Does physician specialty affect the survival of elderly patients with myocardial infarction?

OBJECTIVE: To determine the effect of treatment by a cardiologist on mortality of elderly patients with acute myocardial infarction (AMI, heart attack), accounting for both measured confounding using risk-adjustment techniques and residual unmeasured confounding with instrumental variables (IV) methods. DATA SOURCES/STUDY SETTING: Medical chart data and longitudinal administrative hospital records and death records were obtained for 161,558 patients aged > or =65 admitted to a nonfederal acute care hospital with AMI from April 1994 to July 1995. Our principal measure of significant cardiologist treatment was whether a patient was admitted by a cardiologist. We use supplemental data to explore whether our analysis would differ substantially using alternative definitions of significant cardiologist treatment. STUDY DESIGN: This retrospective cohort study compared results using least squares (LS) multivariate regression with results from IV methods that accounted for additional unmeasured patient characteristics. Primary outcomes were 30-day and one-year mortality, and secondary outcomes included treatment with medications and revascularization procedures. DATA COLLECTION/EXTRACTION METHODS: Medical charts for the initial hospital stay of each AMI patient underwent a comprehensive abstraction, including dates of hospitalization, admitting physician, demographic characteristics, comorbid conditions, severity of clinical presentation, electrocardiographic and other diagnostic test results, contraindications to therapy, and treatments before and after AMI. PRINCIPAL FINDINGS: Patients admitted by cardiologists had fewer comorbid conditions and less severe AMIs. These patients had a 10 percent (95 percent CI: 9.5-10.8 percent) lower absolute mortality rate at one year. After multivariate adjustment with LS regression, the adjusted mortality difference was 2 percent (95 percent CI: 1.4-2.6 percent). Using IV methods to provide additional adjustment for unmeasured differences in risk, we found an even smaller, statistically insignificant association between physician specialty and one-year mortality, relative risk (RR) 0.96 (0.88-1.04). Patients admitted by a cardiologist were also significantly more likely to have a cardiologist consultation within the first day of admission and during the initial hospital stay, and also had a significantly larger share of their physician bills for inpatient treatment from cardiologists. IV analysis of treatments showed that patients treated by cardiologists were more likely to undergo revascularization procedures and to receive thrombolytic therapy, aspirin, and calcium channel-blockers, but less likely to receive beta-blockers. CONCLUSIONS: In a large population of elderly patients with AMI, we found significant treatment differences but no significant incremental mortality benefit associated with treatment by cardiologists.

Effect of folate supplementation on the incidence of dysplasia and cancer in chronic ulcerative colitis. A case-control study.

Folate deficiency has been associated with dysplasia in human cancer models. Patients with ulcerative colitis commonly have decreased folate levels, which are partially due to sulfasalazine, a competitive inhibitor of folate absorption. To study the effect of folate supplementation on the risk of dysplasia or cancer (neoplasia) in ulcerative colitis, records from 99 patients with pancolitis for greater than 7 yr and enrolled in a surveillance program were reviewed. Thirty-five patients with neoplasia were compared with 64 patients in whom dysplasia was never found to determine the effect of folate supplementation on the rate of development of neoplasia using case-control methodology. At the time of the index colonoscopy, patients with neoplasia were older (43 +/- 11 vs. 39 +/- 12 yr) and had disease of longer duration (20 +/- 8 vs. 15 +/- 7 yr, p less than 0.05). Folate supplementation was associated with a 62% lower incidence of neoplasia compared with individuals not receiving supplementation (odds ratio, 0.38; 95% confidence interval, 0.12-1.20). There was no appreciable change in this effect when models were fit to adjust for sulfasalazine dose, duration of disease, age at symptom onset, prednisone dose, sulfa allergy, sex, race, or family history of colon cancer. The statistical power of the association between folate supplementation and neoplasia was 72%. Correction of risk factors before the development of neoplasia may prevent this serious complication. Pending a larger case-control study, folate supplementation during sulfasalazine administration is recommended to possibly prevent the complication of dysplasia or cancer in ulcerative colitis.