To assess whether sleep quality (SQ) at baseline is associated with improvement in pain and disability at 3 months.
Four hundred twenty-two subacute and chronic patients with neck pain (NP) were recruited in 32 physiotherapy, primary care, and specialized centers. NP, referred pain, disability, catastrophizing, depression, and SQ were assessed through validated questionnaires, upon recruitment and 3 months later. Correlations between baseline scores were calculated through the Spearman coefficient. Improvements in NP, disability, and SQ were defined as a reduction of ≥30% of baseline score. Six estimative logistic regression models were developed to assess the association between baseline SQ and improvement of NP, baseline SQ and improvement of disability, baseline NP and improvement of SQ, baseline disability and improvement of SQ, the evolutions of NP and SQ, and the evolutions of disability and SQ.
Most patients were subacute and mildly impaired. Regression models showed that better SQ at baseline was associated with improvement of NP (odds ratio=0.91 [95% confidence interval, 0.83-0.99]), but not disability (1.04 [0.95-1.13]); the improvement of SQ was associated with more severe NP at baseline (1.26 [1.07-1.49)], but not with baseline disability (0.99 [0.97-1.02]); and that improvement in SQ was associated with improvements in NP (3.48 [1.68-7.20]), and disability (5.02 [2.39-10.11]).
NP is less likely to improve in patients with poorer SQ, irrespective of age, sex, catastrophizing, depression, or treatments prescribed for NP. Future studies should confirm these results with more severely impaired patients.
†Spanish Back Pain Research Network, Fundación Kovacs
‡‡IBaD Clínica del Dolor-Majorca Spine and Pain Clinic
¶¶Centro Salud Arquitecto Bennassar
##Unidad de la Espalda Kovacs, Hospital de Cruz Roja Española, Palma de Mallorca
#Centro de Fisioterapia Sergio Melis/Ronda Oeste, Mallorca
‡Institute of Biomedicine (IBIOMED), University of León
‡‡‡Departamento de Fisiología, Universidad de El País Vasco (UPV/EHU), Campus Universitario, Guipúzcoa
§University of the Basque Country, Campus Universitario, Basque Country
†††Escuela Universitaria Ciencias de la Salud, Universidad de León, Campus Universitario, Ponferrada, León
∥CIBER Epidemiología y Salud Pública (CIBERESP)
§§Servicio de Reumatología, Hospital Clínic, Barcelona
¶Unidad de Bioestadística Clínica
∥∥Sección de Rehabilitación Reumatológica, Hospital Ramón y Cajal, IRICYS
††Physical Medicine and Rehabilitation Department, Faculty of Medicine, Complutense University, Madrid
**Fisys Fisioterapia, Cantabria
***Unidad del Dolor, Hospital Mateu Orfila, Mahón
§§§Departamento de Medicina Preventiva y Salud Pública, Universidad de El País Vasco (UPV/EHU), Campus Universitario, Vizcaya, Spain
F.M.K., J.S., A.R., and V.A.: drafted the first version of the study protocol. All the authors have contributed substantially to the conception and design of this study. J.S., S.M., C.S., M.J.D.-A., M.M., A.R., M.N., M.E.M.-R., C.F., M.G., N.M., J.M., V.R.-P., J.T.-U, and N.B.-A., I.G.-F.: contributed to data gathering, and F.M.K., A.R., and V.A.: to data analysis and interpretation. F.M.K. and A.R.: drafted the first version of this manuscript. All the authors have revised it for important intellectual content, and have approved the final version. All authors accept public responsibility for this study and its conclusions.
Supported by the Kovacs Foundation, Baleares, Spain, a Spanish not-for-profit Institution which has no links to the health industry and specializes in neck and back pain research. The authors declare no conflict of interest.
Reprints: Francisco M. Kovacs, MD, PhD, Departamento Científico, Fundación Kovacs, Paseo Mallorca 36, 3°, 1a, Palma de Mallorca 07012, Spain (e-mail: firstname.lastname@example.org).
Received August 5, 2014
Received in revised form September 8, 2014
Accepted August 9, 2014