Comparing sleep problems in multiple sclerosis via Women's Health Inititative Insomnia Rating Scale and Medical Outcomes Study Sleep Scale.
|Title||Comparing sleep problems in multiple sclerosis via Women's Health Inititative Insomnia Rating Scale and Medical Outcomes Study Sleep Scale.|
|Publication Type||Journal Article|
|Authors||Bamer AM, Amtmann D, Cook KF, Johnson KL|
|Journal||International Journal of MS Care|
Background: Research studies suggest that that up to 50% of individuals with multiple sclerosis (MS) complain of sleeprelated problems. However, sleep difficulties have received comparatively little research attention in MS, and few largescale sleep studies have been completed to date. Because sleep is known to have a substantial effect on quality of life, it is important to examine the prevalence of sleep disorders and functioning of sleep instruments in individuals with MS. The purpose of this study was to estimate the prevalence of sleep difficulties in MS with two sleep scales and evaluate the psychometric functioning of both measures in an MS population. Methods: A large cross-sectional sample (N = 1063) of community-dwelling individuals with MS completed a selfreport mail survey. Sleep was assessed with the Medical Outcomes Study Sleep Scale (MOSSS) and the Women’s Health Initiative Insomnia Rating Scale (WHIIRS). Both measures were scored based on recommendations of scale developers, and summary statistics were calculated. Item response theory (IRT) with a graded response model was used to evaluate the psychometric functioning of the scales. Results: Mean scores on the WHIIRS and MOSSS Sleep Index II were 9.8 (standard deviation 5.3) on a scale of 0–20 and 38.9 (19.7) on a scale of 1–100, respectively. These scores indicate that individuals with MS have significantly more sleep problems than the general population and other chronically ill populations. IRT analysis found that both scales have significant numbers of misfitting items, and response categories did not perform as expected. Both scales measured individuals with more sleep difficulties more accurately than those below the mean of this sample. Conclusions: Sleep difficulties appear to be a significant problem for a large percentage of individuals with MS. Further research on sleep difficulties in MS and development of better measurement tools for evaluating sleep difficulties are needed.