The Frequency, Severity, and Economic Consequences of Musculoskeletal Injuries to Firefighters in California

by Seth A. Seabury, Christopher F. McLaren

This Article

RAND Health Quarterly, 2012; 2(3):4

Abstract

The most common work-related injuries among firefighters are musculoskeletal disorders (MSDs). The strict physical demands of the job and limited modified work opportunities suggest that MSDs are potentially more disruptive and costly to firefighters than to others. The importance of understanding the frequency and severity of firefighter MSDs has become heightened due to changes to the California workers' compensation landscape since 2004, including the reduction of permanent-disability ratings that occurred due to the adoption of a new disability rating system and new rules for apportioning disability with respect to job-related causation, the adoption of treatment guidelines to provide utilization review in workers' compensation medical care, and the imposition of caps on the number of times injured workers can be reimbursed for use of chiropractic care and physical therapy. Each of these could have a potentially disadvantageous and disproportionate impact on firefighters with MSDs. This article describes the average frequency and severity of work-related MSDs experienced by California firefighters; examines the impact of work-related MSDs on the firefighters' earnings and employment several years after injury; evaluates the reforms' impact on the ratings of firefighters with permanently disabling MSDs; and assesses whether reforms to the medical delivery system affected the employment outcomes of firefighters with MSDs.

For more information, see RAND MG-1018-CHSWC at https://www.rand.org/pubs/monographs/MG1018.html

Full Text

Firefighting is one of the most important and most dangerous occupations in the United States. While firefighters face a number of unique risk factors in their jobs, the most common work-related injuries among firefighters are musculoskeletal disorders (MSDs). The strict physical demands of the job and limited modified work opportunities suggest that MSDs are potentially more disruptive and costly to firefighters than to people in other lines of work.

The importance of understanding the frequency and severity of firefighter MSDs has become heightened due to recent changes to the California workers' compensation landscape. Since 2004, there have been a number of changes to the workers' compensation system affecting both the level of compensation and the type and quantity of medical treatment provided to injured workers. These changes include the reduction of permanent-disability ratings that occurred due to the adoption of a new disability rating system and new rules for apportioning disability with respect to job-related causation, the adoption of treatment guidelines to provide utilization review in workers' compensation medical care, and the imposition of caps on the number of times injured workers can be reimbursed for use of chiropractic care and physical therapy. Each of these could have a potentially disadvantageous and disproportionate impact on firefighters with MSDs.

To develop a greater understanding of firefighter MSD risk and how these workers are treated by the workers' compensation system, this study pursued the following research objectives:

  • Describe the average frequency and severity of work-related MSDs experienced by firefighters in California.
  • Study the impact of work-related MSDs on the earnings and employment of firefighters several years after injury.
  • Evaluate the impact of reforms to the disability rating system on the ratings of firefighters with permanently disabling MSDs.
  • Assess whether reforms to the medical delivery system affected the employment outcomes of firefighters with MSDs.

We utilize a variety of methods and sources of data to address these questions. In this summary, we highlight our key findings.

Describing Firefighter Musculoskeletal Injury Risk

We use Bureau of Labor Statistics (BLS) injury and illness data from California for the years 2003–2007 to compare injury frequency and severity for firefighters with those of people in other occupations. Our review of these data demonstrates that firefighters face elevated risk from MSDs. Moreover, the risk is especially pronounced for firefighters 55 and older.

Specifically, we find the following:

  • Firefighters are 3.5 times more likely to suffer a workplace injury and 3.8 times more likely to suffer a work-related MSD than a private-sector worker.
  • Firefighters take 1.4 times longer to return to work than workers in the private sector for all injuries; this difference skyrockets for MSDs, as firefighters take twice as long to return to work.
  • The median number of days away from work after an MSD is 1.8 times greater for an MSD than for any other injury for firefighters, whereas this ratio is only 1.25 for private-sector workers.
  • Both the frequency and the severity of injuries, particularly MSDs, are worse for older firefighters than for younger firefighters.
  • Older firefighters are 10.4 times more likely to suffer an MSD than are private-sector workers, and they take more than four times longer to return to work.

The sharp increase in the frequency of MSDs for older firefighters is consistent with the idea that the physical nature of the job exposes them to cumulative trauma, making them more susceptible to disabling MSDs at older ages. We note, however, that firefighters do receive special disability compensation and retirement benefits that could influence the reported severity and frequency of occupational injuries.

