PubMed Health⌕ Search

Biomedical subjects

R J Halbert

Publications and source records attributed to R J Halbert.

At least 19 recordsLinked to original sources
PubMed2006

Global burden of COPD: systematic review and meta-analysis.

The aim of this study was to quantify the global prevalence of chronic obstructive pulmonary disease (COPD) by means of a systematic review and random effects meta-analysis. PubMed was searched for population-based prevalence estimates published during the period 1990-2004. Articles were included if they: 1) provided total population or sex-specific estimates for COPD, chronic bronchitis and/or emphysema; and 2) gave method details sufficiently clearly to establish the sampling strategy, approach to diagnosis and diagnostic criteria. Of 67 accepted articles, 62 unique entries yielded 101 overall prevalence estimates from 28 different counties. The pooled prevalence of COPD was 7.6% from 37 studies, of chronic bronchitis alone (38 studies) was 6.4% and of emphysema alone (eight studies) was 1.8%. The pooled prevalence from 26 spirometric estimates was 8.9%. The most common spirometric definitions used were those of the Global Initiative for Chronic Obstructive Lung Disease (13 estimates). There was significant heterogeneity, which was incompletely explained by subgroup analysis (e.g. age and smoking status). The prevalence of physiologically defined chronic obstructive pulmonary disease in adults aged > or =40 yrs is approximately 9-10%. There are important regional gaps, and methodological differences hinder interpretation of the available data. The efforts of the Global Initiative for Chronic Obstructive Lung Disease and similar groups should help to standardise chronic obstructive pulmonary disease prevalence measurement.

Adult↗
PubMed2006

Scoring system and clinical application of COPD diagnostic questionnaires.

OBJECTIVES: In most primary care settings, spirometric screening of all patients at risk is not practical. In prior work, we developed questionnaires to help identify COPD in two risk groups: (1) persons with a positive smoking history but no history of obstructive lung disease (case finding), and (2) patients with prior evidence of obstructive lung disease (differential diagnosis). For these questionnaires, we now present a scoring system for use in primary care. METHODS: Scores for individual questions were based on the regression coefficients from logistic regression models using a spirometry-based diagnosis of obstruction as the reference outcome. Receiver operator characteristic analysis was used to determine performance characteristics for each questionnaire. Several simplified scoring systems were developed and tested. RESULTS: For both scenarios, we created a scoring system with two cut points intended to place subjects within one of three zones: persons with a high likelihood of having obstruction (high predictive value of a positive test result); persons with a low likelihood of obstruction (high predictive value of a negative test result); and an intermediate zone. Using these scoring systems, we achieved sensitivities of 54 to 82%, specificities of 58 to 88%, positive predictive values of 30 to 78%, and negative predictive values of 71 to 93%. CONCLUSIONS: These questionnaires can be used to help identify persons likely to have COPD among specific risk groups. The use of a simplified scoring system makes these tools beneficial in the primary care setting. Used in conjunction with spirometry, these tools can help improve the efficiency and accuracy of COPD diagnosis in primary care.

Adult↗
PubMed2005

Symptom-based questionnaire for differentiating COPD and asthma.

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 FEV(1)/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.

Adult↗
PubMed2005

Symptom-based questionnaire for identifying COPD in smokers.

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 post-bronchodilator FEV(1)/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.

Adult↗
PubMed2005

Questions for COPD diagnostic screening in a primary care setting.

OBJECTIVES: To test questions usable in an ambulatory clinic to identify persons likely to have chronic obstructive pulmonary disease (COPD). METHODS: Analyses were performed as part of a study to identify patients with likely COPD in the Glenfield UK primary care clinic. Patients age 40 and older were recruited based on one of the following criteria: (1) respiratory medications in previous 2 years; (2) history of smoking or (3) history of asthma with no current medications based on case notes. Consenting patients reported smoking history, symptoms, and personal and family history of respiratory conditions. Spirometry with reversibility was conducted to ATS standards. Analyses were performed on this database to test questions for identifying patients with COPD from a sample of patients with a positive smoking history. Multivariate logistic regression identified the question set that best discriminated COPD from other conditions using receiver operating characteristic curves. The usefulness of a simple scoring system was assessed. RESULTS: The study sample included 369 current and former smokers. Patients were diagnosed as: COPD=62 (16.8%); asthma=30 (8.1%); or no obstructive lung disease=277 (75.1%). The best questions for discriminating between persons with and without COPD included items on age, dyspnoea on exertion, and wheeze. This set of questions identified COPD patients with a sensitivity of 77.4--87.1% and specificity of 71.3--76.2%. CONCLUSIONS: A simple questionnaire can facilitate the diagnosis of COPD in a primary care setting.

