CPAP and survival in moderate-to-severe obstructive sleep apnoea syndrome and hypoxaemic COPD.

Obstructive sleep apnoea syndrome (OSAS) often coexists in patients with chronic obstructive pulmonary disease (COPD). The present prospective cohort study tested the effect of OSAS treatment with continuous positive airway pressure (CPAP) on the survival of hypoxaemic COPD patients. It was hypothesised that CPAP treatment would be associated with higher survival in patients with moderate-to-severe OSAS and hypoxaemic COPD receiving long-term oxygen therapy (LTOT). Prospective study participants attended two outpatient advanced lung disease LTOT clinics in São Paulo, Brazil, between January 1996 and July 2006. Of 603 hypoxaemic COPD patients receiving LTOT, 95 were diagnosed with moderate-to-severe OSAS. Of this OSAS group, 61 (64%) patients accepted and were adherent to CPAP treatment, and 34 did not accept or were not adherent and were considered not treated. The 5-yr survival estimate was 71% (95% confidence interval 53-83%) and 26% (12-43%) in the CPAP-treated and nontreated groups, respectively (p<0.01). After adjusting for several confounders, patients treated with CPAP showed a significantly lower risk of death (hazard ratio of death versus nontreated 0.19 (0.08-0.48)). The present study found that CPAP treatment was associated with higher survival in patients with moderate-to-severe OSAS and hypoxaemic COPD receiving LTOT.

Comparison of spirometry criteria for the diagnosis of COPD: results from the BOLD study.

Published guidelines recommend spirometry to accurately diagnose chronic obstructive pulmonary disease (COPD). However, even spirometry-based COPD prevalence estimates can vary widely. We compared properties of several spirometry-based COPD definitions using data from the international Burden of Obstructive Lung Disease (BOLD)study. 14 sites recruited population-based samples of adults aged > or =40 yrs. Procedures included standardised questionnaires and post-bronchodilator spirometry. 10,001 individuals provided usable data. Use of the lower limit of normal (LLN) forced expiratory volume in 1 s (FEV(1)) to forced vital capacity (FVC) ratio reduced the age-related increases in COPD prevalence that are seen among healthy never-smokers when using the fixed ratio criterion (FEV(1)/FVC <0.7) recommended by the Global Initiative for Chronic Obstructive Lung Disease. The added requirement of an FEV(1) either <80% predicted or below the LLN further reduced age-related increases and also led to the least site-to-site variability in prevalence estimates after adjusting for potential confounders. Use of the FEV(1)/FEV(6) ratio in place of the FEV(1)/FVC yielded similar prevalence estimates. Use of the FEV(1)/FVC

Adolescent smokers are at greater risk for current asthma and rhinitis.

BACKGROUND: The association of tobacco smoke with the prevalence of asthma and rhinitis has not been well-characterized in adolescents. METHODS: As part of the International Study of Asthma and Allergies in Childhood (ISAAC), we conducted a cross-sectional survey of 3000 adolescents aged 13-14 years in northern Argentina. Data included questions about asthma and rhinitis symptoms and about parental and personal smoking. Logistic regression and Pearson chi(2) statistics were used to estimate these associations. RESULTS: Over 13% of respondents described themselves as current smokers, and half indicated that at least one parent smoked at home. Active smoking was associated with both asthma (OR 1.83, 95%CI 1.42-2.35) and rhinitis (OR 1.61, 95%CI 1.33-1.92) in unadjusted analysis. These associations persisted after adjusting for parental smoking status, mother's educational level and sex. Boys were significantly less likely than girls to report current asthma or rhinitis. CONCLUSIONS: Active and passive smoking are both risk factors for asthma and rhinitis in adolescents. Assuming that some children with asthma never started smoking due to symptoms, then the true risk could be higher than reported here. These results reinforce the need to develop better strategies for primary and secondary prevention of tobacco exposure in children.

Can a normal peak expiratory flow exclude severe chronic obstructive pulmonary disease?

