Does diet quality moderate the long-term effects of discrete but extreme PM2.5 exposure on respiratory symptoms? A study of the Hazelwood coalmine fire.

In 2014, a fire at an open cut coalmine in regional Victoria, Australia burned for 6 weeks. Residents of the nearby town of Morwell were exposed to smoke, which included high levels of fine particulate matter (PM2.5). We investigated whether the long-term effects of PM2.5 on respiratory health were moderated by diet quality. A cross-sectional analysis was conducted of data collected 8.5 years after the mine fire from 282 residents of Morwell and 166 residents from the nearby unexposed town of Sale. Primary outcomes were respiratory symptoms. Exposure was coalmine fire-related PM2.5 and diet quality was assessed as Australian Recommended Food Score (ARFS) derived using the Australian Eating Survey (AES). The moderating effect of diet quality on respiratory outcomes associated with PM2.5 was assessed using logistic regression models, adjusting for potential confounders. Diet quality was poor in this sample, with 60% in the lowest category of overall diet quality. Overall diet quality and fruit and vegetable quality significantly attenuated the association between PM2.5 and prevalence of chronic cough and phlegm. Sauce/condiment intake was associated with a greater effect of PM2.5 on COPD prevalence. No other moderating effects were significant. The moderating effects of overall diet quality and vegetable and fruit intake aligned with a priori hypotheses, suggesting potential protective benefits. While more evidence is needed to confirm these findings, improving diets, especially fruit and vegetable intake, may provide some protection against the effects of smoke exposure from fire events.

Long-term effects of extreme smoke exposure on COVID-19: A cohort study.

BACKGROUND: In 2014, the Hazelwood coalmine fire shrouded the regional Australian town of Morwell in smoke and ash for 6 weeks. One of the fire's by-products, PM2.5 , is associated with an increased risk of COVID-19 and severe disease. However, it is unclear whether the effect persisted for years after exposure. In this study, we surveyed a cohort established prior to the pandemic to determine whether PM2.5 from the coalmine fire increased long-term vulnerability to COVID-19 and severe disease. METHODS: From August to December 2022, 612 members of the Hazelwood Health Study's adult cohort, established in 2016/17, participated in a follow-up survey that included standardized items to capture COVID-19 cases, as well as questions about hospitalization and vaccinations. Associations were evaluated in crude and adjusted logistic regression models. RESULTS: A total of 268 (44%) participants self-reported or met symptom criteria for having had COVID-19 at least once. All models found a positive association, with odds of COVID-19 increasing by between 4% and 30% for a 10 µg/m3 increase in coalmine fire-related PM2.5 exposure. However, the association was significant in only 2 of the 18 models. There were insufficient hospitalizations to examine severity (n = 7; 1%). CONCLUSION: The findings are inconclusive on the effect of coalmine fire-related PM2.5 exposure on long-term vulnerability to COVID-19. Given the positive association that was robust to modelling variations as well as evidence for a causal mechanism, it would be prudent to treat PM2.5 from fire events as a long-term risk factor until more evidence accumulates.

Association between PM2.5 from a coal mine fire and FeNO concentration 7.5 years later.

BACKGROUND AND AIM: There are few long-term studies of respiratory health effects of landscape fires, despite increasing frequency and intensity due to climate change. We investigated the association between exposure to coal mine fire PM2.5 and fractional exhaled nitric oxide (FeNO) concentration 7.5 years later. METHODS: Adult residents of Morwell, who were exposed to the 2014 Hazelwood mine fire over 6 weeks, and unexposed residents of Sale, participated in the Hazelwood Health Study Respiratory Stream in 2021, including measurements of FeNO concentration, a marker of eosinophilic airway inflammation. Individual exposure to coal mine fire PM2.5 was modelled and mapped to time-location diaries. The effect of exposure to PM2.5 on log-transformed FeNO in exhaled breath was investigated using multivariate linear regression models in the entire sample and stratified by potentially vulnerable subgroups. RESULTS: A total of 326 adults (mean age: 57 years) had FeNO measured. The median FeNO level (interquartile range [IQR]) was 17.5 [15.0] ppb, and individual daily exposure to coal mine fire PM2.5 was 7.2 [13.8] µg/m3. We did not identify evidence of association between coal mine fire PM2.5 exposure and FeNO in the general adult sample, nor in various potentially vulnerable subgroups. The point estimates were consistently close to zero in the total sample and subgroups. CONCLUSION: Despite previous short-term impacts on FeNO and respiratory health outcomes in the medium term, we found no evidence that PM2.5 from the Hazelwood coal mine fire was associated with any long-term impact on eosinophilic airway inflammation measured by FeNO levels.

