How Often Do Orthopaedic Matched Case-Control Studies Use Matched Methods? A Review of Methodological Quality

Area of Science:

• Orthopaedic research methodology
• Biostatistics in clinical studies
• Epidemiological study design

Background:

• Case-control studies are frequently used in orthopaedics to analyze associations between clinical outcomes and risk factors.
• Matching cases to controls can reduce bias and increase precision but requires appropriate statistical methods.
• The use of matched statistical methods in orthopaedic case-control studies has not been well-documented.

Purpose of the Study:

• To determine the proportion of matched orthopaedic case-control studies that employ appropriate matched statistical analyses.
• To identify study factors associated with the correct application of matched statistical tests in this field.

Main Methods:

• A literature review identified matched case-control studies in the top 10 orthopaedic journals (2007-2016).
• Two independent evaluators assessed the appropriateness of statistical techniques, with a third resolving discrepancies.
• Logistic regression analyzed associations between study factors (journal, year, matching factors, controls per case, statistician coauthor) and appropriate method use.

Main Results:

• Of 83 included studies, only 36% used appropriate matched methods throughout; 51% used inappropriate unmatched methods.
• Inclusion of a statistician coauthor was significantly associated with the use of appropriate methods (OR=3.6, P=0.01).
• Journal and publication year also influenced the likelihood of using appropriate statistical techniques.

Conclusions:

• The majority of orthopaedic case-control studies utilize inappropriate statistical methods, potentially leading to biased or imprecise results.
• A significant number of studies were misclassified, highlighting the need for clearer definitions of study designs.
• Researchers are urged to consult biostatistical experts to ensure methodological rigor in matched analyses.