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is underdiagnosed. One barrier to diagnosis is the limited availability of spirometry testing, but in adults at risk for COPD, a normal pre-bronchodilator (pre-BD) peak expiratory flow (PEF) may rule out clinically significant COPD. OBJECTIVE: To identify post-BD airway obstruction using data from 13 708 individuals aged >or=40 years from the PLATINO and BOLD studies. METHODS: We evaluated different cut-off points of pre-BD. The PEF was obtained from a diagnostic-quality spirometer (not a mechanical PEF meter). At least one of the following COPD risk factors was present in 77% of the subjects: chronic respiratory symptoms; exposure to tobacco smoke, biomass smoke or dust in the workplace; or a previous diagnosis of asthma, COPD, emphysema or chronic bronchitis. RESULTS: Although the positive predictive value was low as expected, a pre-BD PEF of >or=70% predicted effectively ruled out Stages III and IV COPD of the Global Initiative for Chronic Obstructive Lung Disease. Among those with at least one risk factor, only 12% would require confirmatory spirometry using this criterion. CONCLUSIONS: Adding PEF measurement to a screening questionnaire may rule out severe to very severe COPD without the need for pre- and post-BD spirometry testing. Confirmation is needed from a study using inexpensive PEF meters or pocket spirometers with a staged screening protocol.

Harnessing stakeholder perspectives to improve the care of osteoporosis after a fracture.

UNLABELLED: This study used in-depth interviews and focus groups to evaluate osteoporosis care after a fracture. Patients (eligible women aged 67 who sustained a clinical fracture(s)), clinicians, and staff stated that an outreach program facilitated osteoporosis care management, but more-tailored education and support and increased participation of orthopedic specialists appear necessary. INTRODUCTION: Osteoporosis treatment reduces fracture risk, but screening and treatment are underutilized, even after a fracture has occurred. This study evaluated key stakeholder perspectives about the care of osteoporosis after a fracture. METHODS: Participants were from a nonprofit health maintenance organization in the United States: eligible women members aged 67 or older who sustained a clinical fracture(s) (n = 10), quality and other health care managers (n = 20), primary care providers (n = 9), and orthopedic clinicians and staff (n = 28); total n = 67. In-depth interviews and focus groups elicited participant perspectives on an outreach program to patients and clinicians and other facilitators and barriers to care. Interviews and focus group sessions were transcribed and content-analyzed. RESULTS: Patients, clinicians, and staff stated that outreach facilitated osteoporosis care management, but important patient barriers remained. Patient knowledge gaps and fatalism were common. Providers stated that management needed to begin earlier, and longer-term patient support was necessary to address adherence. Orthopedic clinicians and staff expressed lack of confidence in their osteoporosis management but willingness to encourage treatment. CONCLUSIONS: Although an outreach program assisted with the management of osteoporosis after a fracture, more-tailored education and support and increased participation of orthopedic specialists appear necessary to maximize osteoporosis management.

Worldwide burden of COPD in high- and low-income countries. Part I. The burden of obstructive lung disease (BOLD) initiative.

SETTING: Burden of Obstructive Lung Disease (BOLD) Initiative sites worldwide. OBJECTIVE: To measure the prevalence of chronic obstructive pulmonary disease (COPD) and its risk factors, investigate variation in prevalence across countries and develop standardized methods that can be used in industrialized and developing countries. DESIGN: Non-institutionalized adults aged > or =40 years were recruited using population-based sampling plans. Each site targeted a minimum of 600 participants (300 women, 300 men), who filled out questionnaires and performed spirometry before and after administration of 200 mug salbutamol using standardized methods. Random effects meta-analysis models were used to estimate pooled prevalence estimates and risk factor effects and to test for heterogeneity across sites and sex. RESULTS: Data published from 12 sites (n = 8775) showed that the estimated population prevalence of COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] Stage II and higher) was 10.1 +/- SE = 4.8% overall (11.8 +/- 7.9% for men and 8.5 +/- 5.8% for women). Prevalence increased with age and pack-years of smoking, but other less understood risk factors, such as biomass heating and cooking exposures, occupational exposures and tuberculosis, also contribute to the location-specific variations in disease prevalence that BOLD is finding. CONCLUSION: BOLD has estimated the social and economic burden of COPD in 12 countries to date. BOLD and the Proyecto Latinoamericano de Investigación en Obstrucción Pulmonar (the PLATINO study) are developing a growing database of COPD prevalence. Cigarette smoking and age are the most important COPD risk factors, but other risk factors should also be explored.

