Jennifer L. St. Sauver

Incidence, Prevalence, and Clinical Course of Idiopathic Pulmonary Fibrosis: A Population-Based Study

BACKGROUND Limited data exist regarding the population-based epidemiology of idiopathic pulmonary fibrosis (IPF). The objective of the study was to describe the trends in the incidence, prevalence, and clinical course of IPF in the community. METHODS We conducted a population-based study of adult patients with IPF in Olmsted County, Minnesota, from 1997 to 2005. Two methods were used to identify IPF cases, as defined by the 2002 American Thoracic Society/European Respiratory Society consensus statement: (1) usual interstitial pneumonia (UIP) on a surgical lung biopsy specimen or a definite UIP pattern on a high-resolution CT image (narrow criteria) and (2) UIP on a surgical lung biopsy specimen or a definite or possible UIP pattern on CT image (broad criteria). RESULTS Of 596 patients screened for the possibility of pulmonary disease or pulmonary fibrosis over 9 years of follow-up, 47 cases had IPF. Of these, 24 met the narrow criteria. The age- and sex-adjusted incidence was 8.8/100,000 and 17.4/100,000 person-years, for narrow and broad criteria, respectively. The age-adjusted incidence was higher in men than in women, and among patients aged 70-79 years. During the study period, the incidence of IPF decreased (P < .001). On December 31, 2005, the age- and sex-adjusted prevalence was 27.9/100,000 and 63/100,000 persons by narrow and broad criteria, respectively. Thirty-seven patients experienced a total of 53 respiratory exacerbations (26 IPF related, 27 non-IPF related), and 34 (72%) patients died. The primary cause of death was IPF related in 16 (47%) patients. Median survival for narrow-criteria and broad-criteria incidence cases was 3.5 and 4.4 years, respectively. CONCLUSIONS The incidence of IPF in Olmsted County decreased over the study period. Nonprimary IPF respiratory exacerbations are as frequent as primary IPF respiratory exacerbations and an important cause of death.

A Population-Based Study of the Incidence and Complication Rates of Herpes Zoster Before Zoster Vaccine Introduction

OBJECTIVE To establish accurate, up-to-date, baseline epidemiological data for herpes zoster (HZ) before the introduction of the recently licensed HZ vaccine. METHODS Using data from January 1, 1996, to October 15, 2005, we conducted a population-based study of adult residents (Greater than or equal to 22 years) of Olmsted County, MN, to determine (by medical record review) the incidence of HZ and the rate of HZ-related complications. Incidence rates were determined by age and sex and adjusted to the US population. RESULTS A total of 1669 adult residents with a confirmed diagnosis of HZ were identified between January 1, 1996, and December 31, 2001. Most (92%) of these patients were immunocompetent and 60% were women. When adjusted to the US adult population, the incidence of HZ was 3.6 per 1000 person-years (95% confidence interval, 3.4-3.7), with a temporal increase from 3.2 to 4.1 per 1000 person-years from 1996 to 2001. The incidence of HZ and the rate of HZ-associated complications increased with age, with 68% of cases occurring in those aged 50 years and older. Postherpetic neuralgia occurred in 18% of adult patients with HZ and in 33% of those aged 79 years and older. Overall, 10% of all patients with HZ experienced 1 or more nonpain complications. CONCLUSIONS Our population-based data suggest that HZ primarily affects immunocompetent adults older than 50 years; 1 in 4 experiences some type of HZ-related complication.

Use of a Medical Records Linkage System to Enumerate a Dynamic Population Over Time: The Rochester Epidemiology Project

The Rochester Epidemiology Project (REP) is a unique research infrastructure in which the medical records of virtually all persons residing in Olmsted County, Minnesota, for over 40 years have been linked and archived. In the present article, the authors describe how the REP links medical records from multiple health care institutions to specific individuals and how residency is confirmed over time. Additionally, the authors provide evidence for the validity of the REP Census enumeration. Between 1966 and 2008, 1,145,856 medical records were linked to 486,564 individuals in the REP. The REP Census was found to be valid when compared with a list of residents obtained from random digit dialing, a list of residents of nursing homes and senior citizen complexes, a commercial list of residents, and a manual review of records. In addition, the REP Census counts were comparable to those of 4 decennial US censuses (e.g., it included 104.1% of 1970 and 102.7% of 2000 census counts). The duration for which each person was captured in the system varied greatly by age and calendar year; however, the duration was typically substantial. Comprehensive medical records linkage systems like the REP can be used to maintain a continuously updated census and to provide an optimal sampling framework for epidemiologic studies.

The Epidemiology of Community-Acquired Clostridium difficile Infection: A Population-Based Study

