Cynthia Chen

The recovery patterns of back pain among workers with compensated occupational back injuries.

Objectives: To investigate the longitudinal patterns of recovery among workers with compensated occupational back injuries. Methods: A longitudinal cohort study, with one-year follow-up via structured telephone interviews, among respondents off work because of “new” back injuries. Self-reported pain intensity was recorded at baseline and at four follow-up time points over the course of one year. Workers who answered the questionnaire on at least three occasions (n = 678) were classified into clusters according to their patterns of pain intensity over time using a two-step cluster analysis. Results: Four pain recovery patterns were identified: workers with high levels of pain intensity showing no improvement over time (43%); those experiencing recovery in the first four months with no further improvement or possibly even some deterioration, in the second half year (33%); those experiencing a slow consistent recovery but still with considerable back pain at the end of the follow-up (12%); and those quickly progressing to low level of pain or resolution (12%). Trajectories of average Roland-Morris Disability scores and SF-36 Role of Physical scores for above clusters mapped consistently with the corresponding patterns in pain. However, individuals with fluctuating, recurrent pain patterns showed the shortest cumulative duration on 100% benefit and the earliest return-to-work among other clusters. Conclusions: Four clinically sensible patterns were identified in this cohort of injured workers, suggesting inter-individual differences in back pain recovery. The results confirm that recurrent or chronic back pain is a typical condition in respondents with new back injuries. Pain intensity and disability scores are good measures of recovery of back pain at the individual level. After initial return-to-work, or cessation of benefits, administrative measures of percentage of respondents back at work, or no longer on benefits, may not accurately reflect an individual’s condition of back pain.

The impact of co-morbid mental and physical disorders on presenteeism.

OBJECTIVES This study sought to: (i) explore the impact of mood disorders (such as depression, bipolar disorder, mania, or dysthymia) and five age-related chronic physical conditions (arthritis, back pain, diabetes, heart disease, and hypertension) on presenteeism (as indicated by self-reported activity limitations at work), and (ii) examine how mood disorders interact with each physical condition to affect this work outcome. METHODS Using Canadian Community Health Survey (CCHS) data, we modeled the relationships between self-reported restrictions at work and each health condition. We then calculated synergy indices (SI) for the interaction between mood disorders and each of the five physical conditions. RESULTS All six health conditions were associated with presenteeism. The strongest association was observed for back pain [prevalence ratio (PR) 2.70, 95% confidence interval (95% CI) 2.57-2.83] and the weakest for hypertension (PR 1.18, 95% CI 1.11-1.25). The unadjusted SI indicated no interactions between mood disorders and any of the physical conditions, while the adjusted SI indicated statistically significant interactions between mood disorders and each of the five physical conditions. The statistically significant adjusted interactions were in a negative direction, such that having a mood disorder concurrent with a chronic physical condition was associated with a lower burden of presenteeism than expected. Post-hoc analyses revealed that this unexpected finding was attributable to adjustment for other co-morbid health conditions, particularly arthritis and back pain. CONCLUSIONS Our results suggest that targeting chronic physical conditions or mood disorders may be productive in reducing presenteeism. The combined effect on presenteeism when the two types of conditions occur simultaneously is similar to the additive effect of these conditions when each occurs in isolation.

Trends in the health care use and expenditures associated with no-lost-time claims in Ontario: 1991 to 2006.

Objective: To examine trends in health care usage and expenditures associated with no-lost-time claims in Ontario over a 15-year period. Methods: A secondary analysis of administrative workers’ compensation claims occurring between 1991 and 2006 (N = 2,290,101). We used regression analysis to model health care expenditures using a zero-inflated linear model, adjusting for age, gender, industry group and size of payroll. Results: The probability of using health care increased over the time period. Health care expenditures per claim declined between 1991 and 1997, but then increased between 1998 and 2006, coinciding with the introduction of occupational health and safety legislation promoting early return to work in Ontario. Conclusions: Our results provide support to the hypothesis that the increasing use of workplace accommodation since 1998 is a driver of the relatively stable rate of no-lost-time claims in Ontario.

Longitudinal examination of temporality in the association between chronic disease diagnosis and changes in work status and hours worked

Objectives To examine the longitudinal relationship between incidence of diagnosed chronic disease and work status and hours worked. Methods A dynamic cohort approach was taken to construct our study sample using the Canadian National Population Health Survey. Participant inclusion criteria included being employed and without a chronic health condition in the survey cycle prior to diagnosis, and participation in consecutive surveys following diagnosis. Each respondent was matched with up to 5 respondents without a diagnosed health condition. The direct and indirect associations between chronic disease and work status and hours worked following diagnosis were examined using probit and linear regression path models. Separate models were developed for arthritis, back problems, diabetes, hypertension and heart disease. Results We identified 799 observations with a diagnosis of arthritis, 858 with back pain, 178 with diabetes, 569 with hypertension and 163 with heart disease, which met our selection criteria. An examination of total effects at time 1 and time 2 showed that, excluding hypertension, chronic disease diagnosis was related to work loss. The time 2 effect of chronic disease diagnosis on work loss was mediated through time 1 work status. With the exception of heart disease, an incident case of chronic disease was not related to changes in work hours among observations with continuous work participation. Conclusions Chronic disease can result in work loss following diagnosis. Research is required to understand how modifying occupational conditions may benefit employment immediately after diagnosis.

