Robert J. Nordyke
University of California, Los Angeles
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Publication
Featured researches published by Robert J. Nordyke.
Journal of Asthma | 2006
David G. Tinkelman; David Price; Robert J. Nordyke; Ronald J. Halbert
Chronic obstructive pulmonary disease (COPD) is often misdiagnosed as asthma, leading to inappropriate treatment and suboptimal patient outcomes. As part of a prospective study of patients with a history consistent with obstructive lung disease, we compared prior diagnostic labels with a study diagnosis based on spirometric results. We enrolled persons 40 years of age or older with prior diagnoses or medications consistent with obstructive lung disease. Patients were recruited via random mailing to primary care practices in Aberdeen, Scotland, and Denver, Colorado. Prior diagnoses of chronic bronchitis or emphysema (CBE) and asthma were reported by the subjects. Participants underwent pre- and post-bronchodilator spirometry. A study diagnosis of COPD was defined using post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) < 0.70. Spirometric examination was complete in 597 patients, of whom 235 (39.4%) had a study diagnosis of COPD. Among subjects with a spirometry-based study diagnosis of COPD, 121 (51.5%) reported a prior diagnosis of asthma without concurrent CBE diagnosis, 89 (37.9%) reported a prior diagnosis of CBE, and 25 (10.6%) reported no prior diagnosis of obstructive lung disease. Despite the availability of consensus guideline diagnostic recommendations, diagnostic confusion between COPD and asthma appears common. Increased awareness of the differences between the two conditions is needed to promote optimal patient management and treatment.
Respiration | 2006
David Price; David G. Tinkelman; Ronald J. Halbert; Robert J. Nordyke; Sharon Isonaka; Dmitry Nonikov; Elizabeth F. Juniper; Daryl Freeman; Thomas Hausen; Mark L Levy; Anders Østrem; Thys van der Molen; Constant P. van Schayck
Background: Symptom-based questionnaires may enhance chronic obstructive pulmonary disease (COPD) screening in primary care. Objectives: We prospectively tested questions to help identify COPD among smokers without prior history of lung disease. Methods: Subjects were recruited via random mailing to primary care practices in Aberdeen, UK, and Denver, Colo., USA. Current and former smokers aged 40 or older with no prior respiratory diagnosis and no respiratory medications in the past year were enrolled. Participants answered questions covering demographics and symptoms and then underwent spirometry with reversibility testing. A study diagnosis of COPD was defined as fixed airway obstruction as measured by postbronchodilator FEV1/FVC <0.70. We examined the ability of individual questions in a multivariate framework to correctly discriminate between persons with and without COPD. Results: 818 subjects completed all investigations and proceeded to analysis. The list of 54 questions yielded 52 items for analysis, which was reduced to 17 items for entry into multivariate regression. Eight items had significant relationships with the study diagnosis of COPD, including age, pack-years, body mass index, weather-affected cough, phlegm without a cold, morning phlegm, wheeze frequency, and history of any allergies. Individual items yielded odds ratios ranging from 0.23 to 12. This questionnaire demonstrated a sensitivity of 80.4 and specificity of 72.0. Conclusions: A simple patient self-administered questionnaire can be used to identify patients with a high likelihood of having COPD, for whom spirometric testing is particularly important. Implementation of this questionnaire could enhance the efficiency and diagnostic accuracy of current screening efforts.
