Les Toop - Academia.edu (original) (raw)
Papers by Les Toop
AIM The primary care response to the coronavirus disease 2019 (COVID-19) pandemic in early 2020 r... more AIM The primary care response to the coronavirus disease 2019 (COVID-19) pandemic in early 2020 required significant changes to the delivery of healthcare by general practices. This study explores the experiences of New Zealand general practice teams in their use of telehealth during the early stages of the COVID-19 pandemic in New Zealand. METHOD We qualitatively analysed a subtheme on telehealth of the General Practice Pandemic Experience New Zealand (GPPENZ) study, where general practice team members across the country were invited to participate in five surveys between 8 May 2020 to 27 August 2020. RESULTS 164 participants enrolled in the study during survey one, with 78 (48%) completing all surveys. Five telehealth themes were identified: benefits, limitations, paying for consults, changes over time and plans for future use. Benefits included rapid triage, convenience and efficiency, and limitations included financial and technical barriers for practices and patients and concer...
Journal of Primary Health Care
INTRODUCTIONThe delivery of health care by primary care general practices rapidly changed in resp... more INTRODUCTIONThe delivery of health care by primary care general practices rapidly changed in response to the coronavirus disease 2019 (COVID-19) pandemic in early 2020. AIMThis study explores the experience of a large group of New Zealand general practice health-care professionals with changes to prescribing medication during the COVID-19 pandemic. METHODSWe qualitatively analysed a subtheme on prescribing medication from the General Practice Pandemic Experience New Zealand (GPPENZ) study, where general practice team members nationwide were invited to participate in five surveys over 16 weeks from 8 May 2020. RESULTSOverall, 78 (48%) of 164 participants enrolled in the study completed all surveys. Five themes were identified: changes to prescribing medicines; benefits of electronic prescription; technical challenges; clinical and medication supply challenges; and opportunities for the future. There was a rapid adoption of electronic prescribing as an adjunct to use of telehealth, mi...
The Journal of Steroid Biochemistry and Molecular Biology
The increasing use of vitamin D supplements has stimulated interest in identifying factors that m... more The increasing use of vitamin D supplements has stimulated interest in identifying factors that may modify the effect of supplementation on circulating 25-hydroxyvitamin D (25(OH)D) concentrations. Such information is of potential interest to researchers, clinicians and patients when deciding on bolus dose of vitamin D supplementation. We carried out a large randomized controlled trial of 5,110 adults aged 50-84 years, of European/Other (84%), Polynesian (11%) and Asian (5%) ethnicity, to whom we gave a standard dose of vitamin D3 supplements (200,000 IU initially, then 100,000 IU monthly) which was taken with high adherence. All participants provided a baseline blood sample, and follow-up blood samples were collected at 6 months and annually for 3 years in a random sample of 441 participants, and also at 2 years in 413 participants enrolled in a bone density sub-study. Serum 25(OH)D was measured by LC/MSMS. Mixed model analyses were carried out on all 854 participants providing follow-up blood samples in multivariable models that included age, sex, ethnicity, body mass index (kg/m2), tobacco smoking, alcohol intake, physical activity, sun exposure, season, medical prescription of high-dose vitamin D3 (Cal.D.Forte tablets), asthma/COPD and the study treatment (vitamin D or placebo). The adjusted mean difference in 25(OH)D in the follow-up points between vitamin D supplementation and placebo groups was inversely related (all p for interaction <0.05) to baseline 25(OH)D, BMI, and hours of sun exposure, and higher in females, elders, and those with high frequency of alcohol, medical prescription of vitamin D, and asthma/COPD. The mean difference was not significantly related to ethnicity (p = 0.12), tobacco (p = 0.34), and vigorous activity (p = 0.33). In summary, these data show that vitamin D status, BMI, sun exposure hours, sex and asthma/COPD modify the 25(OH)D response to vitamin D supplementation. By contrast, ethnicity, tobacco smoking, and vigorous activity do not.
