Perceived availability and the use of drugs

Sections

(1) Sampling
(2) Questionnaire
Results (i) Multiple regression analysis
TABLE 1 - Predicting specific drug use form (a) demographic characteristics; (b) other drug use and (c) availability of the specific drug
(ii) Availability and drug use in geographic areas
TABLE 2 - Average availability scores* for specific substances
Discussion
Bibliography

Details

Author: Reginald G SMART
Pages: 59 to 63
Creation Date: 1977/01/01

Perceived availability and the use of drugs

Reginald G SMART
Addiction Research Foundation, 38 Russell Street, Toronto, Canada

Surprisingly little is known about how the availability of drugs relates to actual drug use. Availability could be defined as "actual", or "perceived". Actual availability might involve the number of places of purchase, number of sellers, times for purchase or price. However, we usually do not know about actual availability for illicit drugs; there we must depend upon "perceived" availability or estimates of availability. It might be expected that where drugs are readily available there will be both more users and more heavy users. On the other hand if certain psychological or sociological approaches to use are taken, availability might be expected to be unimportant. In some approaches the rate of psychological proneness (e.g., anomie, ghetto dwelling) would be expected to best predict drug use. Differential association theory suggests that users learn about drugs from contact with other users and thus availability would be important in this model of deviance.

Research has apparently not been done on how availability affects the usage of drugs other than alcohol. A large amount of research has been done on how the availability of alcohol relates to use and heavy use. Studies of changes in numbers and types of outlets, hours of sale, price, legal drinking ages and the like have all been done in various ways (see Bruun et al., 1975 for a review). In general, there is clear evidence that large changes in availability, e.g. prohibition, wartime restriction etc., have effects on alcohol use and alcoholism. A major review of this research concluded (Bruun et al., 1975, p. 90) that "the degree of over-all availability of alcohol seems to have an independent effect on the general level of alcohol consumption in a society".

Evidence that availability affects drug use or heavy drug use is difficult to assemble. Apparently no studies of physical or perceived availability have been made, e.g. studies of how street availability, level of police seizures or ease of purchase relates to drug use. It is known that drug use tends to be more common among adolescents whose parents use drugs (Smart and Fejer, 1970) and among young people whose peers use drugs (Kandel, 1973). Also physicians, pharmacists and nurses have higher rates of drug addiction than other professionals, presumably because drugs are more accessible to them in their daily work. On the other hand opiate drug use and addiction are often found not among the farmers who grow poppies but among those who live far away. For example, opiate addiction has been uncommon in Turkey where a great deal of the world's supply of licit opium used to be produced. Opium addiction is believed to be more common among many of the producers in Asian countries. However, general statements are difficult to make about availability and drug use.

The purpose of this paper is to report a study of "perceived" availability and drug use in a large school population. Students were asked to state how difficult it would be for them to obtain various drugs including alcohol.

Analyses were made to determine whether:

  1. perceived availability contributed to the prediction of drug use among users.

  2. in geographic areas where perceived availability is high, drug use is more frequent.

(1) Sampling

A survey of drug use was made among 4,678 students in Ontario. The details of the sampling methods are described in the report by Smart and Goodstadt (1977); only a few are relevant here. The sampling was done in grades 5, 7, 9, 11, and 13 in all areas of Ontario. From each of 7 districts, Boards of Education were selected at random with their numbers proportionate to the total Ontario student enrolment. Schools were chosen from selected boards by a random method. The selection of classes was made in consultation with the school principal to be representative of all students in a grade.

In general, the sampling methods gave a larger representative sample of Ontario students, except for one area of the province where severe weather conditions decreased the expected sample size. Some schools were closed on the day of the survey in mid-western Ontario.

Most schools required parental consent for students to participate but some did not. Over-all, 70 per cent of the students contacted did participate. There were no significant differences in alcohol or tobacco use between the two types of schools. However, students in the ones requiring parental consent reported a slightly lower rate of marijuana use.

