A total of 292 CHWs in 16 Intervention CUs were trained to perform RDTs and 36 retail shops were enrolled to redeem vouchers. The intervention was launched on July 21, August 17, and September 22, 2015 in Bokoli, Kiminini, and Ndivisi sub-counties western Kenya, respectively and continued until May 5, 2017.
Demand for malaria diagnostic testing
The community-based demand analysis relies on 1738 complete surveys from participants in randomly selected households in intervention clusters with an acute illness in the last four weeks (Table 1). Community members were interviewed at 12 or 18 months (47.2% and 52.8% respectively) following the initiation of the intervention. 55% (n = 948) of participants reported having a malaria test for their recent illness while 38.4% (n = 364/948) of those tested reported having had the test at CHW. Among all surveyed participants, 41% (n = 710) were male and 59% (n = 1028) were female. 21.2% (n = 368) of the recent fevers were aged < 5 years, 43.3% (n = 752) were 5–17 years while 36% (n = 618) were 18 > years. Only 21.4% (n = 371) of the participants had completed their secondary education while 45% (n = 778) had completed their primary education. On average, the distance to the nearest public health facility was approximately 2km while the nearest drug shop was approximately 1.3km away.
Table 1
Characteristics of community survey participants
Variables (N = 1738)
|
Participant characteristics (N = 1738)
|
%
|
Tested
|
948
|
54.6
|
Tested at CHW
|
364/948
|
38.4
|
Patient is male
|
710
|
40.9
|
Patient age
|
|
|
Under 5
|
368
|
21.1
|
5–17 y
|
752
|
43.3
|
18 + y
|
618
|
35.6
|
Education level of respondent
|
|
|
Not completed primary
|
589
|
33.9
|
Completed primary
|
778
|
44.8
|
Completed secondary
|
371
|
21.3
|
Distance to nearest public health facility (mean, sd)
|
2.1(sd = 1.2)
|
1.9(1.1–2.9)
|
Distance to nearest drug shop
|
1.3(sd = 0.7)
|
1.3(0.7–1.7)
|
Survey timepoint
|
|
|
12 months
|
821
|
47.2
|
18 months
|
917
|
52.8
|
We first examined demand-side factors that were correlated with uptake of malaria testing for their most recent illness (Table 2). Respondents who delayed seeking care beyond the first 24 hours had higher odds of receiving a test. Being aware of your local CHW increased the odds of having a test from any source, facility or CHW (Adj. OR = 1.50, 95% CI: 1.10–2.04). Respondents from the wealthiest households were 53% more likely to have a test (Adj. OR = 1.53 95%CI: 1.14–2.06). We however noted that being an adult at least 18 years old was negatively associated to taking a test (Adj. OR = 0.59, 95% CI:0.43–0.82). Distance to a health facility greater than 2km (Adj. OR = 0.86, 95% CI:0.67 − 0.11) and use of ITN (Adj. OR = 1.27, 95%CI:0.93–1.74) were not significantly correlated with testing uptake.
Table 2
Association between participant characteristics and having a malaria diagnostic test (either microscopy or RDT) from any source before taking any treatment.
