Validity of vascular trauma codes at major trauma centres.

BACKGROUND: The use of administrative databases in vascular injury research has been increasing, but the validity of the diagnosis codes used in this research is uncertain. We assessed the positive predictive value (PPV) of International Classification of Diseases, tenth revision (ICD-10), vascular injury codes in administrative claims data in Ontario. METHODS: We conducted a retrospective validation study using the Canadian Institute for Health Information Discharge Abstract Database, an administrative database that records all hospital admissions in Canada. We evaluated 380 randomly selected hospital discharge abstracts from the 2 main trauma centres in Toronto, Ont., St.Michael's Hospital and Sunnybrook Health Sciences Centre, between Apr. 1, 2002, and Mar. 31, 2010. We then compared these records with the corresponding patients' hospital charts to assess the level of agreement for procedure coding. We calculated the PPV and sensitivity to estimate the validity of vascular injury diagnosis coding. RESULTS: The overall PPV for vascular injury coding was estimated to be 95% (95% confidence interval [CI] 92.3-96.8). The PPV among code groups for neck, thorax, abdomen, upper extremity and lower extremity injuries ranged from 90.8 (95% CI 82.2-95.5) to 97.4 (95% CI 91.0-99.3), whereas sensitivity ranged from 90% (95% CI 81.5-94.8) to 98.7% (95% CI 92.9-99.8). CONCLUSION: Administrative claims hospital discharge data based on ICD-10 diagnosis codes have a high level of validity when identifying cases of vascular injury. LEVEL OF EVIDENCE: Observational Study Level III.

CONTEXTE: L'utilisation des bases de données administratives pour la recherche sur les lésions vasculaires est en hausse, mais la validité des codes diagnostiques utilisés dans ces recherches est incertaine. Nous avons évalué la valeur prédictive positive (VPP) des codes de lésions vasculaires de la dixième édition de la Classification internationale des maladies (CIM-10) qui figurent dans une base de données administrative ontarienne. MÉTHODES: Nous avons réalisé une étude de validation rétrospective à partir de la base de données de l'Institut canadien d'information sur la santé (ICIS) sur les congés des patients, une base de données administrative qui enregistre toutes les hospitalisations au Canada. Nous avons évalué 380 congés hospitaliers de 2 grands centres de traumatologie de Toronto, en Ontario, soit l'Hôpital St. Michael's et le Centre des sciences de la santé Sunnybrook, entre le 1er avril 2002 et le 31 mars 2010. Nous avons ensuite comparé ces dossiers aux dossiers hospitaliers des patients correspondants pour vérifier la concordance des codes attribués aux interventions. Nous avons calculé la VPP et la sensibilité pour estimer la validité des codes diagnostiques appliqués aux lésions vasculaires. RÉSULTATS: La VPP globale pour les codes de lésions vasculaires a été estimée à 95% (intervalle de confiance [IC] de 95% 92,3­96,8). Parmi les groupes de codes attribués aux lésions affectant le cou, le thorax, l'abdomen, les membres supérieurs et inférieurs, la VPP a varié de 90,8 (IC de 95% 82,2­95,5) à 97,4 (IC de 95% 91.0­99,3), tandis que la sensibilité a varié de 90% (IC de 95% 81,5­94,8) à 98,7% (IC de 95% 92,9­99,8). CONCLUSION: Les données administratives sur les congés hospitaliers basées sur les codes diagnostiques de la CIM 10 ont un degré de validité élevé pour ce qui est des lésions vasculaires. NIVEAU DE PREUVE: Étude d'observation Niveau III.

Fabry's disease: a prospective multicenter cohort study in young adults with cryptogenic stroke.

BACKGROUND: Stroke in young adults is etiologically diverse and may represent a diagnostic challenge remaining cryptogenic in one-fourth of cases. Limited information is available on the prevalence of Fabry's disease, a treatable multisystem inherited lysosomal storage disorder, and disability in young patients with cryptogenic stroke. DESIGN AND METHODS: The Canadian Fabry Stroke Screening Initiative (CFSSI) is a prospective multicenter cohort study of young adults (age 18-55) presenting with an ischemic stroke, transient ischemic attack, or intracerebral haemorrhage of unknown etiology to stroke centres across Canada. Diagnosis of Fabry's disease is made by direct DNA analysis of blood samples for α-galactosidase gene mutations or polymorphisms. Demographics, clinical information, and investigations including brain Magnetic Resonance Imaging (MRI) are collected. Functional neurological assessment includes neurological examination, the National Institutes of Health (NIH) stroke scale, modified Rankin scale, and the Barthel index. A follow-up interview is conducted by telephone or in person approximately six-months after the index stroke/transient ischemic attack/intracerebral haemorrhage to determine patient outcomes, quality of life, and patient use of medications. MAIN OUTCOME: Prevalence of positive DNA mutation or single nucleotide polymorphism screens for Fabry's disease as a proportion of total cryptogenic stroke. Secondary outcomes include incident risk of new or recurrent vascular event at six-months, discharge disposition, disability at six-months as measured by the modified Rankin scale, mean time from symptoms onset to the definite etiological diagnosis, and length of hospital stay. CONCLUSION: This study constitutes the first initiative to determine the prevalence of a positive screen for Fabry's disease in young adults with stroke in Canada. Moreover, the Canadian Fabry Stroke Screening Initiative will provide information on recurrent vascular events, disability at six-months (modified Rankin scale), and disposition in this understudied population.

