Study site and population
This study was conducted at the college of medicine and health sciences, University of Gondar. The university is located in North Gondar Zone of the Amhara regional state, Northwest Ethiopia. The College of medicine and health sciences is one of the oldest medical education institutions in the country. It has a teaching hospital, and different schools including the school of medicine, pharmacy, biomedical and laboratory sciences, institutes of public health, and various departments. Most of the health care profession students receive 4 years training except for the students of medicine (6 years) and Pharmacy (5 years). The study population was students of medicine and health sciences who had clinical attachments for a minimum of about 2 years.
Study design and period
A cross-sectional study was conducted to assess KAP of the fifth year medical and fourth year health science students toward prevention of HBV infection. The study was conducted from February 2015 to June 2015.
Definitions for scoring knowledge, attitude and practices
The following operational definitions were used in this study. Good knowledge: if the respondents were able to answer 70 % or more of knowledge items correctly. Poor knowledge: if the respondents answered less than 70 % of knowledge items. Positive attitude: if the respondents were are able to give the correct answer for 70 % or more of attitude items. Negative attitude: if the respondents answered less than 70 % of attitude items. Good practice: when the study participants were at least able to answer 70 % or more practice items correctly. Malpractice: when the participants were unable to answer 70 % of practice items correctly.
Sample size determination
A single population proportion formula was used to estimate sample size. Since there was no similar study from Ethiopia, the following assumptions have been made: 95 % confidence interval (Zα/2 = 1.96), 50 % proportion, and 5 % margin of error.
$${\text{N}} = \frac{{(Z_{\alpha{/}2}) \times {\text{XP}}(1 - {\text{P}})}}{{d^{2} }},\quad {\text{N}} = \frac{{(1.96^{2} ) \times 0.5(1 - 0.5)}}{{(0.05)^{2} }} = 384$$
However, since the number of source population for the study was 535, which was less than 10,000, we used the following correction formula [27]:
$${\text{nf}} = {\text{ni}} / (1+{\text{ni/N}}), \quad {\text{nf}} = 384/1 + (384/535) = 223.55;$$
where nf = corrected sample size, ni = uncorrected sample size, and N = total number of all the source population.
By adding 10 % non-response rate, we included a total of 246 study subjects. The total sample size was distributed proportionally to each department based on their student population. The study participants were selected by a random sampling technique.
Study variables
Knowledge, attitude, and practice of the study participants towards HBV transmission and prevention were considered as dependent variables; and sex, age, residence areas, and departments of the study population were considered as the independent variables.
Data collection
A self-administered structured questionnaire was used to collect information about the socio-demographic characteristics of respondents, KAP towards transmission and prevention of HBV infection (see an Additional file 1).
Statistical analysis
Data were entered, cleaned and analyzed using SPSS version 20 statistical package software (SPSS Inc., Chicago, IL). Descriptive statistics like frequencies and proportions were used to summarize the data. Bivariate and multivariate analyses were used to examine the relationship between the outcome variables (mean knowledge, attitude, and practice) and selected socio-demographic factors. Adjusted odds ratios (AOR) and their 95 % confidence intervals (CIs) were used as indicators of the strength of association. Statistical significance was set at P values of less than 0.05.
