Effectiveness of routine self monitoring of peak flow in patients with asthma

Can peak expiratory flow predict airflow obstruction in children with asthma?

STUDY OBJECTIVES

A recent trend in the treatment of asthma has been the widespread, independent use of peak expiratory flow (PEF). We examined whether PEF monitoring creates inaccuracies in assessment of children with moderate to severe asthma.

METHODS

We compared the negative predictive value of PEF in relation to the forced expiratory volume in 1 second (FEV(1)), and to the forced expiratory flow between 25% and 75% of the vital capacity (FEF(25-75%)) at different levels of air trapping as determined by the residual volume over total lung capacity ratio (RV/TLC).

RESULTS

The study included 244 patients, ages 4 to 18 years with all classes of asthma severity, with FEV(1) ranging from 28% to 134% of predicted value. We analyzed 367 sets of pulmonary function tests performed throughout a 3-year period. Thirty percent of patients with a normal PEF value had an abnormal FEV(1) or FEF(25-75%). As air trapping increased, the ability of a normal PEF to predict normal FEV(1) and FEF(25-75%) readings fell from 83% to 53%. The negative predictive value was significantly lower for patients with RV/TLC ratio >30 compared with patients with RV/TLC <30.

CONCLUSIONS

The results of this study suggest that it might be possible to identify children for whom the PEF is likely to give false-negative results. As air trapping increases, it causes the PEF to give misleading reassurance of normal pulmonary function. Furthermore, poor predictiveness of PEF is obtained when values 80% of predicted for age are considered normal.

Self-management education and regular practitioner review for adults with asthma

BACKGROUND

A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health outcomes is less well established. This review was conducted to examine the strength of evidence supporting Step 6 of the Australian Asthma Management Plan: "Educate and Review Regularly"; to test whether health outcomes are influenced by education and self-management programmes.

OBJECTIVES

The objective of this review was to assess the effects of asthma self-management programmes, when coupled with regular health practitioner review, on health outcomes in adults with asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register and reference lists of articles.

SELECTION CRITERIA

Randomised trials of self-management education in adults over 16 years of age with asthma.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for confirmation.

MAIN RESULTS

Twenty-five trials were included. Self-management education was compared with usual care in 22 studies. Self-management education reduced hospitalisations (odds ratio 0.57, 95% confidence interval 0.38 to 0.88); emergency room visits (odds ratio 0.71, 95% confidence interval (0.57 to 0.90); unscheduled visits to the doctor (odds ratio 0.57, 95% confidence interval 0.40 to 0.82); days off work or school (odds ratio 0.55, 95% confidence interval 0.38 to 0. 79); and nocturnal asthma (odds ratio 0.53, 95% confidence interval 0.39 to 0.72). Measures of lung function were little changed. Self-management programmes that involved a written action plan showed a greater reduction in hospitalisation than those that did not (odds ratio 0.35, 95% confidence interval 0.18 to 0.68). People who managed their asthma by self-adjustment of their medications using an individualised written plan had better lung function than those whose medications were adjusted by a doctor.

REVIEWER'S CONCLUSIONS

Training in asthma self-management which involves self-monitoring by either peak expiratory flow or symptoms, coupled with regular medical review and a written action plan appears to improve health outcomes for adults with asthma. Training programmes which enable people to adjust their medication using a written action plan appear to be more effective than other forms of asthma self-management.

Limited (information only) patient education programs for adults with asthma

BACKGROUND

A key component of many asthma management guidelines is the recommendation for patient education and regular medical review. A number of controlled trials have been conducted to measure the effectiveness of asthma education programmes. These programmes improve patient knowledge, but their impact on health outcomes is less well established. At its simplest level, education is limited to the transfer of information about asthma, its causes and its treatment. This review focused on the effects of limited asthma education.

OBJECTIVES

The objective of this review was to assess the effects of limited (i.e. information only) asthma education on health outcomes in adults with asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register and reference lists of articles.

SELECTION CRITERIA

Randomised and controlled trials of individual asthma education involving information transfer only in adults over 16 years of age.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for missing information.

MAIN RESULTS

Eleven trials were included. They were of variable quality. Limited asthma education did not reduce hospitalisation for asthma (weighted mean difference -0.03 average hospitalisations per person per year, 95% confidence interval -0.09 to 0.03). There was no effect on doctor visits, lung function and medication use. The effects on asthma symptoms were variable. There was no reduction in days lost from normal activity, but perceived asthma symptoms did improve after limited asthma education (odds ratio 0.40, 95% confidence interval 0.18 to 0.86). In one study, limited asthma education was associated with reduced emergency department visits (weighted mean difference -2.76 average visits per person per year, 95% confidence interval -4.34 to 1.18).

