Psychometric performance of the Oviedo Sleep Questionnaire in patients with severe mental disorder

Abstract

Introduction

The prevalence of sleep disturbances among patients with severe mental disorder ranges from 30 to 80%. Since the impact of these disturbances on patients’ lives is substantial, there is a need for their evaluation and management. The aim of this study was to examine the reliability and validity of the Oviedo Sleep Questionnaire (OSQ) in patients with severe mental disorder.

Material and methods

We performed an observational, prospective (3-month), multicenter study. A total of 259 individuals (184 patients with severe mental disorder and 75 controls) were included. Evaluation: the OSQ, the sleep items of the Bech-Rafaelsen's Scales for Depression (MES item 3) and Mania (MAS item 5), and the Clinical Global Impression Scales for Severity of Mental Disorder (CGI-SMD) and Sleep Disorder (CGI-SSD).

Results

a) Factorial structure: two factors accounted for 57.65% of the variance; factor 1 (insomnia) accounted for 44.65% and factor 2 (hypersomnia) for 13%; b) internal consistency: total OSQ = 0.90, insomnia scale = 0.91, hypersomnia scale = 0.88; c) testretest reliability = 0.87; d) convergent validity: Pearson's correlation coefficients were 0.632 with item 3 of the MES, 0.619 with item 5 of the MAS, and 0.630 with the CGI-SS (p < 0.001); e) discriminant validity: the OSQ was able to differentiate between patients and controls (p = 0.018), and among distinct degrees of mental disorder severity (CGISMD) (p < 0.001) and sleep disorder severity (CGI-SSD) (p < 0.001); f) responsiveness: the OSQ, like the CGI-SSD (p = 0.004), identified a significant decrease in the insomnia severity score after 3 months (p = 0.005).

Conclusions

The OSQ is a valid and reliable method for measuring the sleep/wake cycle in patients with severe mental disorder.

Resumen

Introducción

El 30–80% de los pacientes con trastorno mental grave manifiestan dificultades del sueño. Su impacto es especialmente significativo en ellos por lo que su evaluación y su manejo resultan obligados. El objetivo fue examinar la fiabilidad y validez del Cuestionario Oviedo de Sueño (COS) en pacientes con trastorno mental grave.

Material y métodos

Estudio observacional, prospectivo (3 meses), multicéntrico. Participaron 259 sujetos (184 con trastorno mental grave y 75 como controles). Evaluación: COS, ítems del sueño de las Escalas de Bech-Rafaelsen para Depresión (MES, ítem 3) y para Manía (MAS, ítem 5), escalas de Impresión Clínica Global de Gravedad del Trastorno Mental (ICG-GTM) y del Trastorno del Sueño (ICG-GTS).

Resultados

a) Estructura factorial: dos factores que explican el 57,65% de la variancia; el factor 1, insomnio, explica el 44,65% y el 2, hipersomnio, el 13%; b) consistencia interna: COS total = 0,90, escala insomnio = 0,91, escala hipersomnio = 0,88; c) fiabilidad test-retest, 0,87; d) validadez convergente: coeficiente de correlación de Pearson con ítem 3 MES = 0,632, con ítem 5 MAS = 0,619, y con ICG-GTS = 0,630 (p < 0,001); e) validez discriminante: discriminó entre pacientes y controles (p = 0,018), y entre distintos grados de gravedad del trastorno mental (ICG-GTM) (p < 0,001) y del trastorno del sueño (ICGGTS) (p < 0,001), y f) sensibilidad a los cambios: detectó disminución significativa de la gravedad del insomnio a los 3 meses (p = 0,005) al igual que la ICG-GTS (p = 0,004).

Conclusiones

El COS es un instrumento de medida del ritmo sueño-vigilia válido y fiable en los pacientes con trastorno mental grave.