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(Chest. 2000;117:346S-353S.)
© 2000 American College of Chest Physicians

Utilization in COPD*

Patient Characteristics and Diagnostic Evaluation

Douglas W. Mapel, MD, MPH, FCCP; Maria A. Picchi, MPH; Judith S. Hurley, MS; Floyd J. Frost, PhD; Hans V. Petersen, MS; Vesta M. Mapel, MD and David B. Coultas, MD

* From the Epidemiology and Cancer Control Program (Drs. D.W. Mapel, V.M. Mapel, and Coultas, and Ms. Picchi), University of New Mexico Health Sciences Center, Albuquerque, NM; and the Southwest Center for Managed Care Research (Ms. Hurley, Dr. Frost, and Mr. Petersen), Lovelace Respiratory Research Institute, Albuquerque, NM.

Correspondence to: Douglas W. Mapel, MD, MPH, FCCP, Epidemiology and Cancer Control Program, The University of Mexico Health Sciences Center, 2325 Camino de Salud NE, Albuquerque, NM 87131-5306; e-mail: dmapel{at}salud.unm.edu


   Abstract
TOP
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Study objectives: Information on current practices of COPD diagnosis and treatment is needed to identify opportunities for improving care. This study describes the clinical characteristics and diagnostic evaluations of COPD patients in a health maintenance organization (HMO) and a university-affiliated county medical center (UMC).

Design: Cross-sectional survey performed in a 174,484-member regional HMO and in The University of New Mexico Hospitals and Clinics (UNMH).

Patients: Two hundred COPD patients from each system randomly selected from administrative databases based on discharge diagnoses.

Results: COPD patients in the UMC, compared to those in the HMO, were younger (mean age, 59.3 vs 66.9 years, respectively), were more likely to be using home oxygen (33% vs 20%, respectively), and had fewer chronic medical conditions (mean number of conditions, 3.1 vs 3.7, respectively) (p < 0.01 for all differences). Approximately half of the COPD patients in both groups continued to smoke cigarettes during the study year. Only 38% of patients in the HMO and 42% in the UNMH system had spirometry results documented in their medical records.

Conclusions: The demographic and clinical characteristics of the COPD patients in these two health-care systems were very different, but smoking status and utilization of diagnostic tests were similar. The diagnosis of COPD in most patients was based only on a history of chronic respiratory symptoms and smoking; spirometry often was not used to confirm the diagnosis. An increased emphasis on smoking cessation and more effective utilization of spirometry are needed to improve the management of COPD in these health-care systems.

Key Words: comorbidity • diagnosis • managed-care programs • obstructive lung disease • respiratory function tests • smoking • utilization review


   Introduction
TOP
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
COPD is the fourth leading cause of death in the United States, with 106,027 reported deaths in 1996, and is the only major chronic illness projected to have an increasing mortality rate over the next decade.1 2 The 1995 National Health Interview Survey (NHIS) estimated that > 10.7 million adults in the United States had received a diagnosis of chronic bronchitis and that 1.9 million adults had received a diagnosis of emphysema,3 and the National Health and Nutrition Examination Surveys found evidence of significant airflow obstruction in approximately one of every four adult men.4 COPD is a major cause of chronic disability and a leading reason for visits to office-based physicians.5

In response to the overwhelming burden that COPD poses on our medical system and on society, the National Lung Health Education Program was initiated to improve its diagnosis and management.6 7 Both the American College of Chest Physicians and the American Thoracic Society (ATS) have published supplements to their journals that review the pathogenesis of COPD and make specific recommendations for its diagnosis and management.8 9 Each of the supplements recommends spirometry for all persons with clinical evidence of COPD to confirm the diagnosis and to evaluate the severity and progression of airflow obstruction. The supplements also identify smoking cessation as the first step in COPD treatment. Cigarette smoking is the major causative factor for COPD, and smoking cessation is the only therapy proven to slow the progression of airflow obstruction.10

Although recommendations for the evaluation and treatment of COPD are well established, it is not known how well they are followed in general practice. Most available information on COPD utilization is limited to studies of hospitalized patients with end-stage disease,11 12 and national surveys provide little detail about outpatient diagnostic evaluations or smoking cessation.13 14 Data on the current management of COPD in well-defined health-care systems are needed to identify specific areas for improving care, to help guide health policy, and to identify barriers to policy implementation.15 This study examined the clinical characteristics and diagnostic evaluations of persons diagnosed with COPD in a regional health maintenance organization (HMO) and in a university-affiliated county medical center (UMC).


