculated on the basis of loss of production due to sickness absence. The results show that participants referred to MDP and with less than 60 sick days before rehabilitation have reduced sickness absence after intervention as compared to matched controls. This corresponds to a cost reduction of about 94,494 EUR per referred individual. Further, the results indicate that participants of the OMTP who have more than 60 sick days before rehabilitation have a statistically significant increased risk of disability pension. This means increased cost in terms of loss of production of 44,593 EUR per referred individual. The results of this study show that MPD but not OMTP achieves the goal of working life-oriented rehabilitation. A direct comparison between the rehabilitation programmes strengthened the assumption that long-term sickness absence prior to rehabilitation is associated with more days on sick leave after rehabilitation. This analysis also indicated the importance of participants' pain self-efficacy beliefs and recovery beliefs on rehabilitation outcome. Ó

Annals of Epidemiology, 2003

Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant- and crash-rela... more Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant- and crash-related factors, such as age, gender, seating position and type of MVC are associated with the risk of whiplash injury. A study of occupants in cars covered by motor insurance at one of the largest insurance companies in Sweden, was undertaken during a one-year period. The study population comprised all occupants in cars exposed to an MVC in which at least one occupant was injured (n = 7120). Adjusted estimates of the relative risk of whiplash injury, associated with the different factors, were calculated by means of binomial regression analysis. Considering different MVCs, rear-end collisions were associated with the highest relative risk of whiplash injury when compared with side impacts (1.82; 95% CI 1.68-1.96), while drivers showed the strongest association with respect to seating position when compared with passengers in the rear seat (1.78; 95% CI 1.60-1.97). Females had a somewhat higher relative risk of whiplash injury than males (1.20; 95% CI 1.16-1.25). Regarding age, the relative risk was moderately increased across the different age groups when compared with the oldest age group. No interaction was observed on the additive scale. Given that an MVC had occurred, subjects exposed to a rear-end collision and drivers had a substantial increased risk of whiplash injury, while age and gender were of minor importance.

Pain, 2006

The influence of potential prognostic factors (occupant- and crash-related factors, initial neck ... more The influence of potential prognostic factors (occupant- and crash-related factors, initial neck pain intensity and headache, whiplash injury severity, helplessness, locus of control, socioeconomic status) on neck pain intensity (VAS), disability (DRI), anxiety and depression (HADS) was estimated in a cohort of 3704 subjects with whiplash injury following a motor vehicle crash. Questionnaires were administered (baseline, 1-, 6-, 12-, 24-month follow-ups). VAS was trichotomized; "low" (0-30), "moderate" (31-54), "severe" (55-100). A cumulative logit model with a proportional odds assumption was applied. Results regarding depression differed somewhat from the other outcomes. Overall, initial neck pain intensity was an important prognostic factor, but acted also as an evident effect modifier. Females had slightly increased odds for all outcomes but depression, for which no gender differences were shown. Injury severity was associated with all outcomes, but was most pronounced regarding disability among those who perceived numbness/pain in arms/hands and also had severe initial neck pain (proportional odds ratio [OR] 6.5; 95% confidence interval [CI] 2.5-17.0). Initial headache influenced all outcomes. Income was not related to any of the outcomes, whereas a lower level of education was associated with all outcomes but depression. Locus of control was not a factor of importance. In contrast, helplessness was related to all outcomes, but was most pronounced regarding neck pain intensity and depression for subjects with severe initial neck pain (OR 4.8; 95% CI 2.9-7.8; OR 6.6; 95% CI 2.6-17.0). Associations seem to be established early, and then to be relatively constant over time.

Journal of occupational …, Jan 1, 2006

Study Design: Prospective cohort study with 18-month follow-up. Objective: To investigate if long... more Study Design: Prospective cohort study with 18-month follow-up. Objective: To investigate if long-term sick listed persons' own predictions of their future return to work (RTW) have an impact on their RTW when controlling for other established factors. Method: Postal questionnaires at baseline were sent to persons who had been on sick leave for more than 90 days, and were employed in five municipalities and four county councils in Sweden. A follow-up regarding their RTW was performed 18 months later. Results: After 18 months 135 out of 508 persons (27%) had returned to work, full or part-time. In a multivariate logistic regression, the sick listed persons' own prediction of their RTW proved to be highly significant (OR = 8.28, 95% CI: 3.31-20.69). Only six out of 132 persons with a negative view of their RTW did return to wok. Other predictive factors that were found for RTW were: being on sick leave for a period of less than 1 year (OR = 2.09, 95% CI: 1.19-3.67), having less pain than persons in the quartile with most pain (OR = 2.65, 95% CI: 1.21-5.81), perceiving that one was welcome back to work (OR = 1.98, 95% CI: 1.10-3.58), and being under 55 years of age (OR = 2.37, 95% CI: 1.07-5.23 for age between 45 and 54 years and the same trend for age below 45 years OR = 1.85, 95% CI: 0.82-4.20). Conclusion: Persons with a positive prediction should get help to realise their potential for RTW. Offering traditional rehabilitation measures to a person with a negative prediction of his/her RTW, could be a waste of resources if done ahead of improving self-confidence and view of what is possible. The problems in this group might decrease or be easier to handle if decisions about the future are taken within a year.