Comparing office-based and ambulatory blood pressure monitoring in clinical trials.

Ambulatory blood pressure monitoring (ABPM) is commonly used in clinical trials. Yet, its ability to detect blood pressure (BP) change in comparison to multiple office-based measurements has received limited attention. We recorded ambulatory and five daily pairs of random zero (RZ) BPs pre- and post-intervention on 321 adult participants in the multicentre Dietary Approaches to Stop Hypertension trial. Treatment effect estimates measured by ambulatory monitoring were similar to those measured by RZ and did not differ significantly for waking vs 24-h ambulatory measurements. For systolic BP, the standard deviations of change in mean 24-h ambulatory BP (8.0 mmHg among hypertensives and 6.0 mmHg among nonhypertensives) were comparable to or lower than the corresponding standard deviations of change in RZ-BP based on five daily readings (8.9 and 5.9 mmHg). The standard deviations of change for mean waking ambulatory BP (8.7 and 6.7 mmHg) were comparable to those obtained using three to four daily RZ readings. Results for diastolic BP were qualitatively similar. Ambulatory monitoring was more efficient (ie, a smaller sample size could detect a given BP change) than three to four sets of daily RZ readings and required fewer clinic visits. The average of 33 ambulatory BP readings during the waking hours had an efficiency comparable to that from the mean of four daily pairs of RZ-BPs. Participants readily accepted the ABPM devices, and their use requires less staff training. ABPM provides a useful alternative to RZ-BP measurements in clinical trials.

Effect of lifestyle modifications on blood pressure by race, sex, hypertension status, and age.

Recommendations for control of high blood pressure (BP) emphasize lifestyle modification, including weight loss, reduced sodium intake, increased physical activity, and limited alcohol consumption. The Dietary Approaches to Stop Hypertension (DASH) dietary pattern also lowers BP. The PREMIER randomized trial tested multicomponent lifestyle interventions on BP in demographic and clinical subgroups. Participants with above-optimal BP through stage 1 hypertension were randomized to an Advice Only group or one of two behavioural interventions that implement established recommendations (Est) or established recommendations plus DASH diet (Est plus DASH). The primary outcome was change in systolic BP at 6 months. The study population was 810 individuals with an average age of 50 years, 62% women, 34% African American (AA), 95% overweight/obese, and 38% hypertensive. Participants in all the three groups made lifestyle changes. Mean net reductions in systolic (S) BP in the Est intervention were 1.2 mmHg in AA women, 6.0 in AA men, 4.5 in non-AA women, and 4.2 in non-AA men. The mean effects of the Est Plus DASH intervention were 2.1, 4.6, 4.2, and 5.7 mmHg in the four race-sex subgroups, respectively. BP changes were consistently greater in hypertensives than in nonhypertensives, although interaction tests were nonsignificant. The Est intervention caused statistically significant BP reductions in individuals over and under age 50. The Est Plus DASH intervention lowered BP in both age groups, and significantly more so in older individuals. In conclusion, diverse groups of people can adopt multiple lifestyle changes that can lead to improved BP control and reduced CVD risk.

Insight into patient dissatisfaction with asthma treatment.

