Table 1.
Stillbirth rates during the pretrial (2010) and trial periods by ACT intervention group and site
| Pretrial period | ||||||||||||||||||
| Argentina | Guatemala | Pakistan | Belgaum | Nagpur | Kenya | Zambia | Total | |||||||||||
| Characteristica | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | RR (95 %)b | p-value |
| All babies, N | 1,439 | 1,437 | 2,981 | 2,321 | 5,481 | 7,101 | 8,675 | 9,649 | 5,206 | 4,958 | 3,994 | 5,209 | 2,986 | 4,188 | 30,762 | 34,863 | ||
| Stillbirths, N (Rate/1000)a | 28 (19.5) | 22 (15.3) | 67 (22.5) | 50 (21.5) | 295 (53.8) | 320 (45.1) | 255 (29.4) | 252 (26.1) | 148 (28.4) | 126 (25.4) | 84 (21.0) | 102 (19.6) | 101 (33.8) | 90 (21.5) | 978 (31.8) | 962 (27.6) | 1.17 (1.06,1.29) | 0.003 |
| <5th percentile for weight babies, N | 81 | 99 | 124 | 123 | 717 | 746 | 358 | 389 | 267 | 299 | 167 | 217 | 176 | 214 | 1,890 | 2,087 | ||
| <5th percentile stillbirths, N (Rate/1000)a | 16 (197.5) | 12 (121.2) | 27 (217.7) | 18 (146.3) | 214 (298.5) | 200 (268.1) | 150 (419.0) | 154 (395.9) | 90 (337.1) | 87 (291.0) | 36 (215.6) | 39 (179.7) | 54 (306.8) | 59 (275.7) | 587 (310.6) | 569 (272.6) | 1.15 (1.04, 1.28) | 0.008 |
| Trial period | ||||||||||||||||||
| Argentina | Guatemala | Pakistan | Belgaum | Nagpur | Kenya | Zambia | Total | |||||||||||
| Characteristica | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | Int | Cntl | RR (95 %)b | p-value |
| All babies, N | 2,122 | 2,311 | 5,863 | 3,978 | 7,800 | 8,315 | 15,022 | 16,774 | 7,570 | 7,655 | 5,993 | 7,187 | 4,328 | 5,787 | 48,698 | 52,007 | ||
| Stillbirths, N (Rate/1000)a | 25 (11.8) | 31 (13.4) | 113 (19.3) | 73 (18.4) | 388 (49.7) | 351 (42.2) | 376 (25.0) | 382 (22.8) | 158 (20.9) | 181 (23.6) | 145 (24.2) | 154 (21.4) | 99 (22.9) | 92 (15.9) | 1,304 (26.8) | 1,264 (24.3) | 1.11 (1.02–1.22) | 0.018 |
| Adjusted for pretrial SB rate 1.08 (0.99,1.17) |
0.073 | |||||||||||||||||
| <5th percentile for weight babies, N | 105 | 149 | 390 | 192 | 984 | 890 | 777 | 874 | 464 | 377 | 288 | 252 | 260 | 263 | 3,268 | 2,997 | ||
| <5th percentile stillbirths, N (Rate/1000)a | 14 (133.3) | 18 (120.8) | 44 (112.8) | 26 (135.4) | 224 (227.6) | 203 (228.1) | 244 (314.0) | 256 (292.9) | 107 (230.6) | 122 (323.6) | 53 (184.0) | 63 (250.0) | 62 (238.5) | 51 (193.9) | 748 (228.9) | 739 (246.6) | 0.99 (0.90–1.09) | 0.813 |
| Adjusted for pretrial <5th percentile for weight SB rate 0.97 (0.89, 1.05) |
0.409 | |||||||||||||||||
aThe trial period included births between October 2011 and March 2014, depending on each site’s 18-month enrollment period, with most births occurring in 2012 and 2013. Most births included in the pretrial period occurred in 2010. However, for the four clusters in Belgaum, India which were added after 2010, births from May 2011-May 2012 were included. Stillbirths are ≥ 20 weeks gestational age or ≥ 500 g. The denominator for the stillbirth rate is stillbirths + live births
bGeneralized linear models were used to evaluate the relationship between covariates and the outcomes of interest and to develop point and interval estimates of relative risk (RR) associated with these risk factors. Generalized estimating equations were used to account for the correlation of outcomes within cluster to develop appropriate confidence intervals. Models were log binomial when possible, otherwise Poisson models were utilized. Models were adjusted for randomization strata