Assessing quality of a diagnostic test evaluation.

OBJECTIVE: To develop a standardized scale for assessing the quality of a diagnostic test evaluation. DESIGN: Fourteen participants with formal and practical experience in evaluating diagnostic tests formed a consensus panel. Panel members identified and weighted questions that should be addressed when assessing the quality of a diagnostic test evaluation. SETTING: General internal medicine division at an academic medical center. RESULTS: A 19-item weighted scale was developed. It prioritizes and addresses issues such as description of the proposed purpose of the test; appropriate selection and description of the study population; appropriate performance and description of the diagnostic test; appropriate selection and performance of the reference standard; and adequate presentation of test characteristics. CONCLUSIONS: The scale is proposed as a useful instrument for readers, investigators, reviewers, and editors, because it represents an updated synthesis of important criteria to consider when evaluating diagnostic tests. It can also be used to rate quantitatively the quality of diagnostic test evaluations.

Captopril-stimulated renin secretion in the diagnosis of renovascular hypertension.

Evidence concerning the clinical utility of single dose captopril in the diagnosis of renovascular hypertension was evaluated. Of 173 identified papers, 16 were specifically selected because they used single dose oral captopril and obtained pre-dose and post-dose peripheral renin levels in at least one patient with renovascular hypertension. These 16 studies were appraised independently by three reviewers using standardized forms for evaluation of diagnostic tests. The 16 studies included 805 patients. All studies involved referred hypertensive populations; detailed demographics and clinical characteristics were not provided. Captopril test procedures varied in all studies. Thirteen of 16 studies used arteriography as a gold standard for the diagnosis of renovascular hypertension, and three of 16 used surgical outcome data. In ten studies, patients with renovascular hypertension clearly had a significantly greater increase in plasma renin activity than patients with essential hypertension. In the remaining six, plasma renin activity was increased in patients with renovascular hypertension but control comparisons were not made adequately. Existing data suggest that the captopril test may be useful in identifying patients with renovascular hypertension. However, specific clinical recommendations regarding its use cannot be made until future research better defines test cutoff points and identifies which patients are most likely to benefit from the test.