Table 2.
Results of the validation of the methodology carried out using insectary-reared Anopheles coluzzii mosquitoes at LSHTM
| Time preserved (weeks) | Assessor 1 | Assessor 2 | IRRb | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Correctly identified as parous | Correctly identified as nulliparous | Correctly identified as parous | Correctly identified as nulliparous | |||||||||||
| n/N (prop.) | (95% CI) | Continuity- adjusted χ2a | n/N (prop.) | (95% CI) | Continuity- adjusted χ2a | n/N (prop.) | (95% CI) | Continuity-adjusted χ2a | n/N (prop.) | (95% CI) | Continuity- adjusted χ2a | |||
| Freshly killed | – |
65/66 (0.98) |
(0.95–1.00) | - | 68/70 (0.97) | (0.93–1.00) | - | 65/66 (0.98) | (0.92–1.00) | - | 68/70 (0.97) | (0.93–1.00) | - | 0.94 |
| Dry preserved and rehydrated | 1 | 43/54 (0.80) | (0.69–0.90) |
χ2 = 9.7, P = 0.002* |
44/45 (0.98) | (0.93–1.00) |
χ2 = 0.0, P = 1.000 |
60/65 (0.92) | (0.86–0.99) |
χ2 = 1.6, P = 0.203 |
43/45 (0.96) | (0.89–1.00) |
χ2 = 0.0, P = 1.000 |
0.83 |
| 2 | 48/58 (0.83) | (0.73–0.92) |
χ2 = 7.6, P = 0.006* |
48/51 (0.94) | (0.88–1.00) |
χ2 = 0.1, P = 0.716 |
70/76 (0.92) | (0.86–0.98) |
χ2 = 1.8, P = 0.173 |
45/52 (0.87) | (0.77–0.96) |
χ2 = 3.5, P = 0.062 |
0.76 | |
| 6 | 53/59 (0.90) | (0.82–0.97) |
χ2 = 2.9, P = 0.087 |
42/49 (0.86) | (0.76–0.95) |
χ2 = 3.6, P = 0.058 |
55/58 (0.95) | (0.89–1.00) |
χ2 = 0.4, P = 0.522 |
40/49 (0.82) | (0.71–0.92) |
χ2 = 6.5, P = 0.011* |
0.79 | |
| 9 | 60/67 (0.90) | (0.82–0.97) |
χ2 = 3.2, P = 0.072 |
46/48 (0.96) | (0.90–1.00) |
χ2 = 0.9, P = 0.362 |
62/66 (0.94) | (0.88–1.00) |
χ2 = 0.8, P = 0.362 |
41/46 (0.89) | (0.80–0.98) |
χ2 = 3.2, P = 0.072 |
0.87 | |
| 12 | 49/53 (0.92) | (0.82–0.98) |
χ2 = 0.4, P = 0.242 |
38/48 (0.79) | (0.65–0.89) |
χ2 = 8.2, P = 0.004* |
50/52 (0.96) | (0.91–1.00) |
χ2 = 0.04, P = 0.833 |
45/48 (0.94) | (0.87–1.00) |
χ2 = 1.2, P = 0.665 |
0.77 | |
CI Confidence interval, prop. proportion
* Significant difference between correctly identified parity status of freshly killed and preserved mosquitoes at that time point
adf = 1 for all continuity-adjusted chi-square tests
bInter-rater reliability (IRR) calculated using Cohen’s kappa statistic [21]