Long length of disability in a chronic disabling occupational musculoskeletal disorder population: Characteristics, treatment responsiveness and one-year socioeconomic outcomes

Length of disability (LOD), or the elapsed time from injury to treatment admission, was considered as an important factor affecting outcomes for chronic musculoskeletal disorders. There was a widely held belief that a longer LOD was associated with worse treatment outcomes. However, few studies had actually examined populations with LOD duration longer than 18 months. The purpose of the present study was to systematically examine the effect of long LOD on chronic disabling occupational musculoskeletal disorder (CDOMD) patients undergoing a functional restoration program (FRP). The present study took account the economic condition because the economy might moderate the impact of LOD on socioeconomic and psychosocial outcomes. Following Krause and Ragland's Phases of Disability Model, patients were classified into: Late Rehabilitation (LR, 3-6 months); Chronic Disability (CD, 7-17 months); and Late Chronic Disability (LCD) consisting of 18-23 months (LCD -18), 24-35 months (LCD -24), 36-71 months (LCD -36), and 72+ months (LCD -72) groups. Then, patients were divided according to the market cycle of the economy when they were discharged: the Good Economy (GE, 2004-2007) period, characterized by an economic growth and low unemployment rate, and the Poor Economy (PE, 2009-2013) period, characterized by an economic decline and high unemployment rate. Results demonstrated that patients in the longer LOD groups were likely to have a pre-admission surgery, to retain attorney, to report severe pain intensity, and to be diagnosed with pain disorders. Patients in the longer LOD groups also were more likely to receive SSDI/SSI, particularly in the PE period. Long LOD was found as a risk factor for treatment completion. As such, the longer the disability, the lower the chance patients completed the program and discharged with a work plan. At discharge, patients who completed the FRP reported improved psychosocial outcomes and demonstrated better physical outcomes. The LOD was not found as a predictor for successful return-to-work or work retention at one-year following FRP discharge. CDOMD patients demonstrated a comparable return-to-work and work retention at one-year follow-up, irrespective of the LOD groups. The interaction between LOD and the economy was not found as a predictor for a successful return-to-work or work-retention of CDOMD patients who completed the FRP. Furthermore, the LOD was not found as a predictor for health-seeking behavior at one-year follow-up. Patients demonstrated similar healthcare seeking behavior irrespective of the LOD grouping. In conclusion, the FRP was successful in mitigating the effect of extended LOD in the good or poor economic condition. The long-term LOD, even beyond 6 years, did not have to result in lifelong work disability. With the right assistance, the CDOMD patients could return to work as well as retain work.