Appendix A:
Sensitivity analysis with adjusted odds of higher acute care utilization among only patients with an indexing diagnosis of lumbago who received an OPR compared to those who did not, as well as adjusted odds of higher acute care utilization by patient characteristic
| Patient characteristic | 1 month OR (95% CI) | 3 months OR (95% CI) | 12 months OR (95% CI) |
|---|---|---|---|
| Prescribed OPR | |||
| No | Reference | – | – |
| Yes | 1.80 (1.58-2.04) | 1.47 (1.32-1.63) | 1.23 (1.11-1.37) |
| Age | |||
| 18-30 y | Reference | – | – |
| 31-50 y | 0.84 (0.70-1.01) | 0.82 (0.71-0.95) | 0.73 (0.64-0.84) |
| 51-64 y | 0.88 (0.73-1.07) | 0.84 (0.72-0.98) | 0.68 (0.58-0.79) |
| Race/ethnicity | |||
| White | Reference | – | – |
| Asian | 0.62 (0.49-0.80) | 0.63 (0.52-0.76) | 0.59 (0.49-0.71) |
| Black | 1.10 (0.92-1.30) | 1.10 (0.95-1.28) | 1.31 (1.14-1.51) |
| Hispanic | 0.93 (0.79–1.09) | 0.89 (0.78–1.02) | 0.96 (0.84-1.09) |
| Multiple/other | 0.95 (0.72-1.24) | 0.91 (0.73-1.14) | 1.01 (0.81-1.25) |
| Sex | |||
| Female | Reference | – | – |
| Male | 1.00 (0.88-1.13) | 0.86 (0.78-0.96) | 0.71 (0.64-0.79) |
| Neighborhood median income | |||
| ≤ $80,000 | Reference | – | – |
| > $80,000 | 0.99 (0.86-1.13) | 0.91 (0.81-1.02) | 0.93 (0.83-1.04) |
| Neighborhood median education | |||
| High school or below | Reference | – | – |
| Some college or above | 0.95 (0.79-1.13) | 0.92 (0.80-1.06) | 0.78 (0.68-0.90) |
| CCI | |||
| 0 | Reference | – | – |
| 1–2 | 1.33 (1.16-1.54) | 1.44 (1.28-1.61) | 1.80 (1.61-2.01) |
| 3+ | 1.76 (1.41-2.18) | 2.21 (1.84-2.66) | 3.30 (2.75-4.00) |
| Prior acute care utilization | |||
| No | Reference | – | – |
| Yes | 2.39 (2.01-2.72) | 2.73 (2.46-3.03) | 3.40 (3.07-3.76) |
| ED length of stay | 1.00 (1.00-1.01) | 1.00 (1.00-1.00) | 1.00 (0.99-1.00) |
Separate models were run for the 1-month, 3-month, and 12-month intervals, with higher acute care utilization defined at 1 and 3 months as ≥ 1 urgent care, emergency department, or inpatient encounter and at 12 months as ≥ 2 such encounters. The primary predictor for each time point was opioid prescription at or within 7 days of the index emergency department visit, and all analyses were adjusted for the listed covariates. Primary acute care utilization is defined as ≥ 1 urgent care, emergency department, or inpatient encounter in the 6 months prior to the indexing encounter. Emergency department length of stay is included as a continuous variable with 10-minute units.
CCI = Charlson Comorbidity Index; CI = confidence interval; ED = emergency department; OR = odds ratio; OPR = opioid pain reliever.