Predictive diagnostic value of clinical assessment and nonlaboratory monitoring system recordings in patients with symptoms suggestive of obstructive sleep apnea syndrome.
Obstructive sleep apnea syndrome (OSA) is of increasing importance because of its high prevalence and danger of morbidity to untreated patients. Diagnostic procedures need simplification. We evaluated the qualitative value of a stepwise diagnostic approach using clinical assessment and a home-based screening device according to current recommendations.


METHODS
We investigated 114 patients with symptoms suggestive of obstructive sleep apnea syndrome by means of their clinical features, questionnaire responses, four-channel nonlaboratory monitoring (NLM) and full polysomnography. Operative indices in the diagnosis of OSA were calculated.


RESULTS
A significant correlation (r = 0.7: p < 0.0001) was found between the oxygen desaturation index (ODI) and the respiratory disturbance index (RDI). The calculation of the difference between ODI by NLM and RDI by polysomnography showed a lack of agreement. Home-based monitoring revealed a high sensitivity (94%) but a low specificity (41%) in diagnosing OSA. However, a combination of clinical features, questionnaires and pulse oximetry achieved a specificity of 92%.


CONCLUSIONS
Home-based monitoring provides reasonable negative predictive values in the diagnosis of OSA syndrome in symptomatic patients. It therefore qualifies as a screening method. Combined with clinical features and questionnaires it provides high positive predictive values and may therefore prove useful in simplifying diagnostic procedures.
Schäfer
H
H
Department of Internal Medicine, University of Boun, Germany.
Ewig
S
S
Hasper
E
E
Lüderitz
B
B
D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D010092:Oximetry; D010101:Oxygen Consumption; D017286:Polysomnography; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000503:physiopathology / Q000517:prevention & control*; D011795:Surveys and Questionnaires