Long-term impact of the 2014 Hazelwood coal mine fire on emergency department presentations in Australia.

BACKGROUND: In 2014, wildfires ignited a coal mine in Australia, burning for 6 weeks, releasing large amounts of fine particulate matter ≤2.5 µm in diameter (PM2.5). We investigated the association between individual PM2.5 exposure and emergency department presentations (EDPs) within 5 years post-fire. METHODS: Survey and exposure data for 2725 residents from an exposed and unexposed town were linked with ED administrative data from 2009 to 2019. The association between individual PM2.5 and EDPs was assessed using recurrent survival analysis. RESULTS: A 10 µg/m3 increase in PM2.5 was associated with a 10% increase in respiratory EDPs (HR = 1.10; 95%CI:1.00-1.22) over 5 years post-fire. Increased risks of EDPs for ischaemic heart disease (HR = 1.39; 95%CI:1.12-1.73), atherothrombotic disease (HR = 1.27; 95%CI:1.08-1.50), and cardiovascular disease (HR = 1.10, 95%CI:0.99-1.22) were evident within 2.5 years. CONCLUSION: PM2.5 exposure from a 6-week mine fire increased the 5-year risk of respiratory conditions. An increased risk of CVD within 2.5 years post-fire subsided after this time.

Sociodemographic circumstances, health, and life experience shape posttraumatic distress trajectories among individuals exposed to smoke during a large-scale coal mine fire.

The 2014 Hazelwood coal mine fire in the Latrobe Valley, Australia, distributed toxic smoke into surrounding communities over 45 days. This study investigated risk and protective factors associated with four trajectories of posttraumatic distress (resilient, recovery, delayed-onset, chronic) among exposed adults. Participants (N = 709) completed surveys in 2016-2017 and 2019-2020 assessing mine fire-related particulate matter (PM2.5 ) exposure; sociodemographic, physical, and mental health variables; and exposure to other traumatic and recent stressful events. Mine fire-related posttraumatic distress was measured using the IES-R; trajectories were determined according to established clinical significance thresholds. Relative risk ratios (RRRs) were generated from multivariate multinomial regressions. The resilient trajectory was most common (77.0%). The chronic trajectory (8.5%) was associated with loneliness, RRR = 2.59, 95% CI [1.30, 5.16], and physical health diagnoses, RRR = 2.31, 95% CI [1.32, 4.02]. The delayed-onset trajectory (9.1%) was associated with multiple recent stressful events, RRR = 2.51, 95% CI [1.37, 4.59]; mental health diagnoses, RRR = 2.30, 95% CI [1.25, 4.24]; loneliness, RRR = 2.05, 95% CI [1.09, 3.88]; and male gender, RRR = 2.01, 95% CI [1.18, 3.44]. Socioeconomic advantage protected against chronic, RRR = 0.68, 95% CI [0.53, 0.86], and delayed-onset trajectory membership, RRR = 0.68, 95% CI [0.50, 0.94]; social support protected against chronic trajectory membership, RRR = 0.67, 95% CI [0.49, 0.92]. PM2.5 exposure did not determine trajectory. These findings enhance understanding of longer-term posttraumatic responses to large-scale smoke events and can inform mental health initiatives within at-risk communities.

Collider Bias in Administrative Workers' Compensation Claims Data: A Challenge for Cross-Jurisdictional Research.

