Sample characteristics
The sample included 36 households, which consisted of 280 individuals (60 of whom were added over the course of the study period). The median age of the household respondent, who provided information for children under the age of 18, was 42 years (IQR=23) and 15 (42%) were female. 21 respondents (58%) had at least a primary education (table 1- Panel A).
Of the 280 individuals in the sample (including the household respondent), 151(54%) were female, and 110 (39%) were aged 18 or above. Among the 110 individuals aged 18 or older, 67 (61%) had at least a primary level education. At the baseline survey, 92 (88%) had previously heard of RDTs, and among those who had, 85 (94%) also had previous experience with an RDT (table 1- Panel B).
At baseline, confidence in RDTs and ACTs was low, in spite of high levels of awareness and experience with this technology. Although 82 individuals (92%) believed that a positive RDT results was “very likely” to be correct, only 55 (63%) believed that a negative RDT result was “very likely” to be correct. In addition, only 60 (60%) believed that Artemether Lumefantrine (AL)—the type of ACT frequently used in this area— was “very effective” in treating malaria (table 1-Panel B).
We conducted 5,617 household surveys between June 2017 and December 2019 (including both monthly and annual surveys). In those surveys, 909 people (16%) reported having a malaria-like illness in the past month and 638 (70%) of those were tested with an RDT (from either the study team or elsewhere). 337 (53%) of those tests were reported as being positive for malaria. While 323 (96%) people adhered to a positive test result, only 182 out of the 300 (61%) who reported testing negative adhered to their test result (table 1-Panel C).
Table 1: Sample characteristics
Panel A: Household Characteristics (N=36)
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Median (IQR) or N(%)
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Age of Household Respondent
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41.5 (33.0, 56.0)
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Household Respondent is Female
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15 (41.7%)
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Education Level of Household Respondent
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Less than primary
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15 (41.7%)
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Primary education or more
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21 (58.3%)
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Main source of drinking water
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Piped/protected source
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26 (72.2%)
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Unprotected source
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10 (27.8%)
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Owns more than one acre of land
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16 (44.4%)
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Household size
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5.0 (4.0, 7.5)
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Panel B: Individuals (N=280)
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N(%)
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Female
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151 (53.9%)
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Adult 18 years or older:
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110 (39.3%)
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Among Adults 18 years or older:
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Education
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Less than a primary education
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43 (39.1%)
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Primary education or more
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67 (60.9%)
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Heard of RDTs
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92 (87.6%)
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Previously had an RDT (among those who have heard of RDTs)
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85 (94.4%)
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Beliefs about Malaria at Baseline
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Believe positive RDT very likely correct
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82 (92.1%)
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Believe negative RDT very likely correct
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55 (62.5%)
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Believe AL very effective in treating malaria
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60 (60.0%)
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Reported malarial illness over study period
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227 (84.7%)
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Number of study RDTs received
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0
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56 (20.0%)
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1
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41 (14.6%)
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2
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27 (9.6%)
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3 or more
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156 (55.7%)
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Panel C: Monthly Surveys (N=5617)
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N (%)
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Reported malaria illness in past month
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909 (16.2%)
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Had RDT for malaria illness
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638 (70.2%)
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Tested positive for malaria
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337 (52.8%)
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Adhered to positive test result
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323 (95.8%)
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Adhered to negative test result
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182 (60.7%)
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Notes: The household respondent provided information on malarial illnesses for children under the age of 18. Their beliefs were also used for children under the age of 18.
Confidence in Malaria Testing and Treatment Behavior
Table 2 shows the association between confidence in malaria RDTs and two key malaria treatment behaviors: whether an individual is tested with an RDT when they have a fever or malaria-like illness and whether an individual who is tested adheres to a negative RDT result. We focused on adherence to a negative test because adherence to a positive test is already very high. Compared to those with lower confidence in RDTs, those who believed a negative RDT was “very likely to be correct” were not more likely to get tested with an RDT (aOR=1.31, 95% CI [0.866 1.976], P=0.203), but, when they were tested with RDT, had 78% higher odds of adhering to a negative RDT result (aOR=1.78, 95% CI [1.079 2.934], P=0.024).
