1. systematic r e v i e w s Adam Dubrowski NUR 1022, Lecture 5

11. combining results

12. Meta-Analysis : statistical technique for quantitatively combining the results of multiple studies that measure the same outcomes into a single pooled summary estimate. Combining Results

13. Combining Results Study results are weighted by their sample size, which yields a weighted average. There is usually a statistical test of heterogeneity among study weighted means = is the between study variance greater than expected by chance?

14. Confidence Intervals: range between two values within which it is probably that the true value lies for the whole population of patients from which the study patients were selected. Differences Among Studies

18. Success of Publication Bias Authors decide that reporting a negative study is worthless and uninteresting. Report completion Interim analysis shows that a study is likely to be negative, and the study is dropped. Study completion No registries were kept of approved trials –this has recently changed. Institution/ Ethics Review Board approval Proposal selectively cites positive studies. Trial design, organization, and funding Small studies, which are more likely to be negative less likely to be published. Preliminary and pilot studies Actions Contributing to Bias Phases of research publication

19. Applying the Results to Patient Care