InMS: Chronic insomnia disorder in multiple sclerosis - a Portuguese multicentre study on prevalence, subtypes, associated factors and impact on quality of life.
BACKGROUND
Sleep may be disrupted in Multiple Sclerosis (MS), but the prevalence of chronic insomnia disorder (CID) using standard diagnostic criteria is unknown.


OBJECTIVE
To determine the prevalence of CID in an MS population, the frequency of CID subtypes, associated factors and impact on quality of life (QoL).


METHODS
Multicentre, hospital-based cross-sectional study. An adapted version of the Brief Insomnia Questionnaire was applied to a consecutively recruited MS population. The influence of demographic, MS-related features, fatigue, medical and psychiatric comorbidities, nocturnal symptoms, other sleep disorders, dysfunctional beliefs about sleep in CID was evaluated. The relation between CID and QoL was analysed.


RESULTS
Of 206 MS patients, 22.3% fulfilled criteria for CID, with initial insomnia in 11.7%, maintenance insomnia in 11.2% and terminal insomnia in 10.2% of patients. CID was more frequent in female patients, those with nocturnal symptoms, medical comorbidities, higher levels of anxiety, depression and fatigue. Multivariable analysis identified female sex, medical comorbidities, anxiety and fatigue as independent factors for CID. CID patients had a significantly lower self-reported QoL.


CONCLUSIONS
CID is prevalent in MS patients and associated with psychiatric and medical comorbidities, as well as fatigue. It has a negative impact on QoL.
Department of Neurology, Hospital de Santa Maria, Avenida Professor Egas Moniz, PT-1649-035 Lisboa, Portugal. Electronic address: pedrofaroviana@gmail.com.
Pedro
P
Viana
Department of Neurology, Centro Hospitalar do Funchal, Avenida Luís de Camões, 9004-514 Funchal, Portugal.
Elisabete
E
Rodrigues
Department of Neurology, Hospital Garcia de Orta, Avenida Torrado da Silva, 2801-951 Almada, Portugal.
Carina
C
Fernandes
Department of Neurology, Centro Hospitalar Trás-os-Montes e Alto Douro, Avenida da Noruega, 5000-508 Lordelo, Vila Real, Portugal.
Andreia
A
Matas
Department of Neurology, Centro Hospitalar Entre o Douro e Vouga, Rua Doutor Cândido Pinho, 4520-211 Santa Maria da Feira, Portugal.
Rui
R
Barreto
Department of Neurology, Centro Hospitalar de Lisboa Ocidental, Rua Da Junqueira 126, 1349-019 Lisboa, Portugal; CEDOC, Nova Medical School, Universidade Nova de Lisboa, Campo Mártires da Pátria 130, 1169-056 Lisboa, Portugal.
Marcelo
M
Mendonça
Department of Neurology, Hospital de Santa Maria, Avenida Professor Egas Moniz, PT-1649-035 Lisboa, Portugal; Sleep/EEG Laboratory, Hospital de Santa Maria, Avenida Professor Egas Moniz, PT-1649-035 Lisboa, Portugal.
Rita
R
Peralta
Department of Neurology, Hospital de Santa Maria, Avenida Professor Egas Moniz, PT-1649-035 Lisboa, Portugal; Medical School, University of Lisbon, Avenida Professor Egas Moniz, PT-1649-035 Lisboa, Portugal.
Ruth
R
Geraldes
D000293:Adolescent; D000328:Adult; D000368:Aged; D001007:Anxiety / Q000453:epidemiology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005221:Fatigue / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D015999:Multivariate Analysis; D015995:Prevalence; D011788:Quality of Life; D057566:Self Report; D012737:Sex Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D055815:Young Adult
Associated factors; Fatigue; Insomnia; Multiple sclerosis; Prevalence; Quality of life