   Materials and Methods
TOP
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Study Site
This study was conducted as a part of the New Mexico COPD Outcomes Project, which was established in January 1998 to examine the impact of COPD on the US health-care system. The aims of the New Mexico COPD Outcomes Project include describing current COPD evaluation and management, identifying determinates of utilization and costs among COPD patients, and examining the relationships among clinical symptoms, quality of life, and other outcomes in COPD. As patient demographic characteristics and physician diagnosis and treatment behavior may vary by type of health-care system, the project examines each of the local health-care systems independently. This study focuses on one of the largest HMOs in New Mexico and on the main indigent medical system of the state’s most populous county.

The HMO patients for this study were members of the Lovelace Health Plan (LHP), a part of the CIGNA HealthCare Network (CIGNA Health Corporation; Bloomfield, CT). Facilities that are owned and operated by LHP include an acute-care hospital, two multispecialty clinics, and nine primary-care centers that are located in Albuquerque, Santa Fe, and Las Cruces, NM. LHP employs 285 staff physicians and contracts with an additional 37 hospitals and > 2,000 physicians statewide. LHP is New Mexico’s oldest HMO and served > 700 employer groups and 174,484 plan participants in 1997.

The UMC examined in this study was The University of New Mexico Hospitals and Clinics (UNMH), which provide indigent care for Bernalillo County (1990 population, 480,577) and are the main teaching hospitals for the University of New Mexico Health Sciences Center. In addition to its 340-bed acute-care hospital and adjacent ambulatory-care clinics, UNMH operates four satellite primary-care clinics. In 1997, UNMH treated 15,675 persons aged >= 18 years who identified themselves as Bernalillo County residents.

Inclusion Criteria
The study was designed to capture comprehensive utilization data during the study period, calendar year 1997. Administrative databases were used to identify all patients with diagnosed COPD in both health-care systems. COPD was defined as International Classification of Diseases, 9th revision, codes 491.x (chronic bronchitis), 492.x (emphysema), and 496 (COPD, unspecified), which are the codes that most closely fit the ATS definition of COPD.16 Patients aged < 30 years were excluded to avoid bronchiectasis, cystic fibrosis, and reversible asthma conditions that were not included in the ATS COPD definition.

COPD Case Identification
The case identification methods at the two study sites were slightly different due to differences in the databases. COPD patients in the LHP were identified using the Managed Care Database, an electronic database maintained by the Southwest Center for Managed Care Research. Electronic administrative data from inpatient, outpatient, pharmacy, laboratory, and enrollment records are collected quarterly from the LHP computer systems, normalized, subjected to quality-assurance edits, and formatted into tables in a relational database to ensure the availability of a full year of utilization data. Files from calendar year 1996 were reviewed to identify COPD patients with mild disease who may not have had a COPD discharge code in 1997 and patients who disenrolled from LHP during the study period were excluded. A total of 1,522 patients were identified who met all study criteria; 200 of these were randomly selected for this study.

COPD patients at UNMH were identified using the electronic billing records of the hospital’s inpatient, outpatient, emergency department, and professional staff departments from calendar year 1997. A total of 330 persons were identified who met all study criteria; 200 of these were randomly selected for this study.

Control Group Selection
To compare the clinical characteristics and comorbid conditions of our HMO COPD patients to those of the general HMO population, we matched each case to an age-matched (± 5 years) and gender-matched control subject from the Managed Care Database. Control subjects were selected based on the same study criteria as patients but did not have a COPD discharge code during 1997.

Selection of a control group for the UNMH COPD cohort was more problematic. Since indigent persons without severe illness do not regularly use the UNMH system, there is no readily available local cohort for case-control matching. To compare the prevalence of comorbid conditions in the UNMH cohort to a general population with similar socioeconomic status, we used data for people with a total household income of $10,000 to $19,999 who were between the ages of 45 and 64 years from the 1995 NHIS.3

Chart Abstraction
The abstracting instrument was based on the ATS Respiratory Symptoms Questionnaire, which was modified to ascertain information about histories, examinations, and tests that support a COPD diagnosis.17 Comorbid illnesses were categorized using a system developed to identify prognostically important chronic conditions.18 Experienced professional abstractors were used at both medical centers. Abstractors were instructed to use all actively available medical records to capture information on comorbid medical conditions and diagnostic tests. If more than one test was available, the best study available during a period of clinical stability in calendar year 1997 was selected.

