Table 3. Mean levels of reported willingness to participate in surveys and blood tests by vignette.
| # | Task | Topic | Organization | Incentive | Mean (SD) | Median | 95% CI | Observations | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Blood Test | Diabetes | Local University | US $2 | 5.74 (1.74) | 6 | 5.55-5.92 | 359 | |
| 2 | Blood Test | Diabetes | Local University | US $2 voucher | 5.81 (1.58) | 6 | 5.64-5.98 | 341 | |
| 3 | Blood Test | Diabetes | Local University | Chance | 5.87 (1.58) | 6 | 5.71-6.03 | 371 | |
| 4 | Blood Test | Diabetes | Local University | No incentive | 5.78 (1.55) | 6 | 5.60-5.95 | 317 | |
| 5 | Blood Test | Diabetes | Ministry of Health | US $2 | 6.04 (1.37) | 6 | 5.89-6.19 | 319 | |
| 6 | Blood Test | Diabetes | Ministry of Health | US $2 voucher | 5.85 (1.62) | 6 | 5.67-6.02 | 336 | |
| 7 | Blood Test | Diabetes | Ministry of Health | Chance | 5.94 (1.46) | 6 | 5.78-6.10 | 325 | |
| 8 | Blood Test | Diabetes | Ministry of Health | No incentive | 5.80 (1.71) | 7 | 5.62-5.99 | 336 | |
| 9 | Blood Test | Diabetes | NGOa | US $2 | 5.76 (1.61) | 6 | 5.57-5.96 | 268 | |
| 10 | Blood Test | Diabetes | NGO | US $2 voucher | 5.95 (1.49) | 6 | 5.80-6.10 | 367 | |
| 11 | Blood Test | Diabetes | NGO | Chance | 5.79 (1.61) | 6 | 5.62-5.97 | 321 | |
| 12 | Blood Test | Diabetes | NGO | No incentive | 5.76 (1.73) | 6 | 5.58-5.94 | 356 | |
| 13 | Blood Test | Diabetes | Statistical Office | US $2 | 5.83 (1.57) | 6 | 5.65-6.01 | 283 | |
| 14 | Blood Test | Diabetes | Statistical Office | US $2 voucher | 5.77 (1.6) | 6 | 5.60-5.94 | 335 | |
| 15 | Blood Test | Diabetes | Statistical Office | Chance | 5.72 (1.63) | 6 | 5.53-5.90 | 313 | |
| 16 | Blood Test | Diabetes | Statistical Office | No incentive | 5.76 (1.54) | 6 | 5.60-5.92 | 354 | |
| 17 | Blood Test | HIV | Local University | US $2 | 5.70 (1.8) | 6 | 5.50-5.90 | 311 | |
| 18 | Blood Test | HIV | Local University | US $2 voucher | 5.84 (1.6) | 6 | 5.67-6.02 | 329 | |
| 19 | Blood Test | HIV | Local University | Chance | 5.70 (1.79) | 6 | 5.51-5.90 | 330 | |
| 20 | Blood Test | HIV | Local University | No incentive | 5.67 (1.7) | 6 | 5.49-5.86 | 316 | |
| 21 | Blood Test | HIV | Ministry of Health | US $2 | 5.78 (1.63) | 6 | 5.61-5.96 | 333 | |
| 22 | Blood Test | HIV | Ministry of Health | US $2 voucher | 5.81 (1.63) | 6 | 5.63-5.99 | 320 | |
| 23 | Blood Test | HIV | Ministry of Health | Chance | 6.00 (1.46) | 7 | 5.84-6.16 | 327 | |
| 24 | Blood Test | HIV | Ministry of Health | No incentive | 5.74 (1.67) | 6 | 5.57-5.91 | 365 | |
| 25 | Blood Test | HIV | NGO | US $2 | 5.93 (1.51) | 6 | 5.77-6.10 | 330 | |
| 26 | Blood Test | HIV | NGO | US $2 voucher | 5.90 (1.53) | 6 | 5.73-6.07 | 320 | |
| 27 | Blood Test | HIV | NGO | Chance | 5.85 (1.57) | 6 | 5.68-6.01 | 337 | |
| 28 | Blood Test | HIV | NGO | No incentive | 5.72 (1.7) | 6 | 5.54-5.91 | 327 | |
| 29 | Blood Test | HIV | Statistical Office | US $2 | 5.90 (1.51) | 6 | 5.75-6.05 | 378 | |
| 30 | Blood Test | HIV | Statistical Office | US $2 voucher | 5.92 (1.58) | 7 | 5.75-6.09 | 334 | |
