Nursing intervention studies: a descriptive analysis of issues important to clinicians

When reading a report of an intervention study, clinicians are interested in knowing: whether the intervention is effective, with whom it is effective, how much benefit it produces, and whether associated, adverse outcomes occur. Recommendations have been made in the research literature regarding how to conduct and report intervention studies so as to produce knowledge regarding these questions. This descriptive study was conducted to estimate the frequency with which these recommendations are being used in nursing intervention studies. Data pertinent to five research questions were extracted from 84 experimental and quasi-experimental study reports published between 1998 and 2000. Seventeen percent of the studies used a design that could statistically test for variation in intervention effect depending on the level of an individual characteristic. However, a test of interaction was actually conducted in only 8% of the studies. The magnitude of the intervention's effect was addressed in 38% of the study reports. Providing the proportion of persons in the intervention group who attained a discrete outcome was the most frequently used way of showing intervention magnitude. Associated, adverse outcomes were examined in 23% of the studies, and were most often measured as continuous variables. The low level of use of recommended methods leads the author to suggest dialogue between clinicians and researchers to determine if intervention studies are being conducted and reported in ways that produce knowledge that is useful to clinicians.