TABLE 3.

Means and Proportions of Selected 12th Grade Characteristics by Risk Strata for Future Misuse of Prescription Opioids (SE in Parentheses)

Strata No.	1		2		3		4		5		6		7		8
Range of Predicted Probability for Future Opioid Misuse Post High School	0%–<1.75%		1.75%–<3%		3%–<5%		5%–<10%		10%–<20%		20%–<30%		30%–<45%		≥45%
	No Opioid Misuse Age 19–23	Opioid Misuse Age 19–23	No Opioid Misuse Age 19–23	Opioid Misuse Age 19–23	No Opioid Misuse Age 19–23	Opioid Misuse Age 19–23	No Opioid Misuse Age 19–23	Opioid Misuse Age 19–23	No Opioid Misuse Age 19–23	Opioid Misuse Age 19–23	No Opioid Misuse Age 19–23	Opioid Misuse Age 19–23	No Opioid Misuse Age 19–23	Opioid Misuse Age 19–23	No Opioid Misuse Age 19–23	Opioid Misuse Age 19–23
Number of individualsa	n = 1470	n = 12	n = 1570	n = 23	n = 924	n = 43	n = 842	n = 79	n = 561	n = 138	n = 163	n = 59	n = 134	n = 82	n = 54	n = 66
No. occasions used marijuana in lifetime by 12th grade	0.094 (0.011)	0.075 (0.054)	0.39 (0.031)	0.27 (0.092)	3.54 (0.20)	3.27 (0.97)	17 (0.50)	20 (1.83)	35 (0.74)	34 (1.77)	38 (1.53)	37 (2.51)	49 (1.33)	48 (2.13)	57 (0.98)	57 (1.03)
Proportion who regularly used cigarettes in 12th grade	0.005 (0.0012)	0 (0)	0.020 (0.0024)	0.027 (0.019)	0.10 (0.0069)	0.14 (0.039)	0.22 (0.010)	0.19 (0.033)	0.38 (0.015)	0.37 (0.035)	0.44 (0.032)	0.43 (0.054)	0.47 (0.033)	0.49 (0.045)	0.59 (0.048)	0.63 (0.052)
No. occasions misused opioids in lifetime by 12th grade	0.0020 (0.00082)	0 (0)	0.014 (0.0029)	0.021 (0.021)	0.21 (0.058)	0.32 (0.11)	0.58 (0.081)	0.63 (0.18)	1.50 (0.19)	1.61 (0.30)	5.75 (0.57)	5.88 (0.87)	13 (0.93)	17 (1.78)	26 (1.67)	27 (1.92)
No. occasions misused sedatives/barbiturates in lifetime by 12th grade	0.02 (0.011)	0 (0)	0.020 (0.0050)	0.12 (0.10)	0.15 (0.029)	0.33 (0.26)	0.51 (0.079)	0.92 (0.35)	0.71 (0.11)	1.17 (0.33)	3.43 (0.78)	2.72 (0.57)	4.91 (0.80)	5.71 (1.10)	11 (1.32)	10 (1.26)
Proportion any binge drinking in past 2 wk at 12th grade survey	0.04 (0.0034)	0.03 (0.028)	0.11 (0.0053)	0.09 (0.032)	0.26 (0.010)	0.26 (0.049)	0.37 (0.012)	0.38 (0.042)	0.55 (0.016)	0.54 (0.037)	0.53 (0.033)	0.56 (0.055)	0.66 (0.033)	0.60 (0.045)	0.64 (0.050)	0.71 (0.048)
Proportion who strongly disapproved of marijuana use when in 12th grade	0.86 (0.0070)	0.82 (0.69)	0.67 (0.0083)	0.69 (0.058)	0.49 (0.012)	0.52 (0.057)	0.28(0.012)	0.23 (0.040)	0.11 (0.012)	0.14 (0.028)	0.15 (0.027)	0.098 (0.036)	0.068 (0.021)	0.05 (0.022)	0.055 (0.031)	0.053 (0.030)
Women	0.54 (0.0088)	0.61 (0.083)	0.63 (0.0081)	0.68 (0.053)	0.59 (0.011)	0.59 (0.054)	0.61 (0.012)	0.60 (0.042)	0.58 (0.016)	0.57 (0.036)	0.55 (0.032)	0.54 (0.055)	0.66 (0.030)	0.59 (0.044)	0.64 (0.047)	0.60 (0.050)
Average course marks in 12th grade	2.45 (0.032)	2.55 (0.30)	1.89 (0.031)	1.55 (0.19)	2.39 (0.043)	0.219 (0.21)	2.73 (0.048)	2.50 (0.16)	2.56 (0.059)	2.86 (0.14)	2.77 (0.12)	2.98 (0.23)	2.70 (0.11)	2.85 (0.20)	2.69 (0.20)	2.75 (0.20)
Parent with college degree	0.35 (0.0086)	0.50 (0.084)	0.63 (0.0082)	0.68 (0.054)	0.55 (0.011)	0.61 (0.053)	0.58 (0.013)	0.57 (0.043)	0.60 (0.016)	0.57 (0.037)	0.64 (0.030)	0.52 (0.057)	0.60 (0.032)	0.49 (0.046)	0.65 (0.048)	0.69 (0.045)
Minority	0.51 (0.0089)	0.42 (0.084)	0.17 (0.0064)	0.15 (0.042)	0.15 (0.0082)	0.15 (0.038)	0.17 (0.0092)	0.20 (0.033)	0.07 (0.0077)	0.09 (0.019)	0.10 (0.019)	0.14 (0.042)	0.07 (0.019)	0.03 (0.012)	0.06 (0.020)	0.04 (0.027)

Variables and their coding are described in Table 1. For calculation of average, the number of drug use occasions response categories are coded to their mean value (eg, the response of “1–2” occasions is coded to 1.5, “3–5” occasions is coded to 4, etc), and top value of “40+” is coded to 60.

^an = Number of individuals (on average, each individual contributed 2.2 follow-up observations to analysis pool).