BACKGROUND: Measures of patient satisfaction or dissatisfaction with treatment are increasingly being used as indicators of quality of care. As these measures become more widely used, it is important to know if patient dissatisfaction is associated with important processes or outcomes of medical care. METHODS: Survey of patient-reported asthma management issues using the Asthma Therapy Assessment Questionnaire in a large health maintenance organization in the Pacific Northwest. Associations between patient dissatisfaction with asthma treatment and patient-reported measures of asthma control, patient-provider communication, and belief in asthma medications (self-efficacy) were examined. RESULTS: Of the 5181 adult members with asthma enrolled in the health maintenance organization, 30% indicated dissatisfaction with current treatment. Dissatisfaction was higher among patients with a higher number of asthma control problems, patient-provider communication problems, or belief in medication problems (eg, failure to believe their medications are useful and inability to take asthma medications as directed). The odds of dissatisfaction with treatment were 2.8 (95% confidence interval [CI], 2.4-3.3; P<.001) for asthma control problems, 2.0 (95% CI, 1.6-2.6; P<.001) for communication problems, and 8.0 (95% CI, 6.7-9.5; P<.001) for belief in medication problems compared with patients without these perceived problems. CONCLUSION: Patient dissatisfaction with treatment may be related to important asthma disease management issues.

Specialty differences in the management of asthma. A cross-sectional assessment of allergists' patients and generalists' patients in a large HMO.

OBJECTIVE: To examine the differences in medical management and quality of life between patients with asthma who receive their primary asthma care from allergists and those who receive their care from generalists in a large health maintenance organization (HMO). METHODS: We conducted a cross-sectional study of patients with asthma in a large HMO (Kaiser Permanente, Northwest Region, Portland, Ore). Participants were 392 individuals aged 15 through 55 years with physician-diagnosed asthma, taking antiasthma medications, reporting current asthma symptoms, and receiving asthma care from an allergist or from a generalist. Primary outcomes include characteristics of asthma, health care utilization, and quality of life. RESULTS: Patients cared for by allergists tended to have more severe asthma than those cared for by generalists (P < .01). The allergists' patients tended to be older (38.6 +/- 9.6 years vs 35.7 +/- 12.6 years, P < .01), more atopic (91% vs 78%, P < .01), and more likely to report perennial (rather than seasonal) asthma (26% vs 36%, P < .04) than the generalists' patients. Patients receiving their primary asthma care from an allergist were considerably more likely than generalists' patients to report using inhaled anti-inflammatory agents (P < .01), oral steroids (P < .01), and regular (daily) breathing medications to control their asthma (P < .01). Allergists' patients were more likely to have asthma exacerbations treated in a clinic setting rather than an emergency department (P < .01). Furthermore, allergists' patients reported significantly improved quality of life as measured by several dimensions of the SF-36 scale (physical functioning, role emotional, bodily pain, and general health; P < .05). CONCLUSIONS: These findings suggest that specialist care of asthma is of benefit for patients with asthma in a large HMO. Specifically, the allergists' patients conformed more closely to national asthma management guidelines and reported better quality of life than did the generalists' patients.

Effects of dietary patterns on blood pressure: subgroup analysis of the Dietary Approaches to Stop Hypertension (DASH) randomized clinical trial.