Pain, Jan 1, 2001

A better knowledge of differential treatment outcomes for subgroups of chronic spinal pain patien... more A better knowledge of differential treatment outcomes for subgroups of chronic spinal pain patients may, for instance, help clinicians in treatment planning or pain researchers in treatment outcome research. The purpose of this prospective study was to evaluate the predictive validity of a subgroup classi®cation based on the Swedish version of the (West Haven Yale) Multidimensional Pain Inventory, the MPI-S. Patients referred to a vocational rehabilitation program were classi®ed into one of three groups, labeled`adaptive copers',`dysfunctional' patients, and`interpersonally distressed' patients, and followed over an 18-month follow-up period. The outcome variables were absence from work (de®ned as sick listing plus early retirement), general health status, and utilization of health care resources. To our knowledge, the predictive validity of the MPI subgroups has not been evaluated regarding sick listing and early retirement after rehabilitation. As hypothesized, the results showed that the`dysfunctional' patient group had signi®cantly more registered absences from work and reported higher utilization of health care, over the follow-up period compared to the`adaptive copers'. Furthermore, as hypothesized, the`interpersonally distressed' and`dysfunctional' patient groups report a poorer general health status than the`adaptive copers' over the whole follow-up period. However, contrary to our hypothesis, the proportion of improved patients did not differ signi®cantly between the subgroups. Altogether, the predictive validity of the MPI-S subgroup classi®cation was mainly con®rmed. The clinical implications of this study suggest that the matching of treatment to patient needs may enhance treatment outcome, reduce pain and suffering among chronic spinal pain patients and facilitate a better health economic allocation of treatment resources.

Occupational and …, Jan 1, 2007

ObjectivesTo identify risk factors for new episodes of sick leave due to neck or back pain.Method... more ObjectivesTo identify risk factors for new episodes of sick leave due to neck or back pain.MethodsThis prospective study comprised an industrial population of 2187 employees who were followed up at 18 months and 3 years after a comprehensive baseline measurement. The potential risk factors comprised physical and psychosocial work factors, health‐related and pain‐related characteristics and lifestyle and demographic factors. The response rate at both follow‐ups was close to 73%.ResultsAt the 18‐month follow‐up, 151 participants reported at least one episode of sick‐listing due to neck or back pain during the previous year. Risk factors assessed at baseline for sick leave due to neck or back pain at the follow‐up were blue‐collar work, back pain one or several times during the previous year, 1–99 days of cumulative sickness absence during the previous year (all causes except neck or back pain), uncertainty of one's own working ability in 2 years' time and the experience of few positive challenges at work. After 3 years, 127 participants reported at least one episode of sick leave due to back or neck pain during the year previous to follow‐up. The risk factors for this pain‐related sick leave were blue‐collar work, several earlier episodes of neck pain, no everyday physical activities during leisure time (cleaning, gardening and so on), lower physical functioning and, for blue‐collar workers separately, repetitive work procedures.ConclusionThe most consistent risk factors for new episodes of sick leave due to neck or back pain found during both the follow‐ups were blue‐collar work and several earlier episodes of neck or back pain assessed at baseline. Preventive efforts to decrease sick leave due to neck or back pain may include measures to increase the occurrence of positive challenges at work and to minimise repetitive work procedures. An evidence‐based secondary prevention of neck and back pain including advice to stay active is also warranted.

