Table 2 Frequency of nonadherence types per interval and cumulative probability of adherence to ART among a cohort of mothers (N = 1572) and NVP among a cohort of infants (N = 2370) from 6 weeks to 18 months postpartum in South Africa followed in 2012–2014 (unweighted)
Follow-up intervals from 6 weeks to 18 months postpartum | ||||||
|---|---|---|---|---|---|---|
6 weeks - 14 weeks | 14 weeks - 6 months | 6 months - 9 months | 9 months - 12 months | 12 months - 15 months | 15 months - 18 months | |
Adherence to ART among mothers reported on ART | ||||||
Total number of mothers entering interval | n = 1026 | n = 902 | n = 866 | n = 833 | n = 800 | n = 832 |
Cumulative probability of adherencea | 85.0 (82.8–87.0) | 79.1 (76.6–81.4) | 74.2 (71.6–76.6) | 71.1 (67.0–72.2) | 67.3 (64.6–69.9) | 63.4 (60.7–66.0) |
Total adherence events during interval | 861 | 820 | 801 | 777 | 749 | 763 |
Total nonadherence events during interval | 165 | 82 | 65 | 56 | 51 | 69 |
Taking ART but missed > 5% doses | 25 (15.2) | 17 (20.7) | 17 (26.2) | 9 (16.1) | 8 (15.7) | 8 (11.6) |
Stopped taking ART during interval (not according to care) | 140 (84.8) | 65 (79.3) | 48 (73.8) | 47 (83.9) | 43 (84.3) | 61 (88.4) |
Mothers not included in the analysis at each stage and reason for exclusion | ||||||
Total number of mothers not reporting on ART at interval | n = 546 | n = 670 | n = 706 | n = 739 | n = 772 | n = 740 |
Missed interview | 462 (84.6) | 508 (75.8) | 528 (74.8) | 544 (73.6) | 542 (70.2) | 473 (63.9) |
Non-mother caregiver gave interview | 84 (15.4) | 92 (13.7) | 94 (13.3) | 111 (15.0) | 150 (19.4) | 185 (25.0) |
No longer on ART | 0 (0.00) | 70 (10.5) | 84 (11.9) | 84 (11.4) | 80 (10.4) | 82 (11.1) |
Adherence to NVP among infants reported on NVP | ||||||
Total number of infants assessed for adherence in interval | n = 1145 | n = 702 | n = 426 | n = 248 | n = 125 | n = 52 |
Cumulative probability of adherencea | 96.4 (94.3–97.8) | 92.3 (89.8–94.2) | 88.8 (85.9–91.2) | 86.9 (83.6–89.6) | 81.6 (76.9–85.5) | 74.5 (70.2–81.9) |
Total adherence events during interval | 1102 | 670 | 403 | 236 | 113 | 49 |
Total nonadherence events during interval | 43 | 32 | 23 | 12 | 12 | 3 |
Taking ART but missed > 5% doses | 8 (18.6) | 12 (37.5) | 5 (21.7) | 3 (25.0) | 5 (41.7) | 0 (0.0) |
Stopped taking NVP during interval (not according to care) | 35 (81.4) | 20 (62.5) | 18 (78.3) | 9 (75.0) | 7 (58.3) | 3 (100.0) |
Infants not included in the analysis during each interval and reason for exclusion | ||||||
Total number of infants not reporting on NVP at interval | n = 1225 | n = 1668 | n = 1944 | n = 2122 | n = 2245 | n = 2318 |
Missed interview | 338 (27.6) | 405 (24.3) | 437 (22.5) | 448 (21.1) | 425 (18.9) | 389 (16.8) |
Appropriately stopped NVP | 887 (72.4) | 1263 (75.7) | 1507 (77.5) | 1674 (78.9) | 1821 (81.1) | 1929 (83.2) |
Never breastfed during interval | 850 (95.8) | 1183 (93.7) | 1404 (93.2) | 1542 (92.1) | 1678 (92.2) | 1784 (92.5) |
Clinician said to stop NVP | 37 (4.2) | 80 (6.3) | 103 (6.8) | 132 (7.9) | 143 (7.8) | 145 (7.5) |