Training physicians for the future US Health Care System

Changes in US medical education have not yet paralleled the extraordinary recent advances in biomedical science. This is about to change with recent innovations in undergraduate medical education (UME) pedagogy. These changes include the 'flipped classroom,' new Liaison Committee on Medical Education requirements for learners to function collaboratively on health care teams that include other health professionals, the comprehensive development of professional identity in learning communities and adoption of measurable outcomes, termed 'entrustable professional activities'. These innovations offer the opportunity for a consistent longitudinal educational continuum in the US from UME to Graduate Medical Education (GME) and continuing medical education (CME). Such innovation addresses both individual patient and population health, with the potential for increasing shared decision-making and patient satisfaction. These innovations in US medical education have the potential to address the Institute for Healthcare Improvement's triple aim of improving patient care, improving the health of populations and reducing the per capita cost of health care.

Educational agendas for interdisciplinary end-of-life curricula

The importance of an interdisciplinary end-of-life curricula for the intensive care unit is now recognized. Educational agendas for interdisciplinary end-of-life curricula are being developed across the United States. However, the limited database on palliative care education precludes evidence-based recommendations. Through a case-based approach, the need for an interdisciplinary team is explored, including the definition of an interdisciplinary team and the step-wise incorporation of specific members, such as physicians, nurses, social workers, and the chaplain, as patient care evolves. Core competencies for end-of-life care are enumerated including the approaches to end-of-life care, ethical and legal constraints, symptom management, specific end-of-life syndromes/palliative crises, and development of communication skills for trusting relationships. Finally, four phases of ICU management of curative and comfort care are proposed: phase I, focus on checklist for transfer; phase II, focus on life-saving treatments; phase III, focus on the "whole" patient; and phase IV, focus on palliative care.

Exhaled nitric oxide levels correlate with measures of disease control in asthma

BACKGROUND

Asthma guidelines emphasize maintaining disease control. However, objective measures of asthma disease control are lacking.

OBJECTIVE

We sought to examine the relationship between exhaled nitric oxide (NO) levels and measures of asthma disease control versus asthma disease severity.

METHODS

We performed a cross-sectional study of 100 patients (age range, 7-80 years) with asthma. We administered a questionnaire to identify characteristics of asthma, performed spirometric testing before and after administration of a bronchodilator, and measured exhaled NO levels in all participants.

RESULTS

Exhaled NO was significantly correlated with the following markers of asthma disease control: asthma symptoms within the past 2 weeks (P =.02), dyspnea score (P =. 02), daily use of rescue medications (P =.01), and reversibility of airflow obstruction (P =.02). Exhaled NO levels were not correlated with the following markers of asthma disease severity: history of respiratory failure (P =.20), health care use (P =.08), fixed airflow obstruction (P =.91), or a validated asthma severity score (P =.19). Markers with relevance to both disease control and severity showed either a weak correlation (FEV(1) and FEV(1) percent predicted) or no correlation (controller drug use) with exhaled NO.

CONCLUSION

We conclude that exhaled NO levels are correlated predominantly with markers of asthma control rather than asthma severity. Monitoring of exhaled NO may be useful in outpatient asthma management.

Pneumoperitoneum: a review of nonsurgical causes

OBJECTIVE

To review causes of nonsurgical pneumoperitoneum (NSP), identify nonsurgical etiologies, and guide conservative management where appropriate.

DATA SOURCE

We conducted a computerized MEDLINE database search from 1970 to 1999 by using key words pneumoperitoneum and benign, nonsurgical, spontaneous, iatrogenic, barotrauma, pneumatosis, diaphragmatic defects, free air, mechanical ventilation, gynecologic, and pelvic. We identified 482 articles by using these keywords and reviewed all articles. Additional articles were identified and selectively reviewed by using key words laparotomy, laparoscopy, and complications.

STUDY SELECTION

We reviewed all case reports and reviews of NSP, defined as pneumoperitoneum that was successfully managed by observation and supportive care alone or that required a nondiagnostic laparotomy.

DATA SYNTHESIS

Each unique cause of nonsurgical pneumoperitoneum was recorded. When available, data on nondiagnostic exploratory laparotomies were noted. Case reports were organized by route of introduction of air into the abdominal cavity: abdominal, thoracic, gynecologic, and idiopathic.

CONCLUSIONS

Most cases of NSP occurred as a procedural complication or as a complication of medical intervention. The most common abdominal etiology of NSP was retained postoperative air (prevalence 25% to 60%). NSP occurred frequently after peritoneal dialysis catheter placement (prevalence 10% to 34%) and after gastrointestinal endoscopic procedures (prevalence 0.3% to 25%, varying by procedure). The most common thoracic causes included mechanical ventilation, cardiopulmonary resuscitation, and pneumothorax. One hundred ninety-six case reports of NSP were recorded, of which 45 involved surgical exploration without evidence of perforated viscus. The clinician should maintain a high index of suspicion for nonsurgical causes of pneumoperitoneum and should recognize that conservative management may be indicated in many cases.

