Nursing interventions and patient outcomes: a meta-analysis of studies.

The 84 subject-studies and 4,146 individual subjects in this meta-analysis were obtained from nurse-conducted experimental research over an 8-year period. The entire universe of accessible subject-studies that met criteria was included. Although both published and unpublished research were included to protect the study from publication bias, there was no statistically significant difference in findings. The mean effect size for the sample of comparisons from the 84 studies was .59. The associated U3 value of 72.2 and r of .28 indicate that patients who receive research-based nursing interventions can expect 28% better outcomes than 72% of the patients who receive standard nursing care.