Xugang Tang,1 Qiang Wang,1 Shuang Li,1 Xiuchuan Li,1 Qian Xin,2 Yongjian Yang1 

1Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, People’s Republic of China; 2Department of Cardiology, The Sixth Medical Center of Chinese PLA General Hospital, Beijing, People’s Republic of China

Correspondence: Yongjian Yang, Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, People’s Republic of China, Tel/Fax +86 28 8657 1255, Email yyjcdzyy@sina.com

Purpose: The Athens Insomnia Scale (AIS) is a widely used and authorized questionnaire for evaluating insomnia symptoms. However, its reliability and validity at high altitudes are uncertain. Therefore, this study aimed to confirm the validity and reliability of AIS during a 3658 m altitude exposure.
Patients and Methods: A total of 387 young Chinese males were enlisted in the acute high-altitude exposure group. They flew for about two hours, climbing from 400 m to 3658 m. The high-altitude-acclimated group consisted of 86 young Chinese men who had lived at least six months at 3658 m altitude. The sleep quality of the acute high-altitude exposure group was evaluated using the AIS before the ascent and after exposure to 3658 m for 24 hours, and one week. The sleep quality of the high-altitude-acclimated group was also assessed. The AIS’s internal consistency, reliability, and validity were evaluated.
Results: The respondents’ quality of sleep significantly decreased after being exposed to 3658 m as opposed to 400 m. Two factors comprised the AIS, according to an exploratory factor analysis: “sleep problem” (items 1– 5) and “daytime dysfunction” (items 6– 8). The Cronbach’s α internal consistency coefficients exceeded 0.8, and the corrected item-total correlations were all greater than 0.5 when the subjects were exposed to 3658 m. The model fit index was well within the criterion. The average variance extracted and composite reliability were all higher than 0.5 and 0.7, respectively. The interclass correlation coefficient was deemed “fair to good” at 0.482, which is greater than the 0.4 threshold. The AIS has satisfactory discriminant validity, as shown by the Fornell-Larcker criterion and cross-loading results. The daytime dysfunction R-square values (> 0.33) show that the frameworks have considerable predictive accuracy.
Conclusion: The AIS exhibits strong consistency, reliability, and validity. The AIS’s features and simplicity make it an essential psychometric tool for high-altitude sleep research.

Keywords: athens insomnia scale, high altitude, internal consistency, reliability, sleep, validity