Background and aims: Smoking cessation medications are effective but often underutilised because ... more Background and aims: Smoking cessation medications are effective but often underutilised because of costs and side effects. Cytisine is a plant-based smoking cessation medication with over 50 years of use in Central and Eastern Europe. While cytisine has been found to be well-tolerated and more effective than nicotine replacement therapy, direct comparison with varenicline have not been conducted. This study evaluates the effectiveness, safety and cost-effectiveness of cytisine compared with varenicline. Design: Two arm, parallel group, randomised, non-inferiority trial, with allocation concealment and blinded outcome assessment. Setting: Australian population-based study. Participants: Adult daily smokers (N=1266) interested in quitting will be recruited through advertisements and Quitline telephone-based cessation support services. Intervention and comparator: Eligible participants will be randomised (1:1 ratio) to receive either cytisine capsules (25-day supply) or varenicline tablets (12-week supply), prescribed in accordance with the manufacturer's recommended dosing regimen. The medication will be mailed to each participant's nominated residential address. All participants will also be offered standard Quitline behavioural support (up to six 10-12 minute sessions). Measurements: Assessments will be undertaken by telephone at baseline, 4-and 7-months post-randomisation. Participants will also be contacted twice (two and four weeks post-randomisation) to ascertain adverse events, treatment adherence and smoking status. The primary outcome will be self-reported 6-month continuous abstinence from smoking, verified by carbon monoxide at 7-month follow-up. We will also evaluate the relative safety and cost-effectiveness of cytisine compared with varenicline. Secondary outcomes will include self-reported continuous and 7day point prevalence abstinence and cigarette consumption at each follow-up interview. Comments: If cytisine is as effective as varenicline, its lower cost and natural plant-based composition may make it an acceptable and affordable smoking cessation medication that could save millions of lives worldwide.
OBJECTIVE To develop a patient-level simulation model for predicting lifetime health outcomes of ... more OBJECTIVE To develop a patient-level simulation model for predicting lifetime health outcomes of patients with type 1 diabetes and as a tool for economic evaluation of type 1 diabetes treatment based on data from a large, longitudinal cohort. RESEARCH DESIGN AND METHODS Data for model development were obtained from the Swedish National Diabetes Register. We derived parametric proportional hazards models predicting absolute risk of diabetes complications and death based on a wide range of clinical variables and history of complications. We used linear regression models to predict risk factor progression. Internal validation was performed, estimates of life expectancies for different age-sex strata were computed, and the impact of key risk factors on life expectancy was assessed. RESULTS The study population consisted of 27,841 patients with type 1 diabetes with a mean duration of follow-up of 7 years. Internal validation showed good agreement between predicted and observed cumulative...
To test the effectiveness of a theoretically based text-message intervention to reduce binge drin... more To test the effectiveness of a theoretically based text-message intervention to reduce binge drinking among socially disadvantaged men. A multi-centre parallel group, pragmatic, individually randomized controlled trial. Community-based study conducted in four regions of Scotland. A total of 825 men aged 25-44 years recruited from socially disadvantaged areas who had two or more episodes of binge drinking (> 8 UK units on a single occasion) in the preceding 28 days: 411 men were randomized to the intervention and 414 to the control. A series of 112 interactive text messages was delivered by mobile phone during a 12-week period. The intervention was structured around the Health Action Process Approach, a comprehensive model which allows integration of a range of evidence-based behaviour change techniques. The control group received 89 texts on general health, with no mention of alcohol or use of behaviour change techniques. The primary outcome measure was the proportion of men cons...
To compare the determinants of initial statin prescribing between New Zealand and Australia. New ... more To compare the determinants of initial statin prescribing between New Zealand and Australia. New Zealand has a system-wide absolute risk-based approach to primary care cardiovascular disease (CVD) management, while Australia has multiple guidelines. Classification and Regression Tree (CART) analysis of two observational studies of primary care CVD management from New Zealand (PREDICT-CVD) and Australia (AusHeart). Over 80% of eligible New Zealanders have been screened for CVD risk. PREDICT-CVD is used by approximately one-third of New Zealand GPs to perform web-based CVD risk assessment in routine practice, with the sample consisting of 126,519 individuals risk assessed between 1 January 2007 and 30 June 2014. AusHeart is a cluster-stratified survey of primary care CVD management that enrolled 534 GPs from across Australia, who in turn recruited 1381 patients between 1 April and 30 June 2008. Eligibility was restricted to 55-74year old patients without prior CVD. The CART analyses d...