Increased exhaled nitric oxide in chronic bronchitis: comparison with asthma and COPD

STUDY OBJECTIVES

To test the hypothesis that exhaled nitric oxide (NO) is increased in patients with chronic bronchitis, and to compare the results with exhaled NO in patients with asthma and COPD.

STUDY DESIGN

Cross-sectional survey.

SETTING AND PATIENTS

Veterans Administration pulmonary function laboratory. Patients (n = 179) were recruited from 234 consecutive patients. Two nonsmoking control groups of similar age, with normal spirometry measurements and no lung disease, were used (18 patient control subjects and 20 volunteers).

MEASUREMENTS

Participants completed questionnaires and spirometry testing. Exhaled NO was measured by chemiluminescence using a single-breath exhalation technique.

RESULTS

Current smoking status was associated with reduced levels of exhaled NO (smokers, 9. 2 +/- 0.9 parts per billion [ppb]; never and ex-smokers, 14.3 +/- 0. 6 ppb; p < 0.0001). Current smokers (n = 57) were excluded from further analysis. Among nonsmokers, the levels of exhaled NO were significantly higher in patients with chronic bronchitis (17.0 +/- 1. 1 ppb; p = 0.035) and asthma (16.4 +/- 1.3 ppb; p = 0.05) but not in those with COPD (14.7 +/- 1.0 ppb; p = 0.17) when compared with either control group (patient control subjects, 11.1 +/- 1.6 ppb; outside control subjects, 11.5 +/- 1.5 ppb). The highest mean exhaled NO concentration occurred in patients with both chronic bronchitis and asthma (20.2 +/- 1.6 ppb; p = 0.005 vs control subjects).

CONCLUSIONS

Exhaled NO is increased in patients with chronic bronchitis. The increase of exhaled NO in patients with chronic bronchitis was similar to that seen in patients with asthma. The highest mean exhaled NO occurred in patients with both chronic bronchitis and asthma. Exhaled NO was not increased in patients with COPD. Although chronic bronchitis and asthma have distinct histopathologic features, increased exhaled NO in patients with both diseases suggests common features of inflammation.

Smoking cessation in primary care clinics

OBJECTIVES

To document smoking cessation rates achieved by applying the 1996 Agency for Health Care Policy and Research (AHCPR) smoking cessation guidelines for primary care clinics, compare these quit rates with historical results, and determine if quit rates improve with an additional motivational intervention that includes education as well as spirometry and carbon monoxide measurements.

DESIGN

Randomized clinical trial.

SETTING

Two university-affiliated community primary care clinics.

PATIENTS

Two hundred five smokers with routinely scheduled appointments.

INTERVENTION

All smokers were given advice and support according to AHCPR guidelines. Half of the subjects received additional education with spirometry and carbon monoxide measurements.

MEASUREMENTS AND MAIN RESULTS

Quit rate was evaluated at 9-month follow-up. Eleven percent of smokers were sustained quitters at follow-up. Sustained quit rate was no different for intervention and control groups (9% vs 14%; [OR] 0.6; 95% [CI] 0.2, 1.4). Nicotine replacement therapy was strongly associated with sustained cessation (OR 6.7; 95% CI 2.3, 19.6). Subjects without insurance were the least likely to use nicotine replacement therapy ( p =.05). Historical data from previously published studies showed that 2% of smokers quit following physician advice, and additional support similar to AHCPR guidelines increased the quit rate to 5%.

CONCLUSIONS

The sustained smoking cessation rate achieved by following AHCPR guidelines was 11% at 9 months, which compares favorably with historical results. Additional education with spirometry did not improve the quit rate. Nicotine replacement therapy was the strongest predictor of cessation, yet was used infrequently owing to cost. These findings support the use of AHCPR guidelines in primary care clinics, but do not support routine spirometry for motivating patients similar to those studied here.

Associations of smoking with hospital-based care and quality of life in patients with obstructive airway disease

STUDY OBJECTIVES

To investigate the relationship between direct or environmental tobacco smoke (ETS) exposure and both hospital-based care (HBC) and quality of life (QOL) among subjects with asthma.

STUDY DESIGN

We report baseline cross-sectional data on 619 subjects with asthma, including direct or ETS exposure and QOL, and prospective longitudinal data on HBC using administrative databases for 30 months following baseline evaluation.

SETTING AND PATIENTS

Participants were health maintenance organization members with physician-diagnosed asthma involved in a longitudinal study of risk factors for hospital-based asthma care.

MEASUREMENTS

Demographic characteristics and QOL were assessed with administered questionnaires, including the Marks Asthma Quality-of-Life (AQLQ) and SF-36 questionnaires. HBC was defined as episodes per person-year of hospital-based asthma care, which included emergency department and urgency care visits, and hospitalizations for asthma.

