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Dive into the research topics where Mark Perkins is active.

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Featured researches published by Mark Perkins.


Clinical Infectious Diseases | 1997

Disseminated Bacille Calmette-Guérin Disease After Vaccination: Case Report and Review

Elizabeth A. Talbot; Mark Perkins; Sandra Fagundes M. Silva; Richard Frothingham

The attenuated bacille Calmette-Guérin (BCG) vaccine is administered to prevent tuberculosis. Complications of vaccination are uncommon. We report a new case of disseminated BCG disease and review 27 additional cases identified from a review of > 5,000 reports published between 1980 and 1996. Twenty-four of the 28 total cases were associated with an immune deficiency, including nine cases of AIDS. Seventy-one percent of the cases occurred in children younger than 2 years old. Sixty-eight percent of the patients were male. About one-half of the patients were vaccinated in a developed nation, but 85% of the cases were reported from a developed nation. Response to therapy was poor, with an overall mortality rate of 71%. We made two new observations. Disseminated BCG disease has historically been a disease of infants, but cases now occur in adults and older children coinfected with human immunodeficiency virus. Cases also occur after revaccination of individuals who were anergic following the initial administration of BCG vaccine. Disseminated BCG disease is an uncommon but devastating complication of vaccination that should be considered in the appropriate clinical setting. Immunocompromised infants and patients with late-stage AIDS are at greatest risk and respond poorly to standard therapies.


Health Services Research | 2010

Use of Outpatient Care in Veterans Health Administration and Medicare among Veterans Receiving Primary Care in Community-Based and Hospital Outpatient Clinics

Chuan Fen Liu; Michael K. Chapko; Chris L. Bryson; James F. Burgess; John C. Fortney; Mark Perkins; Nancy D. Sharp; Matthew L. Maciejewski

OBJECTIVE To examine differences in use of Veterans Health Administration (VA) and Medicare outpatient services by VA primary care patients. DATA SOURCES/STUDY SETTING VA administrative and Medicare claims data from 2001 to 2004. STUDY DESIGN Retrospective cohort study of outpatient service use by 8,964 community-based and 6,556 hospital-based VA primary care patients. PRINCIPAL FINDINGS A significant proportion of VA patients used Medicare-reimbursed primary care (>30 percent) and specialty care (>60 percent), but not mental health care (3-4 percent). Community-based patients had 17 percent fewer VA primary care visits (p<.001), 9 percent more Medicare-reimbursed visits (p<.001), and 6 percent fewer total visits (p<.05) than hospital-based patients. Community-based patients had 22 percent fewer VA specialty care visits (p<.0001) and 21 percent more Medicare-reimbursed specialty care visits (p<.0001) than hospital-based patients, but no difference in total visits (p=.80). CONCLUSIONS Medicare-eligible VA primary care patients followed over 4 consecutive years used significant primary care and specialty care outside of VA. Community-based patients offset decreased VA use with increased service use paid by Medicare, suggesting that increasing access to VA primary care via community clinics may fragment veteran care in unintended ways. Coordination of care between VA and non-VA providers and health care systems is essential to improve the quality and continuity of care.


Journal of The American Society of Nephrology | 2015

Trends in the Timing and Clinical Context of Maintenance Dialysis Initiation

Ann M. O’Hare; Susan P. Wong; Margaret K. Yu; Bruce Wynar; Mark Perkins; Chuan Fen Liu; Jaclyn M. Lemon; Paul L. Hebert

Whether secular trends in eGFR at dialysis initiation reflect changes in clinical presentation over time is unknown. We reviewed the medical records of a random sample of patients who initiated maintenance dialysis in the Department of Veterans Affairs (VA) in fiscal years 2000-2009 (n=1691) to characterize trends in clinical presentation in relation to eGFR at initiation. Between fiscal years 2000-2004 and 2005-2009, mean eGFR at initiation increased from 9.8±5.8 to 11.0±5.5 ml/min per 1.73 m(2) (P<0.001), the percentage of patients with an eGFR of 10-15 ml/min per 1.73 m(2) increased from 23.4% to 29.9% (P=0.002), and the percentage of patients with an eGFR>15 ml/min per 1.73 m(2) increased from 12.1% to 16.3% (P=0.01). The proportion of patients who were acutely ill at the time of initiation and the proportion of patients for whom the decision to initiate dialysis was based only on level of kidney function did not change over time. Frequencies of documented clinical signs and/or symptoms were similar during both time periods. The adjusted odds of initiating dialysis at an eGFR of 10-15 or >15 ml/min per 1.73 m(2) (versus <10 ml/min per 1.73 m(2)) during the later versus earlier time period were 1.43 (95% confidence interval [95% CI], 1.13 to 1.81) and 1.46 (95% CI, 1.09 to 1.97), respectively. In conclusion, trends in eGFR at dialysis initiation at VA medical centers do not seem to reflect changes in the clinical context in which dialysis is initiated.