Journal of epidemiology and community health, 2017
Underemployment (defined as when a person in paid employment works for fewer hours than their des... more Underemployment (defined as when a person in paid employment works for fewer hours than their desired full working capacity) is increasingly recognised as a component of employment precarity. This paper sought to investigate the effects of underemployment on the mental health of people with disabilities. Using 14 waves of the Household, Income and Labour Dynamics in Australia survey, we used fixed-effects models to assess whether the presence of a disability modified the association between underemployment and mental health. Both disability and underemployment were assessed as time-varying factors. Measures of effect measure modification were presented on the additive scale. The experience of underemployment was associated with a significantly greater decline in mental health when a person reported a disability (mean difference -1.38, 95% CI -2.20 to -0.57) compared with when they did not report a disability (mean difference -0.49, 95% CI -0.84 to -0.14). The combined effect of bein...
Background Previous studies suggest that poor psychosocial job quality is a risk factor for menta... more Background Previous studies suggest that poor psychosocial job quality is a risk factor for mental health problems, but they use conventional regression analytic methods that cannot rule out reverse causation, unmeasured time-invariant confounding and reporting bias. Methods This study combines two quasi-experimental approaches to improve causal inference by better accounting for these biases: (i) linear fixed effects regression analysis and (ii) linear instrumental variable analysis. We extract 13 annual waves of national cohort data including 13 260 working-age (18-64 years) employees. The exposure variable is self-reported level of psychosocial job quality. The instruments used are two common workplace entitlements. The outcome variable is the Mental Health Inventory (MHI-5). We adjust for measured time-varying confounders. Results In the fixed effects regression analysis adjusted for time-varying confounders, a 1-point increase in psychosocial job quality is associated with a 1.28-point improvement in mental health on the MHI-5 scale (95% CI: 1.17, 1.40; P < 0.001). When the fixed effects was combined with the instrumental variable analysis, a 1-point increase psychosocial job quality is related to 1.62-point improvement on the MHI-5 scale (95% CI: −0.24, 3.48; P = 0.088). Conclusions Our quasi-experimental results provide evidence to confirm job stressors as risk factors for mental ill health using methods that improve causal inference. Keywords cohort, fixed effect regression, instrumental variable analysis, job stress, mental health, work What is already known on this subject? • Previous studies on job stress and mental health are subject to a range of biases and methodological problems. What does this study add? • This article provides an instrumental variable fixed effect regression model to correct for three of these problems: reserve causation, dependent and independent misclassification of subjectively reported job stressors and unmeasured timeinvariant confounding.
Status inconsistency refers to a discrepancy between the position a person holds in one domain of... more Status inconsistency refers to a discrepancy between the position a person holds in one domain of their social environment comparative to their position in another domain. For example, the experience of being overeducated for a job, or not using your skills in your job. We sought to assess the relationship between status inconsistency and mental health using 14 annual waves of cohort data. We used two approaches to measuring status inconsistency: 1) being overeducated for your job (objective measure); and b) not using your skills in your job (subjective measure). We implemented a number of methodological approaches to assess the robustness of our findings, including instrumental variable, random effects, and fixed effects analysis. Mental health was assessed using the Mental Health Inventory-5. The random effects analysis indicates that only the subjective measure of status inconsistency was associated with a slight decrease in mental health (β-1.57, 95% -1.78 to -1.36, p &amp;amp;amp;amp;lt; 0.001). This size of these coefficients was maintained in the instrumental variable analysis. We suggest that status inconsistency might explain some of the relationship between social determinants (such as work and education) and health outcomes.
Many treatments are evaluated using quasi-experimental pre-post studies susceptible to regression... more Many treatments are evaluated using quasi-experimental pre-post studies susceptible to regression to the mean (RTM). Ignoring RTM could bias the economic evaluation. We investigated this issue using the contemporary example of total knee replacement (TKR), a common treatment for end-stage osteoarthritis of the knee. Data (n = 4796) were obtained from the Osteoarthritis Initiative database, a longitudinal observational study of osteoarthritis. TKR patients (n = 184) were matched to non-TKR patients, using propensity score matching on the predicted hazard of TKR and exact matching on osteoarthritis severity and health-related quality of life (HrQoL). The economic evaluation using the matched control group was compared to the standard method of using the pre-surgery score as the control. Matched controls were identified for 56% of the primary TKRs. The matched control HrQoL trajectory showed evidence of RTM accounting for a third of the estimated QALY gains from surgery using the pre-s...
This study investigated the extent that psychosocial job stressors had lasting effects on a scale... more This study investigated the extent that psychosocial job stressors had lasting effects on a scaled measure of mental health. We applied econometric approaches to a longitudinal cohort to: (1) control for unmeasured individual effects; (2) assess the role of prior (lagged) exposures of job stressors on mental health and (3) the persistence of mental health. We used a panel study with 13 annual waves and applied fixed-effects, first-difference and fixed-effects Arellano-Bond models. The Short Form 36 (SF-36) Mental Health Component Summary score was the outcome variable and the key exposures included: job control, job demands, job insecurity and fairness of pay. Results from the Arellano-Bond models suggest that greater fairness of pay (β-coefficient 0.34, 95% CI 0.23 to 0.45), job control (β-coefficient 0.15, 95% CI 0.10 to 0.20) and job security (β-coefficient 0.37, 95% CI 0.32 to 0.42) were contemporaneously associated with better mental health. Similar results were found for the fixed-effects and first-difference models. The Arellano-Bond model also showed persistent effects of individual mental health, whereby individuals&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; previous reports of mental health were related to their reporting in subsequent waves. The estimated long-run impact of job demands on mental health increased after accounting for time-related dynamics, while there were more minimal impacts for the other job stressor variables. Our results showed that the majority of the effects of psychosocial job stressors on a scaled measure of mental health are contemporaneous except for job demands where accounting for the lagged dynamics was important.
