Table 2.

Estimated change (Δ) per year in average daily opioid dose by high-risk subgroup

	Gender		Substance Use Disorders
Time Period	Female	Male	No	Yes
	ΔMean (95% CI)	ΔMean (95% CI)	ΔMean (95% CI)	ΔMean (95% CI)
1: Baseline Jan 2006–Jan 2008	−3.7 (−5.6 to − 1.9)	−5.3 (−9.4 to − 1.3)	−3.8 (−5.8 to − 1.8)	−8.8 (−17.0 to − 0.6)
P*	0.479		0.263
2: Dose reduction Jan 2008–Oct 2010	−5.9 (−7.0 to − 4.8)	−8.8 (−10.8 to − 6.9)	−6.5 (−7.6 to − 5.5)	−10.7 (−14.9 to − 6.5)
P*	0.010		0.064
3: Risk mitigation Oct 2010–Sep 2014	−1.3 (−2.1 to − 0.6)	−1.5 (−2.7 to − 0.3)	−1.5 (−2.1 to − 0.8)	−0.8 (−3.4 to 1.9)
P*	0.851		0.635
	Mental Disorders		Any Sedative Use
Time period	No	Yes	No	Yes
	ΔMean (95% CI)	ΔMean (95% CI)	ΔMean (95% CI)	ΔMean (95% CI)
1: Baseline Jan 2006–Jan 2008	−3.7 (−6.5 to − 1.0)	−5.0 (−7.7 to − 2.3)	−3.8 (−6.0 to − 1.6)	−5.3 (−8.6 to − 2.0)
P*	0.539		0.456
2: Dose reduction Jan 2008–Oct 2010	−5.2 (−6.6 to − 3.8)	−8.2 (−9.7 to − 6.7)	−5.8 (−7.0 to − 4.6)	−9.2 (−11.1 to − 7.2)
P*	0.005		0.004
3: Risk mitigation Oct 2010–Sep 2014	−1.1 (−2.2 to 0.0)	−1.5 (−2.4 to − 0.7)	−1.3 (−2.1 to − 0.6)	−1.6 (−2.7 to − 0.5)
P*	0.605		0.716

CI = confidence interval.

^*Each P value is based on a 1-degree-of-freedom Wald chi-square test for the difference in rates of change between the two groups within the given time period. Boldface indicates statistical significance (P < 0.05).