Systematic review and meta-analysis of the literature regarding the diagnosis of sleep apnea

To establish the evidence base for the diagnosis of sleep apnea (SA) in adu lt patients, a systematic review of the literature from 1980 through Novemb er 1, 1997 was performed. Diagnostic studies were included if they reported results of any test to establish or support a diagnosis of SA, in comparis on to a diagnosis from a full polysomnogram (PSG). Test results were meta-a nalyzed using fixed effects models and summary receiver operating character istic curves (ROCs) to examine consistency of tests within and between diag nostics vs. the "gold standard" of PSG. From a total of 937 studies, 249 fit the broad eligibility criteria for inc lusion in the clinical trial database and its data were extracted from thes e reports; useable data for statistical analyses were reported in 71 studie s (7,572 patients). The sensitivity and specificity of partial channel and partial time PSGs appeared most promising as replacements for full PSG in p atients suspected of obstructive SA. Clinical prediction rules (multivariat e models) were also promising. Studies of portable sleep monitors, radiolog ic or morphologic features, and focused questionnaires were too heterogeneo us to be meta-analyzed. In general, the diversity of study designs and objectives were very high an d the methodological rigor of these studies as assessments of diagnostic te sts was very low. Thus, we are still not in a position to recommend standar dization of diagnostic methodology for sleep apnea. Instead, our recommenda tions for future research include standardization of terms and diagnostic c riteria, and consistently reported statistics to enhance the utility of thi s literature.