TABLE 3

Treatment Success and Subgroup Analyses by Feeding Type

SubgroupDay 7Day 14Day 21
NNo. (%) SuccessesIncidence Ratio for Treatment Success (95% CI)aNNo. (%) SuccessesIncidence Ratio for Treatment Success (95% CI)aNNo. (%) SuccessesIncidence Ratio for Treatment Success (95% CI)a
AllbPlacebo15017 (11)2.08 (1.26 to 3.42)*14436 (25)1.98 (1.46 to 2.70)*14456 (39)1.71 (1.35 to 2.15)*
Probiotic15939 (25)15176 (50)14999 (66)
Breastfedb,c**Placebo11310 (9)3.03 (1.68 to 5.48)*11228 (25)2.27 (1.63 to 3.15)*11241 (37)2.07 (1.60 to 2.68)*
Probiotic11833 (28)11466 (58)11587 (76)
Formula fedc**Placebo377 (19)0.75 (0.27 to 2.15)328 (25)1.05 (0.45 to 2.47)3215 (47)0.73 0.39 to 1.36)
Probiotic416 (15)3710 (27)3412 (35)
  • Treatment success is a ≥50% reduction in crying and/or fussing time from baseline.

  • a Analyses adjusted for sex, age at enrollment, birth weight, birth type (vaginal versus cesarean), family history of atopy, and feeding type (except for subgroup analyses of feeding-type–specific effects).

  • b NNT estimates were computed by inverting adjusted differences in treatment success proportions and 95% CIs from linear-normal mixed effects models with robust SEs. The linear-normal model was used to overcome numerical convergence difficulties arising with a binomial or Poisson model specification. The NNT overall group is as follows: day 7 NNT = 7.9 (95% CI: 4.9 to 20.5); day 14 NNT = 4.0 (95% CI: 2.9 to 6.6); and day 21 NNT = 3.7 (95% CI: 2.6 to 6.0). The breastfed subgroup is as follows: day 7 NNT = 5.4 (95% CI: 3.7 to 10.0); day 14 NNT = 3.1 (95% CI: 2.3 to 4.8); and day 21 NNT = 2.6 (95% CI: 2.0 to 3.6).

  • c Treatment effects were statistically and significantly heterogeneous by feeding type across the 3 time points: F(3574) = 3.64.

  • * P < .05.

  • ** P = .01.