RESULTS

Current smokers reported significantly worse QOL than never-smokers in two of five domains of the AQLQ (p < 0.05). Subjects with ETS exposure also reported significantly worse QOL than those without ETS exposure in two domains (p < 0.05). On the SF-36, current smokers reported significantly worse QOL than never-smokers in five of nine domains (p < 0.05). Subjects with ETS exposure reported significantly worse QOL than those without ETS exposure in three domains (p < 0.05). Current smokers used significantly more hospital-based asthma care than never-smokers (adjusted relative risk [RR], 1.40; 95% confidence interval [CI], 1.01 to 1.95) while ex-smokers did not exhibit increased risk compared with nonsmokers (adjusted RR, 0.94; 95% CI, 0.7 to 1.3). Also, subjects with ETS exposure used significantly more hospital-based asthma care than those without ETS exposure (RR, 2.34; 95% CI, 1.80 to 3.05).

CONCLUSIONS

Direct or environmental tobacco exposure prospectively predicted increased health-care utilization for asthma and reduced QOL in patients with asthma. These findings add to our existing knowledge of the detrimental effects of tobacco smoke and are of relevance specifically to patients with asthma.

Lack of correlation of symptoms with specialist-assessed long-term asthma severity

STUDY OBJECTIVES

To validate three indicators of asthma severity as defined in the National Asthma Education Program (NAEP) guidelines (ie, frequency of symptoms, degree of airflow obstruction, and frequency of use of oral glucocorticoids), alone and in combination, against severity as assessed by pulmonary specialists provided with 24-month medical chart data.

DESIGN

Cross-sectional comparison of questionnaire and clinical-based markers of asthma severity with physician-assessed severity based on chart review. The pulmonologists did not have access to the results of the baseline evaluations when making their severity assessments.

SETTING AND PARTICIPANTS

Study participants were 193 asthmatic members (age range, 6 to 55 years) of a large health maintenance organization who underwent a baseline evaluation as part of a separate longitudinal study. This evaluation consisted of spirometry, skin prick testing, and a survey that included questions on symptoms and medication use. The participants in the ancillary study were selected, based on their baseline evaluation, to reflect a broad range of asthma severity.

RESULTS

Based on the chart review, 86 of the study subjects (45%) had mild disease, 90 (45%) had moderate disease, and 17 (9%) had severe disease. This physician-assessed severity correlated highly (p < or = 0.013) with NAEP-based indices of severity based on oral glucocorticoid use (never, infrequently for attacks, frequently for attacks, and daily use) and on spirometry (FEV1 > 80% predicted, 60 to 80% predicted, and <60% predicted). It did not, however, correlate with current asthma symptoms (< or = once/week, 2 to 6 times/week, daily) (p=0.87). A composite severity score based on spirometry and the glucocorticoid use data still provided an overall agreement of 63%, with a weighted kappa of 0.40.

CONCLUSIONS

While current symptoms are the most important concern of patients with asthma, they reflect the current level of asthma control more than underlying disease severity. Investigators must therefore use caution when comparing groups of patients for whom severity categorization is based largely on symptomatology. This observation, that symptoms alone do not reflect disease severity, becomes even more important as health-care delivery moves closer to protocols/practice guidelines and "best treatment" programs that rely heavily on symptoms to guide subsequent treatment decisions.

20-year trends in the prevalence of asthma and chronic airflow obstruction in an HMO

Although asthma is on the rise in the United States and elsewhere, data on age-sex-specific patterns of change in various types of health care utilization are scarce. We report on 20-yr trends in the treated prevalence of asthma among members of a large health maintenance organization. Data are presented separately for each of six age-sex categories, and include both the treated prevalence of asthma as well as the treated prevalence of the broader category of chronic airflow obstruction (CAO), defined as asthma, chronic bronchitis, or emphysema. During the period 1967-1987 the treated prevalence of asthma and CAO increased significantly in all age-sex categories except males aged 65 and older. These patterns are in contrast to previous studies of this population that showed that increases in asthma hospitalizations and hospital-based episodes of care were limited primarily to young boys. Not only do these findings support other evidence of a real increase in asthma prevalence, but they also highlight the risks associated with drawing inferences about changing disease epidemiology based on a single type of health care utilization.

Characteristics of patients with asthma within a large HMO: a comparison by age and gender

Adequate information about characteristics of asthmatic patients in large health maintenance organizations (HMOs) is still lacking. As part of an ongoing longitudinal study, baseline data were collected on 914 individuals aged 3 to 55 yr with physician-diagnosed asthma within a large HMO, Kaiser Permanente, NW Region. There were no significant differences between men and women in post-bronchodilator FEV1 when expressed as percent (%) predicted yet women with asthma reported more daytime and nocturnal symptoms than men (p = 0.002), and worse quality of life in all but three of 14 subscales in two asthma quality of life instruments. Specifically, women in the 35-55 yr age group uniformly reported worse physical functioning on the SF-36 quality of life scale (71 +/- 23 versus 85 +/- 18; p = 0.001), social functioning (73 +/- 21 versus 77 +/- 20; p = 0.016), and bodily pain (63 +/- 27 versus 72 +/- 24; p < 0.001). Also these women reported use of more health care (p = 0.002) and more medications for asthma than men (p < 0.01). Our data suggest that men and women respond differently to their asthma, and observed gender differences in various measures of asthma such as hospital admissions, quality of life, and use of metered dose inhalers (MDIs), may be related to this difference in response to disease, rather than to real differences in the disease between men and women. Understanding gender related differences in response to a chronic disease such as asthma is important in tailoring an education and management plan to each individual patient.

