Table 3.
Sensitivity analyses for seroprevalence at extremes of test performance
| Weighted seroprevalence, % (95% CI) | Weighted seroprevalence adjusted for test performance, % (95% CI) (Sensitivity 100.00%, specificity 99.63%) |
Weighted seroprevalence adjusted for test performance, % (95% CI) (Sensitivity 95.89%, specificity 99.90%) |
Weighted seroprevalence adjusted for test performance, % (95% CI) (Sensitivity 100.00%, specificity 99.05%) |
|
| Overall | 36.9 (34.5 to 39.4) | 36.7 (34.3 to 39.2) | 38.4 (35.9 to 41.0) | 36.3 (33.9 to 38.8) |
| Age (years) | ||||
| 18–29 | 33.7 (30.1 to 37.6) | 33.5 (29.8 to 37.4) | 35.1 (31.3 to 39.1) | 33.1 (29.4 to 37.0) |
| 30–49 | 36.3 (33.5 to 39.3) | 36.1 (33.3 to 39.1) | 37.8 (34.9 to 40.9) | 35.7 (32.9 to 38.7) |
| 50–69 | 42.5 938.8 to 46.2) | 42.3 (38.6 to 46.0) | 44.3 (40.4 to 48.1) | 41.9 (38.2 to 45.7) |
| ≥70 | 45.3 937.8 to 53.0) | 45.1 (37.6 to 52.8) | 47.2 (39.4 to 55.2) | 44.8 (37.2 to 52.5) |
| Gender | ||||
| Male | 36.1 (33.5 to 38.9) | 35.9 (33.3 to 38.7) | 37.6 (34.9 to 40.5) | 35.5 (32.9 to 38.3) |
| Female | 37.8 (34.5 to 41.30 | 37.6 (34.3 to 41.1) | 39.4 (35.9 to 43.0) | 37.2 (33.9 to 40.7) |
| Residence | ||||
| Urban | 40.2 (36.3 to 44.1) | 40.0 (36.1 to 43.9) | 41.9 (37.8 to 45.9) | 39.6 (35.7 to 43.6) |
| Rural | 35.5 (32.5 to 38.7) | 35.3 (32.2 to 38.5) | 37.0 (33.8 to 40.3) | 34.9 (31.9 to 38.1) |
| Self-reported history of chronic disease | ||||
| Yes | 43.2 (40.4 to 46.1) | 41.9 (37.4 to 46.6) | 43.6 (38.9 to 48.5) | 41.3 (36.8 to 46.1) |
| No | 37.8 (36.4 to 39.1) | 36.2 (33.7 to 38.9) | 37.7 (35.1 to 40.5) | 35.6 (33.1 to 38.3) |
| History of COVID-19-like symptoms | ||||
| Yes | 52.1 (47.6 to 56.6) | 47.4 (37.9 to 57.1) | 49.4 (39.5 to 59.5) | 46.9 (37.3 to 56.7) |
| No | 37.7 (36.4 to 38.9) | 36.3 (33.9 to 38.8) | 37.8 (35.3 to 40.4) | 35.7 (33.3 to 38.2) |
| History of contact with a known COVID-19 case | ||||
| Yes | 49.9 (45.2 to 54.5) | 45.2 (38.3 to 52.2) | 47.1 (39.9 to 54.4) | 44.7 (37.7 to 51.7) |
| No | 37.9 (36.7 to 39.2) | 36.5 (34.1 to 39.0) | 38.0 (35.5 to 40.6) | 35.9 (33.5 to 38.4) |
| Ever tested for COVID-19 (RT-PCR) | ||||
| Yes | 44.4 (41.5 to 47.4) | 41.0 (35.4 to 46.9) | 42.7 (36.9 to 48.9) | 40.4 (34.8 to 46.4) |
| No | 37.6 (36.2 to 38.9) | 36.2 (33.5 to 39.0) | 37.7 (34.9 to 40.6) | 35.6 (32.9 to 38.4) |
| RT-PCR result (n=1088*) | ||||
| Positive | 79.5 (73.0 to 84.9) | 81.8 (74.8 to 87.1) | 85.3 (78.0 to 90.8) | 81.6 (74.6 to 87.0) |
| Negative | 37.8 (34.7 to 41.0) | 38.8 (33.3 to 44.7) | 40.4 (34.7 to 46.6) | 38.2 (32.7 to 44.2) |
RT-PCR, reverse-transcriptase PCR.