Study design
Institution based cross-sectional study was conducted to assess HBV vaccination status and associated factors among HCWs in Shashemene Zonal Town.
Study area and period
The study was conducted in Shashemene Zonal Town, Oromia Region, South Ethiopia from March 16, 2015 to March 31, 2015. The town is located at 250 kms away from the capital city, Addis Ababa due south with a total area of 12,960 sq km and a total population of 153,162. The city administration is divided into eight sub-cities. According to the city administration, Health office report: the public and private organizations which are involved in health care delivery include 1 referral hospital having 171 HCWs, 1 district hospital having 94 HCWs and 3 governmental health centers having 42 HCWs which makes the total number of HCWs in governmental institutions 307 and 1 health center having 19 HCWs, 4 special clinics having 15 HCWs, 6 higher clinics having 55 HCWs, 16 middle clinics having 97 HCWs and 8 primary clinics having 28 HCWs which collectively give a total of 214 non-governmental institution HCWs. Therefore there are a total of 521 HCWs in Shashemene Zonal Town.
Source and study population
The source population was all health care workers working in health care institutions found in Shashemene Zonal Town, during the data collection period and study population were those health care workers selected by using simple random sampling technique.
Sample size
The study employed single population proportion sample size determination formula. Fifty percent vaccination prevalence was considered with 95% CI, and 5% marginal error (where n is desired sample size, Z is value of standard normal variable at 95% confidence interval and, p is proportion of vaccination status of HBV among HCWs and d is marginal error which is 5%) was considered to calculate the sample size. Considering a non-response rate of 10%, the final sample size was calculated to be 423.
Sampling procedure
Samples were taken from all health care institutions in the town, and the samples were allocated proportionally based on the number of HCWs in the institutions by using a simple random sampling technique. Workers payroll was used as a sampling frame. To determine how many samples to take from a single institution, the total sample size needed (423) was multiplied by the total number of HCWs in the institution and divided by the total number of HCWs in the town (521).
Inclusion and exclusion criteria
Inclusion criteria
Health care workers in health care institutions of Shashemene Zonal Town during the study period were the candidates of the study.
Exclusion criteria
Health care workers who were not in the study area during data collection period due to maternity, annual or sick leave and field work were excluded.
Variables
Dependent variable
HBV vaccination.
Independent variables
Age, sex, religion, marital status, occupation category, length of employment, type of institution, knowledge about HBV, perceived price of vaccine and availability of vaccine.
Operational definitions
Health care workers
Those health workers, who do have contact with syringes, needles, other sharp materials, blood and bodily fluids by the virtue of their duties (all types of nurses, health officers, medical doctors, dentists, laboratory technologists, anesthetists and janitors).
Knowledge about HBV
The questionnaire included a total of 21 knowledge questions regarding HBV. There were 10 questions about routes of transmission, 7 questions about natural history and diagnosis and 4 questions about prevention methods. The 21 questions included both correct and incorrect statements. The HCWs were asked to answer each question with ‘true’, ‘false’ or ‘I don’t know’. Each correct answer was given a score of ‘1’ while an incorrect answer and questions answered as ‘I don’t know’ was given a score of ‘0’. The scoring range of the questionnaire was 21 (largest) to 0 (smallest). According to the total score obtained, knowledge of HCWs was classified into ‘Knowledgeable’ and ‘Not knowledgeable’. A total score of 15 and above out of 21 was considered as knowledgeable.
Vaccination status
Since Immunocompetent adults and children who have vaccine-induced anti-HBs levels of ≥10 mIU/mL 1–2 months after having received a complete, ≥3-dose hepatitis B vaccine series are considered sero-protected and deemed vaccine responders [12], in our study, the respondents were grouped into two categories: ‘Fully vaccinated’ and ‘Not fully vaccinated’. ‘Full vaccination’ status was considered when HCWs have received three or more doses of hepatitis B vaccine. Respondents who were considered as not ‘fully vaccinated’ were those partially vaccinated (took one or two doses of hepatitis B vaccine) and not vaccinated (have not received any dose of vaccine) HCWs.
Data collection procedures
A structured questionnaire was used to collect the required quantitative information through a face to face interview. The data was collected by nurses who were educated at the graduate level. Four data collectors and one supervisor were recruited to conduct the study. Those HCWs on the night or weekend shifts were addressed according to their working shifts. The investigators were responsible for coordination and supervision of the data collection process.
Quality assurance
First the questionnaire was developed in English and then translated into Amharic and Affan Oromo, and back to English by different persons to check for consistency. Five percent of the questionnaires were pre tested in health care workers of Ras Desta Hospital. Based on the pretest, questions were revised, edited, and those questions found to be unclear or confusing were removed prior to the actual study. Knowledge questions were checked for content validity by experts. All the data collectors held graduate degrees, and they were given a half day of training. The investigators collected the completed questionnaires every day and checked each for inconsistencies and omissions. Any format with a defect was rejected from the study.
Data management and data analysis
After being coded, the data was entered using EPI info version 7 statistical software and analyzed using SPSS version 21 statistical package. Data cleaning was performed to check for frequencies, accuracy, consistencies, missed values and variables. Any logical or consistency errors identified during data entry were corrected after revision of the original completed questionnaire. The cleaned and edited data was prepared for appropriate statistical analysis. The mean, standard deviation and the proportion of the variables were computed. Both bivariate and multivariable logistic regression analyses were used to measure how the outcome variable (HBV vaccination status) depends on the covariate variables (knowledge about HBV, perceived price of vaccine, availability of vaccine and socio demographic variables). Variables that showed association in the bivariate analyses were taken into the multivariable regression model to control for confounding. The results of the analysis were presented using tables, charts and graphs. 95% CI and p value of less than 0.05 were considered as indicators of statistical significance.