Table 3

Ordinary least squares (OLS) model estimates of treatment effects on self-reported postpartum utilisation of modern contraception

Treatment effects (risk differences)Use of any modern method (primary)Use of long-acting method
Model 1Model 2Model 1Model 2
Panel A Short-term postpartum utilisation of modern contraception, for N=537 study participants
 Short message service (SMS) only−0.02 (−0.20 to 0.16)−0.01 (−0.18 to 0.17)0.00 (−0.12 to 0.12)0.02 (−0.10 to 0.14)
 Standard voucher0.04 (−0.07 to 0.15)0.03 (−0.08 to 0.14)−0.02 (−0.09 to 0.06)−0.03 (−0.11 to 0.05)
 Standard voucher+SMS0.12 (−0.05 to 0.30)0.16 (−0.01 to 0.33)0.08 (−0.06 to 0.21)0.08 (−0.06 to 0.22)
 Deadline voucher0.04 (−0.08 to 0.15)0.06 (−0.06 to 0.18)0.02 (−0.06 to 0.11)0.03 (−0.06 to 0.12)
 Deadline voucher+SMS0.11 (−0.09 to 0.31)0.14 (−0.07 to 0.35)0.02 (−0.12 to 0.17)0.06 (−0.09 to 0.21)
 Reference level (%) (no voucher, no SMS)0.320.320.130.13
Panel B Medium-term postpartum utilisation of modern contraception, for N=418 study participants
 SMS only0.16 (−0.06 to 0.38)0.18 (−0.01 to 0.38)0.01 (−0.19 to 0.21)0.02 (−0.22 to 0.19)
 Standard voucher0.02 (−0.11 to 0.15)0.03 (0.10 to 0.16)0.01 (−0.11 to 0.13)0.01 (−0.11 ti 0.12)
 Standard voucher+SMS0.25 (0.06 to 0.44)0.26 (0.07 to 0.45)0.20 (−0.00 to 0.41)0.18 (−0.04 to 0.39)
 Deadline voucher−0.03 (−0.17 to 0.10)0.01 (−0.12 to 0.15)0.02 (−0.11 to 0.14)0.04 (−0.09 to 0.17)
 Deadline voucher+SMS0.08 (−0.16 to 0.32)0.09 (−0.14 to 0.32)0.06 (−0.16 to 0.28)0.05 (−0.18 to 0.29)
 Reference level (%) (no voucher, no SMS)0.580.580.270.27
  • OLS estimates are presented as risk differences (in proportions), with 95% CIs using robust SEs in italics and brackets. Model 1 includes only stratification variables. Model 2 includes stratification variables and controls for additional covariates described in the text. All treatment arms are compared with the standard of care arm (no voucher, no SMS) as the reference category. See table 1 notes for definition of modern and LARC contraception. Short-term and medium term are defined as 9 weeks and 22 weeks after EDD. See text and technical appendix for more detailed description of main outcomes.