Using Self-Reported Questionnaire Data to Prioritize OSA Patients for Polysomnography

Abstract

Many laboratories have large numbers of patients with suspected obstructive sleep apnea (OSA) waiting to be tested. We assessed the use of simple clinical data to detect those patients with an apnea index <20 (low AI) who could be studied less emergently. Using questionnaires completed by patients prior to evaluation, we collected data on 354 consecutive patients (281 males, 73 females; mean age 48.6 years) referred for OSA and assessed with polysomnography (PSG). The questionnaires included the Epworth sleepiness scale (ESS), height, weight, age, and a history of observed apnea. Analysis of receiver operating characteristics curves revealed that both body mass index (BMI) [area under curve = 0.7258, standard error (SE) = 0.03, p < 0.01] and ESS (area under curve = 0.5581, SE = 0.03, p = 0.03) were significantly better than chance alone in detecting people with AI < 20. ESS < or =12 was found in 37.9% of the subjects but 39.6% of those expected to have a low AI using ESS had an AI > or =20. A BMI < or =28 was found in 24.9% of the subjects; 14.8% of those expected to have a low AI using BMI had an AI > or =20. Combining these variables improved accuracy but resulted in smaller groups; a cut-off of ESS < or =12 and BMI < or =28 resulted in a group of 33 (9.3% of subjects), only two (6%) of whom were falsely called low AI. Adding to this the fact that apnea had not been observed resulted in a group of nine patients (2.5% of subjects), none of whom had an AI > or =20. Thus there is a tradeoff; the more variables used, the greater the accuracy but the smaller the percent of cases selected to have low AI. However, in laboratories with hundreds of patients waiting to be tested, any procedure better than chance to help prioritize patients seems worthwhile.

A systematic review of screening questionnaires for obstructive sleep apnea

“…The characteristics of the included studies are summarized in Table 1. The excluded studies 11,[16][17][18][19][20][22][23][24] and the reasons for their exclusion are listed in Table 2.…”

“…Studies were excluded from the review if there was inadequate information to draw the 2 by 2 contingency tables (seven papers). 11,[16][17][18][19][20] A validated computer program for meta-analysis of test accuracy data (Meta-DiSc, 21 version 1.4, Hospital Ramony Cajal, Madrid, Spain) was used to describe the overall accuracy of the questionnaires and to assess inconsistencies in accuracy parameters (sensitivity and specificity) across studies (heterogeneity). Accuracy parameters with a similar target population were analyzed together (sleep-disorder patients vs patients without history of sleep disorders).…”

German Version of the Epworth Sleepiness Scale

“…For assessment of the test-retest variability, the mean difference (± SD) of the scores was determined [19]. The performance of the ESS in prioritising patients with obstructive sleep apnea for sleep studies was evaluated by plotting receiver operating characteristics (ROC) curves [10, 20]. A probability of p < 0.05 was considered statistically significant.…”

“…In patients with obstructive sleep apnea, ESS scores reflect the degree of breathing disturbance [4]and they have been employed to assess treatment effects in sleep apnea [5, 8]and narcolepsy [9]. Furthermore, the ESS has been proposed as a means to prioritise patients for sleep studies [10], and to estimate the risk for car drivers of being involved in traffic accidents [11]. The ESS is now widely accepted and employed in English-speaking countries.…”

Obstructive sleep apnea, detected by the Berlin Questionnaire: an associated risk factor for coronary artery disease

“…Nonetheless its availability is still limited worldwide. To circumvent this limitation, questionnaires have been developed to screen for OSA 16 . They are easily administered, inexpensive, applicable in large surveys, and useful for screening a diagnosis of OSA.…”