Health Economics | 2011

Importance of health system context for evaluating utilization patterns across systems.

James F. Burgess; Matthew L. Maciejewski; Chris L. Bryson; Michael K. Chapko; John C. Fortney; Mark Perkins; Nancy D. Sharp; Chuan Fen Liu

Measuring health services provided to patients can be difficult when patients see providers across multiple health systems and all visits are rarely captured in a single data source covering all systems where patients receive care. Studies that account for only one system will omit the out-of-system health-care use at the patient level. Combining data across systems and comparing utilization patterns across health systems creates complications for both aggregation and accuracy because data-generating processes (DGPs) tend to vary across systems. We develop a hybrid methodology for aggregation across systems, drawing on the strengths of the DGP in each system, and demonstrate its validity for answering research questions requiring cross-system assessments of health-care utilization. Positive and negative predictive probabilities can be useful to assess the impact of the hybrid methodology. We illustrate these issues comparing public sector (administrative records from the US Department of Veterans Affairs system) and private sector (billing records from the US Medicare system) patient level data to identify primary-care utilization. Understanding the context of a particular health system and its effect on the DGP is important in conducting effective valid evaluations.


BMC Health Services Research | 2012

Use of outpatient care in VA and Medicare among disability-eligible and age-eligible veteran patients

Chuan Fen Liu; Chris L. Bryson; James F. Burgess; Nancy D. Sharp; Mark Perkins; Matthew L. Maciejewski

BackgroundMore than half of veterans who use Veterans Health Administration (VA) care are also eligible for Medicare via disability or age, but no prior studies have examined variation in use of outpatient services by Medicare-eligible veterans across health system, type of care or time.ObjectivesTo examine differences in use of VA and Medicare outpatient services by disability-eligible or age-eligible veterans among veterans who used VA primary care services and were also eligible for Medicare.MethodsA retrospective cohort study of 4,704 disability- and 10,816 age-eligible veterans who used VA primary care services in fiscal year (FY) 2000. We tracked their outpatient utilization from FY2001 to FY2004 using VA administrative and Medicare claims data. We examined utilization differences for primary care, specialty care, and mental health outpatient visits using generalized estimating equations.ResultsAmong Medicare-eligible veterans who used VA primary care, disability-eligible veterans had more VA primary care visits (p < 0.001) and more VA specialty care visits (p < 0.001) than age-eligible veterans. They were more likely to have mental health visits in VA (p < 0.01) and Medicare-reimbursed visits (p < 0.01). Disability-eligible veterans also had more total (VA+Medicare) visits for primary care (p < 0.01) and specialty care (p < 0.01), controlling for patient characteristics.ConclusionsGreater use of primary care and specialty care visits by disability-eligible veterans is most likely related to greater health needs not captured by the patient characteristics we employed and eligibility for VA care at no cost. Outpatient care patterns of disability-eligible veterans may foreshadow care patterns of veterans returning from Afghanistan and Iraq wars, who are entering the system in growing numbers. This study provides an important baseline for future research assessing utilizations among returning veterans who use both VA and Medicare systems. Establishing effective care coordination protocols between VA and Medicare providers can help ensure efficient use of taxpayer resources and high quality care for disabled veterans.


