Study sample characteristics
We enrolled 177 consecutive adults being evaluated for pulmonary TB at enrolled health centers on randomly selected days of the week to participate in the study. Of the 177 enrolled participants, 161 completed the full survey and their data were included and analyzed. Of the 16 participants not included in the study, nine started the survey but stopped before completion, and seven participants were not asked willingness-to-accept experiment questions. Of the 161 participants whose data were included in the analysis, 88 (55%) were female and the median age was 38 years (IQR: 28-48). The majority accessed care at a rural health center (n=110, 68%) and were informally employed (n=132, 82%). The median household income reported was 150,000 USh/month (IQR: 70,000-300,000); Table 1), which is consistent with prior income estimates for this population (6, 39).
Patient barriers to community health center visits for TB care
Participants who indicated that they would be unable to return for either daily, weekly, or monthly health center-based TB care most frequently reported lack of transportation as their largest barrier (for daily medication adherence: n=84 (62%); weekly: n=15; 58%; monthly: n=2; 67%; Table 2). Although 155 (96%) participants indicated that they would be able to return to the health center the following day to retrieve their test results if needed, 40% (n=62) stated that it would be difficult to do so.
Self-reported barriers to health center visits among participants who indicated they would be unable to return for health center-based TB care differed by income quartile. Participants in the lower income quartiles indicated transportation difficulties as their main challenge to health center visits compared to those in higher income quartiles, who cited a mixture of concerns including transportation, inconvenience, and possible job loss (p=0.02) (Table 2). Participants in rural locations noted a lack of transportation as their main barrier to return to community health centers (urban: 37%; rural: 73%), whereas those in urban locations were more likely to indicate inconvenience (urban: 29%; rural: 18%) or possible job loss (urban: 24%; rural: 4%) as their primary concern (p<0.001). Barriers to community health center visits varied slightly by sex (p=0.07), but did not vary by other sociodemographic characteristics such as age (results not shown).
Participant attitudes and perceptions regarding incentives
We evaluated attitudes and perceptions regarding incentives among participants and their communities (n=161) (Table 3). Seventeen participants (11%) had received some form of incentive before, mostly in the form of cash or food as a part of a study-based program to support health outcomes. Participants almost unanimously agreed that incentives were acceptable to themselves and for those within their communities. Receipt of cash, transportation vouchers, or food was reported as acceptable among participants and their communities (cash: n=160, 99%; transportation vouchers: n=159, 99%; food: n=156, 97%). When asked to compare types of potential incentives, the majority of participants preferred cash (n=84; 52%) or transportation vouchers (n=54; 34%) to facilitate return to community health center to complete diagnostic evaluation. While the preferred type of incentive did not vary by income quartile, age, occupation and health center location, women were more likely to choose transportation vouchers (n=48; 55%) compared to men, who instead preferred cash (n=31; 43%; p=0.04).
Preference for incentive conditionality
We assessed participant preference for conditionality of incentives within the context of both single and multi-day TB evaluations to assess whether providing the incentive either before or after the patient completed diagnostic testing would be most helpful in finishing diagnostic evaluation and initiating treatment. For hypothetical single-day evaluation scenarios, where testing and treatment initiation could be completed in the same day, participants in the second and highest income quartiles preferred an incentive conditioned upon completion of diagnostic testing (n=24, 71% and n=17, 65%, respectively). In contrast, participants in the lowest and third income quartiles preferred unconditional incentives provided at the beginning of the diagnostic process, and the receipt of which was not dependent on completion of testing (n=12, 33% and n=14, 39%, respectively; p<0.01). For hypothetical multi-day evaluation scenarios, the proportion of participants who preferred conditional incentives provided only after completion of diagnostic evaluation was high overall but varied slightly by income quartile (overall: n=134, 84%; Table 3). We also assessed preference for conditionality based on participants’ report of whether it would be easy or difficult to return the next day to receive their test results and initiate treatment. In the context of multi-day evaluations, almost all participants (n=57; 95%) who indicated return to the health center would be difficult agreed that conditioning incentive receipt upon return would be helpful in finishing their evaluation; however, only 37% (n=22) felt that conditionality would be helpful for same-day evaluations. Preference for incentive conditionality did not differ by age, sex or health center location.
Willingness to accept incentives for TB testing
Participants’ willingness to accept varying amounts of an incentive to return to clinic are shown in Figure 3. Forty (40) participants (25%) accepted 500 USh, 69 participants (43%) accepted 2,000 USh or less, 112 (70%) accepted 5,000 USh, and the remainder (n=49; 30%) required 10,000 USh or more to facilitate TB diagnostic evaluation (Figure 3). Participants’ willingness to accept different amounts of incentives varied by income quartile, particularly for mid-range incentive values of 2,000 USh (p=0.06) and 5,000 USh (p=0.02). Specifically, participants in the third income quartile were less likely than other income quartiles to accept these mid-range amounts (Table 4).
Bivariate ordered logistic regression analyses revealed that participants who reported that it would be difficult to return the next day to the health center were more likely to require higher incentive amounts compared to those who responded that return would be easy (OR=2.12; 95% CI: 1.48-3.05). Older participants were less likely to require higher incentive amounts to complete TB diagnostic evaluation compared to their younger counterparts (OR=0.55; 95% CI: 0.32-0.94) (Table 5). No significant associations were found for sex (OR=0.98; 95% CI: 0.50-1.96), marital status (OR=1.31; 95% CI: 0.77-2.22), or community health center location (OR=0.64; 95% CI: 0.22-1.86) and accepted amount of hypothetical incentives.
Perceived difficulty in returning to the health center (aOR=2.53, 95% CI: 1.59-4.02) and age (aOR=0.44, 95% CI: 0.22-0.91) remained significant associations in our multivariable analysis (Table 5). The pairwise difference between the third income quartile and the reference income quartile class (aOR=2.38, 95% CI: 1.20-4.69) was associated with willingness to accept higher incentive thresholds (p=0.01). The association between income and level of incentive needed to complete diagnostic evaluation trended towards statistical significance in our final multivariate model, indicating that participants in higher income categories were more willing to complete TB diagnostic evaluation for higher incentive amounts compared to those in the lower income categories (p=0.08).