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Dive into the research topics where Peter C. Wollan is active.

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Featured researches published by Peter C. Wollan.


Mayo Clinic Proceedings | 2007

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

Barbara P. Yawn; Patricia Saddier; Peter C. Wollan; Jennifer L. St. Sauver; Marge Kurland; Lina S. Sy

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.


The Journal of Allergy and Clinical Immunology | 1999

Allergic rhinitis in Rochester, Minnesota residents with asthma: Frequency and impact on health care charges ☆ ☆☆ ★

Barbara P. Yawn; John W. Yunginger; Peter C. Wollan; Charles E. Reed; Marc D. Silverstein; Alan G. Harris

BACKGROUND Asthma is a common and costly condition. Concomitant asthma and allergic rhinitis (AR) have been shown to increase the medication costs for people with asthma. No studies have compared medical care costs of those with and without concomitant AR. OBJECTIVES We sought to determine the prevalence and incremental medical care costs of concomitant AR. METHODS For each member of a population-based asthma cohort, we used all their medical charts within Olmsted County to record age at first diagnosis of asthma; the presence and age of any diagnosis of AR; and the total, ambulatory, and respiratory care-related costs of medical care. Costs were compared for age- and sex-specific strata of people with asthma who did and did not have AR. RESULTS AR was most commonly diagnosed in people whose asthma was diagnosed before age 25 (prevalence of 59%) and uncommonly diagnosed in anyone after age 40 (prevalence <15%). Yearly medical care charges were on average 46% higher for those with asthma and concomitant AR than for persons with asthma alone, controlling for age and sex. We were unable to assess the impact of treatment of AR on medical care charges. CONCLUSIONS Physicians should consider the diagnosis of AR (prevalence >50%) in all symptomatic children and young adults with asthma. Further evaluation is necessary to evaluate the ability of treatment to decrease the incremental costs of AR in persons with asthma.


Journal of Prosthetic Dentistry | 1998

Retrospective review of 1170 endosseous implants placed in partially edentulous jaws

Steven E. Eckert; Peter C. Wollan

STATEMENT OF PROBLEM Implant-supported restorations in the partially edentulous jaw have been performed at the Mayo Clinic for more than 10 years. Clinical performance of the implants and the prostheses should be reported to ensure effectiveness of this procedure. PURPOSE This retrospective study described results for implant survival, implant fracture rate, prosthetic complications, and design changes that may impact these results. MATERIAL AND METHODS A retrospective chart review was conducted of all registered implant patients in a large multispecialty medical center. Patients with a partially edentulous jaw who had received endosseous implants to support and retain dental prostheses were included in this review. Implant survival and fracture, prosthetic complications, and demographic data were recorded and analyzed through Kaplan-Meier methods. RESULTS A total of 1170 implants were placed in four anatomic locations: anterior maxilla, posterior maxilla, anterior mandible, or posterior mandible. Location of implants was shown to have no effect on implant survival (p = 0.7398), implant fracture rates (p = 0.2385), screw loosening (p = 0.8253), or screw fracture (p = 0.2737). Development of new restorative components has resulted in significantly better rates of implant survival without fracture (p = 0.0054), screw function without loosening (p < 0.0001) and screw function without fracture (p = 0.0013). Implant survival seems to have been improved with the new components (p = 0.0513). CONCLUSIONS Implant survival in this study was independent of anatomic location of implants. Virtually all clinical performance factors were improved by design changes in implant restorative components that were brought to market in early 1991.


