Validation of Health Event Capture in the Marshfield Epidemiologic Study Area.

OBJECTIVE: In this study, health event capture is broadly defined as the degree to which a group of people use a particular provider network as their primary source of health care services. The Marshfield Epidemiologic Study Area (MESA) is a valuable resource for population-based health research, but the completeness of health event capture has not been validated in recent years. Our objective was to determine the current level of outpatient and inpatient health event capture by Marshfield Clinic (MC) facilities and affiliated hospitals for people living within MESA. DESIGN: A stratified sample survey with strata defined by MESA region (Central or North) and age group (<18 years or ≥18 years). SETTING: 24 ZIP codes in central and northern Wisconsin, USA. PARTICIPANTS: 2,485 individuals participated of the 4,313 sampled cohort members residing in MESA Central (N=61,041) and MESA North (N=25,906) on February 22, 2011. METHODS: A health care utilization survey was mailed to a random sample stratified by age group and MESA region. Telephone interviews were attempted for nonrespondents. The survey requested information on sources of outpatient care and overnight hospital admissions. Population proportions representing health event capture metrics and corresponding 95% confidence intervals (CI) were estimated with analytic weights applied to account for the survey design. RESULTS: Among those with an outpatient visit during the past 24 months, the most recent visit of an estimated 93% (95% CI, 91% - 94%) was at a MC facility. The most recent admission of an estimated 93% (95% CI, 90% - 96%) of those hospitalized in the past 24 months was at a hospital affiliated with MC. The proportion admitted to MC affiliated hospitals was higher for residents of MESA Central (97%) compared to MESA North (83%). CONCLUSION: A high proportion of outpatient visits and inpatient admissions in MESA Central and MESA North are accessible in the MC electronic health record. This pattern of high health event capture has been demonstrated since the inception of MESA in 1991. The results from this study validate and support the continued use of MESA for population-based epidemiologic and clinical research.

Use of streptogramin growth promoters in poultry and isolation of streptogramin-resistant Enterococcus faecium from humans.

BACKGROUND: Virginiamycin use in poultry selects for Enterococcus faecium with cross-resistance to quinupristin-dalfopristin, a drug for vancomycin-resistant E. faecium in humans. We conducted an epidemiologic study of poultry exposures as risk factors for human carriage of quinupristin-dalfopristin-resistant E. faecium. METHODS: Rectal or fecal samples for E. faecium testing were obtained from 567 newly admitted hospital patients and 100 healthy vegetarians. Participants were interviewed regarding poultry exposure. Retail poultry washes (160 conventional and 26 antibiotic free) were also tested for the presence of E. faecium. Constitutive and inducible quinupristin-dalfopristin resistance were assessed in E. faecium isolates, and resistance genes were identified by polymerase chain reaction. RESULTS: E. faecium was isolated from 105 patients, 65 vegetarians, and 77 conventional and 23 antibiotic-free poultry washes. Constitutive quinupristin-dalfopristin resistance was absent in human E. faecium, but 56% of conventional poultry isolates were quinupristin-dalfopristin resistant. Inducible quinupristin-dalfopristin resistance was more common in samples from patients than in those from vegetarians and in washes of conventional than antibiotic-free poultry. Higher poultry consumption was associated with inducible quinupristin-dalfopristin resistance. vatE was present in 38% of E. faecium isolates from patients and none from vegetarians. Touching raw poultry was associated with the presence of vatE. CONCLUSIONS: Poultry exposure is associated with a quinupristin-dalfopristin resistance gene and inducible quinupristin-dalfopristin resistance in human fecal E. faecium. The continued use of virginiamycin may increase the potential for streptogramin-resistant E. faecium infection in humans.