Figure 2. Posterior distribution of the effect of initial surgical treatment (Initial Laparotomy vs. Initial Drainage) on Death or Neurodevelopmental Impairment (NDI) at 18–22 months corrected age.

Posterior probability distributions of the adjusted risk ratio and risk difference (Initial Laparotomy minus Initial Drainage) derived by combining a prior distribution with trial results. The dashed blue line plots a neutral prior distribution centered at a risk ratio of 1.0, indicating that a priori an equal number of infants would be expected to benefit by either laparotomy or drainage. Light blue shaded areas indicate the posterior probability of reduced death or disability with initial laparotomy (benefit). Dark blue shaded areas indicate the posterior probability of increased death or disability with initial laparotomy (harm). The total area under each probability density curve equals 1. Among infants with a preoperative diagnosis of NEC (a and c), light blue areas indicate a 97% probability that death or NDI in infants treated with Laparotomy is less likely than in infants treated with initial drainage (benefit). Among infants with a pre-operative diagnosis of IP (b and d), the dark blue areas indicate the probability of death or disability among infants treated with Laparotomy is higher than for infants treated with Initial Drainage (harm).