PURPOSE: Workers' compensation claims consist of occupational injuries severe enough to meet a compensability threshold. Theoretically, systems with higher thresholds should have fewer claims but greater average severity. For research that relies on claims data, particularly cross-jurisdictional comparisons of compensation systems, this results in collider bias that can lead to spurious associations confounding analyses. In this study, I use real and simulated claims data to demonstrate collider bias and problems with methods used to account for it. METHODS: Using Australian claims data, I used a linear regression to test the association between claim rate and mean disability durations across Statistical Areas. Analyses were repeated with nesting by state/territory to account for variations in compensability thresholds across compensation systems. Both analyses are repeated on left-censored data. Simulated claims data are analysed with Cox survival analyses to illustrate how left-censoring can reverse effects. RESULTS: The claim rate within a Statistical Area was inversely associated with disability duration. However, this reversed when Statistical Areas were nested by state/territory. Left-censoring resulted in an attenuation of the unnested association to non-significance, while the nested association remained significantly positive. Cox regressions with simulated claims data demonstrated how left-censoring can reverse effects. CONCLUSIONS: Collider bias can seriously confound work disability research, particularly cross-jurisdictional comparisons. Work disability researchers must grapple with this challenge by using appropriate study designs and analytical approaches, and considering how it affects the interpretation of results.

Exploring Differences in Work Disability Duration by Size of Firm in Canada and Australia.

Purpose To identify whether there were differences in work disability duration between injured workers employed by small, medium, large, and self-insured firms and whether these differences varied between workers' compensation jurisdictions in Canada and Australia. Methods Workers' compensation data were used to identify comparable lost-time, work-related injury and musculoskeletal disorder claims in five Canadian and five Australian jurisdictions between 2011 and 2015. Work disability duration was measured using cumulative disability days paid up to one-year post-injury. Jurisdiction-specific quantile regression models were used to estimate differences in cumulative disability days paid to claims from small (< 20 full-time equivalents (FTEs)) medium (20-199 FTEs), large (200 + FTEs) and self-insured firms at the 25th, 50th, and 70th percentiles in the disability distribution, adjusting for confounders. Results Compared to large firms, workers in small firms generally had longer work disability duration at each percentile, particularly in Saskatchewan and Alberta (Canada), Victoria and Australian Capital Territory (Australia), where an additional 31.1, 18.4, 58.5 and 37.0 days were paid at the 75th percentiles, respectively. The disability duration of workers from self-insured firms was longer than large firms in all Canadian jurisdictions but was shorter or no different in Australian jurisdictions. Smaller differences were observed between claims from large and medium-sized firms. Conclusions Workers in small firms had longer work disability duration than those in large firms in all but one of the study jurisdictions. Claims management processes need to be sensitive to the challenges that small firms face in accommodating and returning injured workers back to work.

Regional Differences in Time Off Work After Injury: A Comparison of Australian States and Territories Within A Single Workers' Compensation System.

Purpose Time off work after workplace injury varies by compensation system. While often attributed to features of the compensation system, unaccounted regional factors may drive much of the effect. In this study, we compare disability durations by state and territory of residence within a single national workers' compensation system. Large differences would indicate that factors other than compensation system settings are responsible for system effects observed in previous studies. Methods We applied crude and adjusted Cox proportional hazards models to compare disability durations by state and territory of residence. Confounders included factors known to influence disability duration. Durations were left-censored at two weeks and right-censored at 104 weeks. Results We analysed N = 31,641 claims. In both crude and adjusted models, three of the seven states and territories significantly differed from the reference group, New South Wales. However, two of the three were different between crude and adjusted models. Regional effects were relatively small compared to other factors including insurer type, age, and type of injury. Conclusions Regional factors influence disability duration, which persist with adjustment for demographic, work, insurer type, and injury confounders. However, the effects are inconsistently significant and fairly small, especially when compared to the effect of confounders and system effects found in previous studies. Regional factors likely only account for a small share of the difference in disability duration between compensation systems.

Geographic variation in work disability burden: Identifying hotspots, coldspots, and associated sociodemographic factors.

OBJECTIVES: To identify geographic hotspots and coldspots of work disability burden and their associated sociodemographic factors in Australia. METHODS: Using Australian workers' compensation and census data, we calculated weeks of compensated time off work per 1000 labor force, an indicator of work disability burden, at Statistical Area Level 4, the smallest level of labor force data produced by the Australian Bureau of Statistics. Records included all claims with at least 1 day of compensated time off work lodged between 2010 and 2015. Work disability burden was z-transformed by state and territory and mapped across Australia. Statistical Areas that were more than 1 standard deviation from the state or territory mean were considered hotspots and coldspots. We tested several sociodemographic factors as predictors of work disability burden. RESULTS: Work disability burden hotspots were concentrated in lower socioeconomic suburbs and exurbs of state capitals, in addition to several regional areas. Coldspots were primarily in wealthy central urban and suburban areas. Factors associated with greater work disability burden include higher area socioeconomic disadvantage, rurality, lower labor force participation, higher unemployment, higher proportion of work in production industries and in blue-collar occupations, and higher numbers of those with core activity limitations, those aged 65+ years, and foreign-born residents. CONCLUSIONS: Work disability burden is unequally distributed across Australia and strongly influenced by sociodemographic and occupational factors. The findings can guide more efficient allocation of resources for work disability prevention and rehabilitation.