Table 2: Association between Confidence in Testing and Treatment Behavior
Notes: Beliefs are those of the household respondent if the individual was under the age of 18. Results are from logistic regression models and coefficients are expressed in terms of odds ratios. Columns 2 and 4 include the following controls: age and gender of the individual, education level (of the respondent if the individual was under 18), whether the individual slept under a net the previous night, the main source of household drinking water, whether the household owns more than one acre of land and village fixed effects. *p<0.05, **p<0.01
Experience with Testing and Confidence in Testing and Treatment
Over the 30-month study period, monthly beliefs data collected from all individuals who had a malaria-like illness, regardless of whether they were tested, show that confidence in both RDTs and ACTs increased steadily over time (Figure 1). For RDTs, the proportion of people who said they believed a negative RDT was “very likely” to be correct increased from approximately 55% to 75%. The proportion of people who believed an ACT was “very likely” effective in treating malaria increased from approximately 75% to nearly 95%.
When we compare those who were tested for malaria with those who were not tested, we find further evidence that testing experience is associated with higher confidence in RDTs. Those who had any study RDT over the first study year had approximately three times higher odds of believing a negative RDT was “very likely” to be correct at the end of the year, controlling for their beliefs at the start of the study period (aOR=3.63, 95% CI [1.718 7.679], P=0.001). We find no evidence, however, that the number of tests people had over this time period was associated with their confidence in RDTs (Figure 2).
We also don’t find strong evidence that the results of the test influenced changes in beliefs; those who received at least one positive RDT over the first year had slightly higher odds of strong confidence in RDTs at the end of the year but this association did not hold in the adjusted model and was not observed among those who had received at least one negative RDT during that time (Table 3).
Table 3: Association between Testing Experience and Confidence in Test
Notes: Beliefs are those of the household head if the individual was under the age of 18. Information on whether the individual was tested and the test result is based on sick visit surveys by the study team. Results are from logistic regression models and coefficients are expressed in terms of odds ratios. Columns 2, 4, and 6 include the following controls: age and gender of the individual, education level (of the respondent if the individual was under 18), the main source of household drinking water, whether the household owns more than one acre of land and village fixed effects. *p<0.05, **p<0.01
Lastly, we did not find any statistically significant association between having been tested with an RDT and the odds of saying that AL was “very likely” to be effective in treating malaria at the end of the first year (Appendix Table A1).
Treatment Behavior and Confidence in Testing and Treatment
In Table 4 we show how adherence to the test result affects individuals’ subsequent confidence in RDT testing. We find that those who adhered to their previous malaria test result had approximately twice the odds of saying that a hypothetical negative RDT was “very likely” to be correct compared to those who did not adhere to the previous test result (aOR=2.20, 95% CI [1.661 2.904]. P<0.001]. When we split this out by adherence to a positive versus a negative test result, we find little effect of adherence to a positive test result (aOR=1.07, 95% CI [0.316 3.594, P=0.918), but a significant difference in confidence from those who adhered to a negative test result relative to those who did not adhere (aOR=2.09, 95% CI [1.403 3.116], P<0.001).
Table 4: Association between Adherence to Test Result and Confidence in Testing
Notes: Beliefs are those of the household head if the individual was under the age of 18. Results are from logistic regression models and coefficients are expressed in terms of odds ratios. Columns 2, 4 and 6 include the following controls: age and gender of the individual, education level (of the respondent if the individual was under 18), whether the individual slept under a net the previous night, the main source of household drinking water, whether the household owns more than one acre of land and village fixed effects. *p<0.05, **p<0.01
We also find some evidence that those who adhered to a positive test result were more likely to subsequently say that AL was “very effective” in treating malaria compared to those who did not adhere, however our results are not statistically significant (Appendix Table A2).
Updating beliefs with test result
Figures 3 demonstrates that individuals use the information from the test to update their beliefs about the likelihood that their (or their child’s) illness is malaria. For example, we find that for individuals who tested positive on their RDT, 87% said it was “very likely” their illness was malaria before the test, compared to nearly 100% after the test result (P<0.001). For those who tested negative, 61% said it was “very likely” their illness was malaria before testing, compared to only 14% after the test result (P<0.001).
We also find evidence that the degree to which people update their beliefs based on the test results depends on their prior confidence in testing (Appendix Figure A1). Those who had said that a hypothetical negative RDT was “likely” or “very likely” to be correct, were more likely to revise downwards their belief that an illness was malaria after a negative test result, compared to those who said that they were less confident in a negative RDT result (P<0.001).