(2) Questionnaire

Questions were asked on an anonymous questionnaire. Grade 5 students had difficulty understanding some of the questions and their data has not been used here. The questionnaire covered the following areas:

  1. demographic characteristics (e.g. age, sex, occupation of parents).

  2. the frequency of use of 16 drugs in the past year including alcohol, tobacco, LSD and other hallucinogens, glue and other solvents, tranquillizers, stimulants and sleeping pills with and without prescription, heroin, and cocaine.

  3. the perceived availability of 6 drugs including alcohol, tobacco, cannabis, LSD, non-prescribed tranquillizers and heroin.

Students were asked: "How easy would it be for you to get - if you wanted some?"

The answers were "impossible", "very difficult", "difficult", "easy" and "very easy".

Results (i) Multiple regression analysis

The students' frequency of use of each drug was the criterion variable for the six regression analyses. There were 22 predictors, including six demographic and social characteristics (age, sex, school grades, mother's and father's occupation, existence of parents) 16 drug use variables, some of which became criteria in different analyses (alcohol, tobacco, LSD, other hallucinogens, glue, other solvents, cannabis, heroin, speed, cocaine, prescription and non-prescription use of barbiturates, tranquillizers and stimulants) plus the question on perceived availability of the drug.

TABLE 1 - Predicting specific drug use form (a) demographic characteristics; (b) other drug use and (c) availability of the specific drug

 

Criterion and important predictors

Multiple R

R square

Use of Cannabis
     
1.
Use of tobacco
0.540 0.292
2.
Use of alcohol
0.621 0.386
3.
Use of LSD
0.670 0.449
4.
Availability of cannabis
0.684 0.467
5.
Use of non-prescribed stimulants
0.695 0.483
6.
Sex
0.699 0.489
Use of LSD
     
1.
Use of hallucinogens
0.614 0.377
2.
Use of non-prescribed barbiturates
0.669 0.448
3.
Use of cannabis
0.688 0.474
4.
Use of speed
0.702 0.492
5.
Use of cocaine
0.710 0.504
Use of non-prescribed tranquillizers
     
1.
Use of non-prescribed barbiturates
0.454 0.206
2.
Use of prescribed tranquillizers
0.502 0.252
3.
Use of non-prescribed stimulants
0.537 0.288
4.
Use of cocaine
0.548 0.300
Use of Heroin
     
1.
Use of speed
0.418 0.175
2.
Glue sniffing
0.469 0.220
3.
Use of Cocaine
0.504 0.254
4.
Use of non-prescribed stimulants
0.520 0.270
5.
Solvent sniffing
0.529 0.280
6.
Availability of heroin
0.535 0.287
Use of alcohol
     
1.
Use of cannabis
0.518 0.269
2.
Age
0.620 0.384
3.
Availability of alcohol
0.657 0.432
4.
Use of tobacco
0.673 0.452
Use of tobacco
     
1.
Use of cannabis
0.548 0.301
2.
Use of alcohol
0.583 0.340
3.
Availability of cigarettes
0.600 0.360
4.
School grades
0.611 0.374
5.
Sex
0.618 0.382
6.
Use of non-prescribed stimulants
0.623 0.388

The results are shown in table 1. An arbitrary cut-off point for considering a predictor important was an increase in the R-square statistic of at least 0.005. It can be seen that availability was an important predictor for four of the six drugs including cannabis, heroin, alcohol, and tobacco, but not LSD or non-prescribed tranquillizers. For all drugs use of other drugs was the best predictor. For predicting tobacco use such variables as the student's use of cannabis alcohol and non-prescribed stimulants were important. The use of cannabis was best predicted by the student's use of tobacco, alcohol, LSD and non-prescribed stimulants while alcohol use was best predicted by tobacco and/or cannabis use. Similarly, students' use of LSD, heroin and non-prescribed tranquillizers was often best predicted by their use of other substances. In fact of 31 important predictors, 23 related to other types of drug use, 4 to accessibility, and 4 to social and demographic characteristics.

