This study assessed the prevalence and associated factors of substance use among preparatory school students of Bale Zone, Oromia Regional State, Southeast Ethiopia. The overall current prevalence of substance use among the respondents was 34.8% (210). Specifically, 24% (102) and 17.1% (142) of the respondents drank alcohol and chewed khat, respectively.
A study done among students at northwest of Ethiopia stated that the lifetime prevalence rate of cigarette smoking and khat chewing was 13.1% and 26.7%, respectively. The current prevalence of cigarette smoking was found to be 8.1% and that of khat chewing 17.5%, which was higher than and nearly similar to the prevalence rate of this study, respectively. In Saudi Arabia, the overall prevalence of khat chewing among students was similar to this study. By the year 2006, the prevalence of smoking among Jamaican school-going adolescents was 16.7%, which was higher by more than 10% when compared with the prevalence of cigarette smoking of this study. Similarly, a study conducted among Indian higher secondary school students showed a higher prevalence of substance use of 551 (54%, 95% CI 42%–67%) which might be due to the scope of the study which covered more substances in the case of India. In Nigeria high school students, the overall lifetime prevalence of substance use (caffeine, analgesics, and antimalarial) was higher (87.3%) which could be because of the vast scope of the study. Harare, Zimbabwe, high school students also showed a higher prevalence of cigarette smoking of 28.8% (95% CI 25.3%–32.3%).
A study conducted in Dire Dawa, Ethiopia, high school students showed a higher lifetime prevalence of alcohol drinking (34.2%), cigarette smoking (13%), and shisha smoking (12.8%) but a similar prevalence of khat chewing (18.4%) when compared with this study. The discrepancy might be because the study in Dire Dawa covered grades 9 to 12, but the current study included preparatory schools only. The lifetime prevalence of khat chewing of Harar, Ethiopia, high school students was 24.2%, which was similar to this study.
The mean age at which Bale Zone preparatory school students started substance use was 15.1 (SD ±3.6) years. The median age at first substance use of Indian higher secondary school students was 15.5 years, which was similar to this study. Zimbabwean higher school students also started smoking earlier. It was also similar to the first khat chewing mean (SD) age of Harar, Ethiopia, high school students which was 15.1 (2.33) years.
Through bivariate analysis, gender, age, and substance use status of the respondents’ father, mother, siblings, and best friend showed a statistically significant association with substance use of the respondents. Marital status and intimacy relationship of the respondents’ family (father and mother) did not associate with substance use of the respondents. But among Brazilian school adolescents, marital status and intimacy relationship of their family had a significant association with substance use. Adolescents whose parents were divorced reported more than 50% greater in using substance than those whose parents lived together (prevalence ratio (PR) 1.55, 95% CI 1.26–1.90)[16, 17].
In Brazilian school adolescents, the presence of household members who drink excessively was statistically significant for drug use of the subject (PR 1.50, 95% CI 1.19–1.90) and the presence of other drug users in the household was also statistically significant (PR 1.98, 95% CI 1.42–2.76) which was also significantly associated in this study. Respondents whose father smokes cigarette, whose mother chews khat, and whose sibling(s) smokes cigarette were 2.24, 5.5, and 7.36 times more likely to use substances, respectively, when compared with those whose father, mother, and sibling(s) seldom use these substances, nearly similar to Brazilian school adolescents who were 1.5 times more likely to use substance in the presence of household members who drink alcohol. Among Jamaican school-going adolescents, having smoker parents made them to smoke cigarette 2.38 times more compared with students whose parents were nonsmokers (OR 2.38, 95% CI 1.80–3.16).
Male respondents of this study were six times more likely to use substances which was less among Jamaican school-going adolescents who smoke (OR 2.04, 95% CI 1.56–2.68). Indian high school students who used substance ever were more likely to be males (3.0, 95% CI 2.4–39). But the prevalence of cigarette smoking was higher among Harare high school male students which was estimated to be 18.5% (95% CI 14.3%–23.3%) compared to female students.
A study conducted in Harar, Ethiopia, high school students showed that male students had two times higher odds of chewing khat compared to female students (OR 2.10, 95% CI 1.50–2.93) which was lower by 4 compared to this study.
Age category which was statistically significant in the case of Harar, Ethiopia, high school (OR 1.31, 95% CI 1.16–1.49) but not associated in this study (OR 0.90, 95% CI 0.36–2.22) which might be from the inclusion of grade 9 and 10 students.
After adjusting for variables associated under bivariate analysis, sex, respondents’ father who drinks alcohol and chews khat, and respondents’ sibling(s) who smokes cigarette showed a significant association with substance use of the respondents. Similarly, substance use of the respondents’ best friend also showed a significant association with substance use.
Respondents whose father drinks alcohol and chews khat and whose sibling(s) smokes cigarette were four times more likely to use substances (OR 4.21, 95% CI 2.06–8.62; OR 4.14, 95% CI 1.71–10.02; and OR 4.44, 95% CI 1.11–17.79, respectively) compared with respondents whose father seldom uses any of the substances. Also, among Indian high school students, substance use of family members showed a positive contribution to substance use of the students. Students whose father and sibling(s) use substances were two times more likely to use substance (OR 2.0, 95% CI 1.6–2.7 and OR 2.1, 95% CI 1.5–3.0, respectively) than respondents whose father and sibling(s) do not use substance.
Having a best friend who drinks alcohol at least once a week made the respondents to practice substance use four times more (OR 3.9, CI 1.34–11.36) when compared with those whose best friend does not use any of the substances. Similarly, having a friend who drinks alcohol made Zimbabwean high school students smoke about six times more (OR 5.7, 95% CI 2.9–11.5). Harar, Ethiopia, high school students who have friends who chew khat were eight times more likely to practice khat chewing when compared to those who do not have (OR 7.93, 95% CI 5.40–11.64) which was higher when compared with this study which might be due to socio-demographic differences of the study area.
As the data collection method was self-administered for self-report, it might have contributed to underreporting or overreporting. The time of the data collection period, which was when the students prepared for an entrance exam, could have made the students rush over the questionnaire which might affect the result of the study.