The prevalence of heavy episodic drinking was 13.7% among study participants. A national WHO STEPS based survey for Ethiopian and Kenyan showed that the prevalence of heavy episodic drinking were 12.4% and 12.7%, respectively [21, 22], which are similar to this finding. WHO report indicated that the prevalence of heavy episodic drinking was 9.7% for the Ethiopian population 15 years and older. That report also showed that the prevalence were 18.2% for the global and 17.4% for the African [7].
This study has found that nearly 60% of adults had never consumed alcohol. The national report of Ethiopian showed that half of the population of Ethiopia had a lifetime abstain from taking alcohol [21]. In 2016, the WHO reported that 45% of the global population never consumed alcohol [7]. In this study, around 32% of the study participants were current drinkers (took alcohol in the past 12 months). A systematic review among university students in Ethiopia estimated that the current use of alcohol was 26.65%, [23], which is lower than this finding. The national report showed that nearly 40% of Ethiopian adults age 18–64 years took alcohol one year preceding the survey [21]. A report based on the National Epidemiologic Survey on Alcohol and Related Conditions of United States showed that 73.1% of U.S. adults had taken alcohol in the year preceding the survey, which is significantly higher than this study [24]. According to the WHO report in 2016, 43% of the world population and 32.2% of the African population were current drinkers [7]. With the consideration of the WHO 2016 report, the finding of this result is nearly similar to the African counties. Another finding with a significant difference was related to the source population that varies with the age of the current study and the socioeconomic status.
The difference in the prevalence of heavy episodic drinking among different occupation groups might be related to the availability of alcohol, customs of the member of the group related to the same occupation, or characteristics of certain jobs like job variability, supervision, and qualification [25]. In this study, the likelihood of being heavy episodic drinking was lower among housewives and daily laborer compared to the farmer. An analysis of health survey for England (2003) showed that those involved in skilled non-manual, skilled manual and partially/unskilled manual occupational groups were involved significantly in heavy episodic drinking compared to professional’s occupational groups [26].
The prevalence of heavy episodic drinking decreased as wealth status increased, with a significant decrease among second and third quantile groups compared to the first. Different studies also showed that heavy consumption of alcohol is associated with lower socioeconomic status [27, 28]. Even if the study was conducted among adolescents, a study conducted at the New Zealand showed that lower socioeconomic groups were at higher risk for consumption of alcohol [29].
In this study, the prevalence of heavy episodic drinking was significantly higher among those who live in midland and highland compared to lowland. As altitude increases the temperature decrease [30], which may contribute to an increase in the prevalence of heavy episodic drinking among midlands and highland residents.
Heavy episodic drinking was more common among the study participants who were current tobacco users than their counterparts. Different studies showed that alcohol and tobacco use are highly correlated behaviors and those who drink are very likely to smoke and vice versa [31–34]. Based on Shiffman & Balabanis (1995), the phenomena used to explain for the association of alcohol and tobacco were both the between-person and the situation covariation. The between-persons is explained by the use of one drug that is likely to use the other, which means the use of heavy episodic drink of alcohol increase the probability of smoking and vice versa. Regarding the situation covariation, which indicated that the two drugs tend to be used together, for instance in time of stress [35].
Even if the likelihood of engaging in heavy episodic drinking increased among those involved in moderate and high-level physical activities, the significant difference with low physical activity level was observed with those who involved in high-level physical activities. An analysis of the health survey for England (2003) showed that those involved in sports activities were positively associated with drinking. On further analysis with the consideration of whether they are sport club members or not, it was shown that the prevalence of heavy episodic drinking was reduced among the member of the sports club [26]. A study of US adults showed a positive association between physical activity and alcohol use in US adults [36]. Even if this study and the finding from the survey for England and the US showed that same finding [26, 36], unlike the survey for England, this study does not assess the different reasons for the physical activity.
Khat (Catha edulis) is a chewable fresh-leave used as stimulant commonly in East Africa. It contains amphetamine-like stimulatory, which is a closely similar effect with cathinone [37, 38]. In this finding, those participants who chew Khat were more likely to involve in heavy episodic drinking compare to non-chewers. Different studies found a similar relationship, which indicates that both uses of khat chewing and heavy episodic drinking are associated [39–42]. A study among Ethiopian Universities indicated that the three substances used in combination were khat, alcohol, and cigarettes [39]. Khat chewers use to stay awake, increase productivity or feel ‘high’. Alcohol is needed to rest, calm their nerves and sleep, which commonly used to counteract the stimulating effect of khat [43].
The study used the STEPS guideline, which makes it easy to compare with studies conducted based on a similar method and definition of heavy episode drinking. The data were collected using interview including alcohol intake. This self-reported information regarding alcohol intake use may be subjected to recall errors. Because of the cross-sectional nature of the study, it is difficult to determine which comes first in variables like heavy episode drinking and stress level, khat chewing and tobacco use.