The New Zealand medical journal, 2003
Direct-to-consumer advertising (DTCA) of prescription medicines is legal only in the US and in Ne... more Direct-to-consumer advertising (DTCA) of prescription medicines is legal only in the US and in New Zealand (by default). In both countries the growth in this form of drug promotion has been spectacular. Why is this, and does it matter? The answer to the first question is simple – it is very effective both at increasing total market size and in encouraging widespread switching to advertised brands, which are usually new and more expensive. The answer to the second question depends upon perspective. It clearly matters to many in the pharmaceutical, advertising and print-media industries. The strength and nature of the response by these groups to try to prevent a call from Academic General Practice to the Minister of Health to reconsider banning DTCA shows how important a marketing strategy it has become. It should also matter to us as health professionals, as it has important consequences for public health.
Nutrients
Randomized controlled trials have suggested that vitamin D supplementation can prevent asthma and... more Randomized controlled trials have suggested that vitamin D supplementation can prevent asthma and chronic obstructive pulmonary disease (COPD) exacerbations. For COPD, the benefit appears to be limited to individuals with baseline 25-hydroxyvitamin D (25OHD) levels <25 nmol/L. We performed a post hoc analysis of data from a randomized, double-blinded, placebo-controlled trial to investigate the effect that monthly, high-dose vitamin D supplementation (versus placebo) had on older adults with asthma and/or COPD. Specifically, we investigated whether vitamin D supplementation prevented exacerbations of these conditions. Participants were randomly assigned either to an initial oral dose of 200,000 IU vitamin D3 followed by 100,000 IU monthly or to placebo, with an average follow-up period of 3.3 years. Among the 5110 participants, 775 had asthma or COPD at the beginning of the study, and were eligible for inclusion in this analysis. Exacerbations were defined by the prescription of ...
Clinical Infectious Diseases
Background Although adults with low vitamin D status are at increased risk of acute respiratory i... more Background Although adults with low vitamin D status are at increased risk of acute respiratory infection (ARI), randomized controlled trials of vitamin D supplementation have provided inconsistent results. Methods We performed a randomized, double-blinded, placebo-controlled trial of 5,110 adults, aged 50-84 years. In 2011-2012, participants were randomized to an initial oral dose of 200,000 IU vitamin D3 followed by 100,000 IU monthly (n=2,558) or placebo (n=2,552) until late 2013 (median follow-up 1.6 years). Participants reported upper and lower ARIs on monthly questionnaires. Cox models analyzed time to first ARI (upper or lower) by treatment group. Results Participants’ mean age was 66 years and 58% were male; 83% were of European/Other ethnicity, with the rest Maori, Polynesian or South Asian. Mean (SD) baseline blood 25-hydroxyvitamin D (25OHD) level was 63 (24) nmol/L; 25% were <50 nmol/L. In a random sample (n=441), vitamin D supplementation increased mean 25OHD to 135 ...
The Journal of Steroid Biochemistry and Molecular Biology
Journal of Primary Health Care
Pain, 2018
Observational studies suggest that vitamin D deficiency is associated with higher risk of pain. H... more Observational studies suggest that vitamin D deficiency is associated with higher risk of pain. However, evidence on the effect of vitamin D supplementation on pain is limited and contradictory. The aim of this study was to compare the effect of monthly high-dose vitamin D supplementation on a pain impact questionnaire (PIQ-6) score and prescription of analgesics in the general population. We performed a randomized, double-blind, placebo-controlled trial of 5108 community-dwelling participants, aged 50 to 84 years, who were randomly assigned to receive monthly 100,000-IU capsules of vitamin D3 (n = 2558) or placebo (n = 2550) for a median of 3.3 years. The PIQ-6 was administered at baseline, year 1, and final follow-up. Analgesic prescription data were collected from Ministry of Health. There was no difference in mean PIQ-6 score at the end of follow-up (adjusted mean difference: 0.06; P = 0.82) between the vitamin D (n = 2041) and placebo (n = 2014) participants. The proportion of ...