Physiotherapy …, Jan 1, 1999

Background and Purpose. The intra-and inter-rater reliability of 11 tests assembled by physiother... more Background and Purpose. The intra-and inter-rater reliability of 11 tests assembled by physiotherapists for clinical purposes was investigated. Forty-five patients and 23 healthy volunteers participated in the study. Method. Twenty-one patients were tested simultaneously and independently by two physiotherapists to determine inter-rater reliability for two raters. Twenty-four patients and 11 healthy volunteers were tested by one physiotherapist three times in a week to determine intra-rater reliability over time. Twelve healthy volunteers were tested by three different physiotherapists in a week to determine inter-rater reliability for three raters. Results. Inter-rater agreement for two simultaneous raters was clinically acceptable. Repeatability on three test occasions was clinically acceptable in six of the 11 tests. There were no systematic differences between occasions. Conclusions. Intraand inter-rater reliability was acceptable for six of the 11 tests in the form described here: three gait tests, two functional lifting tests and a functional muscular endurance test in the right leg. If these tests are to be used as outcome measures, account must be taken of the size of the typical fluctuation in measurements shown. The repeatability figures given may be used as guidelines for interpreting the clinical value of possible changes in test values.

Behaviour research and …, Jan 1, 2001

The aim of this study was to identify reliable and valid subgroups of spinal pain patients, using... more The aim of this study was to identify reliable and valid subgroups of spinal pain patients, using data from the Swedish version of the Multidimensional Pain Inventory (MPI-S). A second aim was to test the generalisability of the three patient profiles described in earlier studies on the MPI ("adaptive coper", "dysfunctional" and "interpersonally distressed" patients). The study base consisted of two samples of individuals suffering from long-term, non-specific spinal pain and the results were validated across these samples. Cluster analysis was used to detect distinct groups of patients and the validity of these subgroups was evaluated on variables not used to generate the cluster solution. One subgroup was characterised by lower pain severity, lower interference with everyday activities, lower affective distress and higher life control than the other two subgroups. This patient profile was similar to the MPI adaptive coper patients. A second subgroup resembled the dysfunctional patient profile, thus displaying a worse adjustment to chronic pain than the AC patients. The third patient group reported significantly lower levels of social support from "significant others" than the other subgroups. This patient profile was similar to that of the interpersonally distressed patient group. Taken together, the results support the reliability, validity and generalisability of three subgroups of chronic pain patients derived from the MPI-S. : S 0 0 0 5 -7 9 6 7 ( 9 9 ) 0 0 1 7 5 -8

Spine, Jan 1, 2000

A prospective cohort study including patients with nonspecific spinal pain was performed. To inve... more A prospective cohort study including patients with nonspecific spinal pain was performed. To investigate whether the use of expert judgment in routine practice can provide a basis for reliable decision making concerning the need for intervention in patients with spinal pain and their ability to benefit from treatment. A wide range of instruments and techniques are used to assess and treat patients with spinal pain. Many instruments are used without being clinimetrically tested. A questionnaire concerning the patients' need of treatment and their potential to assimilate it was sent to experts in the health care arena: physicians, physical therapists, social insurance officers. The experts included were those connected with patients participating in a larger outcome study. Two cohorts of patients (sample 1, n = 217; sample 2, n = 257) were followed for 6 and 12 months, during which time the patients' health and work status were mapped. No acceptable agreement was found between any of the experts' ratings of patients' needs and potential for rehabilitation. Logistic regression showed that the experts' judgments were based almost solely on the age of the patient. The prediction analyses showed that the most consistent predictor of the patients' status at the 6-month follow-up assessment was the patients' own belief in the existence of effective treatments and their perceived ability for learning to cope with the condition. Expert judgment as exercised in routine practice cannot be used as basis for reliable decision making concerning the need of the patient with spinal pain for intervention and the patient's ability to benefit from treatment.

Annals of …, Jan 1, 2003

Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant-and crash-relat... more Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant-and crash-related factors, such as age, gender, seating position and type of MVC are associated with the risk of whiplash injury. METHODS: A study of occupants in cars covered by motor insurance at one of the largest insurance companies in Sweden, was undertaken during a one-year period. The study population comprised all occupants in cars exposed to an MVC in which at least one occupant was injured (n ϭ 7120). Adjusted estimates of the relative risk of whiplash injury, associated with the different factors, were calculated by means of binomial regression analysis. RESULTS: Considering different MVCs, rear-end collisions were associated with the highest relative risk of whiplash injury when compared with side impacts (1.82; 95% CI 1.68-1.96), while drivers showed the strongest association with respect to seating position when compared with passengers in the rear seat (1.78; 95% CI 1.60-1.97). Females had a somewhat higher relative risk of whiplash injury than males (1.20; 95% CI 1.16-1.25). Regarding age, the relative risk was moderately increased across the different age groups when compared with the oldest age group. No interaction was observed on the additive scale. CONCLUSIONS: Given that an MVC had occurred, subjects exposed to a rear-end collision and drivers had a substantial increased risk of whiplash injury, while age and gender were of minor importance. Ann Epidemiol 2003;13:66-72.