|
Univariate analysis
|
Multivariate analysis
|
|
Participant characteristics (N = 1738)
|
Unadjusted Odds Ratio
|
P-value
|
Adjusted Odds Ratio (95%CI)
|
P-value
|
Time to seek care (Reference = same day)
|
|
|
|
|
Next day
|
1.21[1.05,1.42]
|
0.01
|
1.23[1.06,1.43]
|
0.01
|
After two days
|
1.01[0.78,1.32]
|
0.94
|
1.13[0.86,1.48]
|
0.38
|
More than two days
|
0.94[0.73,1.22]
|
0.66
|
1.12[0.87,1.44]
|
0.37
|
Use an ITN
|
1.37[0.99,1.92]
|
0.06
|
1.27[0.93,1.74]
|
0.13
|
Distance to public health facility > 2km
|
0.83[0.64,1.06]
|
0.14
|
0.86[0.67,1.11]
|
0.26
|
Aware of a CHW in their village
|
1.43[1.01,2.05]
|
0.04
|
1.50[1.10,2.04]
|
0.01
|
Patient age (Reference = 1-4y)
|
|
|
-
|
-
|
5 to 17y
|
0.76[0.54,1.08]
|
0.12
|
0.79[0.56,1.12]
|
0.18
|
18 + y
|
0.59[0.43,0.81]
|
< 0.01
|
0.59[0.43,0.82]
|
< 0.01
|
Patient is male
|
1.02[0.86,1.23]
|
0.78
|
0.94[0.80,1.10]
|
0.43
|
Respondent education level (Reference = none)
|
|
|
-
|
-
|
Completed primary
|
1.12[0.93,1.36]
|
0.23
|
1.08[0.87,1.33]
|
0.48
|
Completed secondary
|
1.41[1.04,1.90]
|
0.03
|
1.25[0.93,1.70]
|
0.14
|
Wealth quintile (reference = 0-20th )
|
|
|
-
|
-
|
20–40th
|
1.04[0.68,1.62]
|
0.83
|
1.02[0.65,1.59]
|
0.94
|
40–60th
|
1.14[0.86,1.50]
|
0.36
|
1.08[0.82,1.43]
|
0.59
|
60–80th
|
1.10[0.79,1.53]
|
0.56
|
1.03[0.73,1.46]
|
0.86
|
> 80th
|
1.59[1.15,2.21]
|
< 0.01
|
1.53[1.14,2.06]
|
< 0.01
|
We further focused our analysis on those who were tested for malaria by a CHW (Table 3). Out of 948 participants who reported having a test, 38.4% reported having taken a test from a CHW (364/948). We note that wealthier participants prefer being tested at the health facility (Adj. OR for testing at a CHW = 0.32, 95%CI:0.17–0.60), and those with education above secondary school have lower odds of taking a test at the CHW (Adj. OR = 0.68, 95%CI:0.44–1.07). Delaying testing beyond two days also reduced the odds of testing by a CHW. On the other hand, school-aged children between 5–17 years were more than twice as likely to be tested by a CHW compared to those below 5 years old (Adj. OR = 2.39, 95%CI: 1.43–4.01).
Table 3
Association between patient characteristics having a malaria rapid diagnostic test (mRDT) from a CHW before taking any treatment.
|
Univariate analysis
|
Multivariate analysis
|
Participant Characteristics (took a test from CHW (n = 948)
|
Unadjusted Odds Ratio
|
P-value
|
Adjusted Odds Ratio
|
p-value
|
Time to malaria test (Reference = same day)
|
|
|
-
|
-
|
Next day
|
0.96[0.71,1.31]
|
0.80
|
0.96[0.69,1.33]
|
0.81
|
After two days
|
0.73[0.44,1.21]
|
0.22
|
0.68[0.42,1.10]
|
0.12
|
More than two days
|
0.81[0.49,1.34]
|
0.41
|
0.87[0.50,1.52]
|
0.62
|
Use an ITN
|
0.57[0.41,0.78]
|
< 0.01
|
0.77[0.55,1.06]
|
0.11
|
Distance to public health facility > 2km
|
1.32[0.80,2.20]
|
0.28
|
1.29[0.82,2.03]
|
0.27
|
Patient age (Reference = 1-4y)
|
|
|
-
|
-
|
5 to 17y
|
2.43[1.49,3.95]
|
< 0.01
|
2.39[1.43,4.01]
|
< 0.01
|
18 + y
|
0.98[0.67,1.43]
|
0.91
|
1.09[0.72,1.66]
|
0.68
|
Patient is male
|
1.23[0.98,1.54]
|
0.07
|
1.02[0.82,1.26]
|
0.85
|
Respondent education level (Reference = none)
|
|
|
-
|
-
|
Completed primary
|
0.86[0.69,1.09]
|
0.22
|
0.96[0.75,1.22]
|
0.74
|
Completed secondary
|
0.45[0.29,0.68]
|
< 0.01
|
0.68[0.44,1.07]
|
0.10
|
Wealth quintile (reference = 0-20th )
|
|
|
-
|
-
|
