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Response to the Relationship of the Amount of Physical Therapy to Time Lost From Work and Costs in the Workers’ Compensation System

Leung, Nina PhD, MPH; Tao, Xuguang MD, PhD; Bernacki, Edward J. MD, MPH

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Journal of Occupational and Environmental Medicine: February 2020 - Volume 62 - Issue 2 - p e82
doi: 10.1097/JOM.0000000000001758
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To the Editor:

We appreciate the opportunity to respond to the concerns raised by Leung et al.1 We are delighted that our research has garnered interest and intellectual discussion among the research community.

Several concerns were raised by Leung et al1 regarding the provider types associated with current procedural terminology codes as listed in Appendix A of the previously published article. Our manuscript does not focus on specific provider types and instead focuses on the outcomes related to billable, physical methods for the treatment of injury. Similar methodologies in assessing “physical therapy” on healthcare utilization and cost has been applied in previous studies.2,3 We agree that effective physical therapy services may differ between providers and our article was careful to avoid generalizing to specific practitioners and as such, does not assess variations in care by provider types.

Another issue discussed in the comment related to the categorization of physical therapy visits among claimants without services (zero visits) and those with one to three visits. Significant differences were not observed for claim characteristics and were thus combined. Combining such categories allows us to evaluate whether low levels of physical therapy services delivered had an ultimate impact on claim costs. The aim of our study was not intended to evaluate the absence of therapy services in relation to cost and lost-time.

A third concern raised by Leung et al1 was that costs related to physical therapy were applied to all diagnostic categories, not specific diagnoses. We looked at the costs for five major diagnoses. This data is presented in Figures 1 and 2 of the article.1 Costs related to closed, indemnity, and medical-only claims for specific diagnoses including rotator cuff (capsule) sprain, displacement of the lumbar intervertebral disc (without myelopathy), and three other specific diagnoses.1 Costs were also stratified by surgical and non-surgical claims. Lastly, in the multivariate model we controlled for injury severity using extent of impairment and the second reserve.

The authors of the commentary stated that it “is important to clearly define populations, conditions, interventions, and outcome measures that reflect more than just costs.” One of the primary outcome measures include lost-time (or time out from work). One of our primary findings show that claims with a high number of “physical therapy” visits (15+ visits) were four times as likely to have 6 months of lost-time when controlling for all other confounders. The commenters also address significant variables that may impact recovery such as “coordination of care, the skills and abilities of the therapy of service provider, physical demands of the job, and availability of transitional duty” such data was not available for this analysis. We accept that a more thorough discussion within the paper regarding this limitation is a warranted comment.

It is apparent that Leung et al1 have similar goals of returning injured workers safely and expeditiously back to work. In addition, we should not only strive to assess whether care is consistent among practitioners but to also assess whether inefficiencies within the healthcare system are the cause of excess cost and ultimately, poor health outcomes.


1. Leung N, Tao XG, Bernacki EJ. The relationship of the amount of physical therapy to time lost from work and costs in the workers’ compensation system. J Occup Environ Med 2019; 62:635–640.
2. Fritz JM, Childs JD, Wainner RS, Flynn TW. Primary care referral of patients with low back pain to physical therapy: impact on future health care utilization and costs. Spine (Phila Pa 1976) 2012; 37:2114–2121.
3. Fritz JM, Cleland JA, Brennan GP. Does adherence to the guideline recommendation for active treatments improve the quality of care for patients with acute low back pain delivered by physical therapists? Med Care 2007; 45:973–980.
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