artab.htm

1996 National Household Survey on Drug Abuse: Preliminary Results

70617 (204A)             PRELIMINARY DATA - AS OF JUNE 1997

Table 39. Estimated Number (in Thousands) of Persons Who First Used Marijuana During Each Year1962-1995, Their Mean Age at First Use, and Annual Age-Specific Rates of First Use (per 1000Person-Years of Exposure), Based on 1994-1996 NHSDAs

			AGE-SPECIFIC RATE OF FIRST USE¹
YEAR	INITIATES (1000s)	MEAN AGE	12-17	18-25	26-34
1962	68	*	0.3	3.0	0.2
1963	171	22.4	3.0	2.1	3.3
1964	289	18.1	5.3	6.7	1.2
1965	630	19.7	8.1	14.4	5.9
1966	905	19.8	12.2	23.8	0.3
1967	1592	20.1	15.6	44.3	7.8
1968	1537	19.3	18.6	41.6	3.5
1969	2361	19.4	32.8	58.2	5.4
1970	2796	19.1	37.1	68.2	10.1
1971	2867	18.7	42.1	68.6	14.8
1972	2845	18.3	48.1	66.1	8.0
1973	2843	17.9	57.8	59.7	7.0
1974	2875	18.5	53.1	62.6	7.9
1975	3001	18.5	68.4	49.3	11.7
1976	2818	18.8	61.1	53.4	10.5
1977	2808	19.1	65.5	47.7	9.4
1978	2912	18.0	75.1	52.7	7.7
1979	2553	17.5	65.6	54.6	3.2
1980	2600	18.7	60.8	59.5	5.7
1981	2066	17.5	56.4	40.7	3.6
1982	2065	17.7	55.0	42.6	7.0
1983	2066	17.6	54.7	43.6	4.0
1984	1962	19.7	49.3	38.9	4.6
1985	1827	17.5	53.2	39.0	2.0
1986	1884	20.1	49.7	42.8	2.9
1987	1817	17.6	49.7	44.2	2.5
1988	1560	17.3	44.1	39.2	1.3
1989	1370	17.5	36.2	34.8	2.8
1990	1446	17.3	39.1	37.8	1.5
1991	1432	17.1	39.2	36.3	1.2
1992	1715	17.8	45.8	41.4	1.9
1993	1987	16.9	56.5	46.4	2.3
1994²	2400	16.7	74.7	48.9	3.5
1995³	2368	16.7	75.7	47.7	3.3

*Low precision; no estimate reported.

**Estimate rounds to zero.

¹The numerator of each rate equals the number of persons who first used the drug in the year (times 1000). The denominator of each rate equals the number of persons who were exposed to risk of first use during the year, weighted by their estimated exposure time measured in years. For example, for the age group 12-17 in 1990, the denominator is the sum of three components:

(1)those persons 12-17 years old in 1990 who first used the drug in 1989 or earlier, times a weight of zero. The weight is zero since they had zero exposure to the risk of first use in 1990.

(2)those who first used the drug in 1990 times a weight of .5. The weight of .5 assumes that these people, on average, first used the drug at midyear and consequently have a half year of exposure (i.e. the first half of the year.)

(3)those who never used, or those who first used the drug in 1991 or later, times a weight of one. The weight of one assumes their exposure to the risk of first use during 1990 was for the whole year.

Each person is also weighted by his/her sample weight.

²Estimated using 1995 and 1996 data only.

³Estimated using 1996 data only.

Source: SAMHSA, Office of Applied Studies, National Household Survey on Drug Abuse, 1994-1996.

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