Step-downs reduce workers' compensation payments to encourage return to work: are they effective?

OBJECTIVE: To determine whether step-downs, which cut the rate of compensation paid to injured workers after they have been on benefits for several months, are effective as a return to work incentive. METHODS: We aggregated administrative claims data from seven Australian workers' compensation systems to calculate weekly scheme exit rates, a proxy for return to work. Jurisdictions were further subdivided into four injury subgroups: fractures, musculoskeletal, mental health and other trauma. The effect of step-downs on scheme exit was tested using a regression discontinuity design. Results were pooled into meta-analyses to calculate combined effects and the proportion of variance attributable to heterogeneity. RESULTS: The combined effect of step-downs was a 0.86 percentage point (95% CI -1.45 to -0.27) reduction in the exit rate, with significant heterogeneity between jurisdictions (I2=68%, p=0.003). Neither timing nor magnitude of step-downs was a significant moderator of effects. Within injury subgroups, only fractures had a significant combined effect (-0.84, 95% CI -1.61 to -0.07). Sensitivity analysis indicated potential effects within mental health and musculoskeletal conditions as well. CONCLUSIONS: The results suggest some workers' compensation recipients anticipate step-downs and exit the system early to avoid the reduction in income. However, the effects were small and suggest step-downs have marginal practical significance. We conclude that step-downs are generally ineffective as a return to work policy initiative.Postprint link: https://www.medrxiv.org/content/10.1101/19012286.

The Impact of Income Sources on Financial Stress in Workers' Compensation Claimants.

PURPOSE: Workers' compensation schemes usually recompense workers below their regular wage. This may cause financial stress, which has previously been associated with poorer health and work outcomes after injury. We sought to determine the level of financial stress experienced by injured workers and the influence of post-injury income source on financial stress. METHODS: Analysis of a cross-sectional national survey of 4532 adults who had been injured at work and had at least one day of workers' compensation paid. Financial stress at time of survey was measured on a scale of 1-10 and subsequently dichotomised at the top quartile for further analysis. The effect of current main income source on financial stress, adjusted for demographic and psychosocial confounders, was assessed using logistic regression. RESULTS: Sixty-nine percent of workers whose main income was social assistance or insurance and 54% whose main income was workers' compensation were experiencing financial stress. Relative to wages or salaries, workers with a main income from social assistance or insurance (odds ratio: 3.33, 95% CI 2.22-5.00) and workers' compensation (1.71, 1.31-2.24) had higher odds of financial stress. Workers with a main income of an aged pension or superannuation had lower odds of financial stress (0.52, 0.28-0.97). CONCLUSION: Injured workers receiving workers' compensation or social assistance benefits are vulnerable to increased financial stress. Given the potential negative consequences of financial stress on health, particularly mental health, this study suggests the need for careful consideration of income replacement benefits in the design of workers' compensation schemes.

Psychological Distress in Workers' Compensation Claimants: Prevalence, Predictors and Mental Health Service Use.

Purpose To determine the prevalence and predictors of psychological distress among injured and ill workers and their mental health service use. Methods Cross-sectional national survey of adults with work-related musculoskeletal or mental health conditions, accepted workers' compensation claims and at least 1 day off work. Psychological distress was measured using the Kessler-6 scale. Mental health service use was measured using self-report. Results A total of 3755 workers were included in the study (Musculoskeletal disorder = 3160; Mental health condition = 595). Of these, 1034 (27.5%) and 525 (14.0%) recorded moderate and severe psychological distress, respectively. Multivariate ordinal logistic regression revealed that being off work, poor general health, low work ability, financial stress, stressful interactions with healthcare providers and having diagnosed mental health conditions had the strongest associations with presence of psychological distress. Of the subgroup with musculoskeletal disorders and psychological distress (N = 1197), 325 (27.2%) reported accessing mental health services in the past four weeks. Severe psychological distress, being off work, worse general health and requiring support during claim were most strongly associated with greater odds of service use. Conclusions The prevalence of psychological distress among workers' compensation claimants is high. Most workers with musculoskeletal disorders and psychological distress do not access mental health services. Screening, early intervention and referral programs may reduce the prevalence and impact of psychological distress.