20–40th
|
1.13[0.65,1.94]
|
0.671
|
1.11[0.63,1.96]
|
0.72
|
40–60th
|
0.83[0.63,1.09]
|
0.175
|
0.79[0.58,1.05]
|
0.11
|
60–80th
|
0.67[0.47,0.96]
|
0.028
|
0.66[0.45,0.97]
|
0.03
|
> 80th
|
0.26[0.13,0.53]
|
< 0.001
|
0.32[0.17,0.62]
|
< 0.01
|
We next focused on the final survey at 18 months to understand how individual perceptions about malaria testing and treatment, malaria risk, and illness severity affected uptake of testing or testing at a CHW (Table 4). After adjusting for demographic characteristics, patient perceptions were differentially related to testing overall and testing specifically with a CHW. Both confidence in AL treatment (Adj. OR = 2.75, 95% CI: .1.54–4.92) and confidence in the accuracy of an RDT performed by a CHW (Adj. OR = 2.43, 95% CI: 1.12–5.27) were strongly positively associated with testing at a CHW. Those who reported their illness as severe were more likely to be tested (Adj. OR = 2.37, 95% CI: 1.58–3.58 ) but had a lower odd of testing at a CHW (Adj. OR = 0.44, 95% CI: 0.22–0.87). Confidence in an RDT result, either positive or negative was not significantly correlated with receiving a test for a recent illness, but those who reported a high confidence in a negative RDT result had substantially higher odds of testing with a CHW than in a facility, although this did not reach statistical significance at the 95% level (Adj OR = 1.58, 95%CI: 0.89–2.83). Finally, those who reported that between 4–7 or 8–10 fevers of 10 had increasingly higher odds of receiving a test from a CHW (medium prevalence Adj. OR = 2.52, 95%CI: 1.26–5.06, high prevalence Adj. OR = 2.70, 95% CI: 1.17–6.22).
Table 4
Relationship between participant beliefs and perceptions and uptake of testing from any source or uptake of testing from a CHW. Models are adjusted for patient age, gender, household wealth quintile and the education level of the respondent in addition to the variables in the table.
Had a malaria test
(N = 703)
|
Univariate analysis
|
Multivariate analysis
|
|
Odds Ratio
|
P-value
|
Odds Ratio
|
P-value
|
Confidence in a positive RDT result
|
1.02[0.67,1.54]
|
0.93
|
0.87[0.53,1.41]
|
0.57
|
Confidence in a negative RDT result
|
1.34[0.87,2.03]
|
0.19
|
1.24[0.72,2.14]
|
0.43
|
Confidence in AL treatment
|
1.27[0.94,1.71]
|
0.12
|
1.06[0.81,1.40]
|
0.63
|
Trust an RDT by a CHW as much as one at a facility
|
0.85[0.55,1.32]
|
0.48
|
0.66[0.44,0.97]
|
0.03
|
Illness is severe
|
2.36[1.64,3.39]
|
< 0.001
|
2.37[1.58,3.58]
|
< 0.001
|
Prevalence (Reference is low)
|
|
|
-
|
-
|
Medium
|
1.51[0.89,2.57]
|
0.13
|
1.48[0.85,2.58]
|
0.16
|
High
|
1.12[0.70,1.80]
|
0.64
|
1.05[0.63,1.77]
|
0.85
|
Had a test with a CHW
(N=428)
|
Univariate analysis
|
Multivariate analysis
|
|
Odds Ratio
|
P-value
|
Odds Ratio
|
P-value
|
Confidence in a positive RDT result
|
1.45[0.89,2.34]
|
0.13
|
1.04[0.64,1.71]
|
0.86
|
Confidence in a negative RDT result
|
1.61[0.99,2.64]
|
0.06
|
1.58[0.89,2.83]
|
0.12
|
Confidence in AL treatment
|
2.67[1.52,4.70]
|
<0.01
|
2.75[1.54,4.92]
|
<0.01
|
Trust an RDT by a CHW as much as one at a facility
|
2.91[1.29,6.58]
|
0.01
|
2.43[1.12,5.27]
|
0.03
|
Illness is severe
|
0.60[0.35,1.03]
|
0.06
|
0.44[0.22,0.87]
|
0.01
|
Prevalence (Reference is low)
|
|
|
-
|
-
|
Medium
|
2.87[1.48,5.56]
|
<0.01
|
2.52[1.26,5.06]
|
0.01
|
High
|
2.85[1.31,6.23]
|
0.01
