A meta-analysis of critical outcome variables in nonnutritive sucking in preterm infants.

The advantages and limitations of meta-analysis in clinical nursing research are explained and illustrated with five studies of nonnutritive sucking (NNS) in preterm infants. This article addresses steps of locating studies, systematic comparison of studies for like variables, and qualitative decisions needed before quantitative methods are applied to cumulate findings across studies. Several approaches of calculating effect size and confidence intervals were used to interpret the power of the treatment effect of NNS. On average, across the five NNS studies, NNS intervention reduced time to first bottle feeding by 2.9 days and days of hospitalization by 6.3 days.