Table 1.
Characteristics of Included Women at Time of First Dried Blood Spot Sample
| TFV-DP Concentration in DBS (fmol/punch) | ||||||||
|---|---|---|---|---|---|---|---|---|
| All Participants (N = 81) | Cases (n = 61) | Controls (n = 20) | <350 (n = 3) | 350–699 (n = 8) | 700–1249 (n = 38) | 1250–1849 (n = 22) | ≥1850 (n = 10) | |
| Median age (IQR), years | 29 (26–32) | 28 (26–31) | 30 (26–33) | 28 (27–30) | 24 (21–27) | 30 (27–33) | 28 (25–33) | 29 (27–31) |
| Median months on ART (IQR) | 16 (14–20) | 16 (14–20) | 16 (14–20) | 15 (12–18) | 19 (15–22) | 15 (14–20) | 17 (14–20) | 17 (11–22) |
| Median days postpartum (IQR) | 19 (9 - 88) | 18 (9–89) | 23 (9–55) | 39 (6-93) | 55 (5-91) | 14 (9– 52) | 16 (10–42) | 89 (29–91) |
| Attended high school, n (%) | 80 (99) | 60 (98) | 20 (100) | 2 (67) | 8 (100) | 38 (100) | 22 (100) | 10 (100) |
| Employed and/or studying, n (%) | 25 (31) | 19 (32) | 6 (30) | 1 (33) | 4 (50) | 5 (13) | 10 (46) | 5 (50) |
| Married or cohabiting, n (%) | 35 (43) | 24 (39) | 11 (55) | 0 (0) | 4 (50) | 16 (42) | 12 (55) | 3 (30) |
| Previous ART use (ART or PMTCT), n (%) | 20 (25) | 13 (21) | 7 (35) | 0 (0) | 0 (0) | 14 (37) | 4 (18) | 2 (20) |
N = 81. All women were on tenofovir, emtricitabine, and efavirenz taken once daily as a fixed-dose combination and all women had a VL <20 copies/mL at first DBS by design.
Abbreviations: ART, antiretroviral therapy; DBS, dried blood spot; IQR, interquartile range; PMTCT, prevention of mother-to-child transmission; TFV-DP, tenofovir diphosphate.