OBJECTIVE: To determine the effects of dietary patterns on blood pressure in subgroups. METHODS: Dietary Approaches to Stop Hypertension (DASH) was a randomized controlled feeding study conducted at 4 academic medical centers. Participants were 459 adults with untreated systolic blood pressure less than 160 mm Hg and diastolic blood pressure 80 to 95 mm Hg. For 3 weeks, participants were fed a "control" diet. They were then randomized to 8 weeks of (1) control diet; (2) a diet rich in fruits and vegetables; or (3) a combination diet rich in fruits, vegetables, and low-fat dairy foods, and reduced in saturated fat, total fat, and cholesterol (the DASH combination diet). Weight and salt intake were held constant. Change in diastolic blood pressure was the primary outcome variable, and systolic blood pressure a secondary outcome. Subgroups analyzed included race, sex, age, body mass index, years of education, income, physical activity, alcohol intake, and hypertension status. RESULTS: The combination diet significantly lowered systolic blood pressure in all subgroups (P<.008), and significantly lowered diastolic blood pressure (P<.01) in all but 2 subgroups. The fruits-and-vegetables diet also reduced blood pressure in the same subgroups, but to a lesser extent. The combination diet lowered systolic blood pressure significantly more in African Americans (6.8 mm Hg) than in whites (3.0 mm Hg), and in hypertensive subjects (11.4 mm Hg) than in nonhypertensive subjects (3.4 mm Hg) (P<.05 for both interactions). CONCLUSIONS: The DASH combination diet, without sodium reduction or weight loss, significantly lowered blood pressure in virtually all subgroups examined, and was particularly effective in African Americans and those with hypertension. The DASH combination diet may be an effective strategy for preventing and treating hypertension in a broad cross section of the population, including segments of the population at highest risk for blood pressure-related cardiovascular disease.

Body weight versus body fat distribution, adiposity, and frame size as predictors of bone density.

Weight is strongly associated with bone mineral density (BMD), but the mechanism of this effect is not well understood. Weight, height, hip-waist ratio, elbow breadth, adiposity, and BMD were measured in 6705 older women participating in the Study of Osteoporotic Fractures. Adiposity was measured by bioelectric impedance and BMD by single-photon (proximal and distal radius and calcaneus) and dual-energy x-ray absorptiometry (lumbar spine and proximal femur). Age-adjusted associations between weight and BMD were robust at all sites (R2 = 5.9-20.4%), but the addition of other anthropometric variables to the model only marginally improved the association. Adiposity explained a substantial fraction of the effect of weight on BMD, particularly at weight-bearing sites (36-62%). On the other hand, weight explained virtually all the variability of adiposity on BMD at weight-bearing sites (81-100%). At the radial measurement sites, adiposity had more substantial independent contributions. Weight did not seem to influence the relationship between BMD and age. In sum, at weight bearing-sites, the preponderance of the effect of weight on BMD is a direct result of mass effects rather than adiposity, whereas at non-weight-bearing sites, adiposity exerts more important effects, potentially mediated by metabolic factors.

Effect of dietary patterns on ambulatory blood pressure : results from the Dietary Approaches to Stop Hypertension (DASH) Trial. DASH Collaborative Research Group.

We measured ambulatory blood pressure (ABP) in 354 participants in the Dietary Approaches to Stop Hypertension (DASH) Trial to determine the effect of dietary treatment on ABP (24-hour, day and night) and to assess participants' acceptance of and compliance with the ABP monitoring (ABPM) technique. After a 3-week run-in period on a control "typical" American diet, subjects (diastolic blood pressure [BP], 80 to 95 mm Hg; systolic BP, <160 mm Hg; mean age, 45 years) were randomly assigned to 1 of 3 diets for an 8-week intervention period: a continuation of the control diet; a diet rich in fruits and vegetables; and a "combination" diet that emphasized fruits, vegetables, and low-fat dairy products. We measured ABP at the end of the run-in and intervention periods. Both the fruit/vegetable and combination diets lowered 24-hour ABP significantly compared with the control diet (P<0. 0001 for systolic and diastolic pressures on both diets: control diet, -0.2/+0.1 mm Hg; fruit/vegetable diet, -3.2/-1.9 mm Hg; combination diet, -4.6/-2. 6 mm Hg). The combination diet lowered pressure during both day and night. Hypertensive subjects had a significantly greater response than normotensives to the combination diet (24-hour ABP, -10.1/-5.5 versus -2.3/-1.6 mm Hg, respectively). After correction for the control diet responses, the magnitude of BP lowering was not significantly different whether measured by ABPM or random-zero sphygmomanometry. Participant acceptance of ABPM was excellent: only 1 participant refused to wear the ABP monitor, and 7 subjects (2%) provided incomplete recordings. These results demonstrate that the DASH combination diet provides significant round-the-clock reduction in BP, especially in hypertensive participants.