Atherosclerosis, 2018
Long-term statin use increases survival. However, the adherence to and persistence with statin us... more Long-term statin use increases survival. However, the adherence to and persistence with statin use are challenging and this influences the success of statin treatment. Our aim was to explore if monthly vitamin D supplementation (100,000-IU) improves the adherence to and persistence with long-term statin use in older adults. We conducted a secondary analysis of a trial comparing data on dispensed statin prescriptions, between participants allocated to vitamin D supplementation or placebo, for those taking statin therapy. Primary outcomes were defined as adherence to (proportion of days covered by prescriptions ≥80%) and persistence (non-discontinuation of the statin therapy following an allowed 30 days gap between refills) with all statins over a 24-month measurement period of statin therapy. Secondary outcomes were defined as adherence and persistence at other measurement periods for all types of statins and for individual statins. Overall, 2494 participants were on long-term statin...
JAMA oncology, Jan 19, 2018
Previous randomized clinical trials have reported inconsistent results on the effect of vitamin D... more Previous randomized clinical trials have reported inconsistent results on the effect of vitamin D supplementation on cancer incidence. To examine whether high-dose vitamin D supplementation received monthly, without calcium, is associated with a reduction in cancer incidence and cancer mortality in the general population. This is a post hoc analysis of data from the Vitamin D Assessment (ViDA) study, a randomized, double-blind, placebo-controlled trial that recruited participants from family practices and community groups in Auckland, New Zealand, from April 5, 2011, through November 6, 2012, with follow-up completed December 31, 2015. Participants were adult community residents aged 50 to 84 years. Of 47 905 adults invited from family practices and 163 from community groups, 5110 participants were randomized to receive vitamin D3 (n = 2558) or placebo (n = 2552). Two participants withdrew consent, and all others (n = 5108) were included in the primary analysis. Data analysis was by...
Journal of the American Heart Association, Jan 24, 2017
The effects of monthly, high-dose, long-term (≥1-year) vitamin D supplementation on central blood... more The effects of monthly, high-dose, long-term (≥1-year) vitamin D supplementation on central blood pressure (BP) parameters are unknown. A total of 517 adults (58% male, aged 50-84 years) were recruited into a double-blinded, placebo-controlled trial substudy and randomized to receive, for 1.1 years (median; range: 0.9-1.5 years), either (1) vitamin D3 200 000 IU (initial dose) followed 1 month later by monthly 100 000-IU doses (n=256) or (2) placebo monthly (n=261). At baseline (n=517) and follow-up (n=380), suprasystolic oscillometry was undertaken, yielding aortic BP waveforms and hemodynamic parameters. Mean deseasonalized 25-hydroxyvitamin D increased from 66 nmol/L (SD: 24) at baseline to 122 nmol/L (SD: 42) at follow-up in the vitamin D group, with no change in the placebo group. Despite small, nonsignificant changes in hemodynamic parameters in the total sample (primary outcome), we observed consistently favorable changes among the 150 participants with vitamin D deficiency (...
The lancet. Diabetes & endocrinology, Jun 1, 2017
Adults with low concentrations of 25-hydroxyvitamin D (25[OH]D) in blood have an increased risk o... more Adults with low concentrations of 25-hydroxyvitamin D (25[OH]D) in blood have an increased risk of falls and fractures, but randomised trials of vitamin D supplementation have had inconsistent results. We aimed to assess the effect of high-dose vitamin D supplementation on fractures and falls. The Vitamin D Assessment (ViDA) Study was a randomised, double-blind, placebo-controlled trial of healthy volunteers aged 50-84 years conducted at one centre in Auckland, New Zealand. Participants were randomly assigned to receive either an initial oral dose of 200 000 IU (5·0 mg) colecalciferol (vitamin D3) followed by monthly 100 000 IU (2·5 mg) colecalciferol or equivalent placebo dosing. The prespecified primary outcome was cardiovascular disease and secondary outcomes were respiratory illness and fractures. Here, we report secondary outcome data for fractures and post-hoc outcome data for falls. Cox proportional hazards models were used to estimate hazard ratios (HRs) for time to first fr...
