Abraham, Manja D. (1998), Drug use and lifestyle: Behind the superficiality of drug use prevalence rates. Presentation held at the 9th Annual Conference on Drug Use and Drug Policy, Palma de Mallorca, October 2, 1998. Amsterdam, Centrum voor Drugsonderzoek, Universiteit van Amsterdam.
© Copyright 1998 Manja D. Abraham. All rights reserved.

 

Drug use and lifestyle

Behind the superficiality of drug use prevalence rates

Manja D. Abraham

Abstract

Prevalence rates alone are not sufficient to describe drug use in society. They have to be supplemented by other indicators of use patterns and by indicators of the social context of drug use. Possible measures of the first kind are continuation, incidence, experienced use, mean age of first use, and of the latter kind, outgoing orientation. Independent of the lifetime prevalence, they can show drug use dynamics in society. In Amsterdam this can be shown for cannabis and ecstasy use. Lifestyle variables show a considerable covariance with the prevalence of cannabis as well as ecstasy use. Like the above introduced indicators, also this covariance remains stable over a longer period of time.

Introduction

In this paper I want to emphasise the need to look behind the superficiality of drug use prevalence rates. Although prevalence rates are a common way to look at drug use, there exists a need to examine underlying use patterns as well as underlying societal contexts. Sandwijk (et al, 1988) ⁱ in a report on drug use in Amsterdam has already shown the relation between lifestyle and drug use. "Information about drug use should be targeted towards specific lifestyle groups" (Sandwijk et al., 1988 p.82). Departing from lifetime prevalence rates, I want to focus on supplementary measures to look at drug use patterns, and at lifestyles that support the use of drugs. Possible supplementary measures include continuation, incidence, experienced use, mean age of first use, and outgoing orientation. I will examine how the scores on these variables changed over the last decade and what this implies about lifestyle and drug use.

One can compare drug use with a multidimensional space, in which the year of the survey, the prevalence, frequency, amount, age, and social functionality of drug use, and many more represent dimensions. A user is represented by a dot. The user is placed in this space according to his or her drug use. Looking at only prevalence rates is like looking at only one dimension and neglecting the others. In time, drug use can be stable for one dimension and change in an other dimension.

I will focus on two drugs, namely cannabis and ecstasy. Both drugs are now used by small but significant parts of the Amsterdam population. I picked these specific drugs because I expect them to have a different social functionality. Also, the use of cannabis is more socially accepted, whereas the use of ecstasy is upcoming in the last decade and possibly socially (still?) less accepted ^{i i}. I aimed to examine a possible difference in use patterns and in the lifestyle-prevalence correlation.

The paper concludes that in Amsterdam drug use lifetime prevalence rates in general show a slow increase in time, but that in other variables, the drug use situation is very stable.

Analysis of results

This paper is illustrated with data of the Amsterdam drug use population survey of 1997 (Abraham et al, 1998) ^{i i i}. Trends are also based on data of comparable Amsterdam drug use surveys, held in 1987 (Sandwijk et al, 1988), 1990 (Sandwijk et al, 1991) ^{i v} and 1994 (Sandwijk et al, 1995) ^v. The Amsterdam data presented does not hold for the rest of the Netherlands (Langemeijer et al, 1997) ^{v i}.

Let me present some Amsterdam drug use survey results (see Table 1). Cannabis as well as ecstasy use shows increasing lifetime prevalence (cannabis from 23.2% in 1987 to 36.3% in 1997 and ecstasy from 1.3% in 1990 to 6.9% in 1997). The question is whether or not this indicates a change of the use of cannabis and ecstasy use in society.

Last month prevalence is lower than last year prevalence and much lower than lifetime prevalence (last month in 1997 cannabis 8.1% en ecstasy 1.1%). This might be because the use of a drug is experimental or very infrequent for a large part of the user population. Last month prevalence rates show a much smaller increase in time than lifetime prevalence. In my opinion it is better to look at last year and last month prevalence rates instead of lifetime prevalence because they give more information of the current situation and of the dynamics of use. The increase in lifetime prevalence is to a great extend caused by the generation effect (the pool of lifetime users in the whole population increases because elder people who never used any drug decease).

Use patterns

Last month continuation rate expresses what proportion of life time users reports last month use as well. For cannabis this measure is stable through the years, for ecstasy it is increasing. The same holds for experienced use (the proportion of the user population that used the drug 25 times ore more in a lifetime) and incidence (the proportion of the population that started using this drug within a year prior to the interview). For cannabis these measures are stable, for ecstasy they are increasing. This means that the implied change, suggested by increasing lifetime prevalence, only holds for ecstasy and not for cannabis. The mean age of first use remains stable for both drugs.

Lifestyle

I have to answer the question "what is lifestyle" before I can say something about the relation of drug use and lifestyle. Various answers can be given. For this paper I operationalized lifestyle as the score on outgoing orientation. Outgoing orientation is determined by activities in leisure time and measured by the following items: the frequency of evenings spent at home; the frequency of going to a pub, disco, dancehall etc.; the frequency of going to a dining place, restaurant or eat out; the frequency of visiting a cinema or art centre; and the frequency of visiting the theatre, ballet etc. Outgoing orientation scores at an ordinal scale in three categories: high, medium or low.

