Health care utilization of workers' compensation claimants associated with mild traumatic brain injury: a historical population-based cohort study of workers injured in 1997-1998.

OBJECTIVE: To compare the health care use of workers with an injury before and after making a workers' compensation claim for mild traumatic brain injury (MTBI). DESIGN: Cohort study of workers with an MTBI who received workers' compensation benefits. SETTING: Workers' compensation system in Ontario, Canada. PARTICIPANTS: Workers (N=728) who made an incident claim involving MTBI to the Ontario Workplace Safety and Insurance Board between 1997 and 1998. We linked workers' compensation and Ontario Health Insurance Plan files and collected all health care services accrued during the year before and 2 years after the claim was initiated. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We report our results as a 7-day simple moving average of health care services per 1000 claimants per day. We stratified our analysis by age, sex, the preclaim level of health care utilization, diagnostic category, and health care specialty. RESULTS: Over the 2 years, 728 claims related to MTBI were filed by workers with an injury. The majority of the claims (65.8%) were filed by men, and 28.3% were filed by those aged between 25 and 34 years. The cumulative rate of health care utilization was stable (mean=67.6 visits/1000 claimants per day; 95% confidence interval [CI], 65.0-70.2) throughout the year before claim initiation. Health care utilization peaked during the first 4 weeks following the initiation of the claim (mean=274.3 visits/1000 claimants per day; 95% CI, 172.2-376.4) and remained on average 182% higher than that at baseline throughout the 5th to 12th week postclaim. Two years after the initiation of the claim, utilization remained 9.5% higher than the preclaim level. The increase was more pronounced (125% higher) for workers with less than the median preclaim utilization level. CONCLUSIONS: Making a workers' compensation claim involving MTBI is associated with a long-term increase in health care use.

The association between workers' compensation claims involving neck pain and future health care utilization: a population-based cohort study.

PURPOSE: To describe the health care utilization of injured workers who made a workers' compensation claim for neck pain. METHODS: We conducted a cohort study of injured workers who made an incident claim involving neck pain to the Ontario Workplace Safety and Insurance Board between 1997 and 1998. We linked their workers' compensation and Ontario Health Insurance Plan files to collect all health care services accrued during the year prior to and 2 years after the claim was initiated. We report the 7 day simple moving average of health care services per 1,000 claimants per day. We stratified our analysis by age, sex, the pre-claim level of health care utilization, diagnostic category and health care specialty. RESULTS: 58.1 % of claimants were males and 35.1 % were between the ages of 35 and 44 years. The cumulative rate of health care utilization was stable (mean = 60.80 services/1,000 claimants/day; 95 % CI: 59.7-62.0) throughout the year prior to the claim. However, it peaked during the first 4 days following the onset of the claim (mean = 473.3 services/1,000 claimants/day) and remained on average 311 % higher than baseline during the first month post-claim. On average in our sample, the health care utilization remained 11 % higher in the second year after the claim compared to the pre-claim level. This sustained increase was attributable to 6 % of claimants. CONCLUSIONS: We report a long-term increase in the average number of health care services utilized by injured workers who make a workers' compensation claim involving neck pain. This increase was attributable to a minority of claimants. The health reasons for this increase deserve further investigation.

The course of work absenteeism involving neck pain: a cohort study of Ontario lost-time claimants.

STUDY DESIGN: Cohort study. OBJECTIVE: To describe the course of lost-time claims involving neck pain in workers compensated by the Ontario Workplace Safety and Insurance Board (WSIB). SUMMARY OF BACKGROUND DATA: The prevalence of neck pain in workers varies from 27.1% to 47.8%. Very little is known about the course of work absenteeism related to neck pain. METHODS: Our cohort included 5761 injured workers with an incident lost-time claim to the WSIB in 1997 and 1998. Claimants were followed for 2 years. We measured the cumulative time on lost-time benefits using the Kaplan-Meier method and described the number and duration of episodes on benefits. RESULTS: The median cumulative time-on-benefits for the cohort was 13 days (95% CI: 13-14). The cumulative time on benefits was shorter for men than women and for younger than older workers. 14.2% of claimants experienced multiple episodes of work absenteeism during the 2 years after the initial claim. The median time on benefits for claimants with a single episode was 11 days (95% CI: 10-11). The median length of the first episode on benefits was longer for claimants with multiple episodes (19-22 days) compared with those with a single episode (11 days). Age was positively associated with longer time-on-benefits in claimants with a single episode of work absenteeism. CONCLUSION: Most injured workers who make a workers' compensation claim that involves neck pain do not make a second claim in the subsequent 2 years. However, an important minority (14.2%) experience multiple episodes of work absenteeism and these workers accrue 40.4% of all lost-time days. Recurrent claims involving neck pain represent a significant burden of disability in Ontario.

Prevalence of lost-time claims for mild traumatic brain injury in the working population: improving estimates using workers compensation databases.

PRIMARY OBJECTIVE: To test the usefulness of a method to improve the measurement of prevalent mild traumatic brain injury (MTBI) among injured workers with a workers compensation claim. METHODS: Database codes were selected to identify MTBI cases in the Ontario workers compensation lost-time claims database. A random sample of 210 claims was selected, classified as MTBI or not, and used to calculate proportions with MTBI among code groups. The annual prevalence of MTBI in 1997 and 1998 was calculated by weighting the numerators with the appropriate proportions of MTBI within each code group. RESULTS: Four code groups were created: the head region, cranial region, concussion code group and the brain region. The proportion of MTBI in each group was 29%, 19%, 92% and 32%, respectively. The 1997 prevalence depended on the codes used, from 39/10,000 (95% confidence interval (CI): 35-44) for a weighted version of the 'concussion' code to 58/10,000 (95% CI: 50-65) for inclusion of all identified MTBI codes. CONCLUSIONS: Restricting the enumeration of MTBI to specific 'concussion' codes can lead to under-estimation of the prevalence of MTBI in epidemiological studies using workers compensation data. Approximately six out of every 1000 lost-time claims are associated with MTBI. Given lost-time estimates of disability under-estimate the prevalence of this mild injury, MTBI, is an important workplace injury.