Table 4.

Zero-inflated negative binomial regression analyses for number of prescriptions of analgesics in adolescence and young adulthood by background factors as reported in adolescence.

	n	Opioids		Nonopioid analgesics
		Opioids		Paracetamol		NSAIDs
		IRR (95% CI)	P	IRR (95% CI)	P	IRR (95% CI)	P
Analgesics use in adolescence
Age	8199	1.10 (1.05, 1.15)	<0.001	0.92 (0.87, 0.97)	<0.001	1.04 (1.01, 1.06)	0.002
Sex, female	8199	1.97 (1.69, 2.30)	<0.001	1.58 (1.31, 1.89)	<0.001	1.69 (1.56, 1.83)	<0.001
Pubertal development score	7511	1.42 (1.26, 1.60)	<0.001	0.95 (0,82, 1.09)	0.465	1.22 (1.15, 1.30)	<0.001
Family economy below average	7636	1.93 (1.51, 2.46)	<0.001	1.22 (0.89, 1.67)	0.225	1.10 (0.96, 1.27)	0.170
Household structure, not living with both parents	8104	1.30 (1.12, 1.52)	0.001	1.33 (1.11, 1.60)	0.002	1.01 (0.94, 1.10)	0.694
Analgesics use in young adulthood
Age	8199	1.22 (1.19, 1.26)	<0.001	1.22 (1.19, 1.26)	<0.001	1.22 (1.20, 1.24)	<0.001
Sex, female	8199	1.71 (1.55, 1.89)	<0.001	2.22 (1.99, 2.47)	<0.001	1.50 (1.41, 1.60)	<0.001
Family economy below average	7636	2.13 (1.79, 2.52)	<0.001	1.56 (1.29, 1.89)	<0.001	1.29 (1.16, 1.449)	<0.001
Household structure, not living with both parents	8104	1.77 (1.61, 1.95)	<0.001	1.43 (1.28, 1.60)	<0.001	1.21 (1.14, 1.29)	<0.001

Background factors were assessed in unadjusted, separate complete case analyses.

IRR, incidence rate ratio; NSAIDs, nonsteroid anti-inflammatory drugs.