Rising prevalence of vascular comorbidities in multiple sclerosis: validation of administrative definitions for diabetes, hypertension, and hyperlipidemia.
BACKGROUND
Despite the importance of comorbidity in multiple sclerosis (MS), methods for comorbidity assessment in MS are poorly developed.


OBJECTIVE
We validated and applied administrative case definitions for diabetes, hypertension, and hyperlipidemia in MS.


METHODS
Using provincial administrative data we identified persons with MS and a matched general population cohort. Case definitions for diabetes, hypertension, and hyperlipidemia were derived using hospital, physician, and prescription claims, and validated in 430 persons with MS. We examined temporal trends in the age-adjusted prevalence of these conditions from 1984-2006.


RESULTS
Agreement between various case definitions and medical records ranged from kappa (κ) =0.51-0.69 for diabetes, κ =0.21-0.71 for hyperlipidemia, and κ =0.52-0.75 for hypertension. The 2005 age-adjusted prevalence of diabetes was similar in the MS (7.62%) and general populations (8.31%; prevalence ratio [PR] 0.91; 0.81-1.03). The age-adjusted prevalence did not differ for hypertension (MS: 20.8% versus general: 22.5% [PR 0.91; 0.78-1.06]), or hyperlipidemia (MS: 13.8% versus general: 15.2% [PR 0.90; 0.67-1.22]). The prevalence of all conditions rose in both populations over the study period.


CONCLUSIONS
Administrative data are a valid means of tracking diabetes, hypertension, and hyperlipidemia in MS. The prevalence of these comorbidities is similar in the MS and general populations.
Department of Internal Medicine, University of Manitoba, Winnipeg, Canada. rmarrie@hsc.mb.ca
Ruth Ann
RA
Marrie
Bo Nancy
BN
Yu
Stella
S
Leung
Lawrence
L
Elliott
Patricia
P
Caetano
Sharon
S
Warren
Christina
C
Wolfson
Scott B
SB
Patten
Lawrence W
LW
Svenson
Helen
H
Tremlett
John
J
Fisk
James F
JF
Blanchard
D000328:Adult; D016022:Case-Control Studies; D015897:Comorbidity; D057225:Data Mining; D016208:Databases, Factual; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000175:diagnosis / Q000453:epidemiology*; D006973:Hypertension / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000453:epidemiology*; D009313:National Health Programs / Q000706:statistics & numerical data; D015995:Prevalence; D012042:Registries; D015203:Reproducibility of Results; D013997:Time Factors; D014652:Vascular Diseases / Q000175:diagnosis / Q000453:epidemiology*; D055815:Young Adult