Case study: audio feedforward treatment of selective mutism

Selective mutism is a relatively rare and difficult-to-treat disorder. Audio feedforward is a potential intervention that involves having the individual with selective mutism listen to audiotapes edited to depict him or her speaking in situations in which he or she is not currently speaking. The successful use of this intervention for three children with selective mutism is reported. The intervention was used in both school and community settings. This intervention has not always proved successful, sometimes because children refused to make the audiotapes.

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.

Ethics of allocating intensive care unit resources

ICU clinicians commonly make decisions that allocate resources. Because of the high cost of ICU care, these practitioners can expect to be involved in the growing dilemma of trying to meet increasing demand for healthcare services within financial constraints. In order to participate meaningfully in a societal discussion over fairness in allocating scare and expensive resources, ICU practitioners should have more than a superficial knowledge of the principles of distributive justice. Distributive justice refers to fairness in the distribution of limited resources and benefits. Fairness refers to giving equal treatment to all those who are the same with regard to certain morally significant characteristics and treating in a different manner those who are not the same. Although theoretical issues remain unresolved as to which characteristics should be most significant, the United States has a strong cultural value that regards individuals as inherently valuable and having equal social worth. From this, it is likely that only an egalitarian approach to allocation of lifesaving healthcare resources will be acceptable. Studies of how ICU resources have been allocated during times of scarcity indicates that, in general, when beds are scarce, the average severity of illness of those admitted to the ICU increases. However, in some hospitals, political and economic factors appear to play important roles in determining who has access to scarce ICU beds. Of great concern is documentation of a widespread pattern in which fewer hospital resources, including ICU resources, are provided to seriously ill patients of minority status or with low levels of insurance reimbursement. How society's values get translated into allocation decisions is another unresolved issue. One recent example of how this occurred is the Oregon Medicaid Plan. This plan extended Medicaid coverage to additional people in poverty, despite the same amount of state and federal funds. This was accomplished by not reimbursing what were regarded as marginally beneficial services on the basis of medical and community input. Portents of how society might be involved in the future of health care are illustrated by the argument that society should limit access to all therapies except palliative care solely on the basis of advanced age. Until an open consensus develops in U.S. society about how to allocate scarce healthcare resources, the delivery of ICU care will continue to be at risk of covert, de facto rationing based on ability to pay, race, or other nonmedical personal characteristics.

Behavioral characteristics of children with stool toileting refusal

OBJECTIVE

To determine if children with stool toileting refusal have more behavior problems than matched children who are toilet trained.

DESIGN

Case-control study.

SETTING

Suburban private pediatric practice.

PARTICIPANTS

Children 30 to 48 months old who had achieved bladder control but refused to defecate on the toilet were identified as cases. Controls were sex- and age-matched children who were fully toilet trained.

MEASURES

Total behavior problems were assessed using a semi-structured behavior screening interview with the child's parents. The parents also completed the Child Behavior Checklist for ages 2 to 4 and either the Toddler Temperament Scale (30 to 36 months old) or the Behavioral Style Questionnaire (36 to 48 months old). Child compliance with adult instructions was measured during a room clean-up task.

RESULTS

Children with stool toileting refusal were not found to have more behavior problems than the matched children who were toilet trained. There were no differences between the two groups in compliance during the room clean-up task. There was a trend toward children with stool toileting refusal having a more difficult temperament, and these children were reported to have more problems with constipation and painful bowel movements than the controls.

CONCLUSIONS

Children with stool toileting refusal do not have more behavior problems than controls who are toilet trained. Parents do report higher rates of constipation and painful defecation, but it is not clear whether this is a cause or effect of stool toileting refusal.

Self-reported food reactions and their associations with asthma

The role of food reactions in asthma has not been well described. The objectives of this study were to evaluate the types of self-reported reactions to foods in asthmatic patients, and to determine the association between self-reported food reactions and self-reported severity of asthma and asthma health care utilization. We characterized 914 patients, aged 3-55 years, in a large health maintenance organization. We characterized the patients according to demographic data (age, sex, occupation, SES, marital status) and their asthma according to duration, triggers, severity (symptoms, FEV1 percentage predicted) and presence of atopy. Overall, 414 (45.3%) participants, primarily women, reported adverse reactions to food, particularly milk, red wine, eggs, chocolate, and peanuts. Those with food reactions were more likely to report having ever been hospitalized for breathing problems than those without food reactions (31% vs. 22%, two-tailed p = 0.004) although their asthma was not worse. Self-reported food reactions, particularly in females, may be associated with increased asthma health care utilization, and such patients may require closer health care management.