|
2.70[1.17,6.22]
|
0.02
|
Supply of diagnostic testing by CHWs
In total, 32,404 RDTs were conducted by the CHWs over the intervention period and 33.7% (n = 10,870) percent were positive. All RDT interpretations were counterchecked by the study team. Those with a positive test received a voucher for a discounted quality-assured ACT. These vouchers were redeemed at a participating outlet by 93.9% of voucher recipients. We had no instances of stock out of RDTs among our CHWs. We explored factors that may be associated with the CHWs ability to conduct RDTs. We examined the association between testing volume, defined as the mean number of RDTs conducted per month, and the different CHW demographic characteristics (Table 5). Of the 244 trained CHWs, 147 (60.3%) were above 40 years of age, 72 (29.5%) were male. There were 107 (43.8%) CHWs who had not completed secondary education.
Table 5
Association between mean number of tests performed per month and CHW characteristics
Mean number of tests per month
|
4.60 (SD = 3.07)
|
Univariate Analysis
|
Multivariate Analysis
|
|
|
N = 244
|
N = 244
|
CHW characteristics
|
N (sample proportion)
|
Coeff (95%CI)
|
P-value
|
Coeff (95%CI)
|
P-value
|
Male
|
72 (29.5)
|
-0.30[-1.28,0.68]
|
0.52
|
-0.28[-1.24,0.68]
|
0.54
|
Age (Ref = < 40 years)
|
97 (39.7)
|
-
|
-
|
-
|
-
|
> = 40 years
|
147 (60.3)
|
-0.21[-1.06,0.63]
|
0.60
|
-0.42[-1.12,0.28]
|
0.23
|
Married
|
202 (82.8)
|
0.37[-0.57,1.30]
|
0.42
|
0.22[-0.92,1.35]
|
0.69
|
Education
(Ref = below secondary)
|
107 (43.8)
|
-
|
-
|
-
|
-
|
Completed Secondary
|
137 (56.2)
|
0.45[-0.33,1.23]
|
0.24
|
0.23[-0.40,0.87]
|
0.44
|
Formal Employment
|
33 (13.5)
|
1.13[-0.01,2.28]
|
0.05
|
1.37[0.05,2.70]
|
0.04
|
Previously trained in mRDT
|
46 (18.8)
|
-0.46[-1.64,0.72]
|
0.42
|
-1.40[-2.44, -0.37]
|
0.01
|
Households1 (Ref < = 50)
|
134 (54.9)
|
-
|
-
|
-
|
-
|
50–100
|
66 (27.1)
|
2.14[0.63,3.64]
|
< 0.01
|
1.73[0.70,2.74]
|
< 0.01
|
> 100
|
44 (18.0)
|
1.18[-0.40,2.76]
|
0.13
|
1.49[0.74,2.24]
|
< 0.01
|
Cluster-level test positivity2 (Ref < = 25%)
|
141 (58.8)
|
-
|
-
|
-
|
-
|
High (> 25%)
|
103 (42.2)
|
2.54[0.97,4.10]
|
< 0.01
|
2.14[1.05,3.22]
|
< 0.01
|
1 Number of households for which the CHW reported being responsible |
2 Percentage of mRDTs conducted by the CHWs in that cluster which turned positive over the study period. |
In a univariate and multivariate analysis, formal employment, previous RDT training, number of households and RDT-positivity rate at the cluster-level were associated with volume of tests done. Sex, age, being married and education level were not significantly associated with testing volume. CHWs who were formally employed performed on average 1.37 more tests per month (95% CI: CI: 0.05–2.70) but those who reported being trained previously on RDTs performed 1.4 fewer tests per month (95%CI: -2.44,-0.37). We also noted that CHWs serving areas with a high proportion of positive tests (proportion RDT + ve > 25%) tested on average 2 more clients per month than those in lower prevalence areas (Adj coefficient = 2.14, 95%CI: 0.63–3.64). CHWs who were responsible for at least 50 households tested more clients (Adj coeff = 1.73, 95%CI: 0.70,2.74), although this did not increase further with when the number of households exceeded 100 (Adj coeff = 1.49, 95%CI: 0.74–2.24).
