Sample characteristics
The TB REACH repository included 222 projects (Figure 1). After excluding ineligible projects due to lack of CHW engagement (n=43), no ACF activities (n=12), and/or missing project impact indicator (n=7), we identified 123 eligible projects for invitation to the implementer’s survey. We received a total of 57 survey responses over six weeks. Seven projects were excluded due to significant externalities confounding project additionality (see Additional File 1, Table A3: Factors Affecting Additionality) for a final sample of 50 projects from 24 countries (Figure 2).
Pooled analysis provides a percentage additionality of 24·0% (95% CI 21·3% - 26·8%). The percentage additionality yield by projects ranged from -16·1% to 210·8% showing substantial heterogeneity (I2= 99·9%) (Figure 3). When segmenting the sample by additionality into tertiles, we found an average additionality of -2·7% for LI projects, 11·0% for MI projects, and 70·7% for HI projects. The average grant duration was 19·4 months (95% CI 18·0 - 20·9) with an average value of $502,345 (95% CI $433,136 - $571,553). The 50 projects employed a total of 13,991 CHWs with an average of 291 CHWs per project (range: 4 - 3558). These CHWs detected 58,717 TB cases, an average of 1174 per project. Of those detected, 19,481 would not have been identified without ACF activities through these projects. Approximately 68% of projects engaged CHWs to implement community-based active case finding, 6% employed CHWs in a health facility only, and 26% of projects had CHWs conduct activities in both settings. The high impact group had the highest mean number of total CHWs employed (311). 66% of projects were implemented in the African and Eastern Mediterranean WHO region, and 68% (34/50) were conducted in lower-middle income countries (68%).
Table 1
Characteristics of TB REACH projects associated with notification impact
|
LI
(n=15)
|
MI
(n=16)
|
HI
(n=19)
|
Total
(n=50)
|
p-value╪
|
% trend-adjusted additionality
|
0·3 (-7·7 - 3·6)
|
10 (6·8 - 14·4)
|
56·6 (23·9 - 83·2)
|
12·9 (3·8 - 33·6)
|
<0·001*
|
Average grant duration (months)
|
20·8
|
19·9
|
18·0
|
19·4
|
0·268
|
Average grant value (USD)
|
546,133
|
509,739
|
461,548
|
502,345
|
0·606
|
Type of project
|
Community-based active case finding (ACF) only
|
13 (71%)
|
9 (69%)
|
12 (65%)
|
34 (68%)
|
0·353
|
Facility-based ACF only
|
0 (0%)
|
2 (13%)
|
1 (6%)
|
3 (6%)
|
Community & Facility-based ACF
|
2 (29%)
|
5 (19%)
|
6 (29%)
|
13 (26%)
|
Peak number of community health workers (CHWs)3
|
70 (20 - 300)
|
55 (15 - 88)
|
86 (17·5 - 300)
|
60 (17·5 - 276)
|
0·354*
|
Total number of CHWs2
|
100 (20 - 450)
|
60 (25 - 120)
|
86 (17 - 86)
|
76 (20 - 425)
|
0·455*
|
Country regions20
|
Africa
|
7 (48%)
|
6 (38%)
|
8 (42%)
|
21 (42%)
|
0·643
|
Americas
|
2 (13%)
|
1 (6%)
|
0 (0%)
|
3 (6%)
|
South-East Asia
|
2 (13%)
|
4 (25%)
|
2 (10%)
|
8 (16%)
|
Europe
|
0 (0%)
|
1 (6%)
|
0 (0%)
|
1 (2%)
|
Eastern Mediterranean
|
2 (13%)
|
3 (19%)
|
7 (37%)
|
12 (24%)
|
Western Pacific
|
2 (13%)
|
1 (6%)
|
2 (10%)
|
5 (10%)
|
Project population
|
3,769,353
|
3,891,689
|
1,443,028
|
2,924,497
|
0·149
|
Tuberculosis care cascade
|
Number of people verbally screened3
|
150,918 (24,629 - 430,025)
|
95,036 (10,116 - 335,536)
|
175,837 (91,093 - 451,628)
|
106,831 (33,322 - 365,601)
|
0·258*
|
Number of sputum samples collected1
|
7,714 (3,784 - 19,562)
|
6,972 (1,592 - 12,023)
|
5,749 (3,721 - 9,705)
|
6,391 (3,531 - 12,082)
|
0·443*
|
World Bank income classifications21
|
Low
|
3 (20%)
|
6 (38%)
|
1 (5%)
|
10 (20%)
|
0·131
|
Lower-middle
|
9 (60%)
|
9 (56%)
|
16 (84%)
|
34 (68%)
|
Upper-middle
|
3 (20%)
|
1 (6%)
|
2 (11%)
|
6 (12%)
|
1: 1 (2%) respondent missing information on questions asked |
2: 2 (4%) respondent missing information on questions asked |
3: 5 (10%) respondent missing information on questions asked |
╪: Fisher’s exact test and chi-square tests: comparing proportions that is conditional on frequencies; ANOVA test: comparing means |
*: Median and Kruskal-Wallis test |
CHW model characteristics
Table 2 presents key characteristics of CHW models. Most projects (62%) reported that CHWs only performed TB-related activities. For projects on which CHWs performed other tasks, CHWs spent an average of 80% of their time on TB-related activities. The majority of projects (86%) had CHWs complete community outreach and verbal screening. Forty-three projects (88%) provided CHWs with formal written contracts, and 33 (77%) of those projects provided all their CHWs with undifferentiated contracts. Almost all projects conducted training using experts (94%), while roughly half involved peers (54%). Classroom-based training was more commonly used than community-based training (96% vs 64%). Electronic distance learning was used only by a minority of projects exclusively in the HI group (11%). Thirty-one projects hosted periodic refresher trainings (65%).