Adult↗
PubMed2005

Airway obstruction in never smokers: results from the Third National Health and Nutrition Examination Survey.

PURPOSE: Chronic obstructive pulmonary disease (COPD) is usually described as a disease of cigarette smoking. COPD is rarely considered in persons with no smoking history except in the context of another exposure. Accordingly, the disease has not been well characterized in these "never smokers." METHODS: We evaluated airway obstruction (defined as forced expiratory volume in 1 second/forced vital capacity <0.70) in US adults aged 30 to 80 years interviewed in the Third National Health and Nutrition Examination Survey with valid spirometry who had never smoked. Previously described risk factors were examined for their association with obstruction in bivariate and multivariate analyses. RESULTS: Never smokers represented 42% of the Third National Health and Nutrition Examination Survey population aged 30 to 80 years, with obstruction prevalence of 91 per 1000. Never smokers accounted for 4.56 million cases of obstruction, or 23% of the total burden. Among these obstructed never smokers, 19% reported a prior diagnosis of asthma alone, and 12.5% reported COPD (alone or with asthma), leaving 68.5% with no prior respiratory diagnosis. After adjustment for other factors, higher rates of obstruction were significantly associated with increasing age, male sex, lower body mass index, and a history of allergies. CONCLUSIONS: Never smokers represent a significant proportion of airway obstruction in US adults. Only one fifth of obstruction in this group is explained by asthma. COPD may explain much of the remainder, although known risk factors were not explanatory in this dataset. Recommendations that lung health screening programs be limited to smokers should be reconsidered.

Adult↗
PubMed2005

Chronic obstructive pulmonary disease in patients under age 65: utilization and costs from a managed care sample.

OBJECTIVES: Chronic obstructive pulmonary disease (COPD) affects all adult age groups, not just elderly males. We assessed the health care utilization and cost impact of COPD in different age groups. METHODS: We compared burden of illness, utilization, and charges for younger versus older COPD patients and versus age- and gender-matched controls. RESULTS: A total of 16.9% of patients with COPD were under age 65. Patients with COPD (n=19,338) had higher comorbidity than age-matched controls (n=94,384) across all age groups. Younger patients with COPD had lower comorbidity scores and fewer hospitalizations but more COPD-related emergency services than older patients with COPD. Average COPD-related charges were higher for younger patients. Facility-based care was the cost driver across all age groups. CONCLUSIONS: COPD is a burden to younger individuals in the workforce, who are likely to be enrolled in a commercial health plan.

Age Factors↗
PubMed2005

Development of a population-based screening questionnaire for COPD.

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.

Adult↗
PubMed2004

Coordinated diagnostic approach for adult obstructive lung disease in primary care.

AIMS: To present an age-stratified approach to the diagnosis of obstructive lung disease based on asthma and COPD guidelines and epidemiology. METHODS: Asthma guidelines emphasize the role of the history and physical examination, with pulmonary function used primarily to confirm the diagnosis. COPD guidelines begin with symptoms and risk exposure, presenting spirometry as the primary diagnostic maneuver. Data from the National Health Interview Survey and the Third National Health and Nutrition Examination Survey illustrate relationships in prevalence of asthma and COPD in nationally representative samples. RESULTS: Asthma prevalence in adults declines with age from 5-10% at age 20-40 to 4-8% above age 60. COPD is uncommon in adults under age 40 but increases with age, surpassing asthma in older adults. CONCLUSIONS: These trends suggest that asthma screening is most useful in adults up to age 40, after which COPD screening and differential diagnosis are of comparable or greater utility.

Journal Article↗
PubMed2004

The cost of chronic obstructive pulmonary disease and its effects on managed care.

Chronic obstructive pulmonary disease (COPD) designates respiratory disorders characterized by airway obstruction that is not fully reversible. An estimated 10 million adult Americans have COPD, and the prevalence is rising. Direct and indirect costs of managing COPD exceed dollars 32 billion annually, and this health care burden has provoked vigorous efforts by major public health organizations to evaluate and improve quality of care for COPD. The authors review the substantial effects of COPD on managed care and discuss evidence-based strategies for its effective management.

Cost Control↗
PubMed2003

Determinants of quality of life changes among long-term cardiac transplant survivors: results from longitudinal data.

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.

Adult↗
PubMed2003

Population impact of different definitions of airway obstruction.

