Correlates of Hepatitis B Virus Infection among Antenatal Clinic Attendees of Volta Regional Hospital, Ho, Volta Region, Ghana
Ghana is among the high endemic countries in Africa, with HBV prevalence ranging from 4.8% to 12.3% in the general population, 10.8% to 12.7% in blood donors and about 10.6% in antenatal clinic (ANC) attendees. The main objectives of this study were to test how socioeconomic factors, risky behaviors, knowledge and awareness of HBV infection correlate with actual HBV status among antenatal clinic attendees and to determine the predictors of HBV testing among ANC attendees. The study is a cross sectional study. Structured questionnaires were used to determine the knowledge level of the study population. On the knowledge of HBV infection, questions including the transmission of the infection, risk factors, management, prevention and immunization against the infection were asked. Information on the status; presence or absence of hepatitis B surface antigen, and socio-demographic information (Age, Marital status, Residence, Number of children, Religion, Level of education, Occupation), Parity (number of children), history of blood transfusion and sexual history (number of life-time sexual partners) were collected using the structured questionnaire and/or from the antenatal record books of the study subjects. The data was obtained through face-to-face interview and interpretation of the question was either carried in English, Ewe and Twi; and in the participants’ dialect. The population includes pregnant women reporting for routine antenatal check-up between 1st February, 2017 and 27th April, 2017. A systematic random sampling was adopted to give all potential respondents an equal chance of being selected for the study. With an average daily attendance at the booking clinic of about 50, an average of 5 questionnaires was administered/day giving a sampling interval of 10. Using the booking records books at the antenatal clinic the first respondent was selected from the first 10 attendants randomly by balloting. The next respondent was therefore the 10th attendant after the first attendant sampled and then it followed. If an attendant declined to participate, the third attendant after her was selected. Predetermined criteria were the bases for this sampling method. Sample size was determined as expressed in Equation (1): n= ((z^2 ) (p) ( 1-p))/E^2. Where, n = the estimated sample size; E is the desired margin of error (0.05); z is the statistic for the level of confidence (95%) = 1.96; p is the (10.6%) prevalence of HBV infection among pregnant women in the Eastern Region of Ghana in a previous study in 2012. From Equation (1), the minimum sample size is 137. Adding 20% gives a sample size of 164 which catered for unforeseen circumstances such as uncompleted questionnaires. The final study size was 500 participants. Keywords: Binomial Logistic Regression, Hepatitis B Virus Infection, Antenatal Clinic Attendees
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The data for the study was analyzed with the R statistical software (R Core team; version 3.4.4; Released 15 March, 2018). The study employed a cross tabulation which is a joint frequency distribution of cases based on two or more categorical variables which is known as contingency table analysis. The joint frequency distribution was analyzed with the chi -square ( χ 2) statistic to determine whether the variables are statistically independent or if they were associated. In the analysis, other indicator of association, such as Phi -value ( ϕ ) was used describe the degree which the values of one variable predict or vary with those of the other variable if a dependency or association between variables does exist. Scores of respondents on knowledge of HBV infection was converted to 100% and the Kruskal-Wallis test was applied to the data to test for the differences in HBV knowledge scores across HBV status and levels of HBV awareness. HBV knowledge scores, measured on a continuous scale from 0 - 100, was used as the dependent variable for the Kruskal-Wallis test and for independent variables, HBV status and levels of HBV awareness were used. The Kruskal-Wallis test was used because the response variable (HBV knowledge scores) violated the normality test. Pairwise Wilcoxon rank sum test was used to calculate pairwise comparisons between group levels. Box and Whiskers was also used to visualize the variation or differences in HBV knowledge scores, HBV status, and levels of HBV awareness.