Objective The aim of the present study was to quantify and understand the utilisation of linked h... more Objective The aim of the present study was to quantify and understand the utilisation of linked hospital data for research purposes across Australia over the past two decades. Methods A systematic review was undertaken guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 checklist. Medline OVID, PsycINFO, Embase, EconLit and Scopus were searched to identify articles published from 1946 to December 2014. Information on publication year, state(s) involved, type of data linkage, disease area and purpose was extracted. Results The search identified 3314 articles, of which 606 were included; these generated 629 records of hospital data linkage use across all Australian states and territories. The major contributions were from Western Australia (WA; 51%) and New South Wales (NSW; 32%) with the remaining states and territories having significantly fewer publications (total contribution only 17%). WA’s contribution resulted from a steady increase fr...
We investigated the predictors of long-term gains in quality-adjusted life years (QALYs) from tot... more We investigated the predictors of long-term gains in quality-adjusted life years (QALYs) from total knee arthroplasty (TKA) and the patient attributes that predicted cost-effective TKA. Data on TKA patients (n = 570) from 2006 to 2007 were extracted from a single-institution registry. QALY gains over 7 years post surgery were calculated from health-related quality of life (HrQoL) scores measured preoperatively and annually postoperatively using the short-form health survey (SF-12) instrument. Multivariate linear regression analysis investigated the predictors of QALY gain from TKA from a broad range of preoperative patient characteristics and was used to predict QALY gains for each individual. Patients were grouped into deciles according to their predicted QALY gain, and the cost-effectiveness of each decile was plotted on the cost-effectiveness plane. Patient attribute differences between deciles were decomposed. After exclusions and dropout, data were available for 488 patients. The average estimated QALY gain over 7 years was 0.77 (95% confidence interval [CI] 0.70-0.83). Predictors significantly associated with smaller QALY gains were comorbidities (Charlson comorbidity index 3+ coefficient -0.54 CI -0.15 to -0.92), the absence of severe osteoarthritis in the ipsilateral knee (-0.51 CI -0.16 to -0.85), preoperative HrQoL (standardized coefficient -0.34 CI -0.26 to -0.43), the requirement for an interpreter (-0.24 CI -0.05 to -0.44), and age (-0.01 CI -0.01 to -0.02). The largest difference between cost-effective and non-cost-effective deciles was relatively high preoperative HrQoL in the non-cost-effective decile. TKA is likely to be cost-effective for most patients except those with unusually high preoperative HrQoL or a lack of severe osteoarthritis. The poorer outcomes for those requiring an interpreter requires further research.
ObjeCtive To evaluate the effectiveness of feedback on safety of prescribing compared with modera... more ObjeCtive To evaluate the effectiveness of feedback on safety of prescribing compared with moderately enhanced usual care. Design Three arm, highly pragmatic cluster randomised trial. setting anD partiCipants 262/278 (94%) primary care practices in three Scottish health boards. COnClusiOns Feedback of prescribing safety data was effective at reducing high risk prescribing. The intervention would be feasible to implement at scale in contexts where electronic health records are in general use. trial registratiOn Clinical trials NCT01602705.