The New Zealand medical journal, Jan 24, 2017
In this pilot study, the primary aim was to compare four potential methods for undertaking a nati... more In this pilot study, the primary aim was to compare four potential methods for undertaking a national survey of unmet secondary healthcare need in New Zealand (one collecting data from GPs, and three from community surveys). The secondary aim was to obtain an estimate of the prevalence of unmet secondary healthcare need, to inform sample size calculations for a national survey. An electronic system was set up for GPs in Christchurch (Pegasus PHO) and Auckland (Auckland PHO) to record cases of unmet need as encountered in clinics. For the community surveys, a questionnaire developed by the authors was administered to people from the same electoral wards as the GP clinics. Three modes of questionnaire administration were trialled: online, telephone and face-to-face interview. Random population sampling from the Māori and General Electoral Rolls was used to identify eligible survey participants until there were approximately 200 respondents for each method in each city. Data collection...
JAMA cardiology, Jan 5, 2017
Cohort studies have reported increased incidence of cardiovascular disease (CVD) among individual... more Cohort studies have reported increased incidence of cardiovascular disease (CVD) among individuals with low vitamin D status. To date, randomized clinical trials of vitamin D supplementation have not found an effect, possibly because of using too low a dose of vitamin D. To examine whether monthly high-dose vitamin D supplementation prevents CVD in the general population. The Vitamin D Assessment Study is a randomized, double-blind, placebo-controlled trial that recruited participants mostly from family practices in Auckland, New Zealand, from April 5, 2011, through November 6, 2012, with follow-up until July 2015. Participants were community-resident adults aged 50 to 84 years. Of 47 905 adults invited from family practices and 163 from community groups, 5110 participants were randomized to receive vitamin D3 (n = 2558) or placebo (n = 2552). Two participants retracted consent, and all others (n = 5108) were included in the primary analysis. Oral vitamin D3 in an initial dose of 20...
The Australian and New Zealand journal of psychiatry, 2016
AIM The primary care response to the coronavirus disease 2019 (COVID-19) pandemic in early 2020 r... more AIM The primary care response to the coronavirus disease 2019 (COVID-19) pandemic in early 2020 required significant changes to the delivery of healthcare by general practices. This study explores the experiences of New Zealand general practice teams in their use of telehealth during the early stages of the COVID-19 pandemic in New Zealand. METHOD We qualitatively analysed a subtheme on telehealth of the General Practice Pandemic Experience New Zealand (GPPENZ) study, where general practice team members across the country were invited to participate in five surveys between 8 May 2020 to 27 August 2020. RESULTS 164 participants enrolled in the study during survey one, with 78 (48%) completing all surveys. Five telehealth themes were identified: benefits, limitations, paying for consults, changes over time and plans for future use. Benefits included rapid triage, convenience and efficiency, and limitations included financial and technical barriers for practices and patients and concer...
Journal of Primary Health Care
INTRODUCTIONThe delivery of health care by primary care general practices rapidly changed in resp... more INTRODUCTIONThe delivery of health care by primary care general practices rapidly changed in response to the coronavirus disease 2019 (COVID-19) pandemic in early 2020. AIMThis study explores the experience of a large group of New Zealand general practice health-care professionals with changes to prescribing medication during the COVID-19 pandemic. METHODSWe qualitatively analysed a subtheme on prescribing medication from the General Practice Pandemic Experience New Zealand (GPPENZ) study, where general practice team members nationwide were invited to participate in five surveys over 16 weeks from 8 May 2020. RESULTSOverall, 78 (48%) of 164 participants enrolled in the study completed all surveys. Five themes were identified: changes to prescribing medicines; benefits of electronic prescription; technical challenges; clinical and medication supply challenges; and opportunities for the future. There was a rapid adoption of electronic prescribing as an adjunct to use of telehealth, mi...