There is currently no consensus on the criteria for diagnosing chronic obstructive pulmonary disease. This study evaluated the impact of different definitions of airway obstruction on the estimated prevalence of obstruction in a population-based sample. Using the Third National Health and Nutrition Examination Survey, obstructive airway disease was defined using the following criteria: 1) self-reported diagnosis of chronic bronchitis or emphysema; 2) forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) <0.70 and FEV1 <80% predicted (Global Initiative for Chronic Obstructive Lung Disease (GOLD) Stage IIA); 3) FEV1/FVC below the lower limit of normal; 4) FEV1/FVC <88% pred in males and <89% pred in females; 5) FEV1/FVC <0.70 ("fixed ratio"). Spirometry in this dataset did not include reversibility testing, making it impossible to distinguish reversible from irreversible obstruction. Rates in adults varied from 77 per 1,000 (self-report) to 168 per 1,000 (fixed ratio). For persons aged >50 yrs, the fixed ratio criteria produced the highest rate estimates. For all subgroups tested, the GOLD Stage II criteria produced lower estimates than other spirometry-based definitions. Different definitions of obstruction may produce prevalence estimates that vary by >200%. International opinion leaders should agree upon a clear definition of chronic obstructive pulmonary disease that can serve as a population-based measurement criterion as well as a guide to clinicians.

Adult↗
PubMed2003

Interpreting COPD prevalence estimates: what is the true burden of disease?

STUDY OBJECTIVES: To summarize the available data on COPD prevalence and assess reasons for conflicting prevalence estimates in the published literature. DESIGN: We reviewed published studies that (1) estimated COPD prevalence for a population, and (2) clearly described the methods used to obtain the estimates. RESULTS: Thirty-two sources of COPD prevalence rates, representing 17 countries and eight World Health Organization-classified regions, were identified and reviewed. Prevalence estimates were based on spirometry (11 studies), respiratory symptoms (14 studies), patient-reported disease (10 studies), or expert opinion. Reported prevalence ranged from 0.23 to 18.3%. The lowest prevalence rates (0.2 to 2.5%) were based on expert opinion. Sixteen studies had measured rates that could reasonably be extrapolated to an entire region or country. All were for Europe or North America, and most fell between 4% and 10%. CONCLUSIONS: There is considerable variation in the reported prevalence of COPD. The overall prevalence in adults appears to lie between 4% and 10% in countries where it has been rigorously measured. Some of the variation attributed to differences in risk exposure or population characteristics may be influenced by the methods and definitions used to measure disease. Spirometry is least influenced by local diagnostic practice, but it is subject to variation based on the lung function parameters selected to define COPD.

Epidemiologic Factors↗
PubMed2002

Outpatient cancer drug costs: changes, drivers, and the future.

BACKGROUND: To the authors' knowledge, no analysis has examined the specific components of drug spending for overall cancer care. The authors' objective was to quantify and characterize trends in outpatient drug expenditures for cancer patients. METHODS: The authors retrospectively analyzed pharmacy and outpatient professional claims data from commercial and Medicare health maintenance organization enrollees with a solid tumor diagnosis in 1995 and 1998. Charges were subdivided by type of drug (antineoplastic drugs, chemotherapy adjuncts, supportive drugs, and drugs unrelated to cancer treatment). RESULTS: In 1995, 14,663 cancer patients received outpatient drug treatment and 13,829 patients in 1998. Total charges increased from $17.9 million (mean charge of $1218 per patient) to $27.9 million (mean charge of $2003 per patient), an average annual increase of 16%. Antineoplastic therapy constituted the largest component of cancer-related drug costs (67%) and represented 76% of the increase from 1995 to 1998. Most charges were incurred in the professional setting for agents administered by injection. The primary explanation for the increases appeared to be a shift in treatment patterns toward newer, more expensive antineoplastic agents. Supportive therapy represented 17% of the increase in cancer drug costs, followed by chemotherapy adjuncts (7%). Charges for drugs unrelated to cancer therapy increased by 21% per year. CONCLUSIONS: Antineoplastic therapy administered in an office or clinic was the single most important cost driver, with newer more expensive agents replacing older, less expensive drugs. Attempts to understand and control outpatient drug cost increases for cancer patients should focus primarily on antineoplastic therapy, especially the appropriate substitution of newer agents for older, less expensive alternatives. Some non-chemotherapy cancer drugs may offer an opportunity to improve quality of life with a relatively small effect on overall cancer drug costs.

