Validity of discharge diagnoses in the surveillance of stroke.
BACKGROUND
Hospital administrative data have been suggested as a valuable cost-effective tool for providing information about the stroke burden. Nevertheless, the choice of the diagnosis codes has been a critical issue in the development of case ascertainment algorithms.


METHODS
In this study, the Minimum Basic Data Set administrative database was used to analyze the accuracy of different ICD-9-CM algorithms based on the neurologist's clinical judgement as the 'gold standard'.


RESULTS
The most accurate algorithm observed in our study involved the selection of ICD-9-CM codes 430-438 in the primary diagnosis. It yielded a sensitivity of 96.1%, a specificity of 87.5% and a positive predictive value of 82.5%.


CONCLUSIONS
The Minimum Basic Data Set is a valuable source to evaluate stroke frequency when using an accurate algorithm to select events.
Department of Epidemiology, La Rioja Regional Authority, Logroño, Spain.
Enrique
E
Ramalle-Gomara
Elena
E
Ruiz
Marta
M
Serrano
Monica
M
Bartulos
Maria-Angeles
MA
Gonzalez
Belinda
B
Matute
D000465:Algorithms; D016208:Databases, Factual; D006801:Humans; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology*