Psychomotor vigilance task- objective sleep disorder screening tool for Indian population

Abstract

Introduction / Objective: The primary objective of the current pilot observational study was to establish feasibility and acceptability of sleep disorder screening tools, viz, Epworth Sleepiness Scale (ESS) and Psychomotor Vigilance Task (PVT) in Indian Population. The study also aimed to compare the sensitivity and specificity of both the screening tests. The outcome of the study will provide the threshold values for PVT to determine positive and negative diagnosis. Method: It was a community based study in clinical settings. Patients visiting sleep clinic during period of year August 2011 to year September 2012 formed the study population.The sample population included 66 patients; 49 males and 17 females with mean age of 45 (age range 14-75). All subjects administered ESS as well as 10 minute PVT followed by confirmatory tools such as Nocturnal Polysomnogram, MSLT and Actigraphy. ESS score >10 was considered positive. The presence of any of intrinsic or extrinsic sleep disorder is considered a positive diagnosis. Bayesian theorem was applied to determine sensitivity and specificity of tests administered. Results: Sensitivity of PVT was found to be high as 90.16 % as compared to that of ESS as 39.3%. However the specificity for both the tests was found to be equal at 100%. Among PVT measurements, number of lapses and average reaction time were found to be co-relating with a sleep disorder diagnosis. Conclusion: Individuals having low ESS score were diagnosed with sleep problems which were well predicted in their PVT results. For Indian population, PVT assessment is more sensitive screening tool for sleep disorders as compared to ESS. Although, when administered together, chances of missing any sleep problem are minimised. It was a pilot study and needs to be further validated with larger population.