TABLE 3

Probability of NAS According to Varying Exposures of Short-Acting Opioids and Maintenance Opioids, Tobacco, and SSRI Use

VariableShort-Acting (eg, Oxycodone Hydrochloride) 10 mg q6hMaintenance (eg, Buprenorphine Hydrochloride Tablet) 24 mg q24h
Probability (95% CI)Probability (95% CI)
5-wk duration0.011 (0.008–0.016)0.132 (0.085–0.199)
 No cigarette use, SSRI use0.023 (0.016–0.034)0.241 (0.157–0.351)
 5 cigarettes/d, no SSRI0.026 (0.020–0.033)0.165 (0.123–0.219)
 5 cigarettes/d, SSRI0.053 (0.039–0.071)0.293 (0.217–0.383)
 20 cigarettes/d, no SSRI0.037 (0.029–0.047)0.179 (0.137–0.231)
 20 cigarettes/d and SSRI use0.074 (0.056–0.098)0.314 (0.239–0.399)
25-wk duration0.048 (0.028–0.081)0.163 (0.103–0.247)
 No cigarette use, SSRI use0.095 (0.055–0.158)0.289 (0.188–0.416)
 5 cigarettes/d, no SSRI0.073 (0.045–0.115)0.172 (0.123–0.236)
 5 cigarettes/d, SSRI0.141 (0.088–0.220)0.303 (0.218–0.404)
 20 cigarettes/d, no SSRI0.104 (0.068–0.156)0.216 (0.156–0.291)
 20 cigarettes/d and SSRI use0.196 (0.129–0.285)0.366 (0.270–0.474)
  • Results shown after adjustment for maternal age, education, race, infant gender, birth weight, year of birth, interaction drug type and cumulative opioid exposure (0.0002), interaction of number of cigarettes smoked per day and cumulative opioid exposure (P < .001), and interaction of drug type and number of cigarettes smoked per day.

  • Probability can be interpreted as 1 = 100% certainty that an event will occur, and 0 = 0% certainty that an event will occur. As an example, a probability of an outcome equal to 0.37 can be interpreted as among a sample of 100 patients, 37 will have the predicted outcome.

  • As an example, a woman taking oxycodone hydrochloride 10 mg every 6 hours for 5 weeks with no tobacco or SSRI use had a probability of delivering an infant with NAS of 0.011 (95% CI: 0.008–0.016). In contrast, a woman prescribed buprenorphine hydrochloride 24 mg daily for 25 weeks smoking 20 cigarettes (ie, 1 pack) per day and taking SSRIs had a 0.366 (95% CI: 0.270–0.474) probability of delivering an infant with NAS.