We also did univariate and multivariate analyses to test the association between testing volume and CHW perceptions about their role at the midpoint survey (Table 6). High client score was significantly associated with higher testing volume performed by CHWs who perceived that their clients trusted their tests (Adj. coeff = 1.37, 95%CI: 0.11–2.62). The CHWs competency at conducting all 20 steps of the RDT process (RDT score), the number of different activities to which CHWs were committed, whether they named RDT testing as their most important activity, or whether they cited extrinsic motivation (money, airtime, or other) as important reasons for continuing their work were all not significantly correlated with average tests performed per month.
Table 6
Association between testing volume and CHW perceptions about their role at the midpoint survey. Multivariate odds ratios are adjusted for age, gender, education level, formal employment. The analysis includes a random sample of CHWs selected for midpoint evaluation.
|
N = 70
|
Univariate Analysis
|
Multivariate Analysis1
|
|
Characteristics
|
Coeff (95%CI)
|
P-value
|
Coeff (95%CI)
|
P-value
|
RDT Score2 (Ref = Low)
|
-
|
-
|
-
|
-
|
-
|
High
|
54/70 (77.1)
|
0.19[-1.25,1.64]
|
0.78
|
0.11[-1.34,1.57]
|
0.87
|
Number of different activities last month (Ref=<=3)
|
-
|
-
|
-
|
-
|
-
|
> 3 activities
|
19/70 (27.1)
|
0.35[-1.56,2.26]
|
0.70
|
-0.45[-2.04,1.15]
|
0.56
|
Most important activity is malaria testing
|
48/70 (68.6)
|
0.88[-0.25,2.01]
|
0.12
|
0.07[-1.16,1.32]
|
0.90
|
Cited extrinsic motivators as important3
|
28/70 (40.0)
|
0.33[-1.52,2.17]
|
0.71
|
0.67[-0.92,2.25]
|
0.38
|
Client Score4 (Ref = Low)
|
-
|
-
|
-
|
-
|
-
|
High
|
48/70 (68.6)
|
1.46[0.10,2.83]
|
0.04
|
1.37[0.11,2.62]
|
0.04
|
Years of experience as a CHW (Ref: <=5y)
|
-
|
-
|
-
|
-
|
-
|
> 5 years
|
38/70 (54.3)
|
-0.35[-2.68,1.98]
|
0.75
|
-0.51[-2.56,1.55]
|
0.61
|
1 Multivariable models are also adjusted for CHW demographic factors (age, gender, education, employment, and cluster-level prevalence) |
2RDT score - CHW scored > 17 correct steps on a 20-step checklist for RDT preparation and interpretation conducted 6 months after training |
3 CHW cited money, non-monetary incentives or desire for recognition as important motivators for their role as a CHW |
4 Client score was derived from four questions where the CHW reported how confident clients were in the testing they provided. |