Diagnostic test studies in nephrology: quantity, quality, and scope.

Background: Diagnostic errors represent an important cause of preventable harm in health care that may be reduced through evidence-based choice, use, and interpretation of diagnostic tests. We hypothesized that diagnostic errors are reduced through evidence-based choice, use, and interpretation of diagnostic tests. Study Design: Retrospective cohort study. Setting & Population: Diagnostic test studies. Selection Criteria for Studies: Publications from 1966-2008 retrieved from MEDLINE. Intervention: The Quality of Diagnostic Accuracy Studies (QUADAS) tool. Outcomes: Number and coverage of diagnostic studies in nephrology and methodological quality of the test accuracy subset. Results: Fewer diagnostic studies were published in nephrology than other areas of internal medicine, although the proportion of total citations that were diagnostic studies (4.9% +/- 2.8% [SD]) was not statistically different from other specialties (P = 0.2). Within nephrology, some topic areas (eg, urinary tract infections) were over-represented, whereas others (eg, acute kidney injury) had relatively few diagnostic studies (range, 2.7%-12.5%). Examining the randomly selected subset of studies that were diagnostic test accuracy studies (120) showed variable quality. Ninety-seven percent (116 of 120) of studies adequately described index test procedure, but only 27% (32 of 120) adequately blinded investigators to results of index tests, and 36% (43 of 120), to results of reference tests. The quality of nephrology diagnostic test accuracy studies has not improved substantially during the past 30 years. Limitations: Comparing nephrology with other specialties, some potential inequalities of scale could not be addressed, which may influence research output results across specialties. Conclusions: Diagnostic research in nephrology is published less frequently than most other medical specialties. The quality of diagnostic test accuracy studies that are published is variable and leaves room for improvement. Am J Kidney Dis. 58(6): 921-927. (C) 2011 by the National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.