Statistical Analysis
Mean values were compared using the Student’s t test for normally distributed data and the Wilcoxon rank sum method for nonnormal distributions. Pearson’s {chi}2 test was used to compare all proportions except for the prevalence of comorbid conditions in the HMO patient and control groups, where the McNemar test for paired proportions was used. To identify factors associated with the utilization of spirometry, we used forward stepwise conditional logistic regression modeling. All statistical calculations were performed using procedures contained in computer software (SPSS Professional Statistics, version 8.0; SPSS Inc; Chicago, IL).


   Results
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Demographic characteristics of the UNMH COPD patients, the HMO COPD patients, and the HMO control groups were substantially different (Table 1 ). On average, the UNMH patients were much younger with only 34.5% of patients aged >= 65 years compared with 55% of HMO patients. UNMH patients were also more likely to be female than male (64.0% vs 49.0%, respectively). These findings are consistent with the overall demographics of this county’s indigent system, in which most adult patients tended to be relatively young (mean age, 43.2 years) and female (59.5%). The HMO COPD patients were less likely than control subjects to be Hispanic, which is consistent with the historically lower prevalence of smoking among older Hispanic people in this area.19 The medical insurance coverage for all 330 UNMH COPD patients was as follows: Medicare for aged or disabled persons, 57.4%; Medicaid, 10.4%; county assistance, 15.3%; and private medical insurance, 7.0%. The remaining 9.9% of patients did not have any form of medical coverage.


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  		Table 1. Demographic Characteristics

 
The majority of patients in both medical systems had a physician specializing in internal medicine or family practice as their primary provider (Table 1) . However, among UNMH COPD patients, 30% were seen only in the emergency department or in an urgent-care clinic and did not have a regular outpatient physician. Most of the patients with COPD (79%) in both centers who had a pulmonologist as their primary physician were receiving home oxygen therapy or had a second pulmonary disease, such as bronchiectasis, severe asthma, interstitial lung disease, or sleep apnea.

From the data, it was possible to identify the single most common diagnostic term used by clinicians to describe the primary lung disease in UNMH and HMO patients (Fig 1 ). COPD was the primary term used for approximately two thirds of the cases in both medical centers. Chronic bronchitis and emphysema were not often used as the primary diagnosis term but were mentioned as secondary terms for 11% and 14.5%, respectively, of the UMC cases, and 9.5% and 7%, respectively, of the HMO patients, respectively. Thirty-one of the 75 patients (41%) who had asthma or "reactive airways disease" as their primary diagnosis had a history of tobacco use; another 9 patients (12%) had evidence of irreversible airflow obstruction. Bronchiectasis, lung mass, or interstitial lung disease were other primary diagnostic terms used, with COPD mentioned as a secondary diagnosis for only three of these patients. All patients in both cohorts had evidence of lung disease, although the evidence suggested that 17 patients in the HMO group and 3 patients in the UNMH group might more appropriately have been coded as something other than COPD.



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  		Figure 1. Primary diagnostic terms used to describe lung disease in the UMC and HMO patients.

 
In both medical centers, a high proportion of individuals with COPD were documented to be using cigarettes during 1997 (Fig 2 ); 45.5% of patients at UNMH and 46.0% at the HMO were current smokers, compared with 13.5% of the HMO control subjects. Among all adults in New Mexico in 1997, 22.1% were current smokers, 25.3% were former smokers, and 52.6% were never-smokers.20 The mean total pack-year smoking histories for all patients with a history of smoking were significantly different among the three cohorts and are as follows: UNMH patients, 62.6 (95% confidence interval [CI], 54.6 to 70.6); HMO patients, 49.5 (95% CI, 44.7 to 54.3); and HMO control subjects, 34.9 (95% CI, 27.7 to 42.1). Most of the never-smokers in the patient groups (64%) had severe asthma, bronchiectasis, or an interstitial lung disease as their main pulmonary diagnosis.



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  		Figure 2. Cigarette smoking status during 1997 for the UMC patients, the HMO patients, and the HMO control group.

