Study design, study setting and population
A facility based cross-sectional study was conducted among women attending health facilities of Adwa town, North Ethiopia, from March 1st to April 15th, 2017. The town has two governmental health institutions; one health center and one general hospital. The health facilities had an average daily flow of 22 women aged 20–70 years. All women aged 20–70 years attending public health institutions of Adwa town were the source population, and systematically selected women were the study populations.
Sample size and sampling techniques
A sample size of 404 was calculated using single population proportion formula with assumptions of 39.4% prevalence of BSE practice , 5% margin of error, 95% confidence level and 10% non-response rate. All governmental health institutions found in the town were included in the study. The sample size in each public health institution was allocated proportional to the patient flow. Finally, systematic random sampling method was used to select participants from each institution.
Study variables and their measurement
The dependent variable is breast self-examination practice. Factors included in the model as independent variables are:
Socio-demographic and economic factors like age, marital status, educational level, household monthly income, residence, employment and family history of breast cancer or cancer in other body parts.
Knowledge, attitude and perception related factors like knowledge on breast self-examination, attitude towards breast self-examination and perception on breast self- examination.
participants who scored mean and above values from the provided 14 close-ended questions about the knowledge of BSE 
- Good attitude::
participants who scored mean and above values for attitude-related questions towards BSE, which was measured by the provided eight questions 
- Perceived susceptibility::
participants who scored mean and above values regarding their risk of breast cancer from the provided five close-ended questions were considered as having good perceived susceptibility 
- Perceived benefits::
participants who scored mean and above values regarding the benefit of BSE from the provided 6 close-endedquestions were considered as having good perceived benefits 
- Perceived barriers::
participants whose answered to barrier relate questions to do BSE measured by 6 questions, and scored mean above values were considered as having a perceived barrier to do BSE 
- Perceived confidence::
participants whose answered mean and above values regarding confidence to do BSE practice measured by 6 questions, were considered as having good perceived confidence to do BSE 
Data collection and data quality assurance methods
The questionnaire was prepared by reviewing relevant literature. Two days training was given to data collectors and supervisor on the aim of the study, the content of the questionnaire and on how to conduct the interview. A pre-test was done on 5% of the subjects in Aksum health center, found in Aksum town, Ethiopia. Data were collected using APRE-tested and interviewer-administered set of questionnaire. The collected data were cleaned and coded, and then entered into Epi-Info version 7 software and finally exported into SPSS version 21 statistical software for further analysis.
Data processing and analysis methods
Descriptive analysis was conducted and summarized using the mean, standard deviation for continuous variables and proportion for categorical variables. Before inclusion of predictors to multivariable logistic regression analysis, fulfillment of model assumption was checked. The goodness of model fitness was tested using Homers–Lemeshow test. Multi-co linearity was checked using Variance Inflation Factors (VIF).
Both bi-variable and multivariable logistic regression models were used to identify factors that affected BSE practice. Variables with a P-value of ≤ 0.2 in the bi-variable logistic regression model were entered into the multivariable logistic regression model. Variables with a P-value of < 0.05 in the final model were considered as independent factors associated with the BSE practice.
Socio-demographic characteristics of the study participants
Out of the expected 404 study participants, 400 of them give a complete response, with the response rate of 99%. About two-third, 266 (66.5%) of the study participants, were between the ages of 20–29 years. More than two-third, 276 (69%) of the study participants, were married. More than one-third, 156 (39%), of the study participants, were completed secondary education. More than one-fourth, 110 (27.5%), of study participants, were unemployed (Table 1).
Knowledge and attitude of respondents on breast self-examination
To assess the knowledge level of the study participants, 14 close-ended questions were provided from those only 222 (55.5%), with 95% CI (50.8–61.0%), of them score mean and above value. An assessment of the participant’s knowledge of screening methods revealed that 246 (61.5%) participants know about breast cancer screening methods; from those 194 (48.5%) know types of the screening methods. One hundred and seventy-eight, 44.5% of the total respondents, had ever heard about BSE. Television was the predominant source of information to 100 (25%) respondents followed by health professionals 42 (10.5%) and radio 22 (5.5%). Less than half, 185 (46.3%) with 95% CI (41.5–51.5%), of the respondents had good attitude towards BSE (Table 1).
Perception of respondents on breast self-examination
More than half, 212 (53%), of the respondents perceived that they are susceptible to breast cancer. More than half, 212 (53%), of the respondents perceive that performing regular BSE is beneficial to find a lump in the breast, that might become cancerous in the future. One hundred and sixty-eight, 42%, of the respondents had perceived barriers to perform BSE, and 152 (38.0%) of the respondents were not confident enough to do BSE (Table 1).
Breast self-examination practice and factors associated with breast self-examination practice
About one-fourth, 26 (6.5%) with 95% CI (4.3–9.0%), of the study participants, had ever practiced BSE, and only 25 (6.25%) with 95% CI (4–8.6%), of the respondents practiced BSE regularly (Table 2).
In the multivariable logistic regression analysis, being a government employee, having good perceived confidence to do BSE, and having perceived good susceptibility to develop breast cancer, were the variables significantly associated with BSE practice. The odds of practicing BSE among self-employed women were 88% less likely compared to government-employed, [AOR = 0.22; 95% CI (0.071–0.683)]. Women who had a good perceived confidence to do breast self-examination were 5.32 times more likely to practice breast self-examination as compared to women who had low perceived confidence to do BSE, [AOR = 5.32; 95% CI (1.89–14.95)]. Women who had good perceived susceptibility to develop breast cancer were 3.79 more likely to practice BSE as compared to women who had low perceived susceptibility [AOR = 3.79; 95% CI (1.74–9.74)] (Table 3).
According to the result of this study, only 6.5% of the study participants had ever practice breast self-examination. A similar finding was found in studies which were conducted in Kiewit and among female teachers of Kaffa Zone, Southern Ethiopia, both of them were 12% [7, 16]. But this study was found lower as compared to the studies done in Debre Birhan University, West Gojjam, which was 28.1% and 37% respectively [9, 17]. The difference in this study can be explained by the difference in the study participants. The participants in the above-mentioned studies were university students and health extension workers which could have a better understanding of the importance of breast self-examination than participants of this study.
In this study, only 6.25% of the respondents had regular breast self-examination. This is similar to the study conducted in logs, Nigeria, which was 11% . But This result is lower as compared to studies done in west Gojjam and four zones of western Ethiopia, which were 14.4% and 33.7%, respectively [17, 19]. This difference could be due to differences of the study participants. The study participants in the mentioned studies were health extension workers and health professionals who are expected to have better knowledge on breast self-examination.
Self-employed women were 88% more likely to practice breast self-examination as compared to government-employed women. This can be due to the fact that self-employed women could have more time to check their breast and to do breast self-examination. Women who perceived as they are susceptible to breast cancer were 3.79 times more likely to practice breast self-examination as compared to their counterparts. A similar result was found in the study done Kaffa Zone, Ethiopia . This could be explained by, women who perceived as they are susceptible to breast cancer may believe that breast self-examination could have a potential for early detection of a breast lump and to improve the outcome. The other explanation can be the perceived susceptibility to breast cancer may increase the perceived threat of respondents; hence they could practice breast self-examination more.
The odd of BES practice among women who had good perceived confidence were 5.32 times higher as compared to women who had low perceived confidence. A similar result was found in a study done in Iran among school teachers [20, 21]. This could be explained by respondents with good perceived confidence could have better motivation to practice breast self-examination.