The Impact of Permanent Disabilities on the Earnings and Employment of Firefighters

The previous section indicates that firefighters, particularly older firefighters, are at greater risk of injuries, and that these injuries might be more severe in terms of their average number of lost workdays. Lost workdays represent a fairly limited measure of economic impact, however, especially in the case of permanently disabling injuries. Here, we use a large sample of permanent-disability claims for workers in California, including firefighters, to examine the earnings and employment of firefighters up to three years after an injury.*

When we compare across occupations, we find that the impact of a disabling injury on the employment of firefighters is similar to that of other workers in the public sector but considerably less severe than for many private-sector occupations. This finding is highlighted in Figure 1, which reports the relative employment ratios before and after injury, by occupation.** We compare firefighters to some other public safety employees (police officers and corrections officers), other public employees in a nonsafety occupation (teachers), and private-sector workers with physically demanding jobs and similar demographic profiles (construction workers and laborers). It is clear from the figure that the impact of a permanently disabling injury is considerably worse for workers in the two private-sector occupations we consider than for the public-sector workers. There is some recovery after the first six quarters after injury, but the long-term effects are extreme. As we would expect, these differences in relative employment are consistent with the differences we see in earnings losses associated with disability.

Figure 1

Relative Employment Ratios Before and After Injury, by Occupation

>Relative Employment Ratios Before and After
Injury, by Occupation

We also compare the employment outcomes of firefighters with four different categories of injuries: back injuries, knee injuries, shoulder injuries, and heart disease. We find the following:

  • While the losses for firefighters who experience permanent disabilities are substantial on average, a focus on this masks considerable heterogeneity in outcomes across different injury types.
  • Heart disease is associated with the most significant reduction in employment. The relative employment ratio for firefighters with heart disease falls to less than 0.6 in the third year after the date of disability.
  • The losses associated with back injuries and other common types of injuries appear to be relatively minor, particularly compared to those of workers in the private sector.

While losses are relatively minor for firefighters on average, older firefighters experience more significant losses. In Figure 2, we compare the relative employment ratios of workers with back injuries by age and occupation. Each set of bars indicates the relative employment ratios for four different age categories by occupation. In the figure, as was the case with all injuries, it is clear that the decline in employment associated with a disability for firefighters is less severe for younger workers but that, for older firefighters, it is comparable to the private-sector workers (which is not true for the other public workers).

Figure 2

Relative Employment Ratios for Workers with Back Injuries Two Years After Injury, by Age and Occupation

Relative Employment Ratios for Workers with Back
Injuries Two Years After Injury, by Age and Occupation

Assessing the Impact of Reforms on Disability Ratings for Firefighters

The 2004 reforms to the California workers' compensation system were broad in scope and made many changes. Two of these changes were the introduction of a new basis for disability ratings—specifically, the American Medical Association Guides to the Evaluation of Permanent Impairment (AMA Guides) and new rules requiring disability ratings to be reduced to reflect apportionment with respect to causation of disability. These changes have contributed to a dramatic decline in the average disability ratings received by permanent-disability claimants in California. Because disability ratings are used to determine benefit levels, this has led to a large reduction in the average level of compensation. Our study examines how these reforms have affected the disability ratings of firefighters, particularly those with MSDs.

Figure 3 compares the average ratings and apportionment of firefighters to those of the five other occupations considered previously for injuries occurring in 2000–2006. The figure illustrates two series. The first series reports the average ratings of claims that receive a positive rating, meaning that a physician evaluated them under the AMA Guides and found a basis for a positive rating. The second series reports the average ratings including the unrated claims as zero, meaning that no basis for a rating was found. We make this distinction because the adoption of the AMA Guides led both to a decrease in the average ratings of rated claims and to an increase in the number of claims that received no positive rating at all.

Figure 3

Trends in Permanent-Disability Ratings, by Occupation

Trends in Permanent-Disability Ratings, by
Occupation

We find that firefighters experience significant declines in average ratings as a result of the new schedule being adopted. While this decline was substantial, however, it was actually somewhat less than in the other occupations. This appears to be due at least in part to the fact that the average rating for firefighters is lower than that for the other occupations in the sample. The average rating for firefighters at the end of the series appears closer to that for the other occupations. While the overall decline for firefighters is somewhat less than the other occupations, firefighters appear to have a disproportionately large fraction of cases receiving a zero rating.

We also use the Disability Evaluation Unit (DEU) data to examine the impact of apportionment on the disability ratings of firefighters. We find that apportionment has led to a small reduction in the average rating for firefighters, as it has for other workers. But, while the effects are small on average, there is typically a large reduction in ratings whenever apportionment is applied.