 
In the HMO group, patients were more likely than control subjects to have a history of serious comorbid conditions, particularly among diseases related to smoking (Table 2 ). HMO patients had an average of 3.7 chronic medical conditions (including lung disease) vs 1.8 for control subjects (p < 0.0001). The total number and prevalence of various chronic conditions in the HMO control group were similar to those seen in comparable age groups in national surveys.3 21 22 Only 6% of HMO patients did not have another chronic medical condition. UNMH COPD patients were more likely than people of similar age and economic status to have smoking-related chronic illnesses (Table 3 ). UNMH patients had an average of 3.1 chronic conditions (including their lung disease). UNMH patients also had a remarkably higher prevalence of depression or psychiatric illness, cirrhosis, and renal failure than the HMO COPD patients.


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  		Table 2. Prevalence of Chronic Medical Conditions in HMO COPD Patients vs Control Subjects

 

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  		Table 3. Prevalence of Chronic Medical Conditions in COPD Patients vs Control Subjects*

 
Dyspnea and cough were the most common complaints in both COPD groups (Fig 3 ). Wheezing was a more common complaint in the UNMH cohort, which may be related to the higher degree of airflow obstruction in this group. The mean FEV1 percent predicted for patients with documented spirometry was as follows: UNMH patients, 45.2% (95% CI, 43.2 to 47.0%); HMO patients, 60.8% (95% CI, 57.8 to 63.8%). Documentation of an abnormal finding on chest examination was also more common in the UNMH cohort, including wheezing (57% vs 15%; p < 0.01) and diminished breath sounds and/or increased anteroposterior chest diameter (49.5% vs 22%; p < 0.01).



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  		Figure 3. Prevalence of chronic respiratory symptoms in 1997 for the UMC patients, the HMO patients, and the HMO control group.

 
Overall, there was surprisingly low utilization of spirometry in either center (Fig 4 ). Only 42% of UNMH patients and 33.5% of HMO patients had medical chart documentation of ever having had spirometry. By comparison, 81.5% of UNMH patients and 76% of HMO patients had documentation of a chest radiograph, and 63.5% of UNMH patients and 50% of HMO patients had documentation of an ECG. Of the patients with documented chest radiographs, 96 patients (63%) in the HMO group and 59 patients (36%) in the UNMH group had radiographs that were interpreted as having changes consistent with COPD. Of the spirometry tests available, results for 23% of patients from the HMO group and for 7% from the UNMH group were normal, which, therefore, contradicted the diagnosis of COPD.



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  		Figure 4. Prevalence of spirometry, chest radiographs, and ECGs for the UMC patients, the HMO patients, and the HMO control group.

 
We used logistic regression modeling to identify factors that were associated with the utilization of spirometry. The patient groups from both centers were combined for this analysis. The following were examined as independent variables in the model: age >= 65 years; gender; Hispanic ethnicity; primary physician specialty; and documentation of a chest radiograph. Of these factors, only male gender (odds ratio [OR], 1.63; 95% CI, 1.06 to 2.52), documentation of a chest radiograph (OR, 2.30; 95% CI, 1.31 to 4.05), and having a pulmonologist as a primary physician (OR, 10.02; 95% CI, 3.92 to 25.68) were significant.


   Discussion
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
The demographic and clinical characteristics of the COPD patients in our UNMH and HMO cohorts were very different, as can be expected whenever comparing patients from two fundamentally different health-care systems. However, physician diagnostic behavior in these two centers was remarkably similar. Although most COPD patients had documentation of chronic respiratory symptoms and a history of cigarette smoking, only a minority of patients had documented spirometry results available in their medical records. It is important to note that in almost half of the COPD patients in both cohorts, it was documented that cigarettes were still being smoked during the study period.

It is not clear why so few patients in our survey had spirometry, although limited access to a spirometer is one explanation. The HMO and UNMH systems each operate only one pulmonary function laboratory, and these laboratories are located within the main hospitals and are not directly accessible to primary-care clinics. Pulmonologists in both systems have the only outpatient clinics with on-site spirometry equipment and technicians, which also may explain why patients with pulmonologists as primary physicians were 10 times more likely to have spirometry than those with nonpulmonologists as their primary-care physicians.

