The study follows the STROBE Statement for reporting observational studies [41] guidelines.
Study design and settings
This was a cross-sectional study design and was conducted from July 2017 to February 2018, to assess the psychosocial beliefs related to the intention to use HTC services among suspected TB patients in Kassala State, Sudan. The Kassala State is one of the eighteen states of Sudan, situated in the eastern region of the country. The State is divided into eleven localities and extended over an area of 42,282 square kilometres. In 2018, the population of the State was estimated at 2.5 million based on the 2008 population census. According to reports in Kassala State TB program, the TB prevalence in the State was around71 per 100000 population in 2018. The TB/HIV burden among TB patients appears to be high, with an estimated 18.6% of the TB patients being infected with HIV [12]. At the time of the study, twenty-two TBMUs were provided diagnostic services for TB suspected patients and treatment for TB patients. All TBMUs offered HTC services.
Study population and recruitment
A three-sampling stage was performed. The first stage was simple random sampling to select four localities from the sampling frame of all localities in Kassala State. The second stage was a selection of one TBMUs from each locality chosen by simple random sampling. A total of four TBMUs were selected. The third was in-site systematic sampling for selection of participants from each TBMUS where the first participant was randomly selected from the clinic registers. Then every third was interviewed using a constant numeric interval. The number of participants chosen for sampling from each TBMUs was proportional to the number of suspected TB patients attending that TBMU. Any participant who refused to participate for any reason was replaced by the immediate next one until we reached the required sample size. All the TB suspected patients who were attending TBMUs for diagnosis purposes during the study period were considered eligible for this study. We included patients suspected of TB whose age was 18-64 years in the selected TBMUs. A sample size of 383 participants was computed by sample estimation for correlation with pre-specified 95% confidence interval [42]. This sample size allows estimation of a correlation of.05with a width of.10.
Study variables
The independent variable of in this study was the intention to use HTC services in TBMUs in Kassala State in the next three months. The explanatory variables were behavioural beliefs, normative beliefs, and control beliefs regarding the use of HTC services in the TBMUs in the next three months, risk perception of HIV infection, and exposure to HTC services during the last year. Information regarding demographic and socioeconomic variables, including age, gender, residence, marital status, education, working, HIV and HTC related-knowledge, were also collected.
Data collection and Measurements
After attaining consent to participate in the study, trained data collector used a structured questionnaire to collect data from the participants. Uneducated participants were interviewed, and educated ones fill out the questionnaire by themselves.
The questionnaire was based on the RAA, previous studies [43-47] and results of the beliefs elicitation study [48] on the study population.
The intention to use HTC services was measured by three items which were: I intent, I expect, and I want to use HTC services in the next three months and were each measured on a 7–point Likert scale. The higher score indicated a more positive intention.
The behavioural beliefs were measured by asking the participants to rate five statements regarding using HTC services in the next three months. The statements were: "I will Know my HIV status", "Facilitates my treatment if I have HIV positive test result", "I could prevent infecting my family from HIV infection", "I would feel worries about my HIV test result", and "I would have information about HIV infection". The participants replied on a seven-point Likert scale ranging from 1(unlikely) to 7 (likely). The normative beliefs were evaluated by asking respondents to indicate the extent to which their friends, doctor, partner, and parent thought they should use HTC services in the next three months. The participants answered on a seven-point Likert scale (with disagree (1) and agree (7) as anchors).
Five items assessed the control beliefs: "Health care providers keep my HIV test result confidential", "I would fear to be stigmatized if I get HIV positive test result", "I would fear losing my partner if I have HIV positive test result", "I would find it difficult to disclose my HIV positive test result to others", and "I could have the cost to reach HTC services". Responses were on a seven-point Likert scale (unlikely (1) -likely (7)) scale.
Two items assessed the perceived HIV risk: "I think I may be infected with the HIV infection", and “I think my partner may be infected with the HIV infection", scored on a seven-point (disagree (1)-agree (7)) scale.
Previous exposure to HTC services was measured by one item:" In the last year I had an experience with HTC services". Responses were ranged from disagree (1) to agree (7).
Statistical analyses
Data analyses were carried out by R version 3.6.1 [49] and Statistical Package for Social Sciences (SPSS) version 21. Descriptive statistics of the participants demographic and socioeconomic characteristics were presented as frequencies and proportions. Averages were calculated for age and HIV and HTC related-knowledge. The relevance of all studied beliefs regarding the intention to use HTC was assessed by performing Confidence Interval Based Estimation of Relevance (CIBER) analysis [50].
The CIBER is a data visualization method which presents different information on
a diamond plot to facilitate selection of the sub-determinants for intervention. The diamond plot is divided into a left-hand panel and right-hand panels with diamonds. One diamond shape in the left-hand panel represents both the means of the sub-determinants (in this study, the beliefs regarding the use of the HTC services) and its 99.99% confidence interval. While each diamond in the right-hand panel presents the associations (e.g., correlation) between the beliefs and the outcome variable (In this study the intention to use HTC services) with a 95% confidence interval together. The dots around the left-hand panel diamonds are all the participants’ item scores. The question used to assess each belief with its anchors is shown on the side of the left-hand panel. At the top, the plot provides the confidence interval of the explained variance (R2) in the intention to use HTC services based on beliefs that are included in the analysis.