Study Area and period
The study was conducted in Debre Berhan town from April 13–28, 2018 G. C. Debre Berhan town is found in North Showa Zone of Amhara regional state around 130km away from the capital of Ethiopia, Addis Ababa. The town has a latitude and longitude of 9◦41’N 39◦32’E / 9.683◦N 39.533◦E and an elevation or altitude of 2795 above the sea level with a high climatic condition. It has also one referral hospital, 3 health centers, 14 clinics and around 16 pharmacies. Based on Debre Berhan town health administration office report current total population of the town is 103,450 of whom 46,553 are men’s, 56,897 are women’s. From the total population 14,011 are under five children and around 88,369 people are living in urban area of the town and 15,080 are living in rural area of the town. The town is divided into nine kebeles and 5 rural kebeles.
A community based cross sectional study design was used to assess the prevalence and associated factors of diarrhea among under-five children of Debre Berhan town.
All under-five children’s in Debre Berhan town was our source population. All under-five children’s with their mothers or care takers who live in selected kebeles of Debre Berhan town was our study population.
Sample size determination
Sample size was determined based on the formula used to estimate single population proportions assuming that 21.5% the 2-week period prevalence of diarrhea among under-five children in Jebithenan district, West Gojam zone Northwest Ethiopia  and 5% margin of error with 95% confidence level and anticipated 10% non-response rate.
[Due to technical limitations, this equation is only available as a download in the supplemental files section.]
After adjusting for non-response rate of 10% and design effect of 1.5 the final required sample size was 428 mother-child pair.
Multi-stage sampling technique was used to obtain a representative sample of the study participants. First four kebeles were selected from total of fourteen kebeles by lottery method. Then census was conducted in each selected kebeles to know the eligible households. Finally, households were selected by using systematic random sampling techniques and took child with their mother/care taker from each selected household until the required sample size was fulfilled.
Diarrhea—is the passage of three or more loose or watery stool in a twenty-four hours’ period, as re- ported by the mother/caretaker of the child
Care taker- any person who give care for the child other than the mother
Data collection tool and methods
Data were collect by seven trained BSc midwives and three supervisors were deployed for supervision. Structured questionnaire was adopted in English after review of different literatures and guidelines. Finally, English version questionnaire was translated to Amharic language and again translated back to English by experts who were fluent in both languages. Pre-testing was conducted on 5% of the total sample size. Data were collected by face to face interview.
Data processing and analysis:
The data collected from the field were edited, checked for completeness and consistency, and then coded and entered into Epi-info computer software package version 3.5.1. Once entered, the data were exported to SPSS Window Version–16 for cleaning and further analysis. Both descriptive and inferential statistics were employed in the analysis. Bivariate and multivariate logistic regression analysis was used to identify the predictors of childhood diarrhea. Variables with 95% confidence intervals and P-value <0.2 during the bivariate analysis were included in the multivariate logistic regression analysis to see the relative effect of confounding variables. Adjusted odds ratios with 95% confidence intervals were calculated and P-value less than 0.05 were considered as statistically significant.