Study area
A cross-section study was conducted in Jimma University Teaching Hospital (JUTH) which is located in the Southwest part of Ethiopia, 352 km far away from Addis Ababa. JUTH is one of the oldest public hospitals in the country, established in 1937. An out-patient psychiatric clinic was established in 1988 [15] and subsequently a 26 bedded in-patient psychiatric service was developed. Jimma University Teaching Hospital is the only hospital with psychiatry clinic and services in southwest Ethiopia. Data for this study were collected from November 1–30, 2014.
Data collection instrument
-
1.
Outcome variable: Tobacco dependence
A structured interviewer-administered questionnaire (Fagerstrom Test for Nicotine Dependence (FTND)) was used to assess tobacco dependence. The FTND has six items, with a total score ranging from 0 to 10 to measure nicotine dependence [16]. The FTND has been shown to have good test–retest reliability and validity in populations of smokers with mental health problems [17]. At a cut-off score ≥5, the FTND has good sensitivity and specificity (0.75 and 0.80, respectively) [18]. A total FTND score of five indicates moderate nicotine dependence, a score of 6–7 indicates high nicotine dependence and a score of 8–10 indicates very high nicotine dependence [16]. In this study a total score of FTND ≥5 was considered to indicate tobacco dependence [18].
-
2.
Factors associated with tobacco dependence
Socio-demographic variables: A structured interviewer-administered questionnaire was used to assess socio-demographic and socio-economic status of participants (age, sex, religion, ethnicity, marital status, educational level, frequency of attending a place of worship, monthly income, occupation and living condition).
Khat chewing: A structured interviewer-administered questionnaire was used to assess the pattern of khat chewing, including frequency. In this study, current khat chewing was defined as chewing khat during the month prior to the interview.
Alcohol use disorders (AUDs): AUDs was assessed using the four item CAGE questionnaire (Cut down, Annoyed, Guilty, Eye opener). CAGE is short and easily applied in clinical practice. Sensitivity and specificity of CAGE at a cut-off score ≥2 was 0.71 and 0.90, respectively [19]. In this study a total score of ≥2 on CAGE was used to indicate alcohol use disorder.
Reasons for starting tobacco smoking
Patients who had tobacco dependence were asked about their reasons for starting tobacco smoking, categorized as follows: smoking for enjoyment, smoking is fashionable, smoking increases self-esteem, self-treatment for their illness, to forget financial problems, to relieve longstanding stress, having friends who use tobacco and family history of tobacco smoking.
Clinical characteristics
Charts of the patients were reviewed for psychiatric diagnosis and frequency of hospital visit. A self-reported questionnaire was used to assess co-morbid medical illness, including hypertension, diabetes mellitus and gastritis. The data collection instrument was prepared in English and then translated into both Afan Oromo and Amharic, the main languages spoken in the area. Back-translation into English was undertaken for both languages and the final versions obtained through expert consensus.
Data collection procedures
Data were collected by five diploma level psychiatric nurses after one day of training to familiarize them with the study tool. Data collection was carried out after the questionnaire has been pre-tested in 5% of the total sample size at JUTH psychiatric clinic. Data collection was supervised by a BSc level psychiatric nurse. The supervisor monitored data quality and checked all questionnaires for completeness.
Sample size determination and sampling procedure
The sample size was calculated by assuming a prevalence of tobacco dependence of 50%, with the association with any particular outcome to be estimated with a 5% margin of error and 95% confidence interval (∝ = 0.05) and 10% non-response. Based on these assumptions, the sample size for the study was calculated using a single population proportion formula. The total required sample size was 422. All eligible adult patients attending services at outpatient psychiatry clinic during study period were invited consecutively to participate in the study.
Data analysis
After double data entry verification, data were exported to the Statistical Package for Social Science (SPSS version 20 for windows). Descriptive statistics, including frequencies, percentages, mean and standard deviation was used for describing tobacco dependence. Dependent and independent variables were entered into a bivariate logistic regression one by one in order to identify candidate variables for the final model. All variables associated with tobacco dependence or with a P-value of <0.25 in the bivariate logistic regression were entered together into a multivariable logistic regression by default (enter method) to control potential confounders.