Overview of systematic reviews of diagnostic test accuracy studies in physical therapy

Background: Systematic reviews are potentially less biased and provide more precise estimates than primary studies of diagnostic test accuracy. Their use to inform evidence-based diagnosis is rapidly expanding. However, the extent, scope and methodologies of systematic reviews of studies of the accuracy of diagnostic tests relevant to physical therapy have not yet been described. Information about methods used in these systematic reviews could inform future reviews and subsequently improve evidence-based diagnosis in physical therapy.   Objectives: To describe the systematic review methodology of diagnostic test accuracy studies relevant to physical therapy. Methods: All systematic reviews indexed on DiTA (Diagnostic Test Accuracy database) were included. Data on methodology, reporting characteristics, and review topics were extracted. A random sample was assessed for risk of bias using the Risk Of Bias In Systematic Reviews (ROBIS) tool.   Results: The review included 241 reviews published between 1995 and 2022, covering all 10 major physical therapy subdisciplines, although 90% related to musculoskeletal physical therapy. In 72% of reviews, QUADAS and QUADAS-2 were used to assess the risk of bias. In a random sample of included reviews, 47% of reviews displayed a ‘high’ risk of bias.   Conclusions: Systematic reviews of diagnostic test accuracy studies relevant to physical therapists are becoming more prevalent. There is a relatively large number of these reviews however a large proportion use methods that expose them to bias. This makes the interpretation of their results more difficult. Future research could focus on publishing methodology guidelines for physical therapy-relevant diagnostic test accuracy reviews.