OBJECTIVES:Clostridium difficile infection (CDI) is a common hospital-acquired infection with increasing incidence, severity, recurrence, and associated morbidity and mortality. There are emerging data on the occurrence of CDI in nonhospitalized patients. However, there is a relative lack of community-based CDI studies, as most of the existing studies are hospital based, potentially influencing the results by referral or hospitalization bias by missing cases of community-acquired CDI.METHODS:To better understand the epidemiology of community-acquired C. difficile infection, a population-based study was conducted in Olmsted County, Minnesota, using the resources of the Rochester Epidemiology Project. Data regarding severity, treatment response, and outcomes were compared in community-acquired vs. hospital-acquired cohorts, and changes in these parameters, as well as in incidence, were assessed over the study period.RESULTS:Community-acquired CDI cases accounted for 41% of 385 definite CDI cases. The incidence of both community-acquired and hospital-acquired CDI increased significantly over the study period. Compared with those with hospital-acquired infection, patients with community-acquired infection were younger (median age 50 years compared with 72 years), more likely to be female (76% vs. 60%), had lower comorbidity scores, and were less likely to have severe infection (20% vs. 31%) or have been exposed to antibiotics (78% vs. 94%). There were no differences in the rates of complicated or recurrent infection in patients with community-acquired compared with hospital-acquired infection.CONCLUSIONS:In this population-based cohort, a significant proportion of cases of CDI occurred in the community. These patients were younger and had less severe infection than those with hospital-acquired infection. Thus, reports of CDI in hospitalized patients likely underestimate the burden of disease and overestimate severity.

Common sequence variants on 2p15 and Xp11.22 confer susceptibility to prostate cancer

We conducted a genome-wide SNP association study on prostate cancer on over 23,000 Icelanders, followed by a replication study including over 15,500 individuals from Europe and the United States. Two newly identified variants were shown to be associated with prostate cancer: rs5945572 on Xp11.22 and rs721048 on 2p15 (odds ratios (OR) = 1.23 and 1.15; P = 3.9 × 10−13 and 7.7 × 10−9, respectively). The 2p15 variant shows a significantly stronger association with more aggressive, rather than less aggressive, forms of the disease.

History of the Rochester Epidemiology Project: Half a Century of Medical Records Linkage in a US Population

The Rochester Epidemiology Project (REP) has maintained a comprehensive medical records linkage system for nearly half a century for almost all persons residing in Olmsted County, Minnesota. Herein, we provide a brief history of the REP before and after 1966, the year in which the REP was officially established. The key protagonists before 1966 were Henry Plummer, Mabel Root, and Joseph Berkson, who developed a medical records linkage system at Mayo Clinic. In 1966, Leonard Kurland established collaborative agreements with other local health care providers (hospitals, physician groups, and clinics [primarily Olmsted Medical Center]) to develop a medical records linkage system that covered the entire population of Olmsted County, and he obtained funding from the National Institutes of Health to support the new system. In 1997, L. Joseph Melton III addressed emerging concerns about the confidentiality of medical record information by introducing a broad patient research authorization as per Minnesota state law. We describe how the key protagonists of the REP have responded to challenges posed by evolving medical knowledge, information technology, and public expectation and policy. In addition, we provide a general description of the system; discuss issues of data quality, reliability, and validity; describe the research team structure; provide information about funding; and compare the REP with other medical information systems. The REP can serve as a model for the development of similar research infrastructures in the United States and worldwide.

A Population-Based, Longitudinal Study of Erectile Dysfunction and Future Coronary Artery Disease

OBJECTIVE To assess the association between erectile dysfunction (ED) and the long-term risk of coronary artery disease (CAD) and the role of age as a modifier of this association. PARTICIPANTS AND METHODS From January 1, 1996, to December 31, 2005, we biennially screened a random sample of 1402 community-dwelling men with regular sexual partners and without known CAD for the presence of ED. Incidence densities of CAD were calculated after age stratification and adjusted for potential confounders by time-dependent Cox proportional hazards models. RESULTS The prevalence of ED was 2% for men aged 40 to 49 years, 6% for men aged 50 to 59 years, 17% for men aged 60 to 69 years, and 39% for men aged 70 years or older. The CAD incidence densities per 1000 person-years for men without ED in each age group were 0.94 (40-49 years), 5.09 (50-59 years), 10.72 (60-69 years), and 23.30 (> or =70 years). For men with ED, the incidence densities of CAD for each age group were 48.52 (40-49 years), 27.15 (50-59 years), 23.97 (60-69 years), and 29.63 (> or =70 years). CONCLUSION ED and CAD may be differing manifestations of a common underlying vascular pathology. When ED occurs in a younger man, it is associated with a marked increase in the risk of future cardiac events, whereas in older men, ED appears to be of little prognostic importance. Young men with ED may be ideal candidates for cardiovascular risk factor screening and medical intervention.

Generalizability of Epidemiological Findings and Public Health Decisions: An Illustration From the Rochester Epidemiology Project

OBJECTIVE To illustrate the problem of generalizability of epidemiological findings derived from a single population using data from the Rochester Epidemiology Project and from the US Census. METHODS We compared the characteristics of the Olmsted County, Minnesota, population with the characteristics of populations residing in the state of Minnesota, the Upper Midwest, and the entire United States. RESULTS Age, sex, and ethnic characteristics of Olmsted County were similar to those of the state of Minnesota and the Upper Midwest from 1970 to 2000. However, Olmsted County was less ethnically diverse than the entire US population (90.3% vs 75.1% white), more highly educated (91.1% vs 80.4% high school graduates), and wealthier (

Data Resource Profile: The Rochester Epidemiology Project (REP) medical records-linkage system

51,316 vs

Nonalcoholic fatty liver disease increases risk of death among patients with diabetes: a community-based cohort study.

41,994 median household income; 2000 US Census data). Age- and sex-specific mortality rates were similar for Olmsted County, the state of Minnesota, and the entire United States. CONCLUSION We provide an example of analyses and comparisons that may guide the generalization of epidemiological findings from a single population to other populations or to the entire United States.