Table 2
Key characteristics of the community health worker models associated with notification impact
|
LI
(n=15)
|
MI
(n=16)
|
HI
(n=19)
|
Total
|
p-value╪
|
Implementation activities
|
Tuberculosis (TB) and other
|
6 (40%)
|
5 (31%)
|
8 (42%)
|
19 (38%)
|
0·790
|
TB only
|
9 (60%)
|
11 (69%)
|
11 (58%)
|
31 (62%)
|
% time spent on TB activities
|
77·3
|
85
|
77·9
|
80
|
0·649*
|
Community outreach1
|
13/15 (87%)
|
13/15 (87%)
|
16/19 (84%)
|
42/49 (86%)
|
1·00
|
Verbal screening1
|
13/15 (87%)
|
12/15 (80%)
|
17/19 (89%)
|
42/49 (86%)
|
0·730
|
HIV testing1
|
1/15 (7%)
|
1/15 (7%)
|
2/19 (11%)
|
4/49 (8%)
|
1·00
|
Sputum collection and transportation
|
12 (80%)
|
11 (69%)
|
13 (68%)
|
36 (72%)
|
0·712
|
Linkage to treatment
|
11 (73%)
|
9 (56%)
|
15 (79%)
|
35 (70%)
|
0·326
|
Treatment counseling
|
5 (33%)
|
7 (44%)
|
13 (68%)
|
25 (50%)
|
0·106
|
Recruitment and selection
|
Had prior experience2
|
11/15 (73%)
|
10/14 (71%)
|
13/19 (68%)
|
34/48 (71%)
|
0·951
|
Years of education3
|
12 (10 - 14)
|
12 (10 - 12)
|
10 (9 - 12)
|
12 (10 - 12)
|
0·378*
|
Provided written contracts
|
13 (87%)
|
15 (94%)
|
15 (79%)
|
43 (86%)
|
0·462
|
From TB REACH
|
7 (54%)
|
13 (87%)
|
8 (53%)
|
27 (65%)
|
0·095
|
From non-governmental organization
|
4 (31%)
|
2 (13%)
|
4 (27%)
|
10 (23%)
|
0·513
|
From government
|
2 (15%)
|
1 (7%)
|
3 (20%)
|
6 (14%)
|
0·655
|
Provided differentiated contracts5
|
10/12 (83%)
|
14/15 (93%)
|
9/15 (60%)
|
33/42 (79%)
|
0·075
|
Pre-service training¶
|
Training method
|
Expert
|
14 (93%)
|
15 (94%)
|
18 (95%)
|
47 (94%)
|
1·000
|
Peer-to-peer
|
10 (67%)
|
8 (50%)
|
9 (47%)
|
27 (54%)
|
0·495
|
Hands-on
|
14 (93%)
|
13 (81%)
|
17 (90%)
|
44 (88%)
|
0·652
|
E-learning
|
0 (0%)
|
0 (0%)
|
2 (11%)
|
2 (4%)
|
0·323
|
Training setting
|
Classroom-based
|
14 (93%)
|
15 (94%)
|
19 (100%)
|
48 (96%)
|
0·519
|
Community-based
|
8 (53%)
|
9 (56%)
|
15 (79%)
|
32 (64%)
|
0·223
|
Average hours of pre-service trainings4
|
12 (5 - 24)
|
12 (8 - 18)
|
16 (8 - 30)
|
16 (8 - 24)
|
0·366*
|
Refresher training¶
|
Formal refresher trainings2
|
9/13 (69%)
|
11/16 (73%)
|
11/19 (58%)
|
31/48 (65%)
|
0·646
|
Formal training method (n=31)
|
Expert
|
8 (89%)
|
11 (100%)
|
10 (91%)
|
29 (94%)
|
0·740
|
Peer-to-peer
|
7 (78%)
|
10 (91%)
|
4 (36%)
|
21 (36%)
|
0·019
|
Hands-on
|
6 (67%)
|
10 (91%)
|
8 (73%)
|
24 (77%)
|
0·437
|
E-learning
|
0 (0%)
|
0 (0%)
|
2 (18%)
|
2 (7%)
|
0·314
|
Formal training setting
|
Classroom-based
|
8 (89%)
|
10 (91%)
|
7 (64%)
|
25 (81%)
|
0·205
|
Community-based
|
4 (44%)
|
6 (55%)
|
7 (64%)
|
17 (55%)
|
0·692
|
Frequency of refresher trainings4
|
3 (1 - 4)
|
2 (2 - 4)
|
2 (2 - 4)
|
2 (2 - 4)
|
0·978*
|
Average hours of refresher trainings3
|
4 (3 - 8)
