Study setting
A full description of the PopART trial design was previously published. (12) The overall goal of PopART was to assess whether an HIV prevention intervention package, including testing of all community members and linkage to HIV care and treatment, could lead to decreased HIV incidence in communities. PopART communities were defined based on the catchment areas of health care facilities providing ART. The PopART intervention was delivered door-to-door to the total population by Community HIV-care providers (CHiPs). Communities were arranged in 3 triplets matched on geographical location and estimated HIV prevalence. The PopART trial in South Africa was implemented in 9 communities, 6 in the Cape Metro and 3 in the Cape Winelands districts. The populations of the 9 South African PopART communities ranged from 21,386 to 82,953 individuals, with an average of 45,780 individuals. The impact of the PopART intervention on HIV incidence was measured in a research cohort, the Population Cohort (PC). The PC included a randomly selected subset of each community enrolling approximately 2000 adults, aged 18 to 45 years, in each community who were followed up over 3 years.
PopART PC participant selection
The PopART PC was implemented from January 2014 to July2018. PC recruitment was undertaken at baseline (PC0) with baseline surveys completed at enrolment and participants followed-up after 12 months (PC12), 24 months (PC24) and 36 months (PC36). Additional participants were recruited at PC12 (PC12N) and PC24 (PC24N).
A household census was completed prior to PopART implementation which listed and enumerated households. A random selection of households identified in the census were selected for inclusion into the PC. Thereafter, individuals residing in each selected household were enumerated. From this list of enumerated individuals in each household, an eligible individual was randomly selected for inclusion in the PC, who, if accepting study participation, signed informed consent. If the randomly selected individual did not consent to participation, another eligible household member was randomly selected for inclusion.
PopART PC follow-up and retention
Follow-up household visits were completed by research field workers and consisted of completing a questionnaire, obtaining a blood specimen for HIV testing, and offering a HIV point of care test (POCT). The questionnaire covered socio-demographic, behavioural and HIV-related topics and was completed on an electronic data capture device (EDC), which was synced daily to a cloud-based database. Phlebotomy and POCT were completed after the interview by a trained research nurse and samples transported to laboratories for testing. The success of a household visit was defined as the successful completion of the electronic questionnaire during the household visit.
Retention of PC participants was critical for PopART. For enrolment, household visits were conducted by research enumerators (REs) who worked the traditional shift type i.e. weekdays ending at 4 pm. To increase the chance of finding participants at home, and thereby enhancing study retention, the household visit schedule was adjusted during PC12 adding additional shift types, namely a late weekday shift (ending after 4pm) and a Saturday shift (ending at 2pm).
The same research teams rotated through all shift types. With few exceptions, weekday shifts lasted eight hours, while the Saturday shift lasted five hours (see Table 1 for a list of exceptions). This remained unchanged during the remainder of the study. The allocation of participants to early weekday, late weekday and Saturday shifts was not random. Research teams communicated with participants to determine the most convenient time for survey completion in the household. This was done prior each household visit. Therefore, the time of day for completing research activities was based on participant availability. Research teams were systematically allocated to cover a combination of shifts which allowed research activities to be completed during early weekdays, late weekdays and Saturdays, to accommodate participant availability. During each shift type four research teams (two individuals per team) conducted follow-up household visits in each community.
Table 1
Duration of shift days by shift type stratified by PC round
|
Early weekday
shift (n days)
|
Late weekday
shift (n days)
|
Saturday
shift (n days)
|
PC12 (July 2015-June 2016)
|
|
|
|
Duration field teams active (hours)
|
|
|
|
4
|
0
|
0
|
0
|
5
|
1
|
0
|
24
|
6
|
1
|
0
|
0
|
7
|
0
|
16
|
0
|
8
|
53
|
125
|
0
|
Total days worked per shift type
|
55
|
141
|
24
|
Total hours worked per shift type
|
435
|
1,112
|
120
|
PC24 (July 2016-July 2017)
|
|
|
|
Duration field teams active (hours)
|
|
|
|
4
|
1
|
0
|
0
|
5
|
1
|
1
|
17
|
6
|
0
|
0
|
0
|
7
|
0
|
0
|
0
|
8
|
30
|
117
|
0
|
Total days worked per shift type
|
32
|
118
|
17
|
Total hours worked per shift type
|
249
|
941
|
85
|
Early weekday shift = research teams ending before 4pm
Late weekday shift = research teams ending after 4pm
Saturday shift = research teams ending at 2pm
PC= Population Cohort
|
Study design
For this study we conducted a cross sectional evaluation of the association between shift type and household visit success in the PC12 and PC24 in the 9 South African communities, for follow up study visits conducted between June 2015 and July 2017. A household visit was considered successful if the participant completed the electronic survey during the household visit.
Data sources
We used data extracted from the PopART PC survey data and from an electronic contact log. Survey data included questionnaire data on all household visits conducted, detailing sex, age, PC round, community of visit, time and date of visit and whether or not the visit was successfully completed. During the implementation of the PopART PC, household visits were monitored using an electronic contact log (ECL) to track the status of each household visit. ECL data included documentation of the number of household visit attempts prior to completion of a successful visit. Successful visits were excluded (dropped) from analysis if the sex of the research participant was not recorded, if the date of the household visit was missing, or if the visit was completed outside the three household visit shift types.
Data analysis
Only data from South Africa was included in the analyses. The study protocol used in both countries was the same, however there were differences in the management of operational activities. This lead to each country adopting a slightly different approach to reaching research participants.
We compared the rate of successful household visits by different shift type. (Table 1). This rate was calculated as the number of successful visits per day, divided by the number of hours that the research fieldworkers were active during that particular day. Every day during the study period research teams worked according to the same shift type similar in each community, thus by standardizing by hour per day, the outcome was also standardized by community and research team. We used one-way univariate analysis of variance (ANOVA) to describe differences in mean-successful visits and 95% confidence intervals between the shift types within each of the following subgroups: males, females, age 18-24 years, age 25-34 years, age >34 years, PC12, PC24, and separately for each community triplet. To investigate if patterns changed during the study period we also report outcomes per half year (from July 2015-July 2017).