From the study:
Limitations
This study has several limitations. First, although it included a number of key covariates, unmeasured factors may have contributed to increased risk for adverse events in the population who underwent tapering. Nevertheless, the findings are consistent with recent studies of opioid discontinuation
10-
15,
29,
30 and were robust to adjustment for baseline overdose, mental health conditions, and a range of sensitivity analyses. Second, the analyses could not assess tapering circumstances. Recent evidence has shown that the majority of opioid tapering and discontinuation is clinician-initiated,
31 and risks may differ with voluntary vs involuntary tapering.
32,
33 Third, the study design considered any dose reduction of greater than or equal to 15% of the baseline dose as a taper initiation but did not account for subsequent dose trajectory. Fourth, the data set lacked an accurate measure of race, limiting the ability to account for the potential differential opioid prescribing and tapering trends between racial and ethnic groups. Fifth, the data set does not measure illicit opioid use or account for methadone administered in certified treatment programs. Sixth, administrative claims data have inherent measurement error. Seventh, these data were claims from commercially-insured and Medicare Advantage patients in the US, and the generalizability of these findings is uncertain.