DiTA: helping you search for evidence of diagnostic test accuracy in physical therapy.

BACKGROUND: Physical therapists use diagnostic tests in a variety of settings. Choosing the best diagnostic test to apply in a particular situation can be difficult. The choice of diagnostic test should be informed, at least in part, by evidence of test accuracy. Finding evidence of diagnostic test accuracy has, until recently, been challenging. Ideally, there would exist a database that comprehensively indexes evidence on diagnostic tests relevant to physical therapy practice, is free to access, and is easy to use. OBJECTIVE: This Masterclass will describe the DiTA (Diagnostic Test Accuracy) database (dita.org.au) including its development and search interface, and provide advice on how to search and retrieve records. DISCUSSION: DiTA indexes more than 2400 primary studies and systematic reviews of diagnostic test accuracy relevant to physical therapy practice. Users can search DiTA using text fields and dropdown lists to find evidence of diagnostic test accuracy. The database is freely accessible on the internet. Since its launch, DiTA has been accessed from almost every country in the world, the largest number of searches having been conducted from Brazil.

A description of the primary studies of diagnostic test accuracy indexed on the DiTA database.

BACKGROUND AND PURPOSE: PEDro (the Physiotherapy Evidence Database) is a widely used, comprehensive, freely available, online database that indexes studies of the effectiveness of physiotherapy interventions. We have recently built another database, called DiTA, on the same platform as PEDro. DiTA provides a comprehensive index of studies of the accuracy of diagnostic tests used by physiotherapists. This study aims to describe the number and scope of such studies. METHODS: A comprehensive search was conducted for studies of the accuracy of diagnostic tests. The search was conducted on the MEDLINE, EMBASE and CINAHL databases from their inceptions to November 2018. Subsequently, monthly searches have updated the database. To be included on DiTA, studies need to investigate (a) both a pathology and patients that a physiotherapist could assess in clinical practice, and (b) an index test that a physiotherapist would perform themselves rather than one which they would request. RESULTS: To date, the searches have yielded 44,884 titles. Screening has identified 1,419 reports that meet the inclusion criteria. The most frequently studied subdisciplines are "musculoskeletal" (1,050/1,419; 74.0%) and "cardiothoracics" (241; 17.0%); the most frequently studied categories of pathologies are joint pathologies (463; 32.6%) and nervous system pathologies (175; 12.3%); and the most frequently studied body part is the "lower leg or knee" (232; 16.3%). Most studies investigate index tests which are "physical examination" procedures (851; 60.0%); fewer investigate "questions or questionnaires" (420; 29.6%) and "health technologies" (351; 24.7%). DISCUSSION: There is a rapidly growing body of evidence on the accuracy of diagnostic tests relevant to most physiotherapy subdisciplines. While the volume of evidence is substantial, it is not yet clear how much of the evidence is of good enough quality to support clinical decision-making.

Measurement properties of quality assessment tools for studies of diagnostic accuracy.

OBJECTIVES: To determine the reliability, internal consistency, measurement error, convergent validity, and floor and ceiling effects of three quality assessment tools commonly used to evaluate the quality of diagnostic test accuracy studies in physical therapy. A secondary aim was to describe the quality of a sample of diagnostic accuracy studies. STUDY DESIGN AND SETTING: 50 studies were randomly selected from a comprehensive database of physical therapy-relevant diagnostic accuracy studies. Two reviewers independently rated each study with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS), Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) and Diagnostic Accuracy Quality Scale (DAQS) tools in random sequence. RESULTS: Only 7% of QUADAS items, 14% of QUADAS-2 items, and 33% of DAQS items had at least moderate inter-rater reliability (kappa>0.40). Internal consistency and convergent validity measures were acceptable (>0.70) in 33% and 50% of cases respectively. Floor or ceiling effects were not present in any tool. The quality of studies was mixed: most avoided case-control sampling strategies and used the same reference standard on all subjects, but many failed to enroll a consecutive or random sample of subjects or provide confidence intervals about estimates of diagnostic accuracy. CONCLUSION: The QUADAS, QUADAS-2 and DAQS tools provide unreliable estimates of the quality of studies of diagnostic accuracy in physical therapy.