I looked at the distribution of outgoing orientation within the pool of last year drug users. Last year drug use because the size of this group gives an idea of recent drug use. I could not use last month drug use because outgoing orientation demands a measured period longer than one month. The results (in Table 2 and Graph 1) show that outgoing orientation is highly related with last year cannabis use as well as last year ecstasy use. The higher someone's outgoing orientation, the larger one's probability to be a last year drug user. I want to make clear that going out does not cause drug use, but going out behaviour indicates a way of living that is highly related with drug use. The outgoing orientation ratio of low:medium:high expresses the strength of the relation. For ecstasy the ratio is roughly 1:3:12 and for cannabis 1:2:5 (in 1997). So the relation is stronger for ecstasy use than for cannabis use. A explanation for this difference is that cannabis has more sorts of social functionality, whereas the use of ecstasy is highly related to visiting limited types of entertainment facilities. This can partly be explained by the fact that cannabis use is socially more accepted than ecstasy use.

One could suggest that the relation between outgoing orientation and last year drug use is explained by age of the users. After all, young people tend to use drugs more often than older people do, and young people tend to go out more often than older people do. This explanation can be dismissed. Even within age groups this relation maintains (see Table 3), although the relation is stronger in certain age groups. The relation holds stronger for younger age groups.

The outgoing orientation ratio remains stable in the decade under investigation 1987-1997) even though the prevalence of cannabis and ecstasy use increased. This might indicate that the social context of drug use and its social functionality has not changed.

Conclusions and discussion

Prevalence rates alone are not sufficient to describe drug use in society. They have to be supported by measures of use patterns and measures of the social context. Possible measures are continuation, incidence, experienced use, mean age of first use and outgoing orientation. Together they can help to obtain a more profound view of drug use and the context of drug use in society.

Table 1: Cannabis and ecstasy use measures, Amsterdam population age 12 and over 1987 (n=4,377), 1990 (n=4,443), 1994 (n=4,364) and 1997 (n=3798)

	Lifetime prevalence					Last year prevalence
Drug	1987	1990	1994	1997		1987	1990	1994	1997
Cannabis	23.2%	25.2%	29.8%	36.3%		9.5%	10.2%	11.2%	13.1%
Ecstasy	.	1.3%	3.3%	6.9%		.	0.7%	1.6%	3.1%
	Last month prevalence					Unweighted n reported lifetime
Drug	1987	1990	1994	1997		1987	1990	1994	1997
Cannabis	5.6%	6.1%	7.2%	8.1%		995	1096	1272	1285
Ecstasy	.	0.1%	0.7%	1.1%		.	56	137	232
	Last month continuation					Experienced use (per rep. lifetime)
Drug	1987	1990	1994	1997		1987	1990	1994	1997
Cannabis	24%	24%	24%	22%		.	47%	44%	44%
Ecstasy	.	9%	22%	16%		.	7%	17%	18%
	Incidence (per population)					Mean age of first use
Drug	1987	1990	1994	1997		1987	1990	1994	1997
Cannabis	1.0%	1.0%	1.2%	1.1%		20.2	20.3	20.2	20.3
Ecstasy	.	0.7%	0.8%	1.3%		.	26.1	26.1	26.3
. = no data available

Table 2: Cannabis and ecstasy use by outgoing orientation, last year users 1997

	Cannabis					Ecstasy
Outgoing orientation	1987	1990	1994	1997		1987	1990	1994	1997
Low	2.6%	3.1%	2.3%	4.9%		.	0.0%	0.2%	0.6%
Medium	10.5%	11.8%	11.6%	11.9%		.	0.5%	1.2%	2.1%
High	26.0%	23.5%	24.4%	24.8%		.	2.3%	3.9%	7.3%
Total (last year use)	9.5%	10.2%	11.2%	13.1%		.	0.7%	1.6%	3.1%
. = no data available

Graph 1: Cannabis use by outgoing orientation, last year users 1997

Graph 2: Ecstasy use by outgoing orientation, last year users 1997

Table 3: Cannabis and ecstasy use by outgoing orientation, last year users 1997, per age group

Outgoing orientation		Cannabis	Ecstasy
Age 12-15	Low	-	-
	Medium	-	-
	High	-	-
Age 16-19	Low	8%	-
	Medium	19%	-
	High	35%	-
Age 20-24	Low	12%	2%
	Medium	27%	5%
	High	33%	11%
Age 25-29	Low	13%	1%
	Medium	19%	2%
	High	29%	8%
Age 30-34	Low	7%	-
	Medium	16%	-
	High	27%	-
Age 35-40	Low	9%	-
	Medium	7%	-
	High	29%	-
Age 40-49	Low	9%	-
	Medium	13%	-
	High	19%	-
Age 50+	Low	-	-
	Medium	-	-
	High	-	-
- = low precision, no estimate reported

Notes