That availability was a significant predictor on four of six occasions implies that it may be quite important, relative to demographic or other drug use variables, in predicting specific drug substance use. It is the most frequently occurring predictor along with use of non-prescribed stimulants which was also important for four of six drugs. In general, students who claimed that drugs were easier to obtain tended more often to be users and frequent users of those drugs.

(ii) Availability and drug use in geographic areas

Mean availability scores for the various drugs are shown in table 2 within seven regions of Ontario. As expected, tobacco and alcohol are seen as readily available; on the average students stated that they would be easy or very easy to obtain (scores of 4.0 to 5.0). However, cannabis was seen as less easy to obtain while LSD, non-prescribed tranquillizers and heroin were difficult to obtain. The range in perceived availabilities across geographic regions was small and less than expected (e.g. only a range of scores of 2.31 to 2.65 for heroin).

Table 3 shows the correlation between the percentage of total users of each drug in a given area, and (i) non-users' mean availability scores, and (ii) the total sample's mean availability scores. It can be seen that for cannabis, alcohol and tobacco when the total sample perceives these drugs as more available the proportion of users is higher. The same is true for the perceptions of non-users in the case of cannabis and tobacco but not alcohol. The results for LSD, non-prescription tranquillizers and heroin show no significant correlation between availability and percentage of users. Some of these correlations are negative and of borderline statistical significance; because of the small numbers of users in some areas, it is unlikely that they would be replicable.

TABLE 2 - Average availability scores * for specific substances

 

Region

Substance

North Ontario

West Ontario

Midwest Ontario

Niagara

Central Ontario

East Ontario

Ottawa Valley

Cannabis
3.62 3.45 3.12 3.38 3.21 3.58 3.34
LSD
2.72 2.76 2.93 2.66 2.77 2.91 2.73
Non-prescribed tranquillizers
2.79 2.81 2.73 2.72 2.73 2.90 2.71
Heroin
2.35 2.31 2.60 2.32 2.47 2.65 2.40
Alcohol
4.20 4.10 3.73 4.09 3.93 4.00 4.21
Tobacco
4.50 4.27 3.95 4.38 4.13 4.33 4.37

Student rating of availabilty: 1. impossible to obtain substance; 2. very difficult to obtain substance; 3. difficult to obtain substance; 4. easy to obtain substance; 5. very easy to obtain substance.

Discussion

The results indicate tentative support, in part, for the hypothesis that perceived availability is related to drug use. The multiple regression results show that perceived availability is a significant predictor for four of the six drugs--cannabis, heroin, alcohol and tobacco but not for LSD or non-prescribed tranquillizers. It is not the strongest predictor in terms of explaining the largest amount of variance for any drug, however, it is a significant predictor for most drugs, unlike all other variables but one (non-prescription stimulant use). The correlational data indicate that for alcohol, tobacco and cannabis in areas where the total sample view these drugs as more available there are more drug users.

It is worthwhile to repeat this study with larger sample, especially those with more users of illicit drugs, and in areas with more regional divisions. Only seven regions have been used in this study and the range of availability scores is limited. It would also be of interest to gather information on how "actual" availability relates to perceived availability; this could be done by examining police data on drug seizures, street prices for drugs, etc. At present, however, it seems that for the most commonly used drugs among high school students availability is associated with their use.

Bibliography

Bruun, K., G. Edwards, M. Lumio, K. Makela, Pan. Lyn, R.E. Popham, R. Room, W. Schmidt, O. Skog, P. Sulkunen, and E. Osterberg. Alcohol Control Policies in Public Health Perspective. Finnish Foundation for Alcohol Studies, Helsinki, 1975.

Smart, R.G. and Dianne Fejer. Drug use among adolescents and their parents: closing the generation gap in mood modification. Journal of Abnormal Psychology, 1972, 79, 153-160.

Kandel, Denise· Adolescent marihuana use: role of parents and peers.· Science, 1973, 181, 1067-1070.