Periodicity of asthma, emphysema, and chronic bronchitis in a northwest health maintenance organization

STUDY OBJECTIVE

Since seasonal patterns in morbidity may identify triggers provoking hospital-based care for airflow obstruction, this study examined seasonal variation in patterns of hospitalizations for asthma, chronic bronchitis, and emphysema.

DESIGN AND SETTING

The data for this analysis were derived from the abstracted medical records of a large health maintenance organization, Kaiser Permanente, Northwest region, over the period 1979 to 1987.

PATIENTS

In all, 2,060 primary hospital discharges for asthma and 1,121 primary hospital discharges for the combination chronic bronchitis/emphysema were observed.

RESULTS

The monthly patterns varied for asthma and chronic bronchitis/emphysema, and also varied by age and sex. For young children 0 to 14 years, asthma hospitalizations peaked primarily in the fall. In contrast, for young children 0 to 14 years, hospitalizations for chronic bronchitis/ emphysema peaked in the fall/winter months. Seasonal variation decreased as age increased for chronic bronchitis/emphysema, such that for the 65+ year group, there was no seasonal variation.

CONCLUSION

A better understanding of the causes of the age-specific seasonal patterns in these obstructive respiratory diseases may help to reduce the morbidity that is associated with them.

A revised teacher rating scale for reactive and proactive aggression

A teacher rating scale of reactive aggression, proactive aggression, and covert antisocial behavior was evaluated in a normative sample of third- to fifth-grade predominantly white lower middle class boys (N = 186). Factor analysis revealed independent and internally consistent Reactive Aggression (six reactive items), and Proactive Aggression (five proactive items, five covert items) factors. Although the factors were intercorrelated (r = .67), and each factor was significantly correlated with negative peer social status (r = .26 for each, controlling for grade), the independence of the factors was supported by the unique relation of Reactive Aggression with in-school detentions (r = .31), controlling for Proactive Aggression and grade. These results supported the reliability and validity of Reactive and Proactive Aggression as rated by teachers, which should facilitate further research of these constructs.

Use of an automated prescription database to identify individuals with asthma

We used medication-dispensing information for 4 years (1/1/87 through 12/31/90) to examine the utilization of anti-asthma medications among 175,562 members of a large health maintenance organization. A total of 297,863 anti-asthma medications was dispensed during the study period, over one-half of which (55%) were beta-agonists, followed by aminophylline preparations (23%) and inhaled corticosteroids (13%). Next, we compared the predictive value of three algorithms for identifying individuals with asthma: (1) two or more beta-agonist dispensings, (2) both a beta-agonist and an inhaled corticosteroid dispensing, and (3) five or more total anti-asthma dispensings. We performed chart reviews for 40 subjects aged 5-45 years in each of these three groups and made a clinical judgment, based on all available information in the chart, as to whether each patient had asthma. Two levels of certainty were used: "any asthma" and "definite asthma." All 120 charts reviewed presented a clinical picture consistent with asthma. However, patients identified by the algorithm that included both a beta-agonist and an inhaled corticosteroid were more likely to meet our criteria for "definite" asthma and more likely to have moderate to severe asthma. These results demonstrate the feasibility of using an automated outpatient pharmacy database to identify patients with asthma.

Parental knowledge and attitudes toward children with AIDS: influences on educational policies and children's attitudes

Surveyed AIDS-related knowledge and attitudes of parents and their children to provide descriptive information on views about school policies concerning HIV-infected children and to test hypotheses regarding links between parents' and children's AIDS-related knowledge and attitudes. Results indicate that parents desire more information about presence of persons with AIDS (PWA) in the schools than is permissible by law and that a significant minority of parents objected to allowing HIV-infected students in schools. As predicted, more accurate parental knowledge of AIDS and knowing a PWA were associated with greater willingness to allow their children to interact with PWA and with greater acceptance of allowing HIV-infected children to attend regular classes. Support was also found for links between parents' and children's attitudes toward PWA. Implications for educating parents about AIDS transmission and inclusion of parents in the implementation of AIDS educational programs are discussed.

Recruiting hard-to-reach subjects: is it worth the effort?

Little information is available on the utility of spending resources to recruit hard-to-reach subjects. In particular, the compliance of such subjects with study protocols and visit schedules has not been documented. We present recruitment data from a two-phase survey of asthma prevalence in which a subset of respondents to a brief screening survey was recruited to attend a 90-min clinic visit. Although 39% of phase I subjects responding to initial contact attempts participated in the second phase of the study, this dropped to 12% among those responding to the sixth contact attempt (a phone follow-up). In studies in which the representatives of the sample is not of paramount importance, we see little benefit in aggressively seeking to recruit hard-to-reach subjects.

