Douglas W. Mapel

Cardiovascular Comorbidity in COPD: Systematic Literature Review

BACKGROUND Cardiovascular disease (CVD) is common among patients with COPD. However, it is not clear whether this is due to shared risk factors or if COPD increases the risk for CVD independently. This study aimed to provide a systematic review of studies that investigated the association between COPD and CVD outcomes, assessing any effect of confounding by common risk factors. METHODS A search was conducted in MEDLINE (via PubMed) for observational studies published between January 1990 and March 2012 reporting cardiovascular comorbidity in patients with COPD (or vice versa). RESULTS Of the 7,322 citations identified, 25 studies were relevant for this systematic review. Twenty-two studies provided an estimate for CVD risk in COPD, whereas four studies provided estimates of COPD risk in CVD. The crude prevalence for the aggregate CVD category ranged from 28% to 70%, likely due to differences in populations studied and CVD definitions; unadjusted rate ratio (RR) estimates of unspecified CVD among patients with COPD compared with patients without COPD ranged from 2.1 to 5.0. The association between COPD and CVD persisted after adjustment for shared risk factors in the majority of the studies. Two studies found a relationship between the severity of airflow limitation and CVD risk. Increased RRs were observed for individual CVD types, but their estimates varied considerably for congestive heart failure, coronary heart disease, arrhythmias, stroke, arterial hypertension, and peripheral arterial disease. CONCLUSIONS Available observational data support the hypothesis that COPD is associated with an increased risk of CVD.

Burden of Concomitant Asthma and COPD in a Medicaid Population

BACKGROUND Asthma and COPD can significantly affect patients and pose a substantial economic burden for both patients and managed-care plans. This study compares utilization outcomes in patients with asthma, COPD, or co-occurring asthma and COPD in a Medicaid population, and assesses the incremental burden of COPD in patients with asthma. METHODS We queried medical claims of Medicaid patients aged 40 to 64 years with asthma and/or COPD filed between January 1, 2001, and December 31, 2003, from encounter data. COPD patients were identified based on at least one claim with International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) codes 491, 492, 496; and asthma patients were identified on the basis of ICD-9 code 493 as diagnosis. We analyzed annual utilization and cost of hospitalizations, physician, and outpatient services attributable to asthma and/or COPD. RESULTS The analysis included a total of 3,072 asthma, 3,455 COPD, and 2,604 COPD/asthma patients. COPD/asthma co-occurring disease has higher utilization of any service type than either disease alone. Compared with asthma patients, COPD patients were 16% and 51% more likely to use physician (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.01 to 1.34) and inpatient services (OR, 1.51; 95% CI, 1.31 to 1.74), respectively; and 60% less likely to use outpatient services (OR, 0.40; 95% CI, 0.35 to 0.46). Compared with asthma patients, COPD patients and COPD/asthma co-occurring patients cost 50% (OR, 1.50; 95% CI, 1.3 to 1.74) and five times (OR, 5.25; 95% CI, 4.59 to 6.02) more for total medical services, respectively. CONCLUSION Our data suggest that patients with COPD and co-occurring COPD/asthma were sicker and used more medical services than asthma patients. The incremental burden of COPD to patients with asthma is significant.

Idiopathic pulmonary fibrosis: survival in population based and hospital based cohorts

