Prevalence of substance use among students in this study area was 19.1%. This finding was lower than study done among high school adolescents in Woreta Town, Northwest Ethiopia of which current 47.9% (5). The difference might be due to difference in study period when information, education and legislation is being intensified to reduce substance use. Reasons mentioned by respondent to use substance were: to socialize 18(36%) and for entertainment 18(51.4%) whereas the most basic motivation for substance use in this area was peer pressure 55(49.5%). This finding was in line with Study done in Debere Birhan university students and Haramaya University students where the reasons for substance use were enjoyment, to stay awake peer pressure, to socialize and to improve academic performance (2, 9, 10)
In this study area, the most commonly used substance were alcohol 50 (13.4%), khat 35(9.4%) & tobacco29 (7.8%). This is also lower than finding in Dire Dawa secondary school and Ginnir town preparatory school , Bale zone (11,12). This difference may be due to difference in stud area where there is availability of chat and otter substance. On the other hand most of the populations in these two areas (Dire Dawa & Ginnir town, Bale Zone) are Muslim in religion and some research reveal that being Muslim is strongly associated with chewing chat and other substance (13).
The result of multivariate logistic regression revealed that, there were factors associated with substance use among Nekemte preparatory school student. Being male sex was strongly associated with substance use in this study area which is in line with study conducted in Addis Ababa University and Haramaya university health and medical students and jigjiga university students(9,10, 14,). Other finding from systemic review of alcohol consumption in Ethiopia support this finding that, the prevalence of hazardous alcohol consumption was remarkably higher in men than in women (15). Level of education attained or grade of students were found to influence substance use among our respondents where students of 12th grade were more likely to use substance than their counterparts. In Jigjiga university the odds of drinking alcohol was higher among senior students; those at 3rd year those at 4th year; compared with their junior 2nd year students (9, 14)
In our study having many friends using substance were found to affect substance use among preparatory students. In Addis Ababa substance use was high among those students whose friends were drinking alcohol (13) also in Debra Berhan University the study revealed, having substance user families and friends were found to be variables significantly associated with students’ substance use behaviors(2).
Having family or parents using substance was another predictor of substance use among students of our study area which is similar to study conducted in Debra Berhan University students, Haramaya University health and medical science students where students from substance user families were more likely to use substance and in Debra Markos poly technique college history of family drug use was highly associated with students substance use (7, 11, 12,). In this study peer pressure was strongly associated with substance use among students in our study area. In Debra Markos poly technique college students who had experienced peer pressure was more likely to use substance than their counterparts (6).
The study has different limitation First; the study used a descriptive single cross-sectional design that cannot establish trends and causality between substance use and risk factors. Second, the data was collected using self administered questionnaire which may be subjected to recall bias and under-reporting of substance use due to social desirability bias. Finally, the types substance reported in this study were cigarette, alcohol and kchat only. Despite the limitations, our finding has substance finding which encourage the family, community, teachers and other stakeholders to give attention for substance use among students.
Conclusion and recommendation
The prevalence of substance use in this study was low. The most commonly used substances were alcohol, khat and tobacco where the main reasons mentioned by respondents to use substance were: to socialize, for entertainment whereas the most basic motivation for substance use in this area was peer pressure. Being male students, pear pressure, living with parents use substance & friends were found to affect substance use among Nekemte preparatory school students. Awareness creation sessions; Information, Education &Communication intervention should be intensified to further reduce Substance use among students. Further research should be conducted to explore for other factors associated with substance use not only for the three substance mentioned but also other substances in other setting other than preparatory school.