Performance of administrative case definitions for comorbidity in multiple sclerosis in Manitoba and Nova Scotia.

INTRODUCTION: As the population ages and the prevalence of comorbid conditions increases, the need for feasible, validated methods of comorbidity surveillance in chronic diseases such as multiple sclerosis (MS) increases. METHODS: Using kappa (k) statistics, we evaluated the performance of administrative case definitions for comorbidities commonly observed in MS by comparing agreement between Manitoba (MB) administrative data and self-report (n = 606) and Nova Scotia (NS) administrative data and self-report (n = 1923). RESULTS: Agreement between the administrative definitions and self-report was substantial for hypertension (k = 0.69 [NS], 0.76 [MB]) and diabetes (k = 0.70 [NS], 0.66 [MB]); moderate for hyperlipidemia (k = 0.53 [NS], 0.51 [MB]) and heart disease (k = 0.42 [NS], 0.51 [MB]) and fair for anxiety (k = 0.27 [NS], 0.26 [MB]). In NS, agreement was substantial for inflammatory bowel disease (k = 0.71) and moderate for epilepsy (k = 0.48). CONCLUSION: Administrative definitions for commonly observed comorbidities in MS performed well in 2 distinct jurisdictions. This suggests that they could be used more broadly across Canada and in national studies.

TITRE: Performance des définitions administratives de cas pour les affections concomitantes de la sclérose en plaques au Manitoba et en Nouvelle-Écosse. INTRODUCTION: Au fur et à mesure du vieillissement de la population et de l'augmentation de la prévalence d'affections concomitantes, le recours à des méthodes fiables et efficaces de surveillance des affections concomitantes de maladies chroniques telles que la sclérose en plaques (SP) s'avère de plus en plus nécessaire. MÉTHODOLOGIE: Nous avons évalué, au moyen de la statistique kappa (k), la performance des définitions administratives de cas pour les affections concomitantes fréquemment observées en lien avec la SP en comparant les concordances entre les données administratives et les données provenant d'autodéclarations au Manitoba (MB) (n = 606) et en Nouvelle-Écosse (NS) (n = 1 923). RÉSULTATS: Les concordances entre les définitions administratives et les autodéclarations étaient bonnes pour l'hypertension (k = 0,69 [NS] et 0,76 [MB]) et le diabète (k = 0,70 [NS] et 0,66 [MB]), modérées pour l'hyperlipidémie (k = 0,53 [NS] et 0,51 [MB]) et la cardiopathie (k = 0,42 [NS] et 0,51 [MB]) et médiocres pour l'anxiété (k = 0,27 [NS] et 0,26 [MB]). La concordance était bonne en Nouvelle-Écosse pour la maladie inflammatoire chronique de l'intestin (k = 0,71) et modérée pour l'épilepsie (k = 0,48). CONCLUSION: Les définitions administratives étaient performantes dans les deux provinces pour plusieurs affections concomitantes fréquemment observées en lien avec la SP. À la lumière de ces résultats, il semble que ces définitions puissent être utilisées plus largement au Canada et dans les études nationales.

A comparison of health utility measures for the evaluation of multiple sclerosis treatments.

OBJECTIVES: To evaluate the practical application and psychometric properties of three health utility measures in a sample of MS patients with a broad range of neurological disability as measured by the Extended Disability Status Scale (EDSS). METHODS: Patients randomly selected from two MS clinic registries were assessed using standard clinical methods and completed three generic measures of health utility (EQ-5D, HUI Mark III, SF-6D). The proportion of missing data, test/retest reliability, and construct validity of each health utility measure were examined. RESULTS: The assessments were completed by 187 patients. Less than 10% of data were missing for the subscales of the SF-6D (< 3.2%), HUI Mark III (<1.6%), and EQ-5D (< or =7.5%). Severely disabled patients were more likely to omit physical function questions for the SF-6D (20%), and EQ-5D (43%). Retest reliability for the SF-6D (ICC = 0.83), EQ-5D (ICC = 0.81), and HUI Mark III (ICC = 0.87) were adequate for population surveys. Correlations between assessment of clinical function and each health utility measure were strongest for the HUI Mark III (HUI Mark III EDSS rho = -0.77, HUI Mark III ambulation index rho = -0.76, HUI Mark III timed 25 foot walk rho = -0.73, HUI Mark III nine hole peg test rho = -0.65). CONCLUSIONS: The health utility measures were generally feasible and reliable but the HUI Mark III demonstrated highest concordance with the EDSS across the full range of neurological disability. Of the three measures studied, the HUI Mark III may be the most appropriate for cost effectiveness evaluations of MS therapies.

Validity and reliability of the Medical Outcomes Study Short Form-20 questionnaire as a measure of quality of life in elderly people living at home.

BACKGROUND: the Medical Outcomes Study Short Form-20 (SF-20) questionnaire is recommended for health-related quality of life research, but there is little information on its utility in older people. We assessed the validity, reliability and feasibility of using the SF-20 in an elderly community-dwelling population. METHODS: the SF-20 was administered to a stratified, random sample of 333 elderly subjects. FINDINGS: assessment of content validity revealed that important domains were lacking, while others appeared to be inappropriately combined. Using Spearman correlation coefficients, the SF-20 had acceptable convergent and discriminant validity. A principal components analysis provided evidence for internal consistency for some of the subscales. Evidence for test-retest reliability was good. INTERPRETATION: while the reliability and feasibility of the SF-20 appear satisfactory, concerns about validity and responsiveness should temper enthusiasm for its use with elderly people living at home.