Examining the relationship between chronic conditions, multi-morbidity and labour market participation in Canada: 2000–2005

ABSTRACT Relatively little attention has been paid to understanding and addressing the potential health-related barriers faced by older workers to stay at work. Using three representative samples from the Canadian Community Health Survey, we examined the relationship between seven physical chronic conditions and labour market participation in Canada between 2000 and 2005. We found that all conditions were associated with an increased probability of not being able to work due to health reasons. In our adjusted models, heart disease was associated with the greatest probability of not working due to health reasons. Arthritis was associated with the largest population attributable fraction. Other variables associated with not being able to work due to health reasons included older age, female gender and lower educational attainment. We also found particular combinations of chronic conditions (heart disease and diabetes; and arthritis and back pain) were associated with a greater risk than the separate effects of each condition independently. The results of this study demonstrate that chronic conditions are associated with labour market participation limitations to differing extents. Strategies to keep older workers in the labour market in Canada will need to address barriers to staying at work that result from the presence of chronic conditions, and particular combinations of conditions.

Gender differences in injuries attributed to workplace violence in Ontario 2002–2015

Objectives The aim of the study is to compare trends in the incidence of injury resulting from workplace violence for men and women at the population level over the period 2002–2015 among working-age adults in Ontario, Canada. Methods Administrative records of injury resulting from workplace violence were obtained from two population-based data sources in Ontario: 21 228 lost-time workers’ compensation claims (2002–2015) and 13 245 records of non-scheduled emergency department visits (2004–2014), where the main problem was attributed to a workplace violence event. Denominator counts were estimated from labour force surveys conducted by Statistics Canada, stratified by age and sex. Age-standardised rates were calculated using the direct method. Results Over the observation period, workplace violence incidence rates were in the range of 0.2–0.5 per 1000 full-time equivalent workers. Incidence rates of injury due to workplace violence among women increased over the observation period, with an average annual per cent change (APC) of 2.8% (95% CI 1.7% to 3.9%) in compensation claims and 2.7% (95% CI 1.0% to 4.4%) in emergency department visits. In contrast, there was no change in workplace violence injury rates among men in compensation claims (APC: −0.2% (95% CI −1.2% to 0.9%)) or in emergency department visits (APC: −0.5% (95% CI −1.6% to 0.6%)). A pronounced increase in workplace violence injury rates was observed in the education sector with an APC=7.0% (95% CI 5.6% to 8.5%) for women and an APC=4.1% (95% CI 0.9% to 7.4%) for men. Conclusions Differences in the risk of injury resulting from workplace violence for women relative to men in Ontario between 2002 and 2015 were verified by two data sources. The relative risk of violence for men and women also differed across industries.

0382 Increasing male/female inequalities in rates of workplace violence in ontario between 2002 and 2014: a comparison of two data sources

Literature examining male/female differences in rates of workplace violence has produced mixed findings. This study examined trends in rates of workplace violence using two population level data sources. These were: workers’ compensation claims for assaults that required time off work; and emergency department visits for assaults or accidental contact from another person, where the treating physician determined that the payer should be workers’ compensation. For both data sources, denominator information of the population at risk was generated by sex, age groups and time period using the Labour Force Survey. Over the period 2002 to 2014 rates of assault among men remained stable, from 31.5 per 100,000 FTEs to 32.5 per 100,000 FTEs. Conversely among women rates of lost-time claims due to workplace violence increased from 38.9 per 100,000 FTEs to 59.1 per 100,000 FTEs - an absolute increase of 20.2 assaults per 100,000 FTEs, and a relative increase of 52%. These divergent trends were mirrored in the emergency department records, with rates of ED presentations among men remaining stable between 2004 and 2014 (38.2 to 39.8 per 100,000 FTEs); while among women rates of presentation increased from 34.9 per 100,000 FTEs to 52.9 per 100,000 FTEs - a relative increase of over 50%. In both time periods rates of assaults were relatively stable for men and women up till about 2008/09, after which point rates diverged between men and women. Using two data sources this study demonstrates increasing male/female inequalities in workplace violence in Ontario.

O34-1 Understanding the relationships between chronic conditions and labour market participation in canada

This presentation will describe results from two studies examining the impact of chronic conditions and labour market participation, using two different representative population data sets in Canada. The first study examined the relationship between seven physical chronic conditions and labour market participation in Canada between 2000 and 2005 using repeated cross-sectional data from the Canadian Community Health Surveys (N = 122,106). The second study created a dynamic longitudinal cohort from the Canadian National Population Health Survey, to examine the relationship between the initial incidence of five different conditions and labour market participation, both concurrently and two years later. In the first study all conditions were associated with an increased probability of not being able to work due to health reasons. Heart disease was associated with the greatest probability of not working due to health reasons. Arthritis was associated with the largest population attributable fraction. In addition, particular combinations of chronic conditions (heart disease and diabetes; and arthritis and back pain) were associated with super-additive risks of not working. In the second study the onset of all conditions (with the exception of hypertension) was related to work loss concurrently (Time 1) and two year subsequently (Time 2). The relationship between chronic diseases and work loss at Time 2 was completely mediated through Time 1 work status. The results of the first study demonstrate that chronic conditions are associated with labour market participation limitations, but to differing extents. Using a stronger longitudinal design, the second study demonstrates that chronic disease diagnosis is associated with immediate and prolonged work loss. Strategies to keep older workers in the labour market in Canada will need to address barriers to staying at work that result from the initiation and continued presence of chronic conditions, and particular combinations of conditions.