Uses and limitations of mortality and health care utilization statistics in asthma research

Mortality and health care utilization (HCU) statistics for asthma reflect both the acute and chronic aspects of this condition. We present a conceptual model that incorporates this dichotomy and also distinguishes between measures of disease occurrence (e.g., incidence and prevalence) and measures of disease management. We also discuss the use of mortality and HCU statistics in the literature, review their limitations and advantages, and make a number of general recommendations for their use.

Distinguishing instrumental and hostile aggression: does it make a difference?

An analogue task of instrumental and hostile aggression during a competitive game, modified to minimize overlap between aggressive responses, was evaluated in 8- to 14-year-old clinically referred boys (n = 33). Postgame interviews indicated that the hostile response, an aversive noise, was perceived by over 80% of subjects as hostile and not instrumental. In contrast, the instrumental response, blocking the opponent's game, was perceived about equally as having instrumental and hostile functions. The hostile aggressive response was uniquely correlated with continuous performance task impulsive commission errors (r = .51), which supported the theoretical relation of hostile aggression to poor impulse control. These results suggest that instrumental and hostile aggression can be distinguished and when precisely defined are distinct in theoretically important ways.

Developmental progression in children's knowledge of AIDS: implications for education and attitudinal change

The effectiveness of curricula designed to enhance a child's understanding of AIDS may hinge partially upon incorporating information adjusted to the child's developmental status. Accordingly, we examined the developmental progression of children's understanding of illness transmission in general and AIDS in particular, as well as explored the relation between a child's knowledge of AIDS and his/her attitudes toward persons with AIDS. Knowledge of AIDS was manipulated through use of a brief educational intervention. Results support a developmental progression in knowledge about AIDS that is consistent with progressions related to illnesses in general. Knowledge enhancement was associated with positive changes in attitude.

Temporal trends in hospital-based episodes of asthma care in a health maintenance organization

Studies reporting increased asthma hospitalizations and mortality in the United States and abroad have heightened concern about the changing epidemiology of asthma. We studied 20-yr patterns of acute asthma care occurring at two large community hospitals among members of a large health maintenance organization. The presentation focuses on the conceptualization and operationalization of an "episode" of asthma care, defined as a collection of encounters (emergency room visits, urgency care visits, and hospital admissions) that cluster in time, as well as on changes in episode rates over time. We found a statistically significant increase in asthma episodes among boys younger than 5 yr of age that continued unabated from 1967 to 1987 despite a drop in asthma hospitalization rates starting in 1985. We hypothesize that this difference may reflect a change in emergency room management practices and not a true change in the underlying epidemiology of asthma. The concept of an episode of acute asthma care has not been studied in the literature and represents a potentially useful methodologic innovation. Particularly in the context of managed health care systems, studies of such episodes may be less sensitive than studies of hospital admissions to changes in the organization and delivery of acute asthma care, and thus may be better suited for studying changes in the epidemiology 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.

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.

Effect of inhibitors on histamine release from mast cells recovered by bronchoalveolar lavage in basenji-greyhound and mongrel dogs

Studies of rodent mast cells have demonstrated that subpopulations differ in regard to their response to inhibitors of histamine release. To determine whether such compounds have different effects on mast cells from Basenji-Greyhound (BG) dogs with airway hyperreactivity and from mongrel dogs, we investigated the effect of cromolyn sodium, nedocromil sodium, theophylline, and quercetin on calcium ionophore A23187-induced histamine release from mast cells recovered by bronchoalveolar lavage. Mast cells recovered from BG and mongrel dogs were similar in respect to morphology and spontaneous and calcium ionophore-induce histamine release. Histamine release from mast cells from both BG and mongrel dogs was inhibited by quercetin (10(-4) M) and nedocromil sodium (5 x 10(-5) M). In contrast, only the histamine release from mast cells recovered from mongrel dogs was inhibited by cromolyn sodium (10(-4) M) and theophylline (5 x 10(-3) M). Thus, mast cells that are similar in regard to morphology and response to histamine liberators may differ in their response to inhibitors of histamine release.

Endothelium-dependent effects of cigarette smoke components on tone of porcine intrapulmonary arteries in vitro

The acute effects of cigarette smoking on the pulmonary vasculature are poorly understood--both vasodilatory and vasoconstrictive effects have been described. To investigate the mechanisms involved, strips of pig intrapulmonary arteries with and without intact endothelium were exposed to an extract of cigarette smoke made by bubbling smoke through phosphate-buffered saline. After contraction with norepinephrine (2.5 X 10(-7) M), smoke extract (concentration range 0.001 to 0.5%) caused a biphasic response in strips with intact endothelium--relaxation at lower concentrations and contraction at higher concentrations. Both relaxation and contraction responses were absent in strips without endothelium. Blockade of muscarinic, beta adrenergic, serotonergic, and histamine type 1 and 2 receptors did not alter the effects. Indomethacin (5 X 10(-6) M) or acetylsalicylic acid (10(-4) M) blocked the relaxation but not contraction effects of smoke extract, suggesting that relaxation was due to cyclooxygenase products of arachidonic acid. Nicotine caused endothelium-dependent contraction of intrapulmonary arteries and the contractile effects of both nicotine and smoke extract were blocked by hexamethonium (10(-6) M). However, the contractile effects of cigarette smoke components are more potent than those of nicotine. These findings help explain previously described acute effects of smoking on the pulmonary vasculature and provide insight into the mechanisms involved.