The Journal of Steroid Biochemistry and Molecular Biology
The increasing use of vitamin D supplements has stimulated interest in identifying factors that m... more The increasing use of vitamin D supplements has stimulated interest in identifying factors that may modify the effect of supplementation on circulating 25-hydroxyvitamin D (25(OH)D) concentrations. Such information is of potential interest to researchers, clinicians and patients when deciding on bolus dose of vitamin D supplementation. We carried out a large randomized controlled trial of 5,110 adults aged 50-84 years, of European/Other (84%), Polynesian (11%) and Asian (5%) ethnicity, to whom we gave a standard dose of vitamin D3 supplements (200,000 IU initially, then 100,000 IU monthly) which was taken with high adherence. All participants provided a baseline blood sample, and follow-up blood samples were collected at 6 months and annually for 3 years in a random sample of 441 participants, and also at 2 years in 413 participants enrolled in a bone density sub-study. Serum 25(OH)D was measured by LC/MSMS. Mixed model analyses were carried out on all 854 participants providing follow-up blood samples in multivariable models that included age, sex, ethnicity, body mass index (kg/m2), tobacco smoking, alcohol intake, physical activity, sun exposure, season, medical prescription of high-dose vitamin D3 (Cal.D.Forte tablets), asthma/COPD and the study treatment (vitamin D or placebo). The adjusted mean difference in 25(OH)D in the follow-up points between vitamin D supplementation and placebo groups was inversely related (all p for interaction <0.05) to baseline 25(OH)D, BMI, and hours of sun exposure, and higher in females, elders, and those with high frequency of alcohol, medical prescription of vitamin D, and asthma/COPD. The mean difference was not significantly related to ethnicity (p = 0.12), tobacco (p = 0.34), and vigorous activity (p = 0.33). In summary, these data show that vitamin D status, BMI, sun exposure hours, sex and asthma/COPD modify the 25(OH)D response to vitamin D supplementation. By contrast, ethnicity, tobacco smoking, and vigorous activity do not.
The New Zealand medical journal, 2003
Direct-to-consumer advertising (DTCA) of prescription medicines is legal only in the US and in Ne... more Direct-to-consumer advertising (DTCA) of prescription medicines is legal only in the US and in New Zealand (by default). In both countries the growth in this form of drug promotion has been spectacular. Why is this, and does it matter? The answer to the first question is simple – it is very effective both at increasing total market size and in encouraging widespread switching to advertised brands, which are usually new and more expensive. The answer to the second question depends upon perspective. It clearly matters to many in the pharmaceutical, advertising and print-media industries. The strength and nature of the response by these groups to try to prevent a call from Academic General Practice to the Minister of Health to reconsider banning DTCA shows how important a marketing strategy it has become. It should also matter to us as health professionals, as it has important consequences for public health.
Nutrients
Randomized controlled trials have suggested that vitamin D supplementation can prevent asthma and... more Randomized controlled trials have suggested that vitamin D supplementation can prevent asthma and chronic obstructive pulmonary disease (COPD) exacerbations. For COPD, the benefit appears to be limited to individuals with baseline 25-hydroxyvitamin D (25OHD) levels <25 nmol/L. We performed a post hoc analysis of data from a randomized, double-blinded, placebo-controlled trial to investigate the effect that monthly, high-dose vitamin D supplementation (versus placebo) had on older adults with asthma and/or COPD. Specifically, we investigated whether vitamin D supplementation prevented exacerbations of these conditions. Participants were randomly assigned either to an initial oral dose of 200,000 IU vitamin D3 followed by 100,000 IU monthly or to placebo, with an average follow-up period of 3.3 years. Among the 5110 participants, 775 had asthma or COPD at the beginning of the study, and were eligible for inclusion in this analysis. Exacerbations were defined by the prescription of ...