Occupational …, Jan 1, 2006

This thesis presents the results from a prospective industrial population cohort study on epidemi... more This thesis presents the results from a prospective industrial population cohort study on epidemiology and risk factors for low back pain (LBP) in Iran. The four papers in the thesis were based on a cross-sectional survey and one-year follow-up of 18,000 employees in the automotive industry. The main goals of this thesis were: 1) to identify prevalence and incidence of LBP, and 2) to identify work-related exposures and lifestyle factors related to LBP.

Pain, Jan 1, 2006

The influence of potential prognostic factors (occupant- and crash-related factors, initial neck ... more The influence of potential prognostic factors (occupant- and crash-related factors, initial neck pain intensity and headache, whiplash injury severity, helplessness, locus of control, socioeconomic status) on neck pain intensity (VAS), disability (DRI), anxiety and depression (HADS) was estimated in a cohort of 3704 subjects with whiplash injury following a motor vehicle crash. Questionnaires were administered (baseline, 1-, 6-, 12-, 24-month follow-ups). VAS was trichotomized; "low" (0-30), "moderate" (31-54), "severe" (55-100). A cumulative logit model with a proportional odds assumption was applied. Results regarding depression differed somewhat from the other outcomes. Overall, initial neck pain intensity was an important prognostic factor, but acted also as an evident effect modifier. Females had slightly increased odds for all outcomes but depression, for which no gender differences were shown. Injury severity was associated with all outcomes, but was most pronounced regarding disability among those who perceived numbness/pain in arms/hands and also had severe initial neck pain (proportional odds ratio [OR] 6.5; 95% confidence interval [CI] 2.5-17.0). Initial headache influenced all outcomes. Income was not related to any of the outcomes, whereas a lower level of education was associated with all outcomes but depression. Locus of control was not a factor of importance. In contrast, helplessness was related to all outcomes, but was most pronounced regarding neck pain intensity and depression for subjects with severe initial neck pain (OR 4.8; 95% CI 2.9-7.8; OR 6.6; 95% CI 2.6-17.0). Associations seem to be established early, and then to be relatively constant over time.

Journal of clinical …, Jan 1, 2001

Journal of clinical …, Jan 1, 2000

Neck pain is the most frequently reported feature in connection with whiplash injury, but it is a... more Neck pain is the most frequently reported feature in connection with whiplash injury, but it is also a common complaint in the general population. Therefore it is crucial to include an unexposed comparison group when evaluating the association between neck pain and a previous motor vehicle crash (MVC). To determine whether exposure to a rear-end collision, without or with whiplash injury, is associated with future neck or shoulder pain, a cohort study was conducted. The study population consisted of persons covered by traffic insurance at one of the largest insurance companies in Sweden. Claim reports were collected from the period November 1987 to April 1988. Drivers exposed to a rear-end collision were divided into two subgroups, without reported whiplash injury ( n ϭ 204) and with reported whiplash injury ( n ϭ 232). Two comparison groups, unexposed to MVCs, consisting of 1599 and 2089 persons, were selected with consideration taken to the age and gender distribution in the exposed subgroups. A questionnaire concerning neck or shoulder pain and other subjective health complaints was mailed to all the study subjects at follow-up in 1994, 7 years after the rear-end collision. The relative risk of neck or shoulder pain at follow-up was 1.3 (95% CI 0.8-2.0) in the exposed subjects without whiplash injury compared with the unexposed. The corresponding relative risk in subjects with whiplash injury was 2.7 (95% CI 2.1-3.5). We conclude that there is no increased risk of future neck or shoulder pain in drivers who did not report whiplash injury in connection with a rear-end collision 7 years earlier. In drivers with reported whiplash injury, the risk of neck or shoulder pain 7 years after the collision was increased nearly three-fold compared with that in unexposed subjects.

