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.

Hospital discharges and mortality registries: 2 complementary databases for the epidemiological surveillance of stroke.

BACKGROUND: Stroke is a public health concern and the availability of a stroke registry would provide valuable information. Administrative hospital data and mortality registries have been previously suggested as suitable sources of information. The aim of this study was to evaluate the utility of merging data from a hospital discharge database and the mortality registry (MR) to estimate the incidence of stroke in La Rioja, Spain. METHODS: A cross-sectional study about events of stroke occurred in our region in 2009 was carried out. Patients were selected among those registered in the discharge hospital database and in the MR, using the International Classification of Diseases. The databases were merged to detect duplicated occurrences and to estimate the number of cases identified by each source. Characteristics of the study population were analyzed and crude- and age-adjusted incidence rates were assessed. RESULTS: Using both databases, 1133 stroke events were detected, 153 (13.5%) representing coincident or recurrent cases. A total of 980 incident stroke cases were obtained, 150 provided by the MR (15.3%) and 830 by the hospital discharge database (84.7%). Incidence of stroke was similar in men than in women, the ischemic stroke being the major type. Most of the study population (66%) were older than 74 years. Crude incidence rate was 304.6 per 100,000, and age-adjusted rates were 171.1 per 100,000 (adjusted to the European population) and 107.9 per 100,000 (adjusted to the World population). CONCLUSIONS: Considering both the Minimum Basic Data Set and the MR as data sources appears advisable to build a stroke registry to evaluate the incidence and to perform epidemiological surveillance of stroke.

Methionine synthase polymorphism is a risk factor for Alzheimer disease.

Alzheimer disease (AD) patients show increased plasma levels of homocysteine, whose conversion to methionine is catalyzed by methionine synthase (MS). Although altered MS activity may result from the MS A2756G polymorphism, the latter's possible associ-ation with AD remains unexplored. To assess whether the MS A2756G polymorphism holds any influence on AD risk, we have analyzed 172 AD patients and 166 controls. We have also investigated whether the MS-A or MS-G allele interacts with the APOE4 allele. Our results indicate that association with the MS-AA genotype is an APOE4 allele-independent risk factor for AD. These findings provide novel evidence implicating genetic enzymatic alterations of homocysteine metabolic pathways in the pathogenesis of AD.