BMC Health Services Research | 2012

Does the presence of a pharmacist in primary care clinics improve diabetes medication adherence

Beverly M. Kocarnik; Chuan Fen Liu; Edwin S. Wong; Mark Perkins; Matthew L. Maciejewski; Elizabeth M. Yano; David H. Au; John D. Piette; Chris L. Bryson

BackgroundAlthough oral hypoglycemic agents (OHAs) are an essential element of therapy for the management of type 2 diabetes, OHA adherence is often suboptimal. Pharmacists are increasingly being integrated into primary care as part of the move towards a patient-centered medical home and may have a positive influence on medication use. We examined whether the presence of pharmacists in primary care clinics was associated with higher OHA adherence.MethodsThis retrospective cohort study analyzed 280,603 diabetes patients in 196 primary care clinics within the Veterans Affairs healthcare system. Pharmacists presence, number of pharmacist full-time equivalents (FTEs), and the degree to which pharmacy services are perceived as a bottleneck in each clinic were obtained from the 2007 VA Clinical Practice Organizational Survey—Primary Care Director Module. Patient-level adherence to OHAs using medication possession ratios (MPRs) were constructed using refill data from administrative pharmacy databases after adjusting for patient characteristics. Clinic-level OHA adherence was measured as the proportion of patients with MPR >= 80%. We analyzed associations between pharmacy measures and clinic-level adherence using linear regression.ResultsWe found no significant association between pharmacist presence and clinic-level OHA adherence. However, adherence was lower in clinics where pharmacy services were perceived as a bottleneck.ConclusionsPharmacist presence, regardless of the amount of FTE, was not associated with OHA medication adherence in primary care clinics. The exact role of pharmacists in clinics needs closer examination in order to determine how to most effectively use these resources to improve patient-centered outcomes including medication adherence.


The Journal of Infectious Diseases | 2015

Target Product Profile of a Molecular Drug- Susceptibility Test for Use in Microscopy Centers

Claudia M. Denkinger; David L. Dolinger; Marco Schito; William Wells; Frank Cobelens; Madhukar Pai; Matteo Zignol; Daniela M. Cirillo; David Alland; Martina Casenghi; Jim Gallarda; Catharina Boehme; Mark Perkins

BACKGROUND Current phenotypic testing for drug resistance in patients with tuberculosis is inadequate primarily with respect to turnaround time. Molecular tests hold the promise of an improved time to diagnosis. METHODS A target product profile for a molecular drug-susceptibility test (DST) was developed on the basis of a collaborative effort that included opinions gathered from researchers, clinicians, policy makers, and test developers on optimal clinical and operational characteristics in settings of intended use. In addition, the current diagnostic ecosystem and the diagnostic development landscape were mapped. RESULTS Molecular DSTs for detecting tuberculosis in microscopy centers should ideally evaluate for resistance to rifampin, fluoroquinolones, isoniazid, and pyrazinamide and enable the selection of the most appropriate treatment regimen. Performance characteristics of DSTs need to be optimized, but compromises can be made that depend on the trade-off between a false-positive result and a false-negative result. The operational requirements of a test will vary depending on the site of implementation. However, the most-important considerations pertain to quality control, maintenance and calibration, and the ability to export data. CONCLUSION This target product profile defines the needs as perceived by the tuberculosis stakeholder community and attempts to provide a means of communication with test developers to ensure that fit-for-purpose DSTs are being developed.


Allergy, Asthma & Clinical Immunology | 2014

Thiazolidinediones and the risk of asthma exacerbation among patients with diabetes: a cohort study

Seppo T. Rinne; Laura C. Feemster; Bridget F. Collins; David H. Au; Mark Perkins; Christopher L. Bryson; Thomas G O’Riordan; Chuan Fen Liu

BackgroundThiazolidinediones are oral diabetes medications that selectively activate peroxisome proliferator-activated receptor gamma and have potent anti-inflammatory properties. While a few studies have found improvements in pulmonary function with exposure to thiazolidinediones, there are no studies of their impact on asthma exacerbations. Our objective was to assess whether exposure to thiazolidinediones was associated with a decreased risk of asthma exacerbation.MethodsWe performed a cohort study of diabetic Veterans who had a diagnosis of asthma and were taking oral diabetes medications during the period of 10/1/2005 – 9/30/2006. The risk of asthma exacerbations and oral steroid use during 10/1/2006 – 9/30/2007 was compared between patients who were prescribed thiazolidinediones and patients who were on alternative oral diabetes medications. Multivariable logistic regression and negative binomial regression analyses were used to characterize this risk. A sensitivity analysis was performed, restricting our evaluation to patients who were adherent to diabetes therapy.ResultsWe identified 2,178 patients who were on thiazolidinediones and 10,700 who were not. Exposure to thiazolidinediones was associated with significant reductions in the risk of asthma exacerbation (OR = 0.79, 95% CI, 0.62 – 0.99) and oral steroid prescription (OR = 0.73, 95% CI 0.63 – 0.84). Among patients who were adherent to diabetes medications, there were more substantial reductions in the risks for asthma exacerbation (OR = 0.64, 95% CI 0.47 – 0.85) and oral steroid prescription (OR = 0.68, 95% CI 0.57 – 0.81).ConclusionsThiazolidinediones may provide a novel anti-inflammatory approach to asthma management by preventing exacerbations and decreasing the use of oral steroids.