Adolescent↗
PubMed2002

Life satisfaction and adverse effects in renal transplant recipients: a longitudinal analysis.

INTRODUCTION: Previous cross-sectional analyses have identified significant associations between quality of life (QOL), comorbidities and adverse effects in renal transplant recipients. This report examines the longitudinal relationship between adverse effects and QOL, with particular attention to the relative impact of adverse effects associated with immunosuppression. METHODS: The Transplant Learning Center (TLC) is a program designed to improve QOL and preserve graft function in transplant recipients. Self-selected enrollees filled out questionnaires at roughly 3-month intervals. Each questionnaire included QOL scales developed for the program. Repeated measures multiple regression analysis was used to examine the relationship between the QOL scales, comorbidities, adverse effects, adjusting for other factors. RESULTS: A total of 4247 TLC enrollees were included in the analysis, with a mean time since transplant of 5.1 yr. Comorbidities and adverse effects were common, with high blood pressure reported by 87% of respondents and unusual hair growth reported by 69.6%. In bivariate analysis, emotional/psychological problems and headaches had the largest impact on QOL. In multivariate analysis, emotional/psychological problems decreased sexual interest or ability, and headache had the largest adverse QOL effect. CONCLUSIONS: We have identified QOL issues that have been previously underemphasized in transplant recipients. These findings open new areas of research to further explore and define these issues. They provide new opportunities for interventions to address factors adversely impacting QOL and to develop strategies to improve QOL in these patients. Clinicians should actively solicit information about adverse effects of medications, particularly information about sexual and relationship issues, when evaluating renal recipients. These issues should be taken into account when making therapeutic decisions.

Comorbidity↗
PubMed2002

Life satisfaction among kidney transplant recipients: demographic and biological factors.

PURPOSE: The Transplant Learning Center is a program providing education and support for solid-organ transplant recipients taking cyclosporine (Neoral or Sandimmune). One goal of the program is to improve patients' quality of life, which may be influenced by demographic and biological factors, and in turn influences adherence to prescribed medication regimens. We analyzed the results from the initial survey of enrollees to better understand life satisfaction and to test the validity and reliability of the satisfaction scale used in the program. METHOD: Patients enter the program through self-selection: all enrollees who received a kidney transplant were included in this analysis. Satisfaction was measured using the Life Satisfaction Index, which includes 8 questions about aspects of satisfaction with the patient's life. Associations between the Life Satisfaction Index and demographic factors, comorbid medical conditions, adverse effects of immunosuppressants, and medication compliance were examined. RESULTS: All 3676 kidney transplant recipients who completed the initial survey were included. Mean satisfaction scores were highest in persons who were older than 64 years, men, and those who were married. Satisfaction scores were positively correlated with education and income. Mean satisfaction score was significantly lower among persons with medical comorbidities, persons who reported that adverse effects of medications were more frequent, and persons who reported noncompliance with their medication regimen. CONCLUSION: The Life Satisfaction Index is a transplant-specific measure of health-related quality of life that can be used to help detect areas of potential concern in the clinical management of kidney transplant recipients.

Adolescent↗
PubMed2001

Life satisfaction in renal transplant recipients: preliminary results from the transplant learning center.

The Transplant Learning Center (TLC) was designed to improve quality of life (QOL) and preserve graft function in solid-organ transplant recipients. To meet the specific goals of the program, the Life Satisfaction Index and Transplant Care Index were designed to serve as composite measures for measuring transplant-specific QOL and the ability to care for a transplant, respectively. In this study, we analyzed self-reported health information to examine relationships between comorbidities and individual posttransplantation side effects, life satisfaction, and transplant care, defined by renal transplant recipients. Patients entered the TLC through self-referral or referral by a health professional. Included in the analysis were 3,676 TLC enrollees with a mean time since transplantation of 4.8 years. Comorbidities and adverse effects were common, with high blood pressure reported by 89% of respondents and unusual hair growth reported by 70%. Sexual dysfunction and headache had a greater impact on QOL than more common adverse effects, such as changes in body and facial shape, hirsutism, and tremor. Regression modeling was used to identify the most significant associations between QOL indices and structural (nonmedical), medical, and psychosocial factors. Greater life satisfaction was most strongly associated with being in control of one's health and living a normally active life with satisfying emotional relationships. Management of such clinical problems as adverse effects of medication and nonadherence should be informed by the patient's perspective. Clinicians should actively solicit information about physical activity, appearance concerns, side effects of medications, nonadherence, and sexual and relationship issues when evaluating renal transplant recipients.

Adult↗