Respiration | 2006
David G. Tinkelman; David Price; Robert J. Nordyke; Ronald J. Halbert; Sharon Isonaka; Dmitry Nonikov; Elizabeth F. Juniper; Daryl Freeman; Thomas Hausen; Mark L Levy; Anders Østrem; Thys van der Molen; Constant P. van Schayck
Background: Many patients with obstructive lung disease (OLD) carry an inaccurate diagnostic label. Symptom-based questionnaires could identify persons likely to need spirometry. Objectives: We prospectively tested questions derived from a comprehensive literature review and an international Delphi panel to help identify chronic OLD (COPD) in persons with prior evidence of OLD. Methods: Subjects were recruited via random mailing to primary-care practices in Aberdeen, Scotland, and Denver, Colorado. Persons aged 40 and older reporting any prior diagnosis of OLD or any respiratory medications in the past year were enrolled. Participants answered 54 questions covering demographics and symptoms and underwent spirometry with reversibility testing. A study diagnosis of COPD was defined by fixed airway obstruction as measured by post-bronchodilator FEV1/FVC <0.70. We examined ability of individual questions in a multivariate framework to discriminate between persons with and without the study diagnosis of COPD. Results: 597 persons completed all investigations and proceeded to analysis. The list of 54 questions yielded 52 items for analyses, which was reduced to 19 items for entry into a multivariate regression model. Nine items had significant relationships with the study diagnosis of COPD, including increased age, pack-years, worsening cough, breathing-related disability or hospitalization, worsening dyspnea, phlegm quantity, cold going to the chest, and receipt of treatment for breathing. Individual items yielded odds ratios ranging from 0.33 to 20.7. This questionnaire demonstrated a sensitivity of 72.0 and a specificity of 82.7. Conclusions: A short, symptom-based questionnaire identifies persons more likely to have COPD among persons with prior evidence of OLD.
COPD: Journal of Chronic Obstructive Pulmonary Disease | 2005
Peter Calverley; Robert J. Nordyke; Ronald J. Halbert; Sharon Isonaka; Dmitry Nonikov
COPD is commonly under-diagnosed, in part because people at risk are unaware of the relevant risk factors and do not recognize related symptoms. Providing this information might permit earlier disease identification but the questions chosen should identify those with spirometrically defined airflow obstruction. Using a population-based data set, we have determined which questions identify persons most likely to have airflow obstruction. Potential questions were selected by review of COPD risk factors and clinical features. Validation was by retrospective analysis of the NHANES III data set, a population-based U.S. household survey that included spirometry. We examined the predictive ability of individual questions in a multi-variate framework to correctly discriminate between persons with and without spirometric airway obstruction (defined as FEV1/FVC < 0.70). We then tested the discriminatory ability of the questions in combination. The following items showed significant predictive ability: increased age, smoking status, pack-years, cough, wheeze, and prior diagnosis of asthma or COPD. The best performing combination was age, smoking status, pack-years smoked, wheeze, phlegm, body mass index, and prior diagnosis of obstructive lung disease. Using this combination in a population of current and former smokers aged 40 and over, we achieved a sensitivity of 85% and specificity of 45%, with a positive predictive value of 38% and a negative predictive value of 88%. Performance of this tool is comparable to other screening methods designed for use in a general population. Symptom-based questionnaires can be a viable method to identify persons likely to have COPD in the general population. Dissemination of such tools should raise awareness among at-risk persons and help identify COPD patients in the primary care setting.
Respirology | 2005
Constant P. van Schayck; Ronald J. Halbert; Robert J. Nordyke; Sharon Isonaka; Jaman Maroni; Dmitry Nonikov
Objective: Underdiagnosis of COPD is widespread, at least in part due to underuse of spirometry. Symptom‐based questionnaires may be helpful as an adjunct to spirometry. The aim of this study was to determine which types of questions might aid in identifying COPD.
Journal of Heart and Lung Transplantation | 2003
Mark L. Barr; Felicia A. Schenkel; Annalisa Van Kirk; Ronald J. Halbert; J. Harold Helderman; Donald E. Hricik; Arthur J. Matas; John D. Pirsch; Bonita R Siegal; Ronald M. Ferguson; Robert J. Nordyke
BACKGROUND Cross-sectional analyses have identified significant associations between quality of life (QOL), and comorbidities and adverse effects in cardiac transplant recipients. However, little is known about factors that influence changes in QOL over time. This study examines both cross-sectional and longitudinal data from long-term survivors to identify factors that affect differences in QOL among recipients and individual changes in QOL during a 1-year period. METHODS Self-selected enrollees completed questionnaires, including QOL scales, at 3-month intervals. Repeated measures multiple regression analysis was used to examine the association between the QOL scales and comorbidities, adverse effects, and compliance measures, controlling for other factors. RESULTS We included 569 participants in the analysis, with a mean time since transplantation of 8.6 years. Cross-sectional results showed that the number of comorbidities, treatment non-compliance, and several adverse effects were associated with low QOL. In longitudinal results, waiting to take medications and taking less medication because of lifestyle restrictions were associated with decreases in QOL over time. Hair loss, changes in face shape, and decreased sexual interest or ability also had the largest adverse effects on changes in QOL. CONCLUSIONS These findings provide new opportunities for interventions to address factors related to decreases in QOL. Clinicians should actively solicit information about compliance with medication regimens. In addition, information about the adverse effects of medications should be considered when making therapeutic decisions.
