Purpose
To evaluate control group selection in non-randomized studies published in the Journal of Hand Surgery American (JHS).
Methods
We reviewed all papers published in JHS in 2013 to identify studies that used non-randomized control groups. Data collected included type of study design and control group characteristics. We then appraised studies to determine if authors discussed confounding and selection bias and how they controlled for confounding.
Results
Thirty-seven non-randomized studies were published in JHS in 2013. The source of control was either the same institution as the study group, a different institution, a database, or not provided in the manuscript. Twenty-nine (78%) studies statistically compared key characteristics between control and study group. Confounding was controlled with matching, exclusion criteria, or regression analysis. Twenty-two (59%) papers explicitly discussed the threat of confounding and 18(49%) identified sources of selection bias.
Conclusions
In our review of non-randomized studies published in JHS, papers had well-defined controls that were similar to the study group, allowing for reasonable comparisons. However, we identified substantial confounding and bias that were not addressed as explicit limitations, which might lead the reader to overestimate the scientific validity of the data.
Clinical relevance
Incorporating a brief discussion of control group selection in scientific manuscripts should help readers interpret the study more appropriately. Authors, reviewers, and editors should strive to address this component of clinical importance.