ABSTRACT Alcohol is a complex good which is ingrained within the social fabric of Australian cult... more ABSTRACT Alcohol is a complex good which is ingrained within the social fabric of Australian culture. This is even more apparent within rural communities which are considered to have higher levels of risky alcohol consumption. While alcohol provides pleasure to many, it has devastating effects for others. Not only are individuals themselves affected, but also their families and the community at large. This thesis considers a number of the economic aspects associated with alcohol consumption in rural Australia. This thesis was completed in conjunction with a larger ongoing project: Alcohol Action in Rural Communities (AARC), which is a cost-benefit analysis of community-wide interventions to reduce alcohol-related harm in rural Australia. Given the study involves 20 rural communities in New South Wales, Australia; much of the analysis is centred around data collected from these communities. This thesis examines the amount and patterns of alcohol consumption, some of the associated harms, the value of reducing these harms, plus professionals’ and the public’s opinions on interventions, viewed as an optimal solution to reduce alcohol-related harm for the communities within this study. First, those factors which affect individuals’ decisions regarding how much alcohol to consume are examined through econometric modelling of the demand for alcohol. Moreover, a theoretical model is derived whereby individuals choose both the intensity and frequency of alcohol consumption in order to maximise their utility. This is then used to examine those factors that affect the relationship between intensity and frequency of alcohol consumption for individuals within the 20 communities of the study. Secondly, the impact that this alcohol consumption has in terms of the effect on morbidity, crime and traffic accidents within these 20 communities is analysed. The relationship between selfreported quality of life using the EQ5D (a quality of life instrument) and self-reported risky alcohol use are examined using ordered Probit and Tobit models. Also, the relationship between community levels of risky drinking and crime and traffic accidents that occur in alcohol-related times is analysed, controlling for the underlying level of crime in the community by using the rate of incidents that occur in non-alcohol-related times. It is found that rural communities in Australia are experiencing a sizeable amount of potentially avoidable harm due to risky alcohol use. Thirdly, the value of reducing alcohol-related harm in these communities, in terms of the amount households are willing to pay for these reductions, is estimated using contingent valuation methods. Individuals’ willingness to pay for a percentage reduction in alcohol-related harm is estimated using both a postal questionnaire for the 20 communities, plus a face-to-face questionnaire conducted in two of these communities. The face-to-face questionnaire is also used to conduct a double-bounded dichotomous choice experiment, to investigate the willingness of households to pay for a reduction in a number of different types of alcohol-related harm. Finally, the views on the optimal policy options to reduce alcohol-related harm for rural communities in Australia are examined for both professionals and the general public. A sample of drug and alcohol (D&amp;A) professionals were asked to allocate a budget of $100,000 to a number of interventions in order to reduce alcohol-related harm in a hypothetical rural community. The D&amp;A professionals most commonly selected interventions include training general practitioners (GPs), targeting high-risk groups, developing a harm-reduction code of practice, expanding social work services and the training of emergency department staff. Additionally, individuals from the general public were asked via a postal questionnaire to allocate a percentage of total funds to eight intervention areas in order to reduce alcohol-related harm in their communities. The top three intervention areas given the most funding, on average, by the public were school-based interventions, educational messages in the media, and greater police enforcement. There is no doubt that alcohol consumption causes a substantial amount of harm for rural communities within Australia. This thesis has provided information to inform the development of interventions tailored to specific communities and has derived estimates which can be used to help evaluate the cost-benefit of these interventions. There is still additional research to be done in order to obtain more accurate estimates of the exact effect alcohol has on rural communities and thus comprehensively evaluate which interventions are likely to be the most cost-effective in reducing this harm.
McInnes, was also much appreciated. Aileen Paton and Jan Hay must be acknowledged for their suppo... more McInnes, was also much appreciated. Aileen Paton and Jan Hay must be acknowledged for their support in preparing the report and transcribing the interviews. The team would like to thank the health boards for their willingness to participate in this evaluation and in particular to the three case study boards and local leads for their help and advice in identifying participating practices and key informants for their respective areas. This evaluation would not have been possible without the generous participation of a large number of health professionals and patients. learning for the mainstreaming of ABIs into routine health service practice in Scotland and more widely.
Introduction: Quality-adjusted life years are derived using health state utility weights which ad... more Introduction: Quality-adjusted life years are derived using health state utility weights which adjust for the relative value of living in each health state compared with living in perfect health. Various techniques are used to estimate health state utility weights including time-trade-off and standard gamble. These methods have exhibited limitations in terms of complexity, validity and reliability. A new composite approach using experimental auctions to value health states is introduced in this protocol. Methods and analysis: A pilot study will test the feasibility and validity of using experimental auctions to value health states in monetary terms. A convenient sample (n=150) from a population of university staff and students will be invited to participate in 30 auction sets with a group of 5 people in each set. The 9 health states auctioned in each auction set will come from the commonly used EQ-5D-3L instrument. At most participants purchase 2 health states, and the participant who acquires the 2 'best' health states on average will keep the amount of money they do not spend in acquiring those health states. The value (highest bid and average bid) of each of the 24 health states will be compared across auctions to test for reliability across auction groups and across auctioneers. A test retest will be conducted for 10% of the sample to assess reliability of responses for health states auctions. Feasibility of conducting experimental auctions to value health states will also be examined. The validity of estimated health states values will be compared with published utility estimates from other methods. This pilot study will explore the feasibility, reliability and validity in using experimental auction for valuing health states. Ethics and dissemination: Ethical clearance was obtained from Griffith University ethics committee. The results will be disseminated in peer-reviewed journals and major international conferences.
This paper develops a method to conduct non-hierarchical bivariate decomposition of Theil indexes... more This paper develops a method to conduct non-hierarchical bivariate decomposition of Theil indexes. The method has the merits that, first, it treats all variates symmetrically and therefore facilitates the comparison of inequalities associated with different variates; and, second, it highlights the interaction between variates in the creation of inequality. The method is applied to measure gender and ethnic income inequality in Australia.