The improved use of pulmonary function testing, particularly spirometry, could improve the evaluation and management of COPD patients in both the HMO and UNMH in several important ways. First, symptoms of dyspnea, cough, and wheezing are not specific to COPD, and spirometry is necessary to confirm the presence of airflow obstruction and to characterize airway reactivity.8 9 Of the COPD patients in our study who had spirometry, almost 14% had normal results, and undoubtedly some of the patients who did not have spirometry also had misdiagnosed conditions. Second, spirometry has proven utility in patients with COPD as a method for staging the disease and for identifying smokers who are at risk for precipitous decreases in lung function over time.6 7 8 9 It is evident from the low number of patients with mild cases of the disease in both the study centers that lung function tests are not being used to screen for early evidence of COPD. Third, spirometry is an important part of educating COPD patients about their disease. The lack of spirometry among our patients reflects the absence of an organized educational program for COPD patients in either of these cohorts. The Lung Health Study has recognized the importance of spirometry in educating individuals and the public about COPD and recommends that patients "test your lungs, know your numbers" in its public messages.7 Small, simple, and inexpensive hand-held spirometers are currently available, and the diagnostic evaluation of COPD patients in these two health-care systems potentially could be improved by putting spirometry equipment into primary-care clinics.

Smoking cessation has the most potential of any currently available intervention for improving the health of COPD patients in both of the study centers. Ipratropium bromide and inhaled corticosteroids may temporarily improve forced expiratory volume and relieve symptoms for COPD patients who continue to smoke, but they will not stop the deterioration in baseline respiratory function.10 23 Furthermore, COPD patients in both cohorts had a high prevalence of smoking-related comorbid conditions, and smoking cessation is proven to reduce the risks of heart disease, cancer, and neurologic injuries.24 Quitting cigarettes is a difficult task for most smokers, and only 10 to 40% of smokers who quit will achieve complete abstinence for up to 12 months, even with an aggressive treatment program.25 Nevertheless, smoking cessation is an essential part of COPD therapy, and there must be a strong and consistent effort to encourage patients to stop smoking.

The results of this study cannot be directly extrapolated to other centers because of the unique demographic features of our cohorts. There are well-described regional differences in COPD management in the United States,26 and gender and ethnic differences in cigarette smoking also may affect COPD diagnosis and utilization. Nevertheless, it is reasonable to assume that the problems in COPD evaluation and management that have been identified in this study are not unique to our area. COPD is a grossly underdiagnosed disease across the United States: only 3.5% of patients randomly selected from the 1992 Medicaid database were identified as having COPD, while NHISs over the last decade have estimated that physician-diagnosed COPD has a prevalence of approximately 10% among all adults over age 65 years.3 13

Many of the problems in COPD management appear to stem from a sense of nihilism and apathy toward this disease in the medical community. It is often difficult for physicians to convince COPD patients that they must quit smoking, and the low success rate of smoking cessation among COPD patients who do try to quit undoubtedly contributes to their frustration. Managed-care plans in the United States, including the one in our study, typically do not offer smoking-cessation treatment as a standard benefit, and there is not much pressure on them to do so.27

Until recently, there has not been a national public health campaign for educating the public and physicians about COPD as there have been for hypertension, heart disease, asthma, and other chronic conditions.7 COPD is a difficult problem, but the optimal management of COPD can have a tremendously beneficial impact on the lives of patients and on the health of the public as a whole. It is time for health-care professionals, health-care systems, and the public to overcome this neglectful attitude and to make a commitment to effective prevention and treatment of this disease.


   Acknowledgements
 
The authors are grateful to Jim Little, Susan Paine, and Curtis Hunt for assistance with data analysis, and to Rita Elliot for editorial review. We give special thanks to Dr. Eva Lydick and Dr. Cheryl Silberman for their ideas and support.


   Footnotes
 
Abbreviations: ATS = American Thoracic Society; CI = confidence interval; HMO = health maintenance organization; LHP = Lovelace Health Plan; NHIS = National Health Interview Survey; OR = odds ratio; UMC = university-affiliated county medical center; UNMH = The University of New Mexico Hospitals and Clinics

This research was supported by a grant from the SmithKline Beecham Corporation, and National Research Service Award K08 HL03615 from the National Heart, Lung, and Blood Institute, National Institutes of Health (D.W.M.).


   References
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 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

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