Health Care Provider Communication and the Duration of Time Loss Among Injured Workers: A Prospective Cohort Study.

BACKGROUND: In addition to providing injured workers with biomedical treatment, health care providers (HCPs) can promote return to work (RTW) through various communications. OBJECTIVES: To test the effect of several types of HCP communications on time loss following injury. RESEARCH DESIGN: The authors analyzed survey and administrative claims data from a total of 730 injured workers in Victoria, Australia. Survey responses were collected around 5 months postinjury and provided data on HCP communication and confounders. Administrative claim records provided data on compensated time loss postsurvey. The authors conducted multivariate zero-inflated Poisson regressions to determine both the odds of having future time loss and its duration. MEASURES: Types of HCP communications included providing an estimated RTW date, discussing types of activities the injured worker could do or ways to prevent a recurrence, and contacting other RTW stakeholders. Each was measured in isolation as well as modified by a low-stress experience with the HCP. Time loss was the count of cumulative compensated work absence in weeks, accrued postsurvey. RESULTS: RTW dates reduced the odds of future time loss [odds ratio, 0.26; 95% confidence interval (CI), 0.09-0.82] regardless of the stressfulness of the experience. Communications that predicted shorter durations of time loss only did so with low-stress experiences: RTW date [incidence rate ratio (IRR), 0.56; 95% CI, 0.50-0.63], stakeholder contact (IRR, 0.78; 95% CI, 0.70-0.87), and prevention discussions (IRR, 0.87; 95% CI, 0.78-0.98). CONCLUSIONS: HCPs may reduce time loss through several types of communication, particularly when stress is minimized. RTW dates had the largest and most robust effect.

Injured worker experiences of insurance claim processes and return to work: a national, cross-sectional study.

BACKGROUND: Insurance claims management practices may have a significant impact on the health and experiences of injured workers claiming in workers' compensation systems. There are few multi-jurisdictional studies of the way workers experience compensation processes, and limited data on the association between claims experience and return to work outcomes. This study sought to identify worker, claim and injury related factors associated with injured worker experiences of workers' compensation claims management processes, and to examine associations between claims experience and return to work. METHODS: A national, cross-sectional survey of injured workers involved in ten Australian workers' compensation schemes. A total of 10,946 workers completed a telephone survey at 6 to 24 months post claim acceptance. Predictors of positive or negative/neutral claims experience were examined using logistic regression. Associations between claims experience, return to work status and duration of time loss were examined using logistic regression. RESULTS: Nearly one-quarter (23.0%, n = 2515) of workers reported a negative or neutral claims experience. Injury type, jurisdiction of claim, and time to lodge claim were most strongly associated with claims experience. Having a positive claims experience was strongly associated with having returned to work after accounting for injury, worker, claim and employer factors. CONCLUSIONS: There is a strong positive association between worker experiences of the insurance claims process and self-reported return to work status. Revision and reform of workers' compensation claims management practices to enhance worker experience and the fairness of procedures may contribute to improved return to work outcomes.

Factors Associated with Employer Support for Injured Workers During a Workers' Compensation Claim.

Purpose The employer/worker relationship can be an important catalyst for-or obstacle to-successful return to work (RTW). An understanding of factors associated with an injured worker's relationship with their employer, and employer involvement in RTW planning, is warranted. Methods Analysis of n = 8808 cross-sectional survey responses from injured workers in nine Australian workers' compensation (WC) jurisdictions. Workers completed a telephone survey between 6 and 24 months post-WC claim acceptance. Factors associated with the worker's perception of employer support were examined using ordinal regression. Factors associated with employer provision of RTW plans were examined using logistic regression. Results Factors associated with employer support included being aged over 50 years, not having a mental health condition, better self-rated health and less time between injury and claim. Factors associated with having a RTW plan included being female, not having a mental health condition and working for a self-insurer. Factors associated with having a written RTW plan included being female and being under 50 years. There was wide variation in the provision of RTW plans between WC jurisdictions. Conclusions There are strong associations between worker, claim and injury-related factors and the injured worker's experience of employer support. Identification of workers at risk of receiving inadequate support during the RTW process may enable interventions to improve support and RTW outcomes.