|
5 (3 - 8)
|
7 (3 - 8)
|
5·5 (3 - 8)
|
0·725*
|
Supervision
|
Issues addressed by direct supervisor4
|
13/15 (87%)
|
13/13 (100%)
|
16/19 (84%)
|
42/47 (89%)
|
0·420
|
Issues addressed by upper management4
|
3/15 (20%)
|
0/13 (0%)
|
4/19 (22%)
|
7/47 (15%)
|
0·197
|
Female supervisor (%)2
|
58·8
|
53·5
|
29·5
|
45·6
|
0·007
|
Average # community health workers (CHWs) per supervisor3
|
13 (7 - 26)
|
7 (6 - 10)
|
15 (5 - 60)
|
9 (6 - 25)
|
0·247*
|
Average # of supervisor reviews per quarter2
|
9 (3 - 12)
|
6 (3 - 12)
|
6 (3 - 12)
|
6 (3 - 12)
|
0·775*
|
Average # of supervisor direct feedback per quarter2
|
9 (3 - 12)
|
3 (1 - 12)
|
6 (4 - 12)
|
6 (3 - 12)
|
0·293*
|
Sustainability and integration
|
Promoted to a higher role
|
5/14 (36%)
|
8/13 (62%)
|
8/19 (42%)
|
21/46 (46%)
|
0·426
|
CHWs working on the project keep their jobs at the close of the project2
|
All kept their jobs after project
|
7/14 (50%)
|
1/15 (7%)
|
5/19 (26%)
|
13/48 (27%)
|
0·064
|
A subset kept their jobs after project
|
4/14 (29%)
|
11/15 (73%)
|
11/19 (58%)
|
26/48 (54%)
|
None kept their jobs after project
|
4/14 (29%)
|
2/15 (13%)
|
3/19 (16%)
|
9/48 (19%)
|
Continued with the same responsibilities (N=39)
|
8/11 (73%)
|
3/12 (25%)
|
13/16 (81%)
|
24/39 (62%)
|
0·007
|
Data are %, mean or median. % are calculated based on the total number of projects with available data. Percentages within each category are based on the total projects within each category. N sizes are listed for variables with missing values. |
1: 1 (2%) respondent missing information on questions asked |
2: 2 (4%) respondents missing information on questions asked |
3: 6 (12%) respondents missing information on questions asked |
4: 3 (6%) respondents missing information on questions asked |
5: 8 (16%) respondents missing information on questions asked |
╪: Fisher’s exact test and chi-square tests: comparing proportions that is conditional on frequencies; ANOVA test: comparing means |
*: Median (IQR) and Kruskal-Wallis test |
¶: As indicated by WHO CHW training guidelines, expert, peer-to-peer, and hands-on training indicates face-to-face interaction as opposed to distance learning (E-learning). Classroom-based training emphasizes theoretical knowledge; community-based training emphasizes practical application. |
Most projects cited that CHW performance issues were addressed by a direct supervisor (89%) rather than by upper management (15%). Projects employed slightly more male supervisors on average (54·4% male vs 45·6% female). Each supervisor oversaw an average of 33 CHWs, with a higher average in the high impact group (60). All or a subset of CHWs kept their jobs after the TB REACH project ended in 81% of projects.
