Table 2.

Unadjusted risk ratios for enrollment in opioid agonist therapy within 6 months of index event among Medicaid recipients in Rhode Island, July 2013 – June 2018 (N = 17,449)^*

Characteristic	Unadjusted risk ratio (RR) (95% CI)
Age, years†
18–29	0.81 (0.76, 0.86)
30–39	1.24 (1.19, 1.28)
40–59	1.02 (0.99, 1.06)
≥60	0.73 (0.68, 0.78)
Gender (male)	1.01 (0.97, 1.05)
Race (non-white)	0.76 (0.73, 0.79)
Prior diagnoses
Anxiety	0.41 (0.39, 0.43)
Depression	0.48 (0.45, 0.50)
Any other mental illness	0.41 (0.39, 0.43)
Mental health treatment (outpatient)	0.40 (0.39, 0.42)
Mental health treatment (inpatient)	0.35 (0.32, 0.38)
Mental health treatment (outpatient or inpatient)	0.40 (0.38, 0.42)
Alcohol use disorder	0.34 (0.32, 0.37)
Substance use disorder (non-opioid)	0.43 (0.41, 0.45)
Hepatitis C	0.61 (0.55, 0.67)
Back problems	0.42 (0.40, 0.44)
Pregnancy	1.06 (0.99, 1.14)
Complicated pregnancy	1.03 (0.76, 1.39)
One or more prior overdose	0.23 (0.20, 0.26)
Subsequent diagnoses
Subsequent overdose	0.25 (0.18,0.35)
Subsequent diagnosis of OUD	0.63 (0.60,0.65)
Health care utilization
PCP visits above 75th percentile	1.03 (0.99, 1.07)
ED visits above 75th percentile	1.21 (1.16, 1.25)
Socioeconomic factors
Zero wages	0.88 (0.84, 0.91)
Employed at temp agency	0.82 (0.77, 0.88)
Employed in construction	1.03 (0.93, 1.15)
Cash assistance eligibility	1.15 (1.08, 1.23)
Prior incarceration	0.75 (0.72, 0.79)

PCP = primary care provider; ED = emergency department; OUD = opioid use disorder

^*Index event was defined as a patient’s initial opioid overdose or diagnosis of OUD between July 2013 and June 2018.

^†As compared to those who did not belong to a given age category.