Validation of the Russian version of Swiss Narcolepsy Scale for narcolepsy type 1 screening

   Ullanlinna Narcolepsy Scale (UNS) is the most widely used scale for primary screening for narcolepsy. It has a high sensitivity (83.5 %) and specificity (84.1 %). However, the length of the scale and the time taken by patients to complete it may limit its use. The shortest scale for primary detection of narcolepsy type 1 is the Swiss Narcolepsy Scale (SNS), which also has a high sensitivity (89 %) and specificity (88 %).

   Objective: to validate the SNS in Russian language and compare it with English and German versions as well as with some other scales.

   Material and methods. 53 patients with narcolepsy type 1 were included. Narcolepsy was diagnosed according to the ICSD-3 criteria. The control group consisted of patients with obstructive sleep apnea (n = 71) and chronic insomnia (n = 31). Sensitivity and specificity of the Russian version of the scale (RU-SNS) were compared with UNS and Epworth Sleepiness Scale (ESS) questionnaires.

   Results. The mean score of the RU-SNS for patients with narcolepsy was – 33.64 ± 5.14. In the control group, the mean score was 29.75 ± 16.68. The sensitivity and specificity were 84.9 % and 95.1 %, respectively. For UNS, the mean score was 32.79 ± 9.87 in the narcolepsy group and 8.35 ± 4.84 in the control group. Sensitivity was 96.2 % and specificity – 84.3 %. For ESS, the mean score in narcolepsy group was 17.75 ± 4.28 and 8.7 ± 5.7 for controls. The sensitivity was estimated at 94.3 % and specificity at 61.8 %.

   Conclusion. The RU-SNS demonstrated high sensitivity and specificity, while the UNS also has high sensitivity but low specificity. ESS has high sensitivity but low specificity as it is only designed to detect pathological daytime sleepiness. Based on these data, the SNS can be used as a valid tool for the early diagnosis of narcolepsy type 1.

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