Reliability and validity of the Norwegian version of the Functional Outcomes of Sleep Questionnaire

Abstract

The aim of this study was to validate the Norwegian version of a self-administered 30-item quality of life questionnaire designed to assess disorders of excessive sleepiness, the Functional Outcomes of Sleep Questionnaire (FOSQ). In total 226 patients previously evaluated for obstructive sleep apnea were included in the study. The patients received a postal questionnaire with the FOSQ, the Short Form 36 (SF-36) questionnaire, and a scale for assessment of excessive daytime sleepiness, the Epworth sleepiness scale (ESS). Among the 178 respondents, all five subscales of the FOSQ showed good internal consistency reliability (Cronbach's alpha = 0.84-0.93). Test-retest on average 18 days apart was satisfactory with intraclass correlation coefficients ranging from 0.61 to 0.86. The pattern of Spearman's rank correlation coefficients between FOSQ scales and related and unrelated scales SF-36 scales gave support to the construct validity of the FOSQ. In conclusion, the Norwegian translation of the FOSQ showed satisfactory internal consistency reliability, test-retest reliability and construct validity, in line with the original version.

Adaptation of the 10-Item Functional Outcomes of Sleep Questionnaire to Iranian Patients with Obstructive Sleep Apnea

“…FOSQ-10 subscales generally correlated higher with related subscales. These findings were relatively compatible with reports in the USA and Norway [4,14]. Our data demonstrated that the IR-FOSQ-10 was able to distinguish patients with abnormal sleepiness score from those with normal sleepiness score.…”

Reliability and validity of a Norwegian version of the Epworth sleepiness scale

“…A questionnaire was mailed to all 242 patients evaluated for continuous positive airway pressure (CPAP) for treatment of OSA, without any known comorbid conditions, who were referred by a general practitioner, a specialist in neurology, or otolaryngology, and admitted to the pulmonary unit of the Akershus University Hospital from 1993 to 1999 [13]. Patients with a discharge diagnosis of the International Classification of Diseases, ninth revision (ICD-9) code 780.…”

“…A reminder was sent after 2 weeks and another after 4 weeks. We reviewed the medical records of the patients, abstracting relevant information and data from a sleep study before the hospital admission [13]. The apnea-hypopnea index (the total number of episodes of apnea and hypopnea divided by the number of hours of sleep) was calculated for each patient, as a measure of disease severity.…”

Validation of the Chinese Version of the Functional Outcomes of Sleep Questionnaire‐10 in Pregnant Women

“…Discriminant validity was assessed by comparing the C‐FOSQ‐10 total scores of women with and without clinically significant daytime sleepiness (i.e., ESS total score of >10) using independent samples t ‐tests. Based on the theoretically and empirically supported relationships between daytime sleepiness and daily functioning (Korpe et al, ; Stavem et al, ; Verceles et al, ), the C‐FOSO‐10 total scores were expected to be lower in individuals with greater daytime sleepiness.…”

“…The original version of the FOSQ (Weaver et al, ) has 30 items (FOSQ‐30) and has demonstrated satisfactory psychometric properties in different cultural contexts (Banhiran et al, ; Korpe, Lundgren, & Dahlstrom, ; Stavem, Kjelsberg, & Ruud, ). The measure was subsequently shortened to 10 items to improve clinical utility (Chasens, Ratcliffe, Weaver, ).…”