Clinical Infectious Diseases
Background Although adults with low vitamin D status are at increased risk of acute respiratory i... more Background Although adults with low vitamin D status are at increased risk of acute respiratory infection (ARI), randomized controlled trials of vitamin D supplementation have provided inconsistent results. Methods We performed a randomized, double-blinded, placebo-controlled trial of 5,110 adults, aged 50-84 years. In 2011-2012, participants were randomized to an initial oral dose of 200,000 IU vitamin D3 followed by 100,000 IU monthly (n=2,558) or placebo (n=2,552) until late 2013 (median follow-up 1.6 years). Participants reported upper and lower ARIs on monthly questionnaires. Cox models analyzed time to first ARI (upper or lower) by treatment group. Results Participants’ mean age was 66 years and 58% were male; 83% were of European/Other ethnicity, with the rest Maori, Polynesian or South Asian. Mean (SD) baseline blood 25-hydroxyvitamin D (25OHD) level was 63 (24) nmol/L; 25% were <50 nmol/L. In a random sample (n=441), vitamin D supplementation increased mean 25OHD to 135 ...
The Journal of Steroid Biochemistry and Molecular Biology
Journal of Primary Health Care
Pain, 2018
Observational studies suggest that vitamin D deficiency is associated with higher risk of pain. H... more Observational studies suggest that vitamin D deficiency is associated with higher risk of pain. However, evidence on the effect of vitamin D supplementation on pain is limited and contradictory. The aim of this study was to compare the effect of monthly high-dose vitamin D supplementation on a pain impact questionnaire (PIQ-6) score and prescription of analgesics in the general population. We performed a randomized, double-blind, placebo-controlled trial of 5108 community-dwelling participants, aged 50 to 84 years, who were randomly assigned to receive monthly 100,000-IU capsules of vitamin D3 (n = 2558) or placebo (n = 2550) for a median of 3.3 years. The PIQ-6 was administered at baseline, year 1, and final follow-up. Analgesic prescription data were collected from Ministry of Health. There was no difference in mean PIQ-6 score at the end of follow-up (adjusted mean difference: 0.06; P = 0.82) between the vitamin D (n = 2041) and placebo (n = 2014) participants. The proportion of ...
Atherosclerosis, 2018
Long-term statin use increases survival. However, the adherence to and persistence with statin us... more Long-term statin use increases survival. However, the adherence to and persistence with statin use are challenging and this influences the success of statin treatment. Our aim was to explore if monthly vitamin D supplementation (100,000-IU) improves the adherence to and persistence with long-term statin use in older adults. We conducted a secondary analysis of a trial comparing data on dispensed statin prescriptions, between participants allocated to vitamin D supplementation or placebo, for those taking statin therapy. Primary outcomes were defined as adherence to (proportion of days covered by prescriptions ≥80%) and persistence (non-discontinuation of the statin therapy following an allowed 30 days gap between refills) with all statins over a 24-month measurement period of statin therapy. Secondary outcomes were defined as adherence and persistence at other measurement periods for all types of statins and for individual statins. Overall, 2494 participants were on long-term statin...
JAMA oncology, Jan 19, 2018
Previous randomized clinical trials have reported inconsistent results on the effect of vitamin D... more Previous randomized clinical trials have reported inconsistent results on the effect of vitamin D supplementation on cancer incidence. To examine whether high-dose vitamin D supplementation received monthly, without calcium, is associated with a reduction in cancer incidence and cancer mortality in the general population. This is a post hoc analysis of data from the Vitamin D Assessment (ViDA) study, a randomized, double-blind, placebo-controlled trial that recruited participants from family practices and community groups in Auckland, New Zealand, from April 5, 2011, through November 6, 2012, with follow-up completed December 31, 2015. Participants were adult community residents aged 50 to 84 years. Of 47 905 adults invited from family practices and 163 from community groups, 5110 participants were randomized to receive vitamin D3 (n = 2558) or placebo (n = 2552). Two participants withdrew consent, and all others (n = 5108) were included in the primary analysis. Data analysis was by...