BACKGROUND To ascertain whether findings from hospital based clinical series can be extended to patients with idiopathic pulmonary fibrosis (IPF) in the general population, the survival of patients with IPF in a population based registry was compared with that of a cohort of patients with IPF treated at major referral hospitals and the factors influencing survival in the population based registry were identified. METHODS The survival of 209 patients with IPF from the New Mexico Interstitial Lung Disease Registry and a cohort of 248 patients with IPF who were participating in a multicentre case-control study was compared. The determinants of survival for the patients from the Registry were determined using life table and proportional hazard modelling methods. RESULTS The median survival times of patients with IPF in the Registry and case-control cohorts were similar (4.2 years and 4.1 years, respectively), although the average age at diagnosis of the Registry patients was greater (71.7 years versus 60.6 years, p < 0.01). After adjusting for differences in age, sex, and ethnicity, the death rate within six months of diagnosis was found to be greater in the Registry patients (relative hazard (RH) 6.32, 95% CI 2.19 to 18.22) but more than 18 months after diagnosis the death rate was less (RH 0.35, 95% CI 0.19 to 0.66) than in the patients in the case-control study. Factors associated with poorer prognosis in the Registry included advanced age, severe radiographic abnormalities, severe reduction in forced vital capacity, and a history of corticosteroid treatment. CONCLUSIONS The adjusted survival of patients with IPF in the general population is different from that of hospital referrals which suggests that selection biases affect the survival experience of referral hospitals.

Trends and Cardiovascular Co-morbidities of COPD Patients in the Veterans Administration Medical System, 1991–1999

Persons with Chronic Obstructive Pulmonary Disease (COPD) are at risk for developing other smoking-related complications, including cardiac and vascular diseases. Information about the prevalence and incidence of these conditions is needed to anticipate their occurrence in clinical research. We conducted a cohort study using longitudinal administrative data to describe the prevalence and incidence of cardiovascular (CV) diseases among COPD patients treated by the Veterans Administration Medical System. The COPD cohort included all persons with a diagnosis of COPD admitted to a Veterans Administration Medical System hospital (N = 70,679) or seen in a outpatient clinic (N = 314,209) in fiscal year 1998. Each COPD patient was matched to a Veteran of the same age and gender who did not have a COPD diagnosis, creating a non-COPD cohort for comparison. Among all hospitalized Veterans, the prevalence of COPD steadily increased from 1991 to 1999, although the total number of Veterans hospitalized during this time period decreased by more than one-third. Among COPD patients hospitalized in 1998, the prevalence of coronary artery disease, congestive heart failure, and atrial fibrillation were very high (33.6%, 24.4%, and 14.3%, respectively) and significantly higher than those seen among the matched non-COPD cohort (27.1%, 13.5%, and 10.4%; p < 0.001). Among COPD outpatients, increased complications were found in every CV disease category with rate ratios that were greater than observed among inpatients. We conclude that CV diseases are remarkably prevalent among Veterans with COPD, and their incidence is likely to increase as the Veteran population ages.

Undertreatment of COPD: a retrospective analysis of US managed care and Medicare patients

Background We investigated a large population of patients with chronic obstructive pulmonary disease (COPD) to determine their frequency of medication use and patterns of pharmacotherapy. Methods Medical and pharmacy claims data were retrospectively analyzed from 19 health plans (>7.79 million members) across the US. Eligible patients were aged ≥40 years, continuously enrolled during July 2004 to June 2005, and had at least one inpatient or at least two outpatient claims coded for COPD. As a surrogate for severity of illness, COPD patients were stratified by complexity of illness using predefined International Classification of Diseases, Ninth Revision, Clinical Modification, Current Procedural Terminology, Fourth Edition, and Healthcare Common Procedure Coding System codes. Results A total of 42,565 patients with commercial insurance and 8507 Medicare patients were identified. Their mean age was 54.7 years and 74.8 years, and 48.7% and 46.9% were male, respectively. In total, 66.3% of commercial patients (n = 28,206) were not prescribed any maintenance COPD pharmacotherapy (59.1% no medication; 7.2% inhaled short-acting β2-agonist only). In the Medicare population, 70.9% (n = 6031) were not prescribed any maintenance COPD pharmacotherapy (66.0% no medication; 4.9% short-acting β2-agonist only). A subset of patients classified as high-complexity were similarly undertreated, with 58.7% (5358/9121) of commercial and 68.8% (1616/2350) of Medicare patients not prescribed maintenance COPD pharmacotherapy. Only 18.0% and 9.8% of diagnosed smokers in the commercial and Medicare cohorts had a claim for a smoking cessation intervention and just 16.6% and 23.5%, respectively, had claims for an influenza vaccination. Conclusion This study highlights a high degree of undertreatment of COPD in both commercial and Medicare patients, with most patients receiving no maintenance pharmacotherapy or influenza vaccination.

