Appendicitis: higher risk in Mexican Americans?

OBJECTIVES: Mexican Americans (MAs), compared to white non-Hispanics (WNHs), have higher rates of biliary disease, noninsulin dependent diabetes, and endstage renal disease but lower rates of lung cancer, hip fractures, and mortality from coronary heart disease. Relatively little research has been done to identify other ethnic differences in disease incidence. We used surgical procedure rates to confirm known ethnic differences and to explore our clinical suspicion that MAs have higher rates of appendectomy than WNHs. METHODS: We used a registry of surgical procedures at two teaching hospitals in South Texas to calculate proportional operation ratios (PORs) for MAs versus WNHs. These two hospitals are the primary source of acute hospital care for the indigent in the area. The POR is arithmetically identical to proportional incidence and mortality ratios. RESULTS: MAs underwent appendectomy proportionally more often than WNHs at both hospitals (POR = 1.41 and 1.75, p < 0.0001). Other significant PORs were consistent with known ethnic disease differences in biliary tract operations, vascular access for chronic hemodialysis, lung cancer, and coronary artery bypass. CONCLUSIONS: These findings support the hypothesis that MAs may undergo appendectomy more often than WNHs and so may be at higher risk of appendicitis.

Survival among Mexican-Americans, non-Hispanic whites, and African-Americans with end-stage renal disease: the emergence of a minority pattern of increased incidence and prolonged survival.

We undertook this study to determine whether there is a significant difference in survival on treatment for end-stage renal disease between Mexican-Americans, non-Hispanic whites, and African-Americans. A database covering the years 1975 to 1986 was obtained from the Texas Kidney Health Program. Eight-eight percent to 90% of patients starting renal replacement therapy in Texas were included in this database. The patients were followed until death, for 3 years after successful transplantation, or until they were lost to follow-up. Life table analysis as well as age-adjusted analysis using the Cox proportional hazards model were performed comparing ethnic/racial groups, disease etiology, and treatment type. In life-table analyses, African-Americans and Mexican-Americans had a survival advantage in most age, disease, and treatment groups. With age adjustment, this survival advantage remained for all etiologies combined, for diabetes and hypertension cases, and for patients receiving hemodialysis in a center. Multivariate analysis revealed a persistent survival advantage for Mexican-Americans independent of traditional predictor variables, such as age, disease etiology, treatment type, or size of the center in which they received treatment. In this same analysis, African-Americans showed an advantage in the older age groups. Both African-Americans and Mexican-Americans on renal replacement therapy have an increased survival advantage compared with non-Hispanic whites. Given the additional burden of increased incidence of end-stage renal disease in these groups, the cost of renal replacement therapy for these minorities is disproportionately high. Further study should be aimed at elucidation of the mechanisms by which minorities achieve their survival advantage.

The influence of outpatient insurance coverage on the microvascular complications of non-insulin-dependent diabetes in Mexican Americans.

Does poor health insurance coverage contribute to increased microvascular complications (nephropathy and retinopathy) in Mexican Americans with non-insulin-dependent diabetes? Mexican-American subjects with diabetes were identified in a population-based cardiovascular risk factor survey, the San Antonio Heart Study. Retinopathy, nephropathy, source of health care, and type and extent of health insurance coverage were assessed in a special diabetes complications exam. Among Mexican-American subjects with non-insulin-dependent diabetes diagnosed prior to their participation in the survey (n = 255), 26% (n = 67) lacked any type of health insurance, and 28% relied on county- or federal-funded clinics rather than private doctors as their primary source of care. Among those with health insurance (188 of 255), only 68% (127 of 188) or 24% of the total sample had private health insurance, and, of those with private insurance, 48% (35 of 73) received reimbursement for outpatient doctor visits and 57% for outpatient medications. Microvascular complications were more common among those who received their health care from a clinic versus a private doctor, and among those who lacked health insurance coverage for outpatient doctor visits and medications. Thus, poor health insurance coverage in the outpatient setting correlates with higher rates of microvascular complications among Mexican Americans with non-insulin-dependent diabetes mellitus.