USE OF METHODOLOGICAL STANDARDS IN DIAGNOSTIC-TEST RESEARCH - GETTINGBETTER BUT STILL NOT GOOD

Objective.-To determine the frequency and temporal changes in applicat ion of seven accepted methodological standards for the evaluation of d iagnostic tests.Data Sources.-A search of the MEDLINE database yielded 1302 articles about diagnostic test studies, during a 16-year secular interval, 1978 through 1993, in four prominent general medical journa ls. Study Selection.-In the 112 eligible studies, the test was intende d for clinical use, indexes of accuracy (sensitivity and specificity o r likelihood ratios) were provided, and more than 10 patients were enr olled. Data Extraction.-Although each study was critically reviewed by one primary observer, a subset was independently evaluated for interr ater consistency. Data Synthesis.-The percentage of studies that fulfi lled criteria for each of the seven methodological standards are as fo llows: (1) specify spectrum of evaluated patients, 27%; (2) report tes t indexes for clinical subgroups, 8%; (3) avoid workup bias, 46%; (4) avoid review bias, 38%; (5) provide numerical precision for test index es, 11%, (6) report frequency and management of indeterminate results when calculating test indexes, 22%; and (7) specify test reproducibili ty, 23%. Secular increases were found for six of the seven standards i n ranges of use from 14% to 31% during 1978-1981 to 1990-1993. Neverth eless, only one standard, avoidance of workup bias, was fulfilled by m ore than 50% of studies in the most recent secular interval. Conclusio ns.-These results indicate that most diagnostic tests are still inadeq uately appraised. The routine demand for methodological standards coul d raise the quality of diagnostic test information, and the careful pr edissemination evaluation of diagnostic tests could eliminate useless tests before they receive widespread application.