Psychiatric reactions to disaster: the Mount St. Helens experience.

Following the 1980 Mount St. Helens volcanic eruption, psychiatric reactions were studied in the disaster area and in a control community. Using the new criterion-based diagnostic method for psychiatric epidemiologic research, the Diagnostic Interview Schedule, the authors found a significant prevalence of disaster-related psychiatric disorders. These Mount St. Helens disorders included depression, generalized anxiety, and posttraumatic stress reaction. There was a progressive "dose-response" relationship in the comparison of control, low-exposure, and high-exposure groups. The dose-response pattern occurred among both the bereaved and the property-loss victims.

Effects on blood lipids of a blood pressure-lowering diet: the Dietary Approaches to Stop Hypertension (DASH) Trial.

BACKGROUND: Effects of diet on blood lipids are best known in white men, and effects of type of carbohydrate on triacylglycerol concentrations are not well defined. OBJECTIVE: Our goal was to determine the effects of diet on plasma lipids, focusing on subgroups by sex, race, and baseline lipid concentrations. DESIGN: This was a randomized controlled outpatient feeding trial conducted in 4 field centers. The subjects were 436 participants of the Dietary Approaches to Stop Hypertension (DASH) Trial [mean age: 44.6 y; 60% African American; baseline total cholesterol: < or = 6.7 mmol/L (< or = 260 mg/dL)]. The intervention consisted of 8 wk of a control diet, a diet increased in fruit and vegetables, or a diet increased in fruit, vegetables, and low-fat dairy products and reduced in saturated fat, total fat, and cholesterol (DASH diet), during which time subjects remained weight stable. The main outcome measures were fasting total cholesterol, LDL cholesterol, HDL cholesterol, and triacylglycerol. RESULTS: Relative to the control diet, the DASH diet resulted in lower total (-0.35 mmol/L, or -13.7 mg/dL), LDL- (-0.28 mmol/L, or -10.7 mg/dL), and HDL- (-0.09 mmol/L, or -3.7 mg/dL) cholesterol concentrations (all P < 0.0001), without significant effects on triacylglycerol. The net reductions in total and LDL cholesterol in men were greater than those in women by 0.27 mmol/L, or 10.3 mg/dL (P = 0.052), and by 0.29 mmol/L, or 11.2 mg/dL (P < 0.02), respectively. Changes in lipids did not differ significantly by race or baseline lipid concentrations, except for HDL, which decreased more in participants with higher baseline HDL-cholesterol concentrations than in those with lower baseline HDL-cholesterol concentrations. The fruit and vegetable diet produced few significant lipid changes. CONCLUSIONS: The DASH diet is likely to reduce coronary heart disease risk. The possible opposing effect on coronary heart disease risk of HDL reduction needs further study.

Patterns of lung function in asymptomatic nonsmoking men and women in the People's Republic of China.

PURPOSE: To evaluate patterns of lung function in healthy, working Chinese men and women in different geographic areas of the People's Republic of China (PRC). METHODS: We conducted lung function tests on 2926 asymptomatic, never smoking Chinese men and women aged 35-56 years residing in or around Beijing and Guangzhou. Within each of these locations, separate urban and rural samples were recruited. RESULTS: Age and height adjusted lung function was greater in Beijing than in Guangzhou, and within each city for residents of rural vs. urban areas. Among women, estimated rates of lung aging were greater in Beijing than in Guangzhou, and in urban vs. rural areas. Both FEV(1) and FVC exhibited a curvilinear association with body mass index. CONCLUSIONS: Lung function data from this largely working cohort exhibited marked geographic and urban-rural differences in this never smoking, adult Chinese cohort. Such variation is not uncommon and may reflect differences in body size, diet, and environmental and occupational exposures across these different settings. Caution should be used in applying published reference equations to populations from different parts of the PRC.