REVIEWER'S CONCLUSIONS

Use of limited asthma education as it has been practiced does not appear to improve health outcomes in adults with asthma. However the use of information in the emergency department may be effective, but this needs to be confirmed.

Guidelines in pulmonary medicine: a 25-year profile

OBJECTIVE

We attempted to identify clinical practice guideline and pathway articles in the area of pulmonary medicine published in peer-reviewed journals since 1974.

DESIGN

Review.

DATA SOURCES

MEDLINE, the Cochrane Database, Best Evidence, and Abstracts of Clinical Care Guidelines from January 1974 to December 1998.

STUDY SELECTION

All articles contained relevant search terms for pulmonary topics and were included irrespective of setting (primary or specialty, inpatient or outpatient). Controlled and uncontrolled trials as well as observational studies and consensus opinion/statements were all identified. The articles were stratified by design as well as by pulmonary topic.

DATA EXTRACTION

Limited data on study type, study focus, year of publication, and results of study were abstracted.

RESULTS

Our criteria yielded 271 articles, including 115 consensus statements and expert opinion guidelines; 30 controlled studies, meta-analyses, or systematic reviews; and 126 uncontrolled trials and observational studies. Of these, 82 articles (30.3%) related to asthma, 46 articles (17.0%) related to COPD, and 36 articles (13.3%) related to pneumonia. In addition, we tracked the increasing publication of all guideline-related pulmonary articles; randomized, controlled trials (RCTs); systematic reviews; and consensus statements by year for the past 25 years.

CONCLUSION

Pulmonary guidelines are increasingly published in peer-reviewed journals, but few are tested clinically in RCTs. There is continued reliance on consensus statements and expert opinion. Pulmonary guideline publications have continued to dramatically increase in number and in importance since 1974, both on the local level and internationally.

Peak expiratory flow associated with change in positioning of the instrument: comparison of five peak flow meters

To determine if peak expiratory flow (PEF) is altered by incorrect positioning of five peak flow meters (PFMs), 16 adults with clinically stable persistent asthma were evaluated. After inhaling two puffs of albuterol via AeroChamber, patients were instructed over the next 15 min in correct PFM technique and two incorrect techniques (PFM angled 20 degrees left in mouth and PFM pointed 20 degrees downward as patient leaned forward with maximal exhalation). Order of use of five peak flow meters and correct vs. incorrect techniques were random. Although mean values generally indicated no clinically meaningful effect of positioning of the PFM, inaccurate PEFs were recorded for several subjects with both incorrect methods and all PFMs.

Evaluation of a nurse-run asthma school

Important aims of the study were to investigate whether an educational program (the 'Asthma School') directed by a nurse led to improved knowledge of the disease, to improved self-medication and self-management and to improved, self-rated, functional status. A total of 32 patients (6 males, 26 females, mean age 43 years) was included. The following methods were used to collect the data before and one year after the Asthma School was completed; two study-specific questionnaires for collecting demographic data and measuring different aspects of the patients' knowledge of the disease and its treatment, monthly diary cards, lung-function tests (FEV1) and the Sickness Impact Profile (SIP) questionnaire. The main results of the study were an improved knowledge of the disease and its treatment, better self-management, i.e. more frequent use of the peak expiratory flow meter (PEF-meter) and use of inhaled bronchodilators on an as-required basis, fewer patients on sick-leave and a better, self-rated, physical health status. However, in spite of these encouraging results, the lungfunction was found to be unaffected, no pronounced changes in the use of asthma drugs could be found and the patients' need for medical care remained the same.

Peak expiratory flow rate control chart in asthma care: chart construction and use in asthma care

BACKGROUND

The home monitoring of peak expiratory flow rate (PEFR), although recommended in current asthma guidelines, remains seriously underutilized by both patients and physicians. Our assessment is that this is more a statement regarding the inability of current charting methods to fulfill the promises made for PEFR monitoring, rather than a commentary regarding the usefulness of peak expiratory flow rate monitoring per se. We have adapted the theory and charting tool of the discipline of statistical process control to the daily monitoring of PEFR in the care of patients with asthma. Statistical process control charts integrate the actual PEFR values and their day-to-day variation in a manner that permits more informed decision-making. This article introduces our adaptation of statistical process control theory and charts via three case presentations.