Journal of Immigrant Health | 2005
Ninez A. Ponce; Robert J. Nordyke; Sherry Hirota
We inform a county’s efforts to provide health insurance to uninsured working immigrants—a group left out of national and state strategies that aim to expand coverage. We analyzed a population-based survey data administered in English, Spanish, Cantonese, Mandarin, Korean, Vietnamese, and Dari on 5,540 nonelderly adult workers in Alameda County, California. The study models the likelihood of employment-based coverage, estimates the eligibility for public programs, and evaluates the affordability of average employee share of premiums by citizenship status and years lived in the United States (tenure). Immigrant workers in Alameda County are disproportionately uninsured. They constitute 29% of the employee labor force but 54% of uninsured employees. Employment-based coverage increased with citizenship and length of stay (tenure) in the United States. Noncitizens with less than 5 years residency in the United States faced the greatest disadvantage in securing employment-based coverage, an effect that is greater than disadvantages associated with race/ethnicity. A citizenship-tenure divide existed in obtaining employment-based coverage, suggesting that policies focusing on noncitizen and new immigrant workers would greatly relieve the disparate uninsured rates among workers. The expansion of nonemployment-based coverage programs would cover more than 30% of Alameda County’s uninsured immigrant workers; but subsidies will also be needed for the lowest-income workers who are not eligible for these programs.
Respirology | 2005
Shunichi Fukuhara; Masaharu Nishimura; Robert J. Nordyke; Carol A. Zaher; John W. Peabody
Objective: COPD treatment guidelines are available worldwide, yet it is not known how widely they are followed. This study evaluated the clinical care of COPD patients in Japan as compared to guideline recommendations.
Journal of the American Heart Association | 2016
Anthony Wang; Akshara Richhariya; Shravanthi R. Gandra; Brian Calimlim; Lisa Kim; Ruben G.W. Quek; Robert J. Nordyke; Peter P. Toth
Background Apheresis is an important treatment for reducing low‐density lipoprotein cholesterol (LDL‐C) in patients with familial hypercholesterolemia (FH). We systematically reviewed the current literature surrounding LDL‐C apheresis for FH. Methods and Results Electronic databases were searched for publications of LDL‐C apheresis in patients with FH. Inclusion criteria include articles in English published in 2000–2013 that provide descriptions of practice patterns, efficacy/effectiveness, and costs related to LDL‐C apheresis in patients with FH. Data were stratified by country and FH genotype where possible. Thirty‐eight studies met the inclusion criteria: 8 open‐label clinical trials, 11 observational studies, 17 reviews/guidelines, and 2 health technology assessments. The prevalence of FH was not well characterized by country, and underdiagnosis was a barrier to FH treatment. Treatment guidelines varied by country, with some guidelines recommending LDL‐C apheresis as first‐line treatment in patients with homozygous FH and after drug therapy failure in patients with heterozygous FH. Additionally, guidelines typically recommended weekly or biweekly LDL‐C apheresis treatments conducted at apheresis centers that may last 2 to >3 hours per session. Studies reported a range for mean LDL‐C reduction after apheresis: 57–75% for patients with homozygous FH and 58–63% for patients with heterozygous FH. Calculated annual costs (in US
Health Policy | 2002
Robert J. Nordyke
2015) may reach US