Background and aims: Smoking cessation medications are effective but often underutilised because ... more Background and aims: Smoking cessation medications are effective but often underutilised because of costs and side effects. Cytisine is a plant-based smoking cessation medication with over 50 years of use in Central and Eastern Europe. While cytisine has been found to be well-tolerated and more effective than nicotine replacement therapy, direct comparison with varenicline have not been conducted. This study evaluates the effectiveness, safety and cost-effectiveness of cytisine compared with varenicline. Design: Two arm, parallel group, randomised, non-inferiority trial, with allocation concealment and blinded outcome assessment. Setting: Australian population-based study. Participants: Adult daily smokers (N=1266) interested in quitting will be recruited through advertisements and Quitline telephone-based cessation support services. Intervention and comparator: Eligible participants will be randomised (1:1 ratio) to receive either cytisine capsules (25-day supply) or varenicline tablets (12-week supply), prescribed in accordance with the manufacturer's recommended dosing regimen. The medication will be mailed to each participant's nominated residential address. All participants will also be offered standard Quitline behavioural support (up to six 10-12 minute sessions). Measurements: Assessments will be undertaken by telephone at baseline, 4-and 7-months post-randomisation. Participants will also be contacted twice (two and four weeks post-randomisation) to ascertain adverse events, treatment adherence and smoking status. The primary outcome will be self-reported 6-month continuous abstinence from smoking, verified by carbon monoxide at 7-month follow-up. We will also evaluate the relative safety and cost-effectiveness of cytisine compared with varenicline. Secondary outcomes will include self-reported continuous and 7day point prevalence abstinence and cigarette consumption at each follow-up interview. Comments: If cytisine is as effective as varenicline, its lower cost and natural plant-based composition may make it an acceptable and affordable smoking cessation medication that could save millions of lives worldwide.
OBJECTIVE To develop a patient-level simulation model for predicting lifetime health outcomes of ... more OBJECTIVE To develop a patient-level simulation model for predicting lifetime health outcomes of patients with type 1 diabetes and as a tool for economic evaluation of type 1 diabetes treatment based on data from a large, longitudinal cohort. RESEARCH DESIGN AND METHODS Data for model development were obtained from the Swedish National Diabetes Register. We derived parametric proportional hazards models predicting absolute risk of diabetes complications and death based on a wide range of clinical variables and history of complications. We used linear regression models to predict risk factor progression. Internal validation was performed, estimates of life expectancies for different age-sex strata were computed, and the impact of key risk factors on life expectancy was assessed. RESULTS The study population consisted of 27,841 patients with type 1 diabetes with a mean duration of follow-up of 7 years. Internal validation showed good agreement between predicted and observed cumulative...
To test the effectiveness of a theoretically based text-message intervention to reduce binge drin... more To test the effectiveness of a theoretically based text-message intervention to reduce binge drinking among socially disadvantaged men. A multi-centre parallel group, pragmatic, individually randomized controlled trial. Community-based study conducted in four regions of Scotland. A total of 825 men aged 25-44 years recruited from socially disadvantaged areas who had two or more episodes of binge drinking (> 8 UK units on a single occasion) in the preceding 28 days: 411 men were randomized to the intervention and 414 to the control. A series of 112 interactive text messages was delivered by mobile phone during a 12-week period. The intervention was structured around the Health Action Process Approach, a comprehensive model which allows integration of a range of evidence-based behaviour change techniques. The control group received 89 texts on general health, with no mention of alcohol or use of behaviour change techniques. The primary outcome measure was the proportion of men cons...
To compare the determinants of initial statin prescribing between New Zealand and Australia. New ... more To compare the determinants of initial statin prescribing between New Zealand and Australia. New Zealand has a system-wide absolute risk-based approach to primary care cardiovascular disease (CVD) management, while Australia has multiple guidelines. Classification and Regression Tree (CART) analysis of two observational studies of primary care CVD management from New Zealand (PREDICT-CVD) and Australia (AusHeart). Over 80% of eligible New Zealanders have been screened for CVD risk. PREDICT-CVD is used by approximately one-third of New Zealand GPs to perform web-based CVD risk assessment in routine practice, with the sample consisting of 126,519 individuals risk assessed between 1 January 2007 and 30 June 2014. AusHeart is a cluster-stratified survey of primary care CVD management that enrolled 534 GPs from across Australia, who in turn recruited 1381 patients between 1 April and 30 June 2008. Eligibility was restricted to 55-74year old patients without prior CVD. The CART analyses d...
