To the Editor:

The recent article by Rask et al1 indicates that study participants were randomly assigned to an intervention program. The final study results did not support the authors' hypotheses; this outcome may in fact be because of the limitation of the randomization process as applied in this study. For instance, 5 nurses originally assigned to the intervention group reported that they were unable to participate in the experimental group. The authors then considered them to be in the control group. I found this explanation to be lacking in detail and rationale. When researchers refer to using "random assignment," it seems that they mean to interpret their results as being the outcomes of the intervention, not the outcomes of the characteristic of participants. Although the authors were very honest in describing their process of using randomization, the concept of randomization is a basic principle for researchers. Perhaps the authors would have been better advised to instead use a "quasi-experimental study design" and discuss the clinical and contextual biases that they were attempting to control or avoid, noting the difficulties that they experienced with their design.

Including descriptions in research reports that focus on the methodological rigor of a study is necessary for us to critically review intervention studies. Some criteria might be useful for this and other research reports that include the use of randomization, use of interventions, or outcome studies without randomization. For example, helpful sources of such criteria include Newell's 10 internal validity indicators, which were developed to assess methodological rigor of psychological interventions for cancer patients,2 CONSORT for reports of randomized controlled trials,3 or TREND for nonrandomized design.4 Using such criteria will assist us, as readers, to have more confidence in the results of intervention studies and help us, as researchers, not to overestimate the treatment effects of our interventions. I do commend these authors for their transparency in reporting their randomization process.

-Yun-Hsiang Lee, MSN, RN

Doctoral Student

Department of Nursing

College of Medicine

National Taiwan University

Taiwan

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