Histochemical comparison of mast cells obtained from the airways of mongrel dogs and Basenji-Greyhound dogs by bronchoalveolar lavage

An abnormally large number of mast cells in the airway lumen may be an important factor in the pathogenesis of bronchial hyperreactivity. However, it is unclear just how many mast cells are present in the lumen of normal or hyperreactive airways, in part because of differences in the histochemical techniques that have been used to identify mast cells and questions about the heterogeneity of mast cells. The present study was done (1) to compare the effectiveness of six techniques in the identification of mast cells obtained from dogs by bronchoalveolar lavage (BAL), (2) to compare the mast cells in the airways of normal mongrel dogs with those from a breed of dog (Basenji-Greyhound) known to have bronchial hyperreactivity, and (3) to determine whether the two-type histochemical classification used for rodent mast cells (formaldehyde-resistant or typical and formaldehyde-sensitive or atypical) applies meaningfully to the mast cells in BAL fluid from dogs. Cells obtained by BAL were fixed with Mota's basic lead acetate or formaldehyde. Mast cells were identified by metachromatic staining with toluidine blue or methylene blue, staining of highly sulfated proteoglycans with Alcian blue or berberine sulfate, and a histochemical reaction for chloroacetate esterase (mast cell chymase). After Mota's fixation, the methods were relatively similar in their effectiveness in determining the number of mast cells in lavage fluid from the mongrel dogs, in that all of the values fell within a narrow range: 0.53 to 0.96% of the total number of cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional and morphologic characterization of mast cells recovered by bronchoalveolar lavage from Basenji greyhound and mongrel dogs

Mast cells are believed to play an important role in the pathogenesis of asthma, and several investigators have suggested that increased numbers of mast cells in the airway lumen or increased releasability of histamine from these mast cells are responsible for chronic airway hyperreactivity. To determine whether mast cells in the lumen of the airways of hyperreactive Basenji greyhound (BG) dogs differ from those of mongrel dogs with normal airway reactivity, we investigated the morphologic and functional characteristics of mast cells recovered by bronchoalveolar lavage (BAL). BAL was performed in five BG and five mongrel dogs with 900 cc of a buffered salt solution. The recovered lavage fluid contained 115 +/- 19 X 10(6) and 116 +/- 14 X 10(6) (mean +/- SEM) cells in BG and mongrel dogs, respectively. The proportion of all mast cells within the recovered cell population as enumerated after fixation with basic lead acetate and staining with alcian blue was not different in BG and mongrel dogs and averaged 0.80 +/- 0.07% and 1.1 +/- 0.3%, respectively. Typical mast cells as identified after fixation with paraformaldehyde were rare; however, significantly more mast cells were found in mongrel (0.03 +/- 0.009%) than in BG dogs (0.004 +/- 0.002%; p less than 0.02). Mast cells recovered from BG and mongrel dogs were not different in their low spontaneous histamine release (2.0 +/- 0.5% and 2.9 +/- 0.8%), their histamine release on stimulation with the calcium ionophore A23187 (maximum release 44.8 +/- 5.7% and 41.5 +/- 3.9%), and their lack of response to compound 48/80 (maximum release 5.8 +/- 1.8% and 6.1 +/- 6.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet aggregation increases cholinergic neurotransmission in canine airway

To determine whether thromboxane A2 released from aggregating platelets increases the contractile response of airway smooth muscle to cholinergic nerve stimulation and, if so, what the mechanism of action is, we studied in vitro bronchial segments from dogs under isometric conditions. The contractile responses to electrical field stimulation at 30 s and 1 min after the addition of autologous platelets were increased by 11.1 +/- 3.2 (SD) and 20.7 +/- 5.4%, respectively, and were accompanied by the release of thromboxane A2. These effects were inhibited either by pretreatment of platelets with indomethacin or by addition of the thromboxane A2 receptor antagonist SQ 29548. Likewise, the thromboxane A2 mimetic U 46619, in subthreshold doses (i.e., insufficient to increase base-line tension), increased electrical field stimulation-induced contraction by 18.7 +/- 4.8%. The increase was greater in the presence of a concentration of physostigmine that did not cause spontaneous contraction and was blocked by SQ 29548 but not by hexamethonium or by phentolamine. Methacholine-induced contractions were unaffected by U 46619. These results indicate that aggregating platelets, by releasing thromboxane A2, increase the airway contractile response to neural stimulation probably by the accelerated release of acetylcholine.