OBJECTIVE

Report our experience in the use of statistical process control theory and charting to the monitoring of peak expiratory flow in the care of patients with asthma.

METHODS

Discussion of methodology and case reports.

CONCLUSION

This is the first report of the application of statistical process control (SPC) theory and charting to the home monitoring of peak expiratory flow rate and the clinical decision-making processes involved in the day-to-day care of patients with asthma. SPC charts integrate knowledge of actual serial PEFR measurements with knowledge of their associated serial variation. Our adaptation of this theory and its charting methodology results in a tool that loses nothing provided by the charting methods suggested in current guidelines and, at the same time, provides patient specific, statistically driven signals of significant change; facilitates identification of the reason(s) for the change in PEFR; predicts the range in which future function will occur; permits decision-making and care to be provided in an anticipatory manner; and, importantly, permits the early identification of the functionally at-risk patient. This report demonstrates that home monitoring of peak expiratory flow is a robust tool whose usefulness in the care of patients with asthma has been limited more by the paradigm in which we have required it be used than by any of the limitations of the measurement per se.

Asthmatic patients' views of a comprehensive asthma rehabilitation programme: a three-year follow-up

BACKGROUND AND PURPOSE

Twenty-one asthmatic patients aged 27-59 years, with mild to moderate asthma, participated in a 10-week group rehabilitation programme covering physical training and theoretical and practical education in medication, self-management strategies and physiotherapy. This study was undertaken retrospectively to investigate (1) the patients' reasons for joining the programme, (2) their experiences of the programme, and (3) their ways of coping with disease-related problems before joining and three years after completion of the programme.

METHODS

Patients were followed up every six months for three years and were interviewed after the three years. The semi-structured interviews were tape-recorded, transcribed and revised.

RESULTS

The life-situation of most of the patients before the 10-week programme was characterized by helplessness at exacerbations, anxiety/insecurity about medications and their side-effects, and/or concern about future health. More than half of the subjects felt physical limitations in daily life or when exercising. All wished to increase their knowledge of asthma by joining the programme, but only nine patients expected asthma improvement. The experience that they were able to carry out physical exercise to a maximal intensity and that physical training improved their asthma, with increased knowledge about medications were mentioned by all as the most valuable effects of the programme. Moreover, most patients emphasized their increased ability in self-management strategies (stress reduction and breathing technique). The increased knowledge and improved practical skills contributed to a better life-situation after the rehabilitation. After the three years virtually all the patients' lives were characterized by improved self-management, increased physical activity and a sense of security. Almost half of them expressed a wish to take responsibility for the disease.

CONCLUSIONS

In addition to medical therapy and education, physical training and techniques for relaxation and breathing should form part of the treatment of asthma.

School-based management of chronic asthma among inner-city African-American schoolchildren in Dallas, Texas

Asthma, a chronic disease of the respiratory tract, affects approximately five percent of the U.S. population, including almost five million children. Childhood asthma has been identified as the leading cause of school absences. This study was to examined efficacy of a school-based program to prevent exacerbation of asthma symptoms and manage asthma in school children using measured doses of an inhaled anti-inflammatory medication. The sample consisted of 22 African-American children in one inner-city elementary school in Dallas, Texas, ages 5-12 years with confirmed diagnoses of asthma. For three months, each child came to the school clinic two times per day for medication administration and measurement of respiratory peak flow rates. Data were collected for a number of variables including bronchodilator use, school absences, self-report of asthma symptoms, and number of visits to the physician. During the study, mean peak flow rates improved approximately 15%, and bronchodilator use decreased 66%. Improvement also was evident in several other areas.

A randomized trial comparing peak expiratory flow and symptom self-management plans for patients with asthma attending a primary care clinic