Rationale and design of the Dietary Approaches to Stop Hypertension trial (DASH). A multicenter controlled-feeding study of dietary patterns to lower blood pressure.

Epidemiologic studies have found that dietary patterns characterized by high intakes of certain minerals and fiber are associated with low blood pressure. Dietary Approaches to Stop Hypertension (DASH) is a multicenter, randomized, controlled-feeding trial designed to test the effects on blood pressure of two such dietary patterns consumed for 8 weeks. The two experimental diets will be compared with each other and with a control dietary pattern that is relatively low in potassium, magnesium, calcium, and fiber, and has a fat and protein profile mirroring current consumption. The first experimental diet, arguably termed "ideal," is high in fruits, vegetables, whole cereal products, low-fat dairy products, fish, chicken, and lean meats designed to be low in saturated fat and cholesterol; moderately high in protein; and high in minerals and fiber. The second experimental diet tests the effect of fruits and vegetables alone. Its potassium, magnesium, and dietary fiber content will be at the same high levels as the ideal dietary pattern, while its fat, protein, and calcium content will resemble that of the control dietary pattern. The study population will consist of 456 healthy men and women, aged 22 years or older, with systolic blood pressure less than 160 mm Hg and diastolic blood pressure 80 to 95 mm Hg. African-American and other minority groups will comprise 67% of the population. Participants will eat one of the three dietary patterns. The DASH trial has unique features. First, dietary patterns rather than single nutrients are being tested. Second, all food for the experimental diets is provided to the participants using a standardized multicenter protocol. Because the dietary patterns are constructed with commonly consumed food items, the results, if positive, may be conveniently implemented in dietary recommendations to the general public.

Comparing change in longitudinal studies: adjusting for initial value.

Adjustment for initial value may yield misleading results when comparing change over time in two populations. This paper presents a methodology for correcting for the effects of regression to the mean when change over time is regressed on standardized initial level. The results are used to examine the bias introduced by failing to correct for the effects of regression to the mean in the two sample problem. We also examine the implications of adjusting for initial value in certain observational studies. When group assignment is known to be related to initial value, we argue that this adjustment procedure is inappropriate. The results are illustrated using data from a longitudinal study of lung function decline.

Diagnostic accuracy of asthma within a health maintenance organization.

Reported asthma morbidity and mortality are increasing in the U.S. We addressed one explanation, that the accuracy of the diagnosis of asthma is changing. The diagnosis of asthma was evaluated in 320 inpatient and outpatient records bearing the diagnosis of asthma for the periods 1970-73 and 1980-83 in a health maintenance organization (HMO). We determined whether or not our agreement with the chart diagnosis was a function of: sex, period of treatment, inpatient vs outpatient setting, whether or not asthma was the primary or secondary diagnosis, and patient age. The standard of comparison was an expert panel review in which asthma was divided into six categories. In both inpatient (97%) and outpatient settings (94%), the majority of charts examined exhibited a clinical picture consistent with asthma. The rate of the narrowly defined "definite asthma" category varied with respect to age, with the highest proportion in the under 20-year age group (74%) and the lowest (46%) in the over 60 age groups, probably because older individuals often have coexisting smoking related diseases. The increase in "definite asthma" among outpatients from the 1970s to the 1980s likely reflects increasing chart documentation among physicians, illustrating the need for clear, consistent chart documentation of signs and symptoms of asthma.

Twenty year trends in hospital discharges for asthma among members of a health maintenance organization.

We examined trends in hospitalizations for asthma from 1967 to 1987 among members of a large health maintenance organization. During this time asthma discharges increased significantly among children, and especially among boys under the age of 5 years. Ninety-five percent of the increase in discharges among boys was explained by a corresponding increase in the number of boys who were hospitalized. Increased readmissions did not account for the rise. Changes in the International Classification of Diseases coding of asthma and diagnostic shift by physicians accounted for only part of the increase. A decline in hospitalizations since 1984 may reflect changes in the management of asthma in the emergency room and not a decline in severe asthma episodes.