| 31 | Blood Test | HIV | Statistical Office | Chance | 5.93 (1.53) | 6 | 5.76-6.09 | 335 | |
| 32 | Blood Test | HIV | Statistical Office | No incentive | 5.84 (1.49) | 6 | 5.67-6.01 | 295 | |
| 33 | Survey | Diabetes | Local University | US $2 | 5.90 (1.56) | 6 | 5.72-6.07 | 307 | |
| 34 | Survey | Diabetes | Local University | US $2 voucher | 5.95 (1.52) | 6 | 5.78-6.11 | 335 | |
| 35 | Survey | Diabetes | Local University | Chance | 5.91 (1.58) | 7 | 5.74-6.08 | 337 | |
| 36 | Survey | Diabetes | Local University | No incentive | 5.67 (1.68) | 6 | 5.49-5.85 | 335 | |
| 37 | Survey | Diabetes | Ministry of Health | US $2 | 5.82 (1.71) | 7 | 5.62-6.01 | 303 | |
| 38 | Survey | Diabetes | Ministry of Health | US $2 voucher | 5.96 (1.56) | 7 | 5.79-6.13 | 320 | |
| 39 | Survey | Diabetes | Ministry of Health | Chance | 5.81 (1.58) | 6 | 5.65-5.98 | 349 | |
| 40 | Survey | Diabetes | Ministry of Health | No incentive | 5.60 (1.69) | 6 | 5.43-5.78 | 359 | |
| 41 | Survey | Diabetes | NGO | US $2 | 5.96 (1.48) | 6 | 5.81-6.12 | 337 | |
| 42 | Survey | Diabetes | NGO | US $2 voucher | 5.99 (1.46) | 7 | 5.84-6.15 | 350 | |
| 43 | Survey | Diabetes | NGO | Chance | 5.88 (1.53) | 6 | 5.72-6.04 | 339 | |
| 44 | Survey | Diabetes | NGO | No incentive | 5.58 (1.74) | 6 | 5.39-5.77 | 316 | |
| 45 | Survey | Diabetes | Statistical Office | US $2 | 5.86 (1.52) | 6 | 5.7-6.03 | 317 | |
| 46 | Survey | Diabetes | Statistical Office | US $2 voucher | 5.85 (1.54) | 6 | 5.68-6.01 | 336 | |
| 47 | Survey | Diabetes | Statistical Office | Chance | 6.03 (1.49) | 7 | 5.86-6.20 | 301 | |
| 48 | Survey | Diabetes | Statistical Office | No incentive | 5.67 (1.67) | 6 | 5.50-5.85 | 353 | |
| 49 | Survey | HIV | Local University | US $2 | 5.88 (1.59) | 6 | 5.71-6.05 | 334 | |
| 50 | Survey | HIV | Local University | US $2 voucher | 5.87 (1.6) | 6 | 5.69-6.04 | 319 | |
| 51 | Survey | HIV | Local University | Chance | 5.88 (1.57) | 6 | 5.71-6.04 | 337 | |
| 52 | Survey | HIV | Local University | No incentive | 5.65 (1.64) | 6 | 5.48-5.83 | 356 | |
| 53 | Survey | HIV | Ministry of Health | US $2 | 6.03 (1.42) | 7 | 5.88-6.19 | 332 | |
| 54 | Survey | HIV | Ministry of Health | US $2 voucher | 5.87 (1.61) | 7 | 5.69-6.04 | 330 | |
| 55 | Survey | HIV | Ministry of Health | Chance | 6.09 (1.39) | 7 | 5.94-6.25 | 320 | |
| 56 | Survey | HIV | Ministry of Health | No incentive | 5.66 (1.69) | 6 | 5.48-5.85 | 333 | |
| 57 | Survey | HIV | NGO | US $2 | 5.96 (1.43) | 6 | 5.80-6.12 | 313 | |
| 58 | Survey | HIV | NGO | US $2 voucher | 5.99 (1.46) | 7 | 5.83-6.16 | 306 | |
| 59 | Survey | HIV | NGO | Chance | 5.79 (1.67) | 6 | 5.61-5.97 | 326 | |
| 60 | Survey | HIV | NGO | No incentive | 5.63 (1.8) | 6 | 5.44-5.82 | 337 | |
| 61 | Survey | HIV | Statistical Office | US $2 | 6.01 (1.46) | 7 | 5.86-6.17 | 347 | |
| 62 | Survey | HIV | Statistical Office | US $2 voucher | 5.98 (1.49) | 7 | 5.82-6.14 | 330 | |
| 63 | Survey | HIV | Statistical Office | Chance | 5.84 (1.73) | 7 | 5.65-6.02 | 341 | |
| 64 | Survey | HIV | Statistical Office | No incentive | 5.54 (1.7) | 6 | 5.36-5.73 | 333 | |
a
NGO: nongovernmental organization.