Histamine release and circulating cells after antigen inhalation in allergic dogs

Histamine can be recovered from the blood of ragweed-sensitized dogs after aerosol antigen challenge, although its source is unknown. Neutrophils and eosinophils have been recovered from bronchoalveolar lavage fluid (BALF) obtained under identical conditions. We investigated the time course of changes in histamine levels in plasma and BALF taken from ragweed-sensitized dogs after aerosol challenge. Changes in the numbers of circulating neutrophils, eosinophils, lymphocytes, monocytes, and platelets were also studied. After 3 min, total pulmonary resistance (RL) was maximally increased and systolic blood pressure was maximally decreased. Histamine levels in plasma and BALF were increased and circulating eosinophils and neutrophils were decreased. After 15 min, platelet numbers were reduced. By 90 min, changes in RL, blood pressure, plasma and BALF histamine concentrations, and circulating neutrophils and eosinophils had returned to base-line values, but platelet numbers remained significantly decreased. Sham challenge caused no significant changes in any of these variables. Intravenous administration of histamine in doses large enough to attain plasma levels comparable with those achieved after aerosol antigen challenge resulted in no concomitant rise in BALF histamine levels. We conclude that antigen challenge in sensitized dogs causes increases in BALF and plasma histamine levels and is associated with a reduction in circulating neutrophils, eosinophils, and platelets. It is likely that antigen causes airway mast cells to release mediators that move down a concentration gradient from the airways to the pulmonary circulation.

Nitrous oxide has multiple deleterious effects on cobalamin metabolism and causes decreases in activities of both mammalian cobalamin-dependent enzymes in rats

In man, use of the general anesthetic nitrous oxide, N2O, is associated with hematologic and neurologic abnormalities that mimic those seen in cobalamin (Cbl, vitamin B12) deficiency. We have measured a number of aspects of Cbl metabolism in rts exposed to various concentrations of N2O for various periods of time. As little as 2% N2O given for 15 h resulted in 30% inhibition of methionine synthetase (MS) in rat liver. With 50% N2O, inhibition of 70% occurred with 1 h and did not change during the next 48 h. Under these conditions, no inhibition of methylmalonyl-CoA mutase (MMCoAM) was observed. The recovery of MS activity was slow and was only 80% of control values 72 h after N2O was stopped. Studies employing rats previously injected with [57Co]Cbl showed that N2O displaced [57Co]Cbl from MS in a manner that temporally and quantitatively paralleled the loss of MS activity. Recovery of MS activity paralleled the reappearance of [57Co]Cbl on MS. N2O also caused the hepatic content of CH3-[57Co]Cbl to decrease by 20-60%. When [57Co]-Cbl was extracted from liver and analyzed by paper chromatography, [57Co]Cbl analogues were present (10-40% of total [57Co]Cbl) in rats exposed to N2O, but not in control animals. When rats were exposed to 50% N2O for 33 d, the total of endogenous Cbl and Cbl analogues in liver decreased to 35% of control values and endogenous Cbl decreased to 10% of control values. At this time, MS activity was 15% of control values and MMCoAM was only 26% of control values. We conclude that N2O causes multiple defects in Cbl metabolism that include the following: (a) rapid inhibition of MS activity with a slow recovery when N2O is stopped; (b) displacement of Cbl from MS; (c) decreased CH3-Cbl; (d) conversion of Cbl to Cbl analogues; (e) the gradual development of Cbl deficiency and (f) an eventual decrease in MMCoAM activity with a further decrease in MS activity.

Pimozide versus fluphenazine in ambulatory schizophrenics: A 12-month comparison study

In this study, chronic schizophrenic outpatients who had been maintained on various neuroleptics for an average of about 4 years had their previous medications (approximately equivalent to 695 mg of chlorpromazine per day) changed abruptly to either pimozide or fluphenazine given in single daily oral doses on a double-blind basis for a period of 52 weeks. Average daily doses were pimozide 9.6 mg and fluphenazine 12.5 mg. Measurements of the therapeutic effects of the two drugs were made immediately prior to starting the study, at the end of the 2nd and 4th weeks, and thereafter every 4th week to the end of the study. Three psychometric scales were used for evaluation: Brief Psychiatric Rating Scale (BPRS); Evaluation of Social Functioning (ESFR); and Clinical Global Impressions (CGI). In addition, patients participated in a Social Adjustment Inventory (SAI) evaluation. Statistical analysis with the use of several statistical techniques for between- and within-drug group comparisons revealed that pimozide and fluphenazine were equally effective in maintaining control of symptomatology of chronic schizophrenics at a level commensurate with or better than that provided by their previous medication. Side effects were characteristic of marketed neuroleptics, similar in severity and occurrence between study-drug groups, mainly extrapyramidal symptoms, and readily controlled with antiparkinsonian medication. Pimozide, slightly more potent than fluphenazine, proved to be equally effective for the long-term management of chronic schizophrenic patients.