The Journal of Allergy and Clinical Immunology | 2008

Increased risk of serious pneumococcal disease in patients with asthma

Young J. Juhn; Hirohito Kita; Barbara P. Yawn; Thomas G. Boyce; Kwang H. Yoo; Michaela E. McGree; Amy L. Weaver; Peter C. Wollan; Robert M. Jacobson

BACKGROUND Individuals with asthma have been reported to be at increased risk of invasive pneumococcal disease (IPD). These findings need to be confirmed in a different population-based study setting. OBJECTIVE We assessed whether serious pneumococcal disease (SPD), defined as an IPD, pneumococcal pneumonia, or both, was associated with asthma status. METHODS This is a retrospective case-control study using criteria-based methods for ascertaining SPD, as well as asthma. Subjects were residents of Rochester, Minnesota, who had SPD between 1964 and 1983 (the primarily pre-pneumococcal vaccine era) and their age- and sex-matched control subjects using 1:2 matching. Potential cases and control subjects were identified by using the Rochester Epidemiology project database and confirmed by medical record reviews. All cases and control subjects were merged with the database comprising the entire pool of Rochester residents with and without asthma between 1964 and 1983. RESULTS A total of 3941 records of potential patients with SPD were reviewed, and we identified 174 cases of SPD (51% male subjects and 94% white subjects). SPD was associated with a history of asthma among all ages (odds ratio, 2.4; 95% CI, 0.9-6.6; P = .09) and among adults (odds ratio, 6.7; 95% CI, 1.6-27.3; P = .01), controlling for high-risk conditions for IPD and smoking exposure. The population-attributable risk percentage was 17% in the adult population. CONCLUSION Adults with asthma might be at increased risk of SPD.


Bone | 2000

Long-term trends in the incidence of Paget’s disease of bone

Robert D. Tiegs; Christine M. Lohse; Peter C. Wollan; L. J. Melton

Existing data on the epidemiology of Pagets disease of bone are limited by the lack of directly determined secular trends in clinically diagnosed Pagets disease. In the current study, we examine trends in Pagets disease incidence in Olmsted County, MN, using data from the Rochester Epidemiology Project medical records linkage system. During the period 1950 through 1994, 236 Olmsted County, MN residents were diagnosed for the first time with Pagets disease of bone at a mean age of 69.6 years. Overall, there were 129 (54.7%) men and 107 women, and the age-adjusted incidence of Pagets disease was 12.7 per 100,000 person-years (95% CI 10.4-14.9) among the men compared with 7.0 per 100,000 person-years (95% CI 5.6-8.3) among Olmsted County women (male/female ratio of 1.8:1). The higher incidence in males compared with females and the increase in incidence with older age were statistically significant. The incidence of Pagets disease in Olmsted County seems to have increased over the first part of the study period and then declined. This may have resulted from ascertainment bias: the introduction of a 12-test automated serum chemistry panel in 1974 might have led to a sudden increase in the apparent incidence of Pagets disease followed by a compensatory decrease. In addition, there was a decrease in the proportion of patients who were symptomatic at diagnosis, from 36% in 1950-1959 to 27% in 1980-1994. This finding also suggests that routine measurement of alkaline phosphatase may have led to more diagnosis of asymptomatic individuals. The subsequent fall in the incidence of Pagets disease is consistent with previous reports, although this apparent decline could be artifactual to the extent that the reservoir of undiagnosed cases in the population was exhausted by earlier testing.


Mayo Clinic Proceedings | 2011

Herpes zoster recurrences more frequent than previously reported

Barbara P. Yawn; Peter C. Wollan; Marge Kurland; Jennifer L. St. Sauver; Patricia Saddier

OBJECTIVE To present population-based estimates of herpes zoster (HZ) recurrence rates among adults. PATIENTS AND METHODS To identify recurrent cases of HZ, we reviewed the medical records (through December 31, 2007) of all Olmsted County, Minnesota, residents aged 22 years or older who had an incident case of HZ between January 1, 1996, and December 31, 2001. Kaplan-Meier curves and Cox regression models were used to describe recurrences by age, immune status, and presence of prolonged pain at the time of the incident HZ episode. RESULTS Of the 1669 persons with a medically documented episode of HZ, 95 had 105 recurrences (8 persons with >1 recurrence) by December 31, 2007, an average follow-up of 7.3 years. The Kaplan-Meier estimate of the recurrence rate at 8 years was 6.2%. With a maximum follow-up of 12 years, the time between HZ episodes in the same person varied from 96 days to 10 years. Recurrences were significantly more likely in persons with zoster-associated pain of 30 days or longer at the initial episode (hazard ratio, 2.80; 95% confidence interval, 1.84-4.27; P<.001) and in immunocompromised individuals (hazard ratio, 2.35; 95% confidence interval, 1.35-4.08; P=.006). Women and anyone aged 50 years or older at the index episode also had a greater likelihood of recurrence. CONCLUSION Rates of HZ recurrence appear to be comparable to rates of first HZ occurrence in immunocompetent individuals, suggesting that recurrence is sufficiently common to warrant investigation of vaccine prevention in this group.


