The developed competent and simple designed ABQ, validated in Sleep Disordered Breathing Unit, Chest department Faculty of Medicine, Mansoura University, demonstrates that ABQ is an excellent tool for the estimation of OSA risk in patients referred to the outpatient clinic of Sleep Disordered Breathing Unit.
The predictive performance of the Berlin questionnaire for OSA varies greatly among different patient populations. In primary care patients, the sensitivity and specificity were found to be 86% and 77%, respectively, at a cutoff of AHI greater than 5, and 54% and 97%, respectively, at a cutoff of AHI greater than 15.[14
] In a group of patients preselected by excluding all patients with any typical symptoms of OSA or any comorbidity that could significantly increase the risk of having OSA, a modified version of the Berlin questionnaire showed a sensitivity of 86% and a specificity of 95% at a cutoff of AHI greater than 5.[13
] However, the sensitivity and specificity of the Berlin questionnaire were 62.5% and 53.8%, respectively, with a cutoff of AHI of 10 or greater in 153 patients undergoing pulmonary rehabilitation. In patients referred to a sleep laboratory, the Berlin questionnaire again showed a very low predictive value. The sensitivity and specificity of the Berlin questionnaire were 68% and 49%, respectively, at respiratory disturbance index greater than 5, 62% and 43%, respectively, at respiratory disturbance index greater than 10, and 57% and 43%, respectively, at respiratory disturbance index greater than 15.[22
Compared with the aforementioned studies, our results showed that the Arabic Berlin questionnaire had high levels of sensitivity and specificity in OSA-suspected patients (97% and 90%, respectively) and high positive and negative predictive values (96% and 93%, respectively). These findings provide initial evidence toward the reliability and validity of the Arabic Berlin questionnaire as screening tool for detection of OSA at-risk patient attending outpatient clinic for evaluation of OSA in the Arabic nations.
Our study does not agree with the recent study by Ahmadi et al
] who reported that the BQ performed with only 0.62 sensitivity and 0.43 specificity with large number of false negatives and positives but this study was a retrospectives; the BQ data were obtained from the charts of the patients, BQ had been completed by the patients before their initial consultation with a sleep specialist, and data were collected from large sleep clinic including the department of psychiatry of a tertiary care center; the patient population is very diverse and diagnosis includes various sleep disorders, not only OSA patient as in our study.
The results of this study were greater than finding in the previous studies.[14
] However, Netzer et al
] Who primarily validated the BQ in a primary care population reported a sensitivity and specificity of 86% and 77%, respectively, for prediction of OSA because of the following: First, they use RDI >5, which is less comparable with AHI ≥5 used in this research. The AHI is the total number of apneas and hypopneas per hour of sleep. The RDI is generally larger than the AHI, because the RDI considers the frequency of respiratory effort-related arousals, plus apneas and hypopneas.[24
Second, the mean BMI of the population in this study was 41.19 ± 10.70 in high-risk patients and BMI were >30 in 97.1% in high-risk patients that were much higher than that reported in the study of Ahmadi et al
] with mean BMI of 28; this increase the sensitivity and specificity of the ABQ, as the BMI also objective factor heavily into the of The ABQ.
Lastly, patients with OSA commonly endorse symptoms of EDS[25
] Hence, this study also determines the relationship between ABQ and Epworth sleepiness scale with significant comparison with each other. The questionnaire had symptoms about snoring, EDS, obesity, and hypertension. The population in this study was assessed for sleep-related breathing disorders. So, it was homogenous population.
Internal consistency of the Arabic version using alpha Cronbach's test of the three category items were 0.92 and both the first two categories were of good to excellent range. These results are somewhat comparable with the Sharma et al
. Report of internal consistency of 0.92 to 0.96 and Netzer et al
] who demonstrated internal consistency (Cronbach's a correlations[13
] 0.86 to 0.92).