Table 3.

Risk differences of persistent opioid use and misuse among mothers with or without exposure to opioids after vaginal delivery in Medicaid Analytic eXtract 2009–2013

Analysis	Risk Difference, % (95% CI)
Primary outcome
≥10 opioid prescription fills/ >120 days’ supply
Unadjusted	3.26 (3.15 – 3.37)
1:1 propensity score matching	2.21 (2.08 – 2.33)
Instrumental variable analysis	1.31 (1.06 – 1.56)
Secondary outcome
≥180 days’ supply opioids
Unadjusted	1.48 (1.41 – 1.55)
1:1 propensity score matching	1.01 (0.93 – 1.10)
Instrumental variable analysis	0.57 (0.39 – 0.74)
Opioid use disorder
Unadjusted	1.57 (1.48 – 1.67)
1:1 propensity score matching	0.81 (0.69 – 0.92)
Instrumental variable analysis	1.26 (1.02 – 1.50)
Overdose
Unadjusted	0.02 (0.01 – 0.04)
1:1 propensity score matching	0.02 (0.01 – 0.03)
Instrumental variable analysis	0.04 (0.01 – 0.07)