Table 3.

The relationship between EOP and length of disability.

Study	Exposure	Variables Adjusted for in Multivariable Analysis	Association between EOP and LOD
Gasper 2021 [36]	Not reported	No report of adjusted variables. Descriptive statistics were used to assess the relationship between EOP and LOD.	The opioid group had a longer median LOD by 4 days when compared to the no opioid group (medians = 30 vs. 26 days).
Shraim 2019 [37]	MEA	Age, gender, tenure, industry, injury severity, early MRI, lumbar surgery, litigation status, live–work in the same state, wage replacement rate, waiting period, retroactive period, state medical fee schedule, treating provider choice, treating provider change, MRI facility rate, Wage replacement rate, State medical fee schedule, and unemployment rate.	Increase in EOP by 100 mg MEA was associated increase in mean LOD by 0.4 day (95% CI 0.3, 0.5).
Lee 2016 [30]	MEA	Adjusted for age, gender, job tenure, early MRI, and injury severity.	The EOP group had a higher mean LOD than the no EOP group (100.8 vs. 104 days). EOP was associated with an increased hazard of longer disability duration, but this was not statistically significant (hazard ratio 1.02, 95% CI 0.91, 1.13).
Shraim 2015 [15]	MEA	Age, gender, tenure, industry, injury severity, early MRI, lumbar surgery, litigation status, live-work in the same state, wage replacement rate, waiting period, retroactive period, state medical fee schedule, treating provider choice, and treating provider change.	Increase in EOP by 100 mg MEA was associated increase in LOD by 0.4 day (95% CI 0.3, 0.4).
Gross 2009 [38]	Not reported	Adjusted for age, gender, annual salary, year, number of previous claims, and injury type.	The EOP group had a higher hazard of continuation of time loss benefits by 1.94 (95% CI 1.86, 2.02).
Webster 2007 [17]	MEA	Adjusted for age, gender, job tenure, and lower back injury severity group.	As compared to subjects who did not receive EOP, subjects who received EOP had increased mean LOD days with increasing MEA dosage: 5.2 days (95% CI −14.6, 25.0) for 1–140 mg, 21.9 days (95% CI 3.2, 40.6) for 141–225 mg, 43.8 days (95% CI 23.7, 63.9) for 226–450 mg, and 69.1 (95% CI 49.3, 89.0) for 450+ mg.

CI: confidence interval; EOP: early opioid prescribing; LOD: length of disability; MEA: Morphine Equivalent Amount; MRI: Magnetic Resonance Imaging.