Cardiovascular outcomes after a change in prescription policy for clopidogrel.

BACKGROUND: Drug-reimbursement policies may have an adverse effect on patient outcomes if they interfere with timely access to efficacious medications for acute medical conditions. Clopidogrel in combination with aspirin is the recommended standard of care for patients receiving coronary stents to prevent thrombosis. We examined the population-level effect of a change by a Canadian provincial government in a pharmacy-benefits program from a prior-authorization policy to a less restrictive, limited-use policy on access to clopidogrel among patients undergoing percutaneous coronary intervention (PCI) with stenting after acute myocardial infarction. METHODS: We conducted a population-based, retrospective, time-series analysis from April 1, 2000, to March 31, 2005, of all patients 65 years of age or older with acute myocardial infarction who underwent PCI with stenting in Ontario, Canada. The primary outcome was the composite rate of death, recurrent acute myocardial infarction, PCI, and coronary-artery bypass grafting at 1 year, with adjustment for sex and age. The secondary outcome was major bleeding. RESULTS: The rate of clopidogrel use within 30 days after hospital discharge following myocardial infarction increased from 35% in the prior-authorization period to 88% in the limited-use period. The median time to the first dispensing of a clopidogrel prescription decreased from 9 days in the first period to 0 days in the second period. The 1-year composite cardiovascular outcome significantly decreased from 15% in the prior-authorization group to 11% in the limited-use group (P=0.02). Rates of bleeding in the two groups did not change. CONCLUSIONS: The removal of a prior-authorization program led to improvement in timely access to clopidogrel for coronary stenting and improved cardiovascular outcomes.

Cardiovascular disease and hypertension risk in living kidney donors: an analysis of health administrative data in Ontario, Canada.

BACKGROUND: Knowledge of any harm associated with living kidney donation guides informed consent and living donor follow-up. Risk estimates in the literature are variable, and most studies did not use a healthy control group to assess outcomes attributable to donation. METHODS: We observed a retrospective cohort using health administrative data for donations which occurred in Ontario, Canada between the years 1993 and 2005. There were a total of 1278 living donors and 6359 healthy adults who acted as a control group. Individuals were followed for a mean of 6.2 years (range, 1-13 years) after donation. The primary outcome was a composite of time to death or first cardiovascular event (myocardial infarction, stroke, angioplasty, and bypass surgery). The secondary outcome was time to a diagnosis of hypertension. RESULTS: There was no significant difference in death or cardiovascular events between donors and controls (1.3% vs. 1.7%; hazard ratio 0.7, 95% confidence interval 0.4-1.2). Donors were more frequently diagnosed with hypertension than controls (16.3% vs. 11.9%, hazard ratio 1.4, 95% confidence interval 1.2-1.7) but were also seen more often by their primary care physicians (median [interquartile range] 3.6 [1.9-6.1] vs. 2.6 [1.4-4.3] visits per person year, P<0.001). CONCLUSIONS: Based on administrative data, the risk of cardiovascular disease was unchanged in the first decade after kidney donation. The observed increase in diagnosed hypertension may be due to nephrectomy or more blood pressure measurements received by donors in follow-up and requires prospective study.

Suboptimal use of statin therapy in elderly patients with atherosclerosis: a population-based study.

BACKGROUND: Current evidence suggests that statin use plays an important role in improving adverse cardiovascular outcomes in patients with atherosclerosis. However, limited population-based data are available on use of statin therapy in these patients in Canada. We sought to study trends in statin use to treat these patients in Ontario during a 10-year period. METHODS: We conducted a population-based cross-sectional time series analysis between April 1, 1995, and March 31, 2004, using health care data from Ontario, Canada. RESULTS: During the study period, 343,154 elderly patients with atherosclerosis were identified. Of these, 235,615 (68.7%) had coronary artery diseases (CAD), 115,012 (33.5%) had cerebrovascular disease (CVD), and 23,886 (7.0%) had peripheral arterial disease (PAD). About 46% were women, and mean patient age was 77.1 (SD, 7.5) years. During the study period, the percentage of patients treated with a statin in each group increased considerably, from 9.8% to 55.3% in all atherosclerotic patients (P < .01), from 11.8% to 61.2% in CAD patients (P < .01), from 5.3% to 41.2% in CVD patients (P < .01), and from 6.8% to 43.3% in PAD patients (P < .01). During the entire study period, the percentage of statin users was lowest among PAD and CVD patients, followed by patients with both a history of PAD and CVD. CONCLUSION: The use of statin therapy in elderly patients with symptomatic atherosclerosis has increased substantially during the past decade, but many patients remain untreated. The suboptimal use is greatest among patients with PAD or CVD, or both, and lowest in patients with CAD. Given the heightened risk of cardiovascular adverse outcomes in patients with atherosclerosis, these data have important and immediate implications.