journal of Asthma, 29(1), 21-28 (1992)

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Features of Asthma in Older Adults William C. Bailey, M.D.,' James M. Richards, Jr., Ph.D.,f C. Michael Brooks, Ed.D.,t Seng-jaw Soong, Ph.D.,S and A. Lynne Brannen, M.D.1 *Department of Medicine Division of Pulmonary and Critical Care Medicine University of Alabama at Birmingham and Department of Veterans Affairs Medical Center TOffice of Educational Development University of Alabama at Birmingham $Department of Biostatistics and Biomathematics and Bwstatistics Unit Comprehensive Cancer Center University of Alabama at Birmingham Birmingham, Alabama 35294 13623 J. Dewey Gray Circle-100 Augusta, Georgia 3091 0

ABSTRACT A study compared clinical and functional features of elderly patients with asthma to younger patients at a university medical center. Older patients had a larger than predicted reduction in pulmonary function parameters even though physician-assessed severity, duration of diagnosed asthma, and smoking status were no different between groups. A significant increase in the comorbid diagnosis of chronic obstructive pulmonary disease was noted in older patients with asthma. These two points sup port the hypothesis that long-standing asthma may lead

Address reprint requests to: William C. Bailey, M.D., UAB Lung Health Center, 619 South 19th Street, Birmingham, AL 35233.

21 Copyright 0 1992 by Marcel Dekker, Inc.

Bailey et al.

22 to irreversible airflow obstruction. Older patients reported better medication compliance and decreases in some respiratory symptoms and demonstrated lower health care utilization.

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INTRODUCTION

Asthma in the elderly may often be unrecognized or misdiagnosed, leading to inappropriate treatment (1-3).Respiratory symptoms may differ qualitatively and quantitatively in older patients compared with younger adults with asthma in the same population. Cognitive, functional, and metabolic impairments aeeociatedwith aging may create the need for special educational techniques and materials. Coexisting disease with older patients may increase the likelihood of drug interaction as well as add to the complexity of asthma treatment in other ways. For example, arthritis in the hands may affect the use of metered dose inhalers. To highlight these concerns,this study reports the demographic characteristics, clinical features, and health care utilization of a group of elderly patients with asthma in a university medical center population and compares them with a group of younger adults with asthma. METHODOLOGY

Patients with asthma were identified from the registry of the University of Alabama at Birmingham Lung Health Center. Demographic features of these patients (n = 479) were recorded by chart review and personal interviews. A subset (n = 267) who were eligible and willing were enrolled in an ongoing Adult Asthma Education Project at the Center and administered a series of questionnaires by trained interviewem. These questionnaires included details of demographics, comorbid health problems, current medications and adherence to regimen, smoking status, and health care resource utilization (4).

Respiratory symptoms were assessed by asking patients to quantify during the past 7 days, their experiences of cough, wheezing,

shortness of breath, sputum characteristics, and exercise tolerance on a scale from zero to three where 0 = no symptoms, 1 = slight, 2 = moderate, and 3 = severe symptoms. These were then totaled and a mean score derived for each patient. Similarly, respiratory illnesses were assessed by asking patients to report the frequency of respiratory illnesses characterized by coughing, shortness of breath, colds or upper respiratory infections, bronchitis, and pneumonia. Scores were based on a scale from zero to two where 0 = no episodes, 1 = one to three episodes, and 2 = four or more episodes in a given time interval. These were then totaled and a mean score obtained for each patient. Medication adherence was measured by two 6-item scales modeled after those of Morisky et al. (5).The patient’s personal physician was asked to estimate the patient’s asthma severity. Pulmonary function assessment by standard spirometric techniques was obtained at baseline on all education project patients (Cybermedic Moose CM-555) or from chart review from the remainder of the registry of patients. The best value from routine clinic visits during the previous 12 months was reported for the statistical analysis. Standard pulmonary function test procedures at UAB include the avoidance of agonists, such as beta blockers, that affect airflow in asthma patients. Spirometric procedures met American Thoracic Society (ATS) guidelines (6). Spirometric prediction standards were those of C r a w et al. (7)for a Cybermedic spirometer. STATISTICAL ANALYSIS

Patients were classified into three age groups: those under 60 years old, those 60-69 years old, and those 70 years or older. The under 60 age group was 17-59years old with mean = 40.2 and standard deviation = 11.3. The results then were expressed in terms of

23

Features of Asthma in Older Adults Table 1. Relationship of Age to Asthma Severity and Duration AGE CATEGORY UNDER 60 (n = 260)

60-69 (n = 57)

70 O R OLDER (n = 46)

CHI SQUARE

Mild

40.8%

3 5 , 1010

39.1 "lo

4.20

Moderate

4 1.5010

52.6%

34.7%

Severe

17.7%

12 .3 010

22.4%

Physician judgment of severity

J Asthma Downloaded from informahealthcare.com by University of Sydney on 01/04/15 For personal use only.

Years since first diagnosis of asthma

< 10

45.1 '10

47.5%

54.3 'lo

10-29

38.6 '10

3 1.1 010

30.4%

2 30

16.3%

2 1.3 010

15.2%

2.84

Note. Results in this and subsequent tables pertain to columns, not rows. Neither Chi square was significant at the .10 level. Respiratory Symptom Scale: Results in 257 adult asthmatics. A score is assigned based on severity of symptoms from 0 = none, 1 = slight, 2 = moderate, 3 = severe symptoms. The score for all 7 questions is summed for a total scale score.

means and standard deviations or percentages of the groups expressing given features. Comparisons of means were performed using a simple three groups analysis of variance (ANOVA) design. This design uses the F statistic to test group differences. Comparisons of the three groups with respect to clinical features were performed by Chisquare analysis. Because the number of older patients was rather low, the statistical power was limited (8). In such circumstances, methodologists (8) suggest that a less stringent significance (beta)level be specified, and accordingly in the present research, p values less than .10 were considered significant.

RESULTS The relationship of age to physician judgment of severity of disease compared with duration since asthma was first diagnosed is summarized in Table 1.Neither severity nor duration of asthma was sigmfmmtly different between age groups. Despite this, however, the results of pulmonary function tests were considerably different (Table 2), showing a reduction in spirometric values with age out of proportion to age-corrected predictions. As expected, however, older adults had significantly greater associated comorbid health problems (Table 41, including arthritis, diabetes mellitus, and hypertension. Of

Table 2. Relationship of Age to Pulmonary Function Tests AGE CATEGORY PULMONARY FUNCTION TEST

UNDER 60 (n = 259)

60-69

(n = 59)

70 OR OLDER (n = 49)

F 6.75a

FVC % of predicted

80.56 f 20.58

74.24 f 20.80

69.96 f 20.03

FEV, % of predicted

72.33 f 23.66

65.74 f 23.48

65.04 f 25.06

3.22b

Ratio of FEV, to FVC

73.44 f 13.75

69.39 f 14.27

68.54 f 13.51

4.25b

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Features of asthma in older adults.

A study compared clinical and functional features of elderly patients with asthma to younger patients at a university medical center. Older patients h...
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