Journal of epidemiology and community health, 2017
Underemployment (defined as when a person in paid employment works for fewer hours than their des... more Underemployment (defined as when a person in paid employment works for fewer hours than their desired full working capacity) is increasingly recognised as a component of employment precarity. This paper sought to investigate the effects of underemployment on the mental health of people with disabilities. Using 14 waves of the Household, Income and Labour Dynamics in Australia survey, we used fixed-effects models to assess whether the presence of a disability modified the association between underemployment and mental health. Both disability and underemployment were assessed as time-varying factors. Measures of effect measure modification were presented on the additive scale. The experience of underemployment was associated with a significantly greater decline in mental health when a person reported a disability (mean difference -1.38, 95% CI -2.20 to -0.57) compared with when they did not report a disability (mean difference -0.49, 95% CI -0.84 to -0.14). The combined effect of bein...
Background Previous studies suggest that poor psychosocial job quality is a risk factor for menta... more Background Previous studies suggest that poor psychosocial job quality is a risk factor for mental health problems, but they use conventional regression analytic methods that cannot rule out reverse causation, unmeasured time-invariant confounding and reporting bias. Methods This study combines two quasi-experimental approaches to improve causal inference by better accounting for these biases: (i) linear fixed effects regression analysis and (ii) linear instrumental variable analysis. We extract 13 annual waves of national cohort data including 13 260 working-age (18-64 years) employees. The exposure variable is self-reported level of psychosocial job quality. The instruments used are two common workplace entitlements. The outcome variable is the Mental Health Inventory (MHI-5). We adjust for measured time-varying confounders. Results In the fixed effects regression analysis adjusted for time-varying confounders, a 1-point increase in psychosocial job quality is associated with a 1.28-point improvement in mental health on the MHI-5 scale (95% CI: 1.17, 1.40; P < 0.001). When the fixed effects was combined with the instrumental variable analysis, a 1-point increase psychosocial job quality is related to 1.62-point improvement on the MHI-5 scale (95% CI: −0.24, 3.48; P = 0.088). Conclusions Our quasi-experimental results provide evidence to confirm job stressors as risk factors for mental ill health using methods that improve causal inference. Keywords cohort, fixed effect regression, instrumental variable analysis, job stress, mental health, work What is already known on this subject? • Previous studies on job stress and mental health are subject to a range of biases and methodological problems. What does this study add? • This article provides an instrumental variable fixed effect regression model to correct for three of these problems: reserve causation, dependent and independent misclassification of subjectively reported job stressors and unmeasured timeinvariant confounding.
Status inconsistency refers to a discrepancy between the position a person holds in one domain of... more Status inconsistency refers to a discrepancy between the position a person holds in one domain of their social environment comparative to their position in another domain. For example, the experience of being overeducated for a job, or not using your skills in your job. We sought to assess the relationship between status inconsistency and mental health using 14 annual waves of cohort data. We used two approaches to measuring status inconsistency: 1) being overeducated for your job (objective measure); and b) not using your skills in your job (subjective measure). We implemented a number of methodological approaches to assess the robustness of our findings, including instrumental variable, random effects, and fixed effects analysis. Mental health was assessed using the Mental Health Inventory-5. The random effects analysis indicates that only the subjective measure of status inconsistency was associated with a slight decrease in mental health (β-1.57, 95% -1.78 to -1.36, p &amp;amp;amp;amp;lt; 0.001). This size of these coefficients was maintained in the instrumental variable analysis. We suggest that status inconsistency might explain some of the relationship between social determinants (such as work and education) and health outcomes.
Many treatments are evaluated using quasi-experimental pre-post studies susceptible to regression... more Many treatments are evaluated using quasi-experimental pre-post studies susceptible to regression to the mean (RTM). Ignoring RTM could bias the economic evaluation. We investigated this issue using the contemporary example of total knee replacement (TKR), a common treatment for end-stage osteoarthritis of the knee. Data (n = 4796) were obtained from the Osteoarthritis Initiative database, a longitudinal observational study of osteoarthritis. TKR patients (n = 184) were matched to non-TKR patients, using propensity score matching on the predicted hazard of TKR and exact matching on osteoarthritis severity and health-related quality of life (HrQoL). The economic evaluation using the matched control group was compared to the standard method of using the pre-surgery score as the control. Matched controls were identified for 56% of the primary TKRs. The matched control HrQoL trajectory showed evidence of RTM accounting for a third of the estimated QALY gains from surgery using the pre-s...
This study investigated the extent that psychosocial job stressors had lasting effects on a scale... more This study investigated the extent that psychosocial job stressors had lasting effects on a scaled measure of mental health. We applied econometric approaches to a longitudinal cohort to: (1) control for unmeasured individual effects; (2) assess the role of prior (lagged) exposures of job stressors on mental health and (3) the persistence of mental health. We used a panel study with 13 annual waves and applied fixed-effects, first-difference and fixed-effects Arellano-Bond models. The Short Form 36 (SF-36) Mental Health Component Summary score was the outcome variable and the key exposures included: job control, job demands, job insecurity and fairness of pay. Results from the Arellano-Bond models suggest that greater fairness of pay (β-coefficient 0.34, 95% CI 0.23 to 0.45), job control (β-coefficient 0.15, 95% CI 0.10 to 0.20) and job security (β-coefficient 0.37, 95% CI 0.32 to 0.42) were contemporaneously associated with better mental health. Similar results were found for the fixed-effects and first-difference models. The Arellano-Bond model also showed persistent effects of individual mental health, whereby individuals&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; previous reports of mental health were related to their reporting in subsequent waves. The estimated long-run impact of job demands on mental health increased after accounting for time-related dynamics, while there were more minimal impacts for the other job stressor variables. Our results showed that the majority of the effects of psychosocial job stressors on a scaled measure of mental health are contemporaneous except for job demands where accounting for the lagged dynamics was important.
