Inter-observer reliability of candidate predictive morphometric measurements for women with suspected obstructive sleep apnea.

OBJECTIVE: Obstructive sleep apnea (OSA) is increasingly recognized as a public health concern. Definitive diagnosis is by overnight polysomnographic (PSG) examination. Identification of clinical predictors would be beneficial in helping prioritize high-risk patients for assessment. Practical application of morphometric predictive variables would require a high level of reproducibility in a clinical setting. In this study, our objective was to evaluate reliability between observers in measurements of candidate morphometric parameters in women. DESIGN AND METHODS: This was a prospective study of 71 women who had been referred for PSG with suspected OSA. Selected morphometric parameters were measured independently in the sleep laboratory by two trained sleep physicians.
RESULTS: Neck circumference and truncal measurements for lower costal, midabdominal, and hip circumferences had higher reliability coefficients (intraclass correlation coefficients [ICC] of 0.78, 0.95, 0.95, and 0.81) than the smaller dimension measurements, including cricomental distance or retrognathia (ICC of 0.04 and 0.17). Of the women participating in this study, 50 of 71 had apnea-hypopnea indexes (AHI) ≥ 5. Body mass index (BMI), neck circumference, lower costal girth, midabdominal girth, and hip girth were all significantly higher (p < 0.001-0.004) in women with AHI ≥ 5.
CONCLUSIONS: There was wide variation in inter-observer reliability for different physical dimensions. We propose that any clinical morphologic measurement employed in predictive modeling should be reliably reproducible in clinical setting conditions. Our findings support the use of several truncal measures, BMI, and neck circumference as predictive measures in women undergoing evaluation for OSA.