Predicting risk of airflow obstruction in primary care: Validation of the lung function questionnaire (LFQ)

The Lung Function Questionnaire (LFQ) is being developed as a case finding tool to identify patients who are appropriate for spirometry testing to confirm the diagnosis of chronic obstructive pulmonary disease (COPD). The cross-sectional study reported herein was conducted to validate the LFQ, to identify item-response scales associated with the best accuracy, and to determine the impact on accuracy of the addition of another item on activity limitations (AL). Patients >or= 40 years old seen at 2 primary care offices completed the LFQ, a demographic questionnaire followed by spirometry. Of the 837 evaluable patients, 18.6% had airflow obstruction (forced expiratory volume in 1 s/forced vital capacity [FEV(1)/FVC] < 0.70). The 5 items (age, wheeze, dyspnea, smoking, and cough) previously identified in initial LFQ development predicted airflow obstruction and showed good evidence of screening accuracy. Screening accuracy was significantly better with 5-point ordinal item-response scales (78%) than binary (yes/no) item-response scales (74%)(p < 0.05). Screening accuracy was good regardless of whether airflow obstruction was defined as FEV(1)/FVC < 0.70 or FEV(1)/FVC < 0.70 and FEV(1) < 80% of predicted. Based on <or=18 was selected to suggest presence of airflow obstruction with area under the receiver operating characteristic curve 0.652; sensitivity 82.6%; specificity 47.8%; 54.3% correctly classified. While the specificity of LFQ is low, its high sensitivity suggests that it can serve to identify patients who should be further assessed using spirometry. Our results confirm the screening accuracy of the LFQ, a simple and effective tool to facilitate early recognition and diagnosis of COPD.

Cost-effectiveness of fluticasone propionate/salmeterol (500/50 μg) in the treatment of COPD

OBJECTIVE We examine the lifetime cost-effectiveness of treatment with fluticasone propionate/salmeterol (500/50 microg) compared with no maintenance treatment in COPD in the US. METHODS A decision-analytic model was developed to estimate lifetime costs and outcomes associated with fluticasone propionate/salmeterol 500/50 microg treatment, salmeterol 50 microg, and fluticasone propionate 500 microg compared to no maintenance treatment in treating COPD from a third-party US payer perspective. The patient population was similar to that of the TORCH clinical trial. Model structure and inputs were obtained from published literature and clinical trial data. All costs are presented in 2006 US dollars. Outcomes included cost per life year (LY) saved and cost per quality-adjusted life year (QALY) gained. Costs and outcomes were discounted at 3% annually. Univariate and multivariate sensitivity analyses were conducted to assess model robustness. RESULTS Compared to no maintenance treatment, treatment with fluticasone propionate/salmeterol 500/50mug results in a lifetime incremental cost-effectiveness ratio (ICER) of

Development of the Lung Function Questionnaire (LFQ) to identify airflow obstruction.

33,865/QALY. Treatment with salmeterol 50 microg was found to have an ICER of

Adherence to controller therapy for chronic obstructive pulmonary disease: a review.

20,797/QALY. These results are robust to changes in input parameters. Fluticasone propionate 500 microg was dominated by no treatment, though the results were not robust to changes in parameters. CONCLUSIONS Treatment of COPD with fluticasone propionate/salmeterol 500/50 microg appears to be cost-effective (<or=

Changes in COPD demographics and costs over 20 years

50,000/QALY) compared to no maintenance treatment. Similarly, salmeterol 50 microg may be cost-effective compared to no maintenance treatment. Compared with no maintenance treatment, fluticasone propionate 500 microg was effective in reducing number of exacerbations, but failure to differentiate from no maintenance treatment in mortality resulted in it being dominated in the base case.