There were select notable differences between the three impact groups. There was an inverse relationship between the number of projects that provided their CHWs with the same contracts rather than differentiated labor agreements. We measured a higher proportion of projects using community-based training in the HI group, while lower impact projects completed more peer-to-peer training (see Additional File 1, Table A6: Differentiated contracts stratified by impact level). Projects in the HI category employed male supervisors significantly more frequently. Finally, there was a significant relationship between CHWs continuing with the same responsibilities after the close of a project and project impact (p=0·007).
Table 3 shows the results of the univariate and multivariate linear regression. Full results from the univariate analysis are listed in Additional File 1, Table A3: Factors Affecting Additionality. Compared with projects that did not provide pre-service training through e-learning, projects that provided e-learning (β̂ =98·44, p<0·001) were associated with higher additionality. An increase of one CHW per supervisor is associated with a 0·35 increase in the project’s additionality.
Table 3
Associations between community health worker factors and project’s trend adjusted percent additionality
|
Univariate analysis (N= 50)
|
Multivariate analysis (N= 41)
|
n
|
Coef. (95% CI)
|
p-value
|
n
|
Coef. (95% CI)
|
p-value
|
Peak number of CHWs
|
45
|
0·05 (0·01 - 0·09)
|
0·022
|
41
|
0·005 (-0·04 - 0·05)
|
0·817
|
Total number of CHWs
|
48
|
0·03 (0·01 - 0·05)
|
0·013
|
41
|
0·008 (-0·01 - 0·03)
|
0·482
|
Pre-service training - E-learning
|
Yes
|
2
|
94·83 (29·65 - 160·01)
|
0·005
|
2
|
98·44 (44·82 - 152·06)
|
< 0·001
|
No
|
48
|
ref
|
|
39
|
|
|
Average CHWs per supervisor
|
44
|
0·38 (0·20 - 0·57)
|
<0·001
|
41
|
0·35 (0·12 - 0·58)
|
0·002
|
CHW compensation
Table 4 details compensation schemes employed on the TB REACH projects. Thirty-seven projects (74%) included or utilized a fixed component in their compensation, while 56% included or utilized variable compensation. The average total remuneration was US$ 153·31 per month. The average fixed component per month was US$ 124·44 and the average variable component per month was US$ 28·87. A breakdown of CHW compensation by income group and World Bank country income classification is provided in Additional File 1, Table A4: CHW compensation by fixed and variable component and World Bank country classification and Additional File 1, Table A5: CHWs compensation by World Bank country classification.
There was no significant difference in total, fixed or variable compensation across the three impact groups. The greatest average total compensation per month was provided by the MI group (US$ 201·62); the total compensation by LI and HI groups were comparable (US$ 127·77 and US$ 153·32, respectively). There was a larger proportion of projects from the HI and MI groups where CHWs were given priority access to disease testing (p=0·294).
Table 4
Monetary and non-monetary compensation of community health workers associated with notification impact
|
LI
(n=15)
|
MI
(n=16)
|
HI
(n=19)
|
Total
(n=50)
|
p-value╪
|
Monetary compensation
|
Earned only a fixed component (salary or stipend)
|
5 (33%)
|
6 (38%)
|
7 (37%)
|
18 (36%)
|
0·783
|
Earned only a variable component (incentives)1
|
3 (20%)
|
3 (19%)
|
2 (11%)
|
8 (16%)
|
Earned both a fixed and variable component
|
5 (33%)
|
7 (44%)
|
7 (37%)
|
19 (38%)
|
No monetary compensation
|
2 (13%)
|
0 (0%)
|
3 (16%)
|
5 (10%)
|
Average total compensation/month (USD)2
|
127·77
|
210·62
|
127·51
|
153·31
|
0·106
|
Average fixed compensation/month (USD)
|
97·31
|
172·31
|
107·61
|
124·44
|
0·219
|
Average variable compensation/month (USD)
|
30·46
|
38·31
|
19·91
|
28·87
|
0·523
|
Non-monetary incentives3
|
Priority access to TB/HIV or other disease testing
|
3/13 (23%)
|
4/12 (33%)
|
9/18 (50%)
|
16/43 (37%)
|
0·294
|
Health insurance
|
2/13 (15%)
|
1/11 (9%)
|
4/19 (22%)
|
7/43 (17%)
|
0·780
|
N sizes are listed for variables with missing values. |
1: 2 (4%) respondent missing information on questions asked |
2: 8 (16%) respondent missing information on questions asked |
3: 7 (14%) respondent missing information on questions asked |
╪ Fisher’s exact test and chi-square tests: comparing proportions that is conditional on frequencies; ANOVA test: comparing means |