Evaluating the Impact of Medical Reforms on Employment Outcomes for Firefighters

A number of reforms have been adopted in California affecting the medical treatment after a workplace injury. In particular, Labor Code 4604.5 imposes a limit of 24 visits to a doctor of chiropractic (DC) or physical therapist (PT) for the life of a workers' compensation claim occurring on or after January 1, 2004, unless the employer authorizes additional treatments. Furthermore, Labor Code 4610 was also adopted, requiring employers to implement utilization review systems consistent with the American College of Occupational and Environmental Medicine (ACOEM) guidelines or some other approved set of guidelines.

To evaluate the impact of the reforms, we employ a variety of methods. First, we perform a systematic literature review and analyze the Medical Expenditure Panel Survey (MEPS) to determine average utilization rates for DC and PT treatments. Next, we perform a systematic literature review to assess the existing evidence on the effectiveness of DC and PT treatments, with a focus on long-term treatments, relative to alternative methods. Finally, we conduct our own empirical analyses to evaluate whether the employment outcomes of firefighters were affected by the reforms.

Chiropractic and Physical-Therapy Utilization

Based on our utilization literature review, rates for DC and PT treatments vary by type of injury, workers' compensation status, and geographic location. Specifically, we find the following:

  • Estimates from nationally representative samples of DC and PT utilization fall in the range of 10–13 visits per year.
  • Median rates are significantly lower due to a small proportion of patients consuming a large majority of visits.
  • Rates tend to be higher for patients with chronic low back pain and for workers' compensation claimants.
  • The highest averages reported were from California workers' compensation claimants prior to the recent reforms.
  • After the implementation of the cap on the number of DC and PT treatments in California, utilization rates are more comparable to national estimates.

Our analysis of MEPS yields consistent estimates with previous nationally representative samples of DC and PT utilization. Further, we find that approximately 10–15 percent of patients who go to a DC or PT at least once will exceed 24 visits. Workers' compensation claimants with an MSD who went to a physical therapist represent the highest proportion of more than 24 visits, at 15.7 percent.***

Existing Studies on Chiropractic and Physical-Therapy Effectiveness

Most studies evaluating the health effects of DC and PT treatments found mildly positive results relative to general practitioner (GP) care and significant improvements relative to placebos. The evidence regarding return-to-work (RTW) outcomes and cost-effectiveness was mixed and weak. While some studies do find that DC and PT treatments are marginally cost-effective and return injured workers to work faster, they are sparse, and many studies find that alternative treatments from a GP are more cost-effective. However, there is still a lack of evidence on long-term treatments.

Using our findings, we can draw some conclusions as to the overall impact of the recent cap on DC and PT treatments on firefighter outcomes:

  • ACOEM guidelines suggest that virtually all injuries treated by a DC or PT injury conditions can be treated well within the new 24-treatment cap, and our utilization estimates confirm that most individuals do not exceed the caps.
  • DC and PT treatment does not appear to be correlated with significantly better health, RTW, or cost-effectiveness outcomes for injured workers relative to treatment from a GP.
  • While there is no evidence that the firefighters would experience differential effects of treatment, the issue has not been adequately studied.
  • Firefighter DC and PT treatment levels are probably more likely to be affected by utilization review than by the cap, because utilization review is based in part on more limited ACOEM treatment guidelines.

Empirical Analysis of the Impact of the Medical Reforms

We use a statistical model that isolates the impact of the reforms from other potentially confounding factors in order to estimate whether the reforms had an impact on the employment outcomes of injured workers. Specifically, we estimate a series of multivariate regression models that estimate the likelihood that the injured worker has positive earnings in the eighth quarter after injury as a function of other characteristics of individuals. The results of our statistical analysis are reported in Table 1.

Table 1

Estimates from a Statistical Model of the Impact of the Medical Reforms on Employment Outcomes for Disabled Workers: Dependent Variable as Likelihood of Working Two Years After Injury

Injury

Estimated Impact of Reforms

Standard Error

p-Value

All workers

All injuries

–0.03

0.01

0.01

Back injuries

–0.03

0.02

0.11

Shoulder injuries

–0.05

0.03

0.18

Knee injuries

–0.02

0.02

0.44

Firefighters

All injuries

0.02

0.03

0.52

Back injuries

0.02

0.05

0.75

Shoulder injuries

0.03

0.07

0.70

Knee injuries

0.03

0.04

0.43

Heart disease

–0.15

0.20

0.46

Back injuries versus other injuries

–0.09

0.07

0.20

NOTE: The table reports the estimated effect of the medical reforms on the relative employment ratio of workers in the eighth quarter after injury. The analysis uses data on permanent-disability claims from the California Disability Evaluation Unit linked to data on earnings from the California Employment Development Department.

