Table 2.
Crude and Adjusted Incidence Rate Ratios for Serious Infections by Immunosuppressive Properties of the Long-acting Opioid Among Tennessee Medicaid Enrollees (1995–2015)
| Opioid Type | Infections During Current Use (n) | Incidence per 100 Person-years of Current Use | Crude IRR (95% CI) |
PS Spline-adjusted IRR (95% CI)a |
IPTW-adjusted IRR (95% CI)b |
|||
|---|---|---|---|---|---|---|---|---|
| Previously described immunosuppressive properties | ||||||||
| Immunosuppressivec | 1012 | 4.28 | 1.00 | (reference) | 1.00 | (reference) | 1.00 | (reference) |
| Nonimmunosuppressived | 205 | 2.46 | 0.58 | (0.49, 0.67) | 0.78 | (0.66, 0.91) | 0.79 | (0.67, 0.92) |
Abbreviations: CI, confidence interval; IPTW, inverse-probability of treatment weighting; IRR, incidence rate ratio.
aAdjusted for cubic spline of the propensity score for treatment with non-immunosuppressive opioids, cubic spline of the cumulative opioid dose, and cubic spline of age, and calendar year.
bAdjusted for cubic spline of the cumulative dose, cubic spline of age, calendar year, and using IPTW with the propensity score for treatment with nonimmunosuppressive opioids.
cOpioids with evidence of immunosuppressive properties in experimental studies: morphine, fentanyl, methadone.
dOpioids without evidence or weak evidence of immunosuppressive properties in experimental studies: oxycodone, oxymorphone, tramadol.