Study setting and design
Cross sectional study was conducted from May to June, 2015 in Addis Ababa high schools. Addis Ababa is the capital city of Ethiopia with an area of 530 km2 and a total population of 3 million. Also Addis Ababa city administration is divided into ten administrative sub-cities.
Study participants and sampling procedure
All high school adolescents aged 12–19 years who attended high schools in Addis Ababa were included in the study. To estimate disordered eating attitude among adolescents aged 12–19 years, sample size was calculated using Epi-info version 3.7 by considering the following assumptions; 50% prevalence of expected disordered eating attitude since there was no previous study conducted in the country, 95% level of confidence, 5% margin of error, 10% non-response rate and a design effect of 2. Thus, a minimum sample size of 847 was obtained.
Regarding to sampling technique, firstly two sub cities (Arada and Gullele) were selected randomly using lottery method among ten Sub cities of Addis Ababa. Then, two schools, Lideta catholic cathedral high school with a total number of 1679 students from Arada and Dileber high school with a total number of 1267 students from Gullele sub city were schools selected by randomly. The sampling frame of students in each of the grade level and section was obtained from the academic director offices of schools.
Lastly, students were selected from each school and grade level (9–12) using a systematic sampling technique after identifying an initial starting student by use of a random number. The sample sizes were distributed to each grade and section proportionally according to the class size of the grade level. Adolescents in the selected grade level were further selected and given self-administrated questionnaires.
Data collection tools and procedure
Data were collected using structured, pretested, and self- administered questionnaire to obtain socio-demographic information and disordered eating attitude. The questionnaire was first translated from English to Amharic and retranslated back to English by language experts to maintain its consistency. Final the questionnaire was administered in Amharic for data collection. Five data collectors and two field supervisors were recruited for the study. One day exhaustive training regarding the objective of the study, confidentiality of information, and data collection techniques was given to data collectors and supervisors. The questionnaire was piloted on 5% (42) school adolescents out of the study area. During pre-test, the acceptability and applicability of the procedures and tools were evaluated. All filled questioners were checked for completeness, accuracy and consistency by the supervisor and the primary investigator.
Operational definitions and study variables
The outcome variable of the study was disordered eating attitude. Eating attitude was determined by using eating attitude test-26 (EAT-26) items which were grouped into three factors from subscales . Factor I is ‘dieting’ with 13 subscales; “example, terrified of being overweight”, Factor II is ‘bulimia and food preoccupation’ with six subscales; “example, find myself preoccupied with food” and Factor III is ‘oral control’ with seven subscales; “example, avoid eating when I am hungry. For all items except #26, each of the responses receives the following value (six-point scale from ‘always’ to ‘never’): with 3 points to ‘always’, 2 points to ‘very often’, 1 point to ‘often’, and 0 points to ‘sometimes, rarely and never’. Thus, eating attitude was computed with a maximum score of seventy-eight (78). The EAT-26 scores of 20 or higher defined as disordered eating attitude (unfavorable eating attitude) and below 20 perceived as favorable eating attitude.
The independent variables incorporated in the study were: socio demographic characteristics, environmental influences (parental influence, peer pressure and media) and nutritional status.
Data was checked, coded and entered to Epi-info version 7 and was exported to SPSS (Statistical Package for Social science) version 20 for analysis. Reliability analysis was performed to ensure that items with in each factor were consistent. Internal consistency was checked by calculating Cronbach’s alpha for each of the items to examine the extent to which adolescents answered consistently to the items in each of the three factors. Descriptive and analytical statistics including bivariate and multivariate analysis was employed. All variables with a P value of less than 0.2 in bivariate analysis were entered to multivariate analysis to control the possible effect of confounders. Both crude odds ratio (COR) and adjusted odds ratio (AOR) were estimated to show the strength of association. In multivariate analysis, variables with a P value of ≤0.05 were considered as statistically significant.