Journal of rehabilitation …, Jan 1, 2001

The effects of two different prevention programmes on: (1) reported neck, shoulder and back pain,... more The effects of two different prevention programmes on: (1) reported neck, shoulder and back pain, (2) perceived physical exertion at work and perceived work-related psychosocial factors, were evaluated by questionnaires after 12 and 18 months. Female nursing aides and assistant nurses (n = 282) working in the home-care services, were randomly assigned to one of three groups for: (1) individually designed physical training programme, (2) work-place stress management, (3) control group. Results revealed no signi cant differences between the three groups. However, improvements in low back pain were registered within both intervention groups for up to 18 months. Perceived physical exertion at work was reduced in the physical training group. Improvements in neck and shoulder pain did not differ within the three groups. Dissatisfaction with work-related, psychosocial factors was generally increased in all groups. As the aetiology of neck, shoulder and back disorders is multifactorial, a combination of the two intervention programmes might be preferable and should be further studied.

Scandinavian journal of public health, Jan 1, 2004

The scientific evidence on the causes for sick leave attributed to back and neck disorders was re... more The scientific evidence on the causes for sick leave attributed to back and neck disorders was reviewed. Categories were established for acute, recurring, and chronic problems based on the duration of the sick leave period. Forty-eight articles were found to be relevant, ...

Pain, Jan 1, 1998

The psychological assessment of chronic pain is often accomplished using questionnaires such as t... more The psychological assessment of chronic pain is often accomplished using questionnaires such as the (West Haven-Yale) Multidimensional Pain Inventory ((WHY)MPI) which is constructed to capture the multidimensionality of chronic pain. The (WHY)MPI theoretically originates from behavioural and cognitive behavioural theories of pain. It is divided into three parts and measures psychosocial and behavioural consequences of pain. This questionnaire has displayed satisfactory psychometric properties and translations of the original English version into German and Dutch have been demonstrated to be reliable and valid. The aim of this study was to test the reliability and factor structure of a Swedish translation of the (WHY)MPI, the MPI-S, and also to test the generalisability of the factor structure found for the (WHY)MPI. We performed analyses of internal consistency using Cronbach's alpha, and carried out a confirmatory factor analysis (CFA) employing LISREL-8 on a population of 682 patients suffering from chronic musculoskeletal pain. Test-retest analysis was accomplished on a sub-sample of 54 individuals taken from the aforementioned population. For sections 1 and 2 of the MPI-S the overall reliability and stability were good, and after the exclusion of four items, the factor structure was similar to other versions of the MPI. For section 3, despite removal of five questions, the proposed factor structure could not be replicated. This part of the inventory is designed to measure the extent of different types of activities, and our results suggest that this section may only be used for assessing general activity level. We conclude that, with a few adjustments, the analyses yielded satisfactory results for sections 1 and 2 of the MPI-S regarding its factor structure, reliability and generalisability. For section 3 the hypothesised factor structure could not be confirmed.

Pain, Jan 1, 2005

The aim of the present study was to evaluate the long-term outcome of a behavioural medicine reha... more The aim of the present study was to evaluate the long-term outcome of a behavioural medicine rehabilitation programme and the outcome of its two main components, compared to a 'treatment-as-usual' control group. The study employed a 4!5 repeated-measures design with four groups and five assessment periods during a 3-year follow-up. The group studied consisted of blue-collar and service/care workers on sick leave, identified in a nationwide health insurance scheme in Sweden. After inclusion, the subjects were randomised to one of the four conditions: behaviour-oriented physiotherapy (PT), cognitive behavioural therapy (CBT), behavioural medicine rehabilitation consisting of PTCCBT (BM) and a 'treatment-as-usual' control group (CG). Outcome variables were sick leave, early retirement and health-related quality of life. A cost-effectiveness analysis, comparing the programmes, was made. The results showed, consistently, the full-time behavioural medicine programme being superior to the three other conditions. The strongest effect was found on females. Regarding sick leave, the mean difference in the per-protocol analysis between the BM programme and the control group was 201 days, thus reducing sick leave by about two-thirds of a working year. Rehabilitating women has a substantial impact on costs for production losses, whereas rehabilitating men seem to be effortless with no significant effect on either health or costs. In conclusion, a full-time behavioural medicine programme is a cost-effective method for improving health and increasing return to work in women working in blue-collar or service/care occupations and suffering from back/neck pain. q

Pain, Jan 1, 1994

PfCI. 57 (1994) lh7-172 ,cm IYY4 Elsevier Science B.V. All rights resewed 0304-395Y/94/$07.0!) lh... more PfCI. 57 (1994) lh7-172 ,cm IYY4 Elsevier Science B.V. All rights resewed 0304-395Y/94/$07.0!) lh7 PAIN 74x1