Journal of the American Heart Association, Jan 24, 2017
The effects of monthly, high-dose, long-term (≥1-year) vitamin D supplementation on central blood... more The effects of monthly, high-dose, long-term (≥1-year) vitamin D supplementation on central blood pressure (BP) parameters are unknown. A total of 517 adults (58% male, aged 50-84 years) were recruited into a double-blinded, placebo-controlled trial substudy and randomized to receive, for 1.1 years (median; range: 0.9-1.5 years), either (1) vitamin D3 200 000 IU (initial dose) followed 1 month later by monthly 100 000-IU doses (n=256) or (2) placebo monthly (n=261). At baseline (n=517) and follow-up (n=380), suprasystolic oscillometry was undertaken, yielding aortic BP waveforms and hemodynamic parameters. Mean deseasonalized 25-hydroxyvitamin D increased from 66 nmol/L (SD: 24) at baseline to 122 nmol/L (SD: 42) at follow-up in the vitamin D group, with no change in the placebo group. Despite small, nonsignificant changes in hemodynamic parameters in the total sample (primary outcome), we observed consistently favorable changes among the 150 participants with vitamin D deficiency (...
The lancet. Diabetes & endocrinology, Jun 1, 2017
Adults with low concentrations of 25-hydroxyvitamin D (25[OH]D) in blood have an increased risk o... more Adults with low concentrations of 25-hydroxyvitamin D (25[OH]D) in blood have an increased risk of falls and fractures, but randomised trials of vitamin D supplementation have had inconsistent results. We aimed to assess the effect of high-dose vitamin D supplementation on fractures and falls. The Vitamin D Assessment (ViDA) Study was a randomised, double-blind, placebo-controlled trial of healthy volunteers aged 50-84 years conducted at one centre in Auckland, New Zealand. Participants were randomly assigned to receive either an initial oral dose of 200 000 IU (5·0 mg) colecalciferol (vitamin D3) followed by monthly 100 000 IU (2·5 mg) colecalciferol or equivalent placebo dosing. The prespecified primary outcome was cardiovascular disease and secondary outcomes were respiratory illness and fractures. Here, we report secondary outcome data for fractures and post-hoc outcome data for falls. Cox proportional hazards models were used to estimate hazard ratios (HRs) for time to first fr...
The New Zealand medical journal, Jan 24, 2017
In this pilot study, the primary aim was to compare four potential methods for undertaking a nati... more In this pilot study, the primary aim was to compare four potential methods for undertaking a national survey of unmet secondary healthcare need in New Zealand (one collecting data from GPs, and three from community surveys). The secondary aim was to obtain an estimate of the prevalence of unmet secondary healthcare need, to inform sample size calculations for a national survey. An electronic system was set up for GPs in Christchurch (Pegasus PHO) and Auckland (Auckland PHO) to record cases of unmet need as encountered in clinics. For the community surveys, a questionnaire developed by the authors was administered to people from the same electoral wards as the GP clinics. Three modes of questionnaire administration were trialled: online, telephone and face-to-face interview. Random population sampling from the Māori and General Electoral Rolls was used to identify eligible survey participants until there were approximately 200 respondents for each method in each city. Data collection...
JAMA cardiology, Jan 5, 2017
Cohort studies have reported increased incidence of cardiovascular disease (CVD) among individual... more Cohort studies have reported increased incidence of cardiovascular disease (CVD) among individuals with low vitamin D status. To date, randomized clinical trials of vitamin D supplementation have not found an effect, possibly because of using too low a dose of vitamin D. To examine whether monthly high-dose vitamin D supplementation prevents CVD in the general population. The Vitamin D Assessment Study is a randomized, double-blind, placebo-controlled trial that recruited participants mostly from family practices in Auckland, New Zealand, from April 5, 2011, through November 6, 2012, with follow-up until July 2015. Participants were community-resident adults aged 50 to 84 years. Of 47 905 adults invited from family practices and 163 from community groups, 5110 participants were randomized to receive vitamin D3 (n = 2558) or placebo (n = 2552). Two participants retracted consent, and all others (n = 5108) were included in the primary analysis. Oral vitamin D3 in an initial dose of 20...
The Australian and New Zealand journal of psychiatry, 2016