Medical Care | 2012

Measures of adherence to oral hypoglycemic agents at the primary care clinic level: the role of risk adjustment.

Edwin S. Wong; John D. Piette; Chuan Fen Liu; Mark Perkins; Matthew L. Maciejewski; George L. Jackson; David K. Blough; Stephan D. Fihn; David H. Au; Chris L. Bryson

Background:Prior research found that in the Veterans Affairs health care system (VA), the proportion of patients adherent to oral hypoglycemic agents varies from 50% to 80% across primary care clinics. This study examined whether variation in patient and facility characteristics determined those differences. Methods:Retrospective cohort study of 444,418 VA primary care patients with diabetes treated in 559 clinics in fiscal year (FY) 2006–2007. Patients’ adherence to each oral hypoglycemic agent was computed for the first 3 months of FY2007, and averaged across agents to produce an adherence score for the patient’s overall regimen. Patients with an adherence score over 0.8 were defined as adherent. Risk adjustment used hierarchical logistic regression accounting for patient factors and facility effects by clustering patients within clinics and clinics within parent VA medical centers. We then assessed the influence of risk adjustment using observed-to-expected (O/E) ratios computed for each clinic. Results:The mean unadjusted proportion of adherent patients in clinics was 0.715 (interdecile range 0.559–0.826). The percent variation in patient’s likelihood of being adherent explained at the patient, clinic, and parent VA medical center levels was 2.94%, 0.27%, and 0.76%, respectively. The mean clinic-level observed-to-expected ratio was 1.001 (interdecile range 0.975–1.027). Conclusions:The variation in the proportion of patients adherent across clinics remained large after risk adjustment. As patient and facility effects explained only 4% of the variance in adherence, comparing clinics based on unadjusted scores is a reasonable starting point unless more predictive patient, provider, and facility factors are identified.


BMC Health Services Research | 2014

Factors affecting medication adherence: patient perspectives from five veterans affairs facilities.

Clarissa Hsu; Jaclyn M. Lemon; Edwin S. Wong; Elizabeth Carson-Cheng; Mark Perkins; Margaret S. Nordstrom; Chuan Fen Liu; Carol Sprague; Christopher L. Bryson

BackgroundIn the United States, more than 25 million people have diabetes. Medication adherence is known to be important for disease control. However, factors that consistently predict medication adherence are unclear and the literature lacks patient perspectives on how health care systems affect adherence to oral hypoglycemic agents (OHAs). This study explored facilitators and barriers to OHA adherence by obtaining the perspectives of Veterans Affairs (VA) patients with OHA prescriptions.MethodsA total of 45 patients participated in 12 focus groups that explored a wide range of issues that might affect medication adherence. Participants were patients at clinics in Seattle, Washington; San Antonio, Texas; Portland, Oregon; Salem, Oregon, and Warrenton, Oregon.ResultsKey system-level facilitators of OHA adherence included good overall pharmacy service and several specific mechanisms for ordering and delivering medications (automated phone refill service, Web-based prescription ordering), as well as providing pillboxes and printed lists of current medications to patients. Barriers mirrored many of the facilitators. Poor pharmacy service quality and difficulty coordinating multiple prescriptions emerged as key barriers.ConclusionsVA patient focus groups provided insights on how care delivery systems can encourage diabetes medication adherence by minimizing the barriers and enhancing the facilitators at both the patient and system levels. Major system-level factors that facilitated adherence were overall pharmacy service quality, availability of multiple systems for reordering medications, having a person to call when questions arose, counseling about the importance of adherence and providing tools such as pillboxes and updated medication lists.

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Chuan Fen Liu

University of Washington

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Nancy D. Sharp

University of Washington

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David H. Au

University of Washington

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Edwin S. Wong

University of Washington

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Catharina Boehme

Foundation for Innovative New Diagnostics

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