Objective The aim of the present study was to quantify and understand the utilisation of linked h... more Objective The aim of the present study was to quantify and understand the utilisation of linked hospital data for research purposes across Australia over the past two decades. Methods A systematic review was undertaken guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 checklist. Medline OVID, PsycINFO, Embase, EconLit and Scopus were searched to identify articles published from 1946 to December 2014. Information on publication year, state(s) involved, type of data linkage, disease area and purpose was extracted. Results The search identified 3314 articles, of which 606 were included; these generated 629 records of hospital data linkage use across all Australian states and territories. The major contributions were from Western Australia (WA; 51%) and New South Wales (NSW; 32%) with the remaining states and territories having significantly fewer publications (total contribution only 17%). WA’s contribution resulted from a steady increase fr...
We investigated the predictors of long-term gains in quality-adjusted life years (QALYs) from tot... more We investigated the predictors of long-term gains in quality-adjusted life years (QALYs) from total knee arthroplasty (TKA) and the patient attributes that predicted cost-effective TKA. Data on TKA patients (n = 570) from 2006 to 2007 were extracted from a single-institution registry. QALY gains over 7 years post surgery were calculated from health-related quality of life (HrQoL) scores measured preoperatively and annually postoperatively using the short-form health survey (SF-12) instrument. Multivariate linear regression analysis investigated the predictors of QALY gain from TKA from a broad range of preoperative patient characteristics and was used to predict QALY gains for each individual. Patients were grouped into deciles according to their predicted QALY gain, and the cost-effectiveness of each decile was plotted on the cost-effectiveness plane. Patient attribute differences between deciles were decomposed. After exclusions and dropout, data were available for 488 patients. The average estimated QALY gain over 7 years was 0.77 (95% confidence interval [CI] 0.70-0.83). Predictors significantly associated with smaller QALY gains were comorbidities (Charlson comorbidity index 3+ coefficient -0.54 CI -0.15 to -0.92), the absence of severe osteoarthritis in the ipsilateral knee (-0.51 CI -0.16 to -0.85), preoperative HrQoL (standardized coefficient -0.34 CI -0.26 to -0.43), the requirement for an interpreter (-0.24 CI -0.05 to -0.44), and age (-0.01 CI -0.01 to -0.02). The largest difference between cost-effective and non-cost-effective deciles was relatively high preoperative HrQoL in the non-cost-effective decile. TKA is likely to be cost-effective for most patients except those with unusually high preoperative HrQoL or a lack of severe osteoarthritis. The poorer outcomes for those requiring an interpreter requires further research.
ObjeCtive To evaluate the effectiveness of feedback on safety of prescribing compared with modera... more ObjeCtive To evaluate the effectiveness of feedback on safety of prescribing compared with moderately enhanced usual care. Design Three arm, highly pragmatic cluster randomised trial. setting anD partiCipants 262/278 (94%) primary care practices in three Scottish health boards. COnClusiOns Feedback of prescribing safety data was effective at reducing high risk prescribing. The intervention would be feasible to implement at scale in contexts where electronic health records are in general use. trial registratiOn Clinical trials NCT01602705.
