RT Journal
A1 Gomes T, Mamdani MM, Dhalla IA, Paterson J, Juurlink DN
T1 OPioids and dose-related deaths—association or causation?—reply
JF Archives of Internal Medicine
JO Archives of Internal Medicine
YR 2011
FD October 10
VO 171
IS 18
SP 1687
OP 1689
DO 10.1001/archinternmed.2011.453
UL http://dx.doi.org/10.1001/archinternmed.2011.453
AB 
We believe Dr Williamson has misinterpreted some aspects of the methodology of our study and its findings. Dr Williamson states that an unadjusted analysis reveals no association between higher opioid dose categories and opioid-related mortality. This is incorrect. Although not reported in our published article,1 the association between dose and opioid-related mortality was consistent in our unadjusted conditional logistic regression model for the primary outcome (odds ratio, 2.32, 2.97, and 3.69 among those prescribed 50-99 mg of morphine equivalents per day [ME/d], 100-199 mg of ME/d, and ≥200 mg of ME/d, respectively, compared with the 1-19 mg of ME/d group; P < .001 for all comparisons). Although the 95% confidence intervals overlap between high and moderate dose categories, a clear and significant association between higher doses of opioids and opioid-related mortality is apparent in both unadjusted and adjusted models.