Method of development and validation of data collection instrument

The data collection instruments used comprised of two questionnaires (one for data collection from community adult respondents and the other from females of reproductive age group) and one data extraction tool for collection of data from health facilities medical records. The data collection instruments were developed by the authors after careful review of literature, followed by development of indicators required for hypotheses testing. Semi-structured, closed and open-ended and interviewer administered questionnaires and data collection tool with specified indicators were finally designed. The adult´s respondent questionnaire contained two sections and nine questions. Section 1 collected data on socio-demographic characteristics while Section 2 collected data on respondent knowledge of Antenatal HIV Testing. The female of reproductive age questionnaire contained two sections and eight questions. Section 1 collected data on socio-demographic characteristics while Section 2 collected data on attitude and practice of female respondent with respect to Antenatal HIV Testing. The Data Extraction Tool contained two sections. Section 1 collected data on characteristics of the health facilities while Section 2 was used to extract data on the number of pregnant women that received Antenatal HIV Testing pre and post intervention from medical records.

We pre-tested the data collection instrument on a sample of 20 respondents in five communities to validate it. Pretesting helped to detect deficiencies and ambiguities in the questionnaires and data extraction tool. Appropriate corrections were made to the questionnaires and data extraction tools after pretesting by eliminating irregular questions and questions having same interpretation and ensuring utilization of SMART indicators. This lessened the time taken to complete the questionnaire and data collection tool. The initial drafts had overall 26 questions that were reduced to 17 questions. Interviewers were also trained on providing guidance to respondents on interpretation of questionnaire items and proper transcription of data to increase validity.

Procedure for data collection: data was collected using data collection instruments administered to 600 respondents (300 Adult Respondents and 300 Women of Reproductive Age) from the 30 LGAs of the State. Data was also extracted from Medical Records obtained from 30 selected health facilities where pregnant women were linked to access Antenatal Care and Antenatal HIV Testing.

Source of data: data was sourced from 600 respondents and medical records on Antenatal Attendance from 30 Health Facilities utilizing data collection instrument (questionnaire and data extraction tool).

Variable: the study had the following variables: 1) predictor variables comprise of age, sex, occupation, type of facility; 2) exposure variable prior utilization of Antenatal HIV Testing; 2) outcome variable-knowledge of importance of Antenatal HIV Testing, knowledge of barriers to antenatal HIV testing, attitude to Antenatal HIV Testing, antenatal HIV testing attendance.

Sampling method: convenient sampling method was utilized for the study. The 600 respondents were divided into 300 Adult Respondents and 300 women of reproductive age. The 300 Adult Respondents were selected at 10 per LGA while the 300 women of reproductive age were selected at 10 per LGA respectively. The 30 Health Facilities where data was collected were selected based on higher monthly attendance. The non-usage of random sampling introduces potential source of bias especially selection bias.

Sample size: the sample size was estimated using the Cochran formula for cross-sectional studies below.

Where n = sample size: z = level of significance; p= prevalence of attribute in the population; Assume p = 40% = 0.4 (most recent Antenatal HIV Testing coverage = 39.8%); q = 1-p =1-0.4= 0.6; d= precision. Setting precision at 4% then d=4%=0.04 z=1.96. Therefore