Table 1.

Intracohort (rows) comparisons of lifetime and past-year prevalence (%) of nonmedical prescription opioid use

	Age ranges (n)		Estimated use, % [95% CI]
Birth cohort	NLAES 1991–1992	NESARC 2001–2002	NLAES 1991–1992	NESARC 2001–2002	Intracohort differencea
Lifetime use
1974–1983	—	18–27 (7,168)	—	3.9 [3.4, 4.5]	—
1964–1973	18–27 (7,746)	28–37 (8,527)	3.2 [2.8, 3.6]	3.4 [2.9, 3.9]	6%
1954–1963	28–37 (10,221)	38–47 (8,840)	4.2 [3.7, 4.6]	4.1 [3.6, 4.7]	−2%
1944–1953	38–47 (7,820)	48–57 (6,862)	2.8 [2.4, 3.2]	2.6 [2.1, 3.0]	−7%
1934–1943	48–57 (5,056)	—	1.1 [0.8, 1.5]	—	—
Total (1944–1973)	18–47 (25,787)	28–57 (24,229)	3.4 [3.2, 3.7]	3.4 [3.1, 3.7]	0
Past–year use
1974–1983	—	18–27 (7,168)	—	2.5 [2.0, 2.9]	—
1964–1973	18–27 (7,746)	28–37 (8,527)	1.3 [1.0, 1.6]	1.6 [1.2, 1.9]	23%
1954–1963	28–37 (10,221)	38–47 (8,840)	0.9 [0.7, 1.1]	1.4 [1.1, 1.7]	56%*
1944–1953	38–47 (7,820)	48–57 (6,862)	0.5 [0.3, 0.7]	0.8 [0.6, 1.0]	60%*
1934–1943	48–57 (5,056)	—	0.1 [0.0, 0.2]	—	—
Total (1944–1973)	38–47 (7,820)	28–57 (24,229)	0.9 [0.8, 1.0]	1.3 [1.1, 1.5]	44%***
Past–year use among lifetime users
1974–1983	—	18–27 (255)	—	62.5 [54.8, 69.3]	—
1964–1973	18–27 (260)	28–37 (266)	41.3 [34.5, 48.0]	46.9 [39.6, 54.3]	14%
1954–1963	28–37 (398)	38–47 (332)	20.9 [16.6, 25.2]	34.3 [27.8, 40.8]	64%***
1944–1953	38–47 (237)	48–57 (177)	18.2 [12.5, 23.9]	31.7 [23.8, 39.8]	74%*
Total (1944–1973)	18–47 (895)	28–57 (775)	26.3 [23.0, 29.5]	37.9 [33.7,42.1]	44%***

Notes: NLAES = National Longitudinal Alcohol Epidemiologic Survey; NESARC = National Epidemiologic Study on Alcohol and Related Conditions.

^aDifference between 2001-2002 (NESARC) and 1991-1992 (NLAES) lifetime prevalence estimates for a given birth cohort.

^*p <.05;

^***p < .001.