Effectiveness of employer financial incentives in reducing time to report worker injury: an interrupted time series study of two Australian workers' compensation jurisdictions.

BACKGROUND: Early intervention following occupational injury can improve health outcomes and reduce the duration and cost of workers' compensation claims. Financial early reporting incentives (ERIs) for employers may shorten the time between injury and access to compensation benefits and services. We examined ERI effect on time spent in the claim lodgement process in two Australian states: South Australia (SA), which introduced them in January 2009, and Tasmania (TAS), which introduced them in July 2010. METHODS: Using administrative records of 1.47 million claims lodged between July 2006 and June 2012, we conducted an interrupted time series study of ERI impact on monthly median days in the claim lodgement process. Time periods included claim reporting, insurer decision, and total time. The 18-month gap in implementation between the states allowed for a multiple baseline design. In SA, we analysed periods within claim reporting: worker and employer reporting times (similar data were not available in TAS). To account for external threats to validity, we examined impact in reference to a comparator of other Australian workers' compensation jurisdictions. RESULTS: Total time in the process did not immediately change, though trend significantly decreased in both jurisdictions (SA: -0.36 days per month, 95% CI -0.63 to -0.09; TAS: 0.35, -0.50 to -0.20). Claim reporting time also decreased in both (SA: -1.6 days, -2.4 to -0.8; TAS: -5.4, -7.4 to -3.3). In TAS, there was a significant increase in insurer decision time (4.6, 3.9 to 5.4) and a similar but non-significant pattern in SA. In SA, worker reporting time significantly decreased (-4.7, -5.8 to -3.5), but employer reporting time did not (-0.3, -0.8 to 0.2). CONCLUSIONS: The results suggest that ERIs reduced claim lodgement time and, in the long-term, reduced total time in the claim lodgement process. However, only worker reporting time significantly decreased in SA, indicating that ERIs may not have shortened the process through the intended target of employer reporting time. Lack of similar data in Tasmania limited our ability to determine whether this was a result of ERIs or another component of the legislative changes. Further, increases in insurer decision time highlight possible unintended negative effects.

Age, sex, and the changing disability burden of compensated work-related musculoskeletal disorders in Canada and Australia.

BACKGROUND: The objectives of this study were (1) to identify age and sex trends in the disability burden of compensated work-related musculoskeletal disorders (MSDs) in Canada and Australia; and (2) to demonstrate a means of comparing workers' compensation data internationally. METHODS: All non-fatal, work-related MSD claims with at least one day of compensated time-loss were extracted for workers aged 15-80 during a 10-year period (2004-2013) using workers' compensation data from five Canadian and eight Australian jurisdictions. Disability burden was calculated for both countries by sex, age group, and injury classification, using cumulative compensated time-loss payments of up to two years post-injury. RESULTS: A total of 1.2 million MSD claims were compensated for time-loss in the Canadian and Australian jurisdictions during 2004-2013. This resulted in time-loss equivalent to 239,345 years in the Canadian jurisdictions and 321,488 years in the Australian jurisdictions. The number of time-loss years declined overall among male and female workers, but greater declines were observed for males and younger workers. The proportion of the disability burden grew among older workers (aged 55+), particularly males in the Canadian jurisdictions (Annual Percent Change [APC]: 7.2, 95% CI 6.7 to 7.7%) and females in the Australian jurisdictions (APC: 7.5, 95% CI 6.2 to 8.9%). CONCLUSIONS: The compensated disability burden of work-related MSDs is shifting towards older workers and particularly older females in Australia and older males in Canada. Employers and workers' compensation boards should consider the specific needs of older workers to reduce injuries and time off work. Comparative research made possible through research-stakeholder partnerships offers a unique opportunity to use existing administrative data to identify long-term trends in disability burden. Future research can apply similar approaches for estimating long-term trends in occupational health.