The table provides little evidence to suggest that the reforms had a significant negative impact on employment outcomes for injured workers, and essentially no evidence of an effect on firefighters. The only coefficient that is statistically significant at conventional levels is the first estimate—the impact of the reforms on all workers for all injuries. The effect suggests a reduction of –0.03 to the relative employment ratio. The average employment level in quarter 8 of workers in our sample is 0.62, so this represents a reduction in the likelihood of working of about –4.8 percent.

It can be challenging to draw policy implications from a null result such as this. We feel that it is important to stress that our findings do not mean that the medical reforms had no effect. Rather, our findings suggest either that any effect on firefighters was too small in the average worker for us to detect or that any effect was offset by other changes in the economy or the workers' compensation system. Whether the reforms had a more significant impact on workers in other occupations is unclear, though we feel that it is a subject worthy of further research.

This research was sponsored by the RAND Center for Health and Safety in the Workplace on behalf of the California Commission on Health and Safety and Workers' Compensation.

References

AMA Guides—See Cocchiarella and Andersson (2001).

California Labor Code, Section 4604.5.

———, Section 4610.

Cocchiarella, Linda, and Gunnar Andersson, eds., Guides to the Evaluation of Permanent Impairment, 5th ed., Chicago, Ill.: American Medical Association, 2001.

Peterson, Mark A., Robert T. Reville, Rachel Kaganoff Stern, and Peter S. Barth, Compensating Permanent Workplace Injuries: A Study of the California System, Santa Monica, Calif.: RAND Corporation, MR-920-ICJ, 1998. As of May 25, 2010: http://www.rand.org/pubs/monograph_reports/MR920/

Reville, Robert T., Leslie I. Boden, Jeff E. Biddle, and Christopher Mardesich, An Evaluation of New Mexico Workers' Compensation Permanent Partial Disability and Return to Work, Santa Monica, Calif.: RAND Corporation, MR-1414-ICJ, 2001. As of June 4, 2010: http://www.rand.org/pubs/monograph_reports/MR1414/

Reville, Robert T., Jay Bhattacharya, and Lauren R. Sager Weinstein, “New Methods and Data Sources for Measuring Economic Consequences of Workplace Injuries,” American Journal of Industrial Medicine, Vol. 40, No. 4, October 2001, pp. 452–463. Reprint available as of May 15, 2010: http://www.rand.org/pubs/reprints/RP972/

Reville, Robert T., and Robert F. Schoeni, Disability from Injuries at Work: The Effects on Earnings and Employment, Santa Monica, Calif.: RAND Corporation, DRU-2554, 2001. As of May 15, 2010: http://www.rand.org/pubs/drafts/DRU2554/

Reville, Robert T., Robert F. Schoeni, and Craig Martin, Trends in Earnings Loss from Disabling Workplace Injuries in California: The Role of Economic Conditions, Santa Monica, Calif.: RAND Corporation, MR-1457-ICJ, 2002. As of June 4, 2010: http://www.rand.org/pubs/ monograph_reports/MR1457/

Reville, Robert T., Seth A. Seabury, Frank W. Neuhauser, John F. Burton Jr., and Michael D. Greenburg, An Evaluation of California's Permanent Disability Rating System, Santa Monica, Calif.: RAND Corporation, MG-258-ICJ, 2005. As of May 15, 2010: http://www.rand.org/pubs/monographs/MG258/

Notes

* We measure economic outcomes using the matching methodology developed in, among others, Peterson et al. (1998); Reville, Boden, et al. (2001); Reville, Bhattacharya, and Weinstein (2001); Reville and Schoeni (2001); Reville, Schoeni, and Martin (2002); and Reville, Seabury, et al. (2005).

** The relative employment ratios are defined as the average likelihood that an injured worker is employed compared to that of the uninjured control workers. So, a relative employment ratio of 0.8 in a quarter indicates that the injured worker is, on average, 20 percent less likely to be employed in that quarter than they would have been absent the injury.

*** The reason our MEPS estimates for PT utilization are slightly higher than for DC utilization is probably because MEPS combines PT and occupational therapy into one category.

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