Great emphasis is placed on educating asthmatics to use action plans to achieve better control of symptoms. The use of peak flow meters (PFM) has been recommended as an important part of self-management plans. We studied 92 (47 F) adult patients with asthma in a primary care setting to compare the effectiveness of action plans using either peak flow monitoring or symptoms to guide self-management. Each patient was instructed in the use of the action plan in the context of a 6-mo asthma education program taught by a nurse. Patients were already using inhaled corticosteroids or were newly prescribed corticosteroids by their family physician. Forty-four patients were randomized to the PFM group and 48 to the symptoms group. Spirometry, symptom scores, quality of life, medication use, and measures of health care utilization and morbidity (emergency department visits, hospitalizations, unscheduled doctor visits, and days lost from work or school) were recorded at baseline and throughout the study period. PC20 methacholine was measured at the first and at the final visits. There were significant improvements within groups for FEV1, symptoms score, PC20 methacholine, and quality of life, but no between-group differences. A significant shift from higher to lower daily use of beta-agonists (p < 0.008 for both groups) and significant shifts to higher daily doses of inhaled steroids (p < 0.001) occurred in each group. Adherence to the self-management plans was only 65% in the PFM group and 52% in the symptoms group. Outcomes for health care utilization were similar except for fewer patients making unscheduled doctor visits within the PFM group. Our findings show that education, regular follow-up, and an action plan are effective in improving asthma control and quality of life, but the routine use of PFM to guide interventions is not the only way to accomplish these objectives.

Relationship between airway obstruction and respiratory symptoms in adult asthmatics

STUDY OBJECTIVES

To characterize the relationship between symptoms and the degree of airway obstruction as determined by the FEV1 and peak expiratory flow (PEF) in a cohort of adult patients attending a university-based urban asthma clinic.

DESIGN

Each of six current asthma symptoms, including cough, dyspnea, wheeze, chest tightness, sputum production, and nocturnal awakening was rated by patients on a 0 (none) to 4 (constant) scale at initial and first follow-up clinic evaluations. Spirometry and PEF were measured at the initial clinic visit and PEF was measured at all follow-up visits.

PATIENTS

Sixty-seven adult patients with chronic asthma.

MEASUREMENTS AND RESULTS

Asthma symptoms did not correlate with the degree of airway obstruction as determined by the FEV1 (percent predicted FEV1 vs total symptoms: r=0.143; p=0.263; n=70) and only correlated poorly with PEF (percent predicted PEF vs total symptoms: r=0.384; p=0.0029; n=58). Subjective wheezing was the best individual predictor of the level of airway obstruction in this group of patients. When reassessed an average of 7.9 weeks later, patients reported significant improvement in several symptoms, including those of wheeze, chest tightness, dyspnea, and nocturnal awakening. However, this symptomatic improvement was not associated with improvement in the level of airway obstruction.

CONCLUSIONS

Asthma symptoms correlate poorly with the level of airway obstruction as determined by the FEV1 and PEF. Following treatment, subjective improvement in asthma symptoms may occur without improvement in the level of airway obstruction. These results support the recommendation to measure airway obstruction objectively when assessing adult patients with chronic asthma.

Self-management of asthma by adult patients

Review of eighteen adult self-management education program evaluations comprising clinical trials showed significant achievement in five categories of outcome: (1) asthma knowledge; (2) patient perceptions and psychological status; (3) behavior related to medicine use, delivery devices and environmental triggers; (4) functioning and control of symptoms; and (5) health care use. Not every program achieved in all of these categories, probably because interventions of adequate power to elicit change in one category of outcome were not powerful enough to realize change in another category. An alternative explanation may be that in some studies assessment measures were inadequate. Asthma management by patients is influenced by their social environment and this aspect of control is least well understood. A small qualitative study suggested themes among adult patients that describe intra- and interpersonal factors enabling or hindering self-management including: the ability to acquire information; self-regulation; relations with family, friends and coworkers; and, relationships with clinicians. Research is needed that provides greater understanding of social environments in asthma management, produces standardized measurement tools, and tests more robust and theory-based interventions.

The effect of a peak flow-based action plan in the prevention of exacerbations of asthma

STUDY OBJECTIVE

To determine the effect of a symptom-based and a peak flow-based action plan in preventing acute exacerbations in subjects with poorly controlled asthma.

DESIGN

A randomized controlled trial in which subjects who had required urgent treatment for their asthma were allocated to receive no action plan, a symptom-based plan, or a peak flow-based action plan.

SETTING

A university hospital asthma clinic.

POPULATION

One hundred fifty subjects were recruited after attending an emergency department or a clinic for urgent treatment of asthma.

INTERVENTIONS

All subjects received evaluation and education for asthma before being randomly allocated to receive no action plan, a symptom-based action plan, or a peak flowmeter and a peak flow-based action plan.

MEASUREMENTS

Subjects were assessed by questionnaire at 3 and 6 months after enrollment with questions relating to their asthma control and their need for urgent treatment or hospital admission for asthma.