A Prospective Cohort Study of the Impact of Return-to-Work Coordinators in Getting Injured Workers Back on the Job.

Purpose To assess the impact of workplace-based return-to-work (RTW) Coordinators' interpersonal and functional activities on RTW outcomes. Methods Multivariable logistic regression analyses of cross-sectional and longitudinal survey responses of 632 injured workers with at least 10 days of work absence in Victoria, Australia, adjusting for demographic and other workplace factors. Outcome was being back at work for at least 1 month, measured at both baseline and 6 month follow-up survey. Participant responses to stressfulness of Coordinator interactions were dichotomised into good and poor and evaluated as a proxy for Coordinators' interpersonal activities, while having a RTW plan was evaluated as a proxy for functional activities. Results At baseline, RTW plans doubled the odds of RTW (OR 2.02; 95% CI 1.40-2.90) and attenuated the impact of good Coordinator interactions (1.14; 0.77-1.70). At 6-month follow-up, the opposite was observed: good interactions nearly doubled odds of RTW (1.90; 1.22-2.95) while RTW plans were non-significant (1.02; 0.68-1.54). Conclusions Differences between when the two Coordinator activities were effective may be due to the nature of claimants who RTW in each survey period. Length of shorter-duration claims are influenced by injury related factors, while psychosocial factors tend to be more important for longer-duration claims. Such factors may determine whether a claimant is more likely to respond to Coordinators' functional or interpersonal activities. The findings have important implications for increasing Coordinator effectiveness.

Associations Between Firearm and Suicide Rates: A Replication of Kleck (2021).

OBJECTIVE: Using data from n = 194 nation-states, Kleck found that firearm availability was only associated with firearm suicide rates, but not total or non-firearm suicides. He thus concluded that while firearm availability influences how people commit suicide, it does not affect total numbers. However, the study contains numerous logical and methodological issues and is at odds with the evidence base. Therefore, I attempt to reproduce the original results. METHOD: I reproduce the original study's methods: ordinary least squares regression, weighted by the square root of the population, with log-transformed suicide rates and three separate firearm availability measures: global estimates from the Small Arms Survey, proportion of suicides committed with firearms, and a European Union survey of firearm ownership. I also test several methodological variations and include U.S. suicide data. RESULTS: In contrast to Kleck, global analyses with Small Arms Survey data found a significant and positive association between firearm availability and total suicides, as did U.S. analyses. Analyses with other firearm availability measures comported with the original study, finding no association. CONCLUSION: The main result in Kleck failed to reproduce, finding instead a significant association between firearm availability and suicide rates, as did U.S. analyses. While reproductions of Kleck's other analyses continued to show no association, they were based on unreliable methods. I therefore reject Kleck's conclusion that that firearm availability does not influence suicide rates. HighlightsUsing data global data, I find firearm availability is positively associated with suicide rates.I identify serious flaws in the logic and methods of Kleck and an earlier review.For transparency, data and code have been archived on a public repository.

Injured worker outcomes after compensation system overhaul: an interrupted time series study.

OBJECTIVE: In 2015, South Australia replaced its workers' compensation system with the aim of improving return to work rates. We examined whether this was achieved by focusing on the duration of time off work, as well as claim processing times and claim volumes to understand how this may have been achieved. METHODS: The primary outcome was mean weeks of compensated disability duration. Secondary outcomes tested alternative mechanisms of a change in disability duration: (1) mean employer report and insurer decision times to evaluate whether there had been changes in claim processing and (2) claim volumes to determine whether the new system altered the cohort under investigation. Outcomes were aggregated into monthly units and analysed with an interrupted time series design. Three condition subgroups-injury, disease and mental health-were compared in separate analyses. RESULTS: While disability duration steadily declined before the RTW Act came into effect, afterwards it flatlined. A similar effect was observed in insurer decision time. Claim volumes gradually increased. Employer report time gradually decreased. Condition subgroups mostly followed a similar pattern to overall claims, though the increase in insurer decision time appears largely driven by changes in injury claims. CONCLUSIONS: The increase in disability duration after the RTW Act took effect may be attributable to an increase in insurer decision time, which itself could be due to the disruption of overhauling a compensation system or the elimination of provisional liability entitlements that incentivised early decision making and provided early intervention.