Mayo Clinic Proceedings | 1996

Epithelioid Sarcoma: A Clinicopathologic Review of 55 Cases

Amy C. Halling; Peter C. Wollan; Douglas J. Pritchard; Richard Vlasak; Antonio G. Nascimento

OBJECTIVE To identify any clinical and pathologic features of treatment modalities that are predictive of outcome in patients with epithelioid sarcoma, a rare slow-growing soft tissue tumor most commonly occurring in the distal extremities of young adults. DESIGN We reviewed the institutional files for cases of epithelioid sarcoma for the period 1956 to 1991 and analyzed the effect of various factors on survival. MATERIAL AND METHODS Fifty-five cases of epithelioid sarcoma were found, and the relevant clinical, pathologic, treatment, follow-up, and outcome features were assessed. RESULTS All tumors were treated initially by operative resection. The recurrence rate progressively decreased with increasing aggressiveness of the initial operation; however, no difference was noted in metastatic rate. Overall, the recurrence rate was 38% and the metastatic rate was 47%. At the end of a mean follow-up of 102 months, 69% of patients had no evidence of disease, 27% had died of the disease, and 4% were alive with disease. Increasing tumor size, necrosis of more than 30%, and vascular invasion correlated significantly with a worse prognosis. CONCLUSION Epithelioid sarcoma should be considered a malignant neoplasm with a significant potential for aggressive behavior, and close follow-up of affected patients should be maintained for many years. Initial treatment should be aggressive in an attempt to prevent recurrence.


Mayo Clinic Proceedings | 2009

Health Care Utilization and Cost Burden of Herpes Zoster in a Community Population

Barbara P. Yawn; Robbin F. Itzler; Peter C. Wollan; James M. Pellissier; Lina S. Sy; Patricia Saddier

OBJECTIVE To conduct a population-based study to assess health care utilization (HCU) and costs associated with herpes zoster (HZ) and its complications, including postherpetic neuralgia (PHN) and nonpain complications, in adults aged 22 years and older. PATIENTS AND METHODS Medical record data on HCU were abstracted for all confirmed new cases of HZ from January 1, 1996, through December 31, 2001, among residents of Olmsted County, Minnesota. Herpes zoster-related costs were estimated by applying the Medicare Payment Fee Schedule to health care encounters and mean wholesale prices to medications. All costs were adjusted to 2006 US dollars using the medical care component of the Consumer Price Index. RESULTS The HCU and cost of the 1669 incident HZ cases varied, depending on the complications involved. From 3 weeks before to 1 year after initial diagnosis, there were a mean of 1.8 outpatient visits and 3.1 prescribed medications at a cost of


The Journal of Allergy and Clinical Immunology | 2010

Increased risk of serious pneumococcal disease in patients with atopic conditions other than asthma

Ji A. Jung; Hirohito Kita; Barbara P. Yawn; Thomas G. Boyce; Kwang H. Yoo; Michaela E. McGree; Amy L. Weaver; Peter C. Wollan; Robert M. Jacobson; Young J. Juhn

720 for cases without PHN or nonpain complications compared with 7.5 outpatient visits and 14.7 prescribed medications at a cost of


Journal of the American College of Cardiology | 1997

Exercise Tolerance in Patients With Ebstein’s Anomaly ☆

Susan G MacLellan-Tobert; David J. Driscoll; Carl D Mottram; Douglas W. Mahoney; Peter C. Wollan; Gordon K. Danielson

3998 when complications, PHN, or nonpain complications were present. CONCLUSION The annual medical care cost of treating incident HZ cases in the United States, extrapolated from the results of this study in Olmsted County, is estimated at

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