RESULTS

At 6 months after enrollment, although all three intervention groups experienced improvement in their asthma control, there was a striking reduction in emergency department visits for asthma only in the peak flow-based action plan group (p=0.006). No significant difference in emergency visits was apparent between the symptom-based action plan and no action plan groups.

CONCLUSIONS

We conclude that a peak flow-based action plan is effective, at least in the short term, in protecting patients with asthma against severe exacerbations of their disease.

Is asthma self-management cost-effective?

Many clinical studies have shown that self-management and educational programs in asthma are effective. However, these programs are costly themselves and could also lead to higher drug costs due to higher rates of compliance. On the other hand, if better usage of available treatment leads to better asthma control, the patients' utilization of other health care resources and absence from work might be reduced. An interesting question is therefore whether the self-management and educational programs in asthma have been cost-effective. This study holds a review of the evidence of cost-effectiveness of self-management and educational programs in asthma. Several methodological flaws were detected (for example, a common effectiveness, variable is lacking in the literature) and suggestions of improvements were given. The overall picture is, however, that self-management and educational programs in asthma are cost-effective interventions, both for children and for adults. As would be expected, it also seems as if programs directed at high risk groups and patients with severe asthma are even more cost-effective. Costs for absence from work were often excluded, which could lead to further societal savings. Also, some studies showed that the effect of the self-management and educational programs had effects even after the initial year. Since most studies only covered the initial year of treatment, the cost-effectiveness of self-management and educational programs in asthma is likely to be underestimated in the reported studies.

Development and validation of a rhinoconjunctivitis and asthma symptom score for use as an outcome measure in clinical trials

BACKGROUND

The measurement of health outcomes has become a priority for assessing and containing health care costs.

OBJECTIVE

To develop and fully validate a simple symptom scale assessing both asthma and rhinoconjunctivitis, two interdependent conditions.

METHODS

A self-administered questionnaire of 31 items was tested in 102 patients with asthma and rhinoconjunctivitis between September 1992 and December 1994. The items were rated on a six-point Likert scale ranging from none to extremely severe and included commonly recorded symptoms of inflammation such as irritation, congestion, and discharge in the skin, eyes, nose, sinus, pharynx, and chest.

RESULTS

Validation included (1) responsiveness: scores for 18 patients evaluated during an emergency room visit were statistically significantly different from those recorded after recovery and in a control group of 24 patients with asthma; (2) reliability: external consistency was 0.8 at 1 week, and internal consistency was 0.8 for individual organs and 0.7 for individual symptoms; (3) validity: a five-point scale better captured the distribution of values; irrelevant and redundant items were eliminated. The optimal questionnaire included 21 items.

CONCLUSIONS

The symptom score was applicable, responsive, reliable, and valid. Used with existing validated tools such as treatment needs and quality of life assessment, it may provide a comprehensive picture of allergic airway disease for quality assurance or research purposes.

Improving perception of air flow obstruction in asthma patients

OBJECTIVE

The objective of the study was to train asthma patients to improve their ability to discriminate added resistive loads.

METHODS

Training consisted of a task in which patients judged the relative difficulty of breathing through two circuits. Difficulty of breathing through the circuits was varied by addition of resistive loads. We assigned 45 patients randomly to one of three conditions: a feedback plus fading condition, a feedback condition, and a control condition.

RESULTS

Feedback of accuracy of judgments coupled with fading resulted in reduction of difference threshold. Neither feedback alone nor a control condition in which patients were given experience in making judgments without feedback resulted in threshold change.

CONCLUSIONS

Perception training with added resistive loads may help patients to detect an increase in air flow obstruction due to asthma before it becomes severe.

Asthma: better outcome at lower cost? The role of the expert in the care system

Asthma is a common disease for which morbidity and mortality have been increasing. This despite advances in the scientific understanding of asthma and in the pharmacologic armamentarium available to treat it. The dichotomy between knowledge and outcomes led us to review asthma from a systems perspective. We have presented data first to document failure in the current system of care and then to examine factors associated with improved outcomes. We found a disparity in outcome and costs when care given by experts was contrasted with care given by generalists. We conclude that "expert-based" care systems are superior from the perspective both of the patient and of the insurer; medical outcomes are better at lower overall cost. Managed care companies are in a unique position to identify asthmatics and to shift them from generalist to expert-based care when appropriate.