ABSTRACT Alcohol is a complex good which is ingrained within the social fabric of Australian cult... more ABSTRACT Alcohol is a complex good which is ingrained within the social fabric of Australian culture. This is even more apparent within rural communities which are considered to have higher levels of risky alcohol consumption. While alcohol provides pleasure to many, it has devastating effects for others. Not only are individuals themselves affected, but also their families and the community at large. This thesis considers a number of the economic aspects associated with alcohol consumption in rural Australia. This thesis was completed in conjunction with a larger ongoing project: Alcohol Action in Rural Communities (AARC), which is a cost-benefit analysis of community-wide interventions to reduce alcohol-related harm in rural Australia. Given the study involves 20 rural communities in New South Wales, Australia; much of the analysis is centred around data collected from these communities. This thesis examines the amount and patterns of alcohol consumption, some of the associated harms, the value of reducing these harms, plus professionals’ and the public’s opinions on interventions, viewed as an optimal solution to reduce alcohol-related harm for the communities within this study. First, those factors which affect individuals’ decisions regarding how much alcohol to consume are examined through econometric modelling of the demand for alcohol. Moreover, a theoretical model is derived whereby individuals choose both the intensity and frequency of alcohol consumption in order to maximise their utility. This is then used to examine those factors that affect the relationship between intensity and frequency of alcohol consumption for individuals within the 20 communities of the study. Secondly, the impact that this alcohol consumption has in terms of the effect on morbidity, crime and traffic accidents within these 20 communities is analysed. The relationship between selfreported quality of life using the EQ5D (a quality of life instrument) and self-reported risky alcohol use are examined using ordered Probit and Tobit models. Also, the relationship between community levels of risky drinking and crime and traffic accidents that occur in alcohol-related times is analysed, controlling for the underlying level of crime in the community by using the rate of incidents that occur in non-alcohol-related times. It is found that rural communities in Australia are experiencing a sizeable amount of potentially avoidable harm due to risky alcohol use. Thirdly, the value of reducing alcohol-related harm in these communities, in terms of the amount households are willing to pay for these reductions, is estimated using contingent valuation methods. Individuals’ willingness to pay for a percentage reduction in alcohol-related harm is estimated using both a postal questionnaire for the 20 communities, plus a face-to-face questionnaire conducted in two of these communities. The face-to-face questionnaire is also used to conduct a double-bounded dichotomous choice experiment, to investigate the willingness of households to pay for a reduction in a number of different types of alcohol-related harm. Finally, the views on the optimal policy options to reduce alcohol-related harm for rural communities in Australia are examined for both professionals and the general public. A sample of drug and alcohol (D&amp;A) professionals were asked to allocate a budget of $100,000 to a number of interventions in order to reduce alcohol-related harm in a hypothetical rural community. The D&amp;A professionals most commonly selected interventions include training general practitioners (GPs), targeting high-risk groups, developing a harm-reduction code of practice, expanding social work services and the training of emergency department staff. Additionally, individuals from the general public were asked via a postal questionnaire to allocate a percentage of total funds to eight intervention areas in order to reduce alcohol-related harm in their communities. The top three intervention areas given the most funding, on average, by the public were school-based interventions, educational messages in the media, and greater police enforcement. There is no doubt that alcohol consumption causes a substantial amount of harm for rural communities within Australia. This thesis has provided information to inform the development of interventions tailored to specific communities and has derived estimates which can be used to help evaluate the cost-benefit of these interventions. There is still additional research to be done in order to obtain more accurate estimates of the exact effect alcohol has on rural communities and thus comprehensively evaluate which interventions are likely to be the most cost-effective in reducing this harm.
McInnes, was also much appreciated. Aileen Paton and Jan Hay must be acknowledged for their suppo... more McInnes, was also much appreciated. Aileen Paton and Jan Hay must be acknowledged for their support in preparing the report and transcribing the interviews. The team would like to thank the health boards for their willingness to participate in this evaluation and in particular to the three case study boards and local leads for their help and advice in identifying participating practices and key informants for their respective areas. This evaluation would not have been possible without the generous participation of a large number of health professionals and patients. learning for the mainstreaming of ABIs into routine health service practice in Scotland and more widely.
Introduction: Quality-adjusted life years are derived using health state utility weights which ad... more Introduction: Quality-adjusted life years are derived using health state utility weights which adjust for the relative value of living in each health state compared with living in perfect health. Various techniques are used to estimate health state utility weights including time-trade-off and standard gamble. These methods have exhibited limitations in terms of complexity, validity and reliability. A new composite approach using experimental auctions to value health states is introduced in this protocol. Methods and analysis: A pilot study will test the feasibility and validity of using experimental auctions to value health states in monetary terms. A convenient sample (n=150) from a population of university staff and students will be invited to participate in 30 auction sets with a group of 5 people in each set. The 9 health states auctioned in each auction set will come from the commonly used EQ-5D-3L instrument. At most participants purchase 2 health states, and the participant who acquires the 2 'best' health states on average will keep the amount of money they do not spend in acquiring those health states. The value (highest bid and average bid) of each of the 24 health states will be compared across auctions to test for reliability across auction groups and across auctioneers. A test retest will be conducted for 10% of the sample to assess reliability of responses for health states auctions. Feasibility of conducting experimental auctions to value health states will also be examined. The validity of estimated health states values will be compared with published utility estimates from other methods. This pilot study will explore the feasibility, reliability and validity in using experimental auction for valuing health states. Ethics and dissemination: Ethical clearance was obtained from Griffith University ethics committee. The results will be disseminated in peer-reviewed journals and major international conferences.
This paper develops a method to conduct non-hierarchical bivariate decomposition of Theil indexes... more This paper develops a method to conduct non-hierarchical bivariate decomposition of Theil indexes. The method has the merits that, first, it treats all variates symmetrically and therefore facilitates the comparison of inequalities associated with different variates; and, second, it highlights the interaction between variates in the creation of inequality. The method is applied to measure gender and ethnic income inequality in Australia.
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Papers by Dennis Petrie