Potential effects of correction of inaccuracies of the mini-Wright peak expiratory flow meter on the use of an asthma self-management plan

BACKGROUND

Patient self-management plans for asthma use peak expiratory flow (PEF) meter readings for decisions on adjusting asthma treatment. PEF meters have been shown to be inaccurate and the effect of this inaccuracy on such treatment plans has been determined.

METHODS

PEF measurements were made by 127 severe asthmatic patients at least twice a day for at least two weeks using a mini-Wright meter. The daily variation from "best" PEF and the within day PEF variability were calculated before and after correction for the meter's known inaccuracy. The effect of this data correction on the number of days when trigger points were reached for changing asthma therapy was then determined.

RESULTS

Continuous PEF readings were available from 114 subjects with a median of 157.5 days of data per subject (range 15-489 days). Correction of the PEF data led to the number of days of satisfactory asthma control being reduced in 72% of subjects with just one subject showing an increase in satisfactory control. Data correction reduced the percentage of total days of satisfactory control from 46% to 36% of days, and increased the days requiring more inhaled steroids from 33% to 36%. The days on which a course of oral corticosteroids was required increased from 16% to 23%.

CONCLUSIONS

The accuracy of PEF meters significantly influences the interpretation of currently used asthma self-management plans. Managing asthma with the corrected PEF data would have increased the amount of treatment received by these patients since the severity of the asthma was underestimated by the raw data.

Short-term compliance with peak flow monitoring: results from a study of inner city children with asthma

The objective of the study was to assess the feasibility of initiating daily peak flow monitoring in a research study of asthma in inner city children. We performed a descriptive study of patterns of peak flow monitoring in children randomized to receive a simple mini-Wright (SM) or an electronic recording meter (ERM). The ERM served as a "covert" meter, providing objective documentation of actual peak flow use. Sixty-five Hispanic or African-American children, ages 5-9 years, with a history of physician-diagnosed asthma participated in the study. All children resided in census tracts with 40% or more of the population living at or below the poverty level. Subjects were instructed to use a peak flow meter (the SM or ERM) at least twice daily over a 3 week period, and to record peak flow values in a paper diary. Subjects who received the ERM were not made aware that measurements were also recorded electronically. Differences in patterns of use of the SM and ERM were assessed with the Wilcoxon signed rank test and Wilcoxon sum rank test. Adherence to peak flow monitoring was evaluated by comparing the percent days with missing values in the manually completed diary with those obtained by computer record. The Friedman statistic was used to compare changes in compliance (percent of days with missing peak flow entries) over time. Accuracy of peak flow readings was assessed by comparing the manual and electronic recordings with paired and unpaired t-tests and with Pearson product moment correlations. The percent of days with missing peak flow entries on diaries increased from 1.4% to 10.6% from the first to third week of monitoring (P < 0.004). The ERMs indicated a significantly greater percent of missing data than did the manual records (P < 0.0002). The difference in the percent of missing data for the electronic and manual records was most notable during the third study week, when the ERM and the manually completed records indicated that 52% and 15% of days, respectively, were without peak flow measures. Large inter-subject variations in the relationship between manually and electronically recorded peak flow measurements were observed, suggesting that errors in reading and transcribing peak flow rates occur in a subset of asthmatics. We conclude that children and caretakers in the inner city may have considerable difficulty initiating and maintaining peak flow recordings. Data obtained by manual records may considerably overestimate actual use. Compliance with monitoring decreases markedly between the first and third week of monitoring.

Lung function measurement in general practice: a comparison of the Escort spirometer with the Micromed turbine spirometer and the mini-Wright peak flow meter

It is important that new types of spirometer for widespread clinical use are pragmatically evaluated in primary care. This study compared measurements taken by a new portable Fleisch pneumotachograph spirometer (known as the Escort) with those of the commonly used mini-Wright peak flow meter and the Micromed Pocket turbine spirometer. A pragmatic study was conducted in two phases during routine surgeries at Aldermoor Health Centre, Southampton. Phase I compared the new spirometer with the mini-Wright peak flow meter and Phase 2 compared the new spirometer and the turbine spirometer. One hundred patients aged 5-88 years (56 patients with a history of chronic respiratory complaints and 44 patients without) entered Phase 1, and 100 patients aged 6-82 years (62 patients with a history of chronic respiratory complaints and 38 patients without) entered Phase 2. Each patient contributed only once to each phase, but some entered both phases on separate occasions. Ninety-five percent limits of agreement (mean +/- SD) were wide for all comparisons. Graphical plots revealed trends towards higher Escort values as mean values rose compared with both mini-Wright and turbine readings for peak expiratory flow rate and forced expiratory volume in one second. Possible over-reading of peak expiratory flow rate with the mini-Wright meter at low mean values was also seen. Readings taken with these different types of meter cannot be interchanged with confidence in clinical practice. The clinical significance of the theoretically more accurate measures of lung function produced with the new meter, and indeed of spirometry itself, needs further investigation.

Asthma: lessons from patient education

Asthma is a common condition. Recent understanding of the disease has meant that the inflammatory process in the airways is likely to be treated by the regular use of preventative therapy even when the patient is well. The evidence suggests that such treatment is often not taken. Audit suggests that poor communication and lack of information remains a common problem. There is increasing use of a team approach to the management of asthma, often necessitated by the sheer numbers of patients requiring regular review. Such an approach combined with the giving of control of their own condition to the patients, has now been shown to improve outcomes.

A community-wide promotion of asthma self-management in New Zealand

Asthma affects approximately 9% of young adults in New Zealand, with evidence of an increase in prevalence over recent years. Morbidity and mortality from this condition have caused widespread concern. In response to identified deficiencies in asthma management, initiatives to promote self-management using an asthma action plan were promoted throughout the Canterbury region in 1991 as part of a regional pilot study. A resource kit was prepared and self-management principles were promoted to general practitioners in discussion workshops. A community-wide promotion of the action plan was followed by a process and outcome evaluation. The plan and associated resources were well received by doctors and patients. Seventy-seven percent of doctors responding to a questionnaire had used the plan, and of these, 94% indicated that they would continue to use the plan in the future. Patients who obtained a completed plan experienced a greater reduction in nocturnal waking with asthma and improved self-management skills.

Home peak expiratory flow rate monitoring in patients with asthma

OBJECTIVE

To describe how the peak expiratory flow rate (PEFR) is measured, review published studies of the accuracy in which patients and physicians can estimate the severity of asthma by clinical observations only, and review published studies of the benefits of home PEFR monitoring.

DESIGN

A review of home PEFR monitoring and its associated benefits for both the physician and the patient is presented.

RESULTS

An accurate assessment of the severity of asthma is crucial for the optimal treatment of the patient with asthma; however, patients and their physicians are often unable to estimate correctly the degree of airway obstruction. Peak flow measurement is a simple, inexpensive method of objectively determining airflow obstruction. Management of asthma based on home PEFR measurements can result in early recognition and prompt treatment of asthma exacerbations. Home PEFR monitoring in the setting of a comprehensive self-management program can lead to fewer symptoms of asthma, fewer days absent from work or school, fewer emergency examinations, fewer hospitalizations, lower requirements of inhaled beta-antagonists and oral corticosteroid therapy, and better pulmonary function.

CONCLUSION

For best results, home PEFR monitoring should be coupled with a thorough educational program on asthma and periodic office spirometry.

Peak expiratory flow meters (PEFMs)--who uses them and how and does education affect the pattern of utilisation?

BACKGROUND

Asthma control may be assisted by educating patients to use peak expiratory flow meters (PEFMs).

AIMS

To find out the sociodemographic and clinical characteristics of asthmatics attending an Emergency Room (ER) who owned PEFMs.

METHODS

We undertook a study of 352 asthmatics aged seven to 55 years who attended an ER. The following were analysed: their pattern of peak flow monitoring (PFM), the factors associated with 'appropriate' or daily PFM on entry to the study and then prospectively; whether asthma education influenced utilisation and whether there was a reduction in ER use or admissions in those who acquired a PEFM.

RESULTS

Those owning a PEFM at entry to the study (54%) had more asthma morbidity (p = 0.0001), had had asthma for longer (p = 0.0001), had seen their medical practitioners more often in the previous nine months (p = 0.0001), were on more asthma medications (p = 0.0001) and were more likely to have been to an Asthma Clinic (p = 0.0001). Those not owning a PEFM were more likely to be of lower social class (p = 0.016) and of Pacific Island origin (p = 0.0001) suggesting that distribution is not ideal and is influenced by disease severity, amount of health care use and sociodemographics. Patients with a self-management plan (35% of PEFM owners) and those receiving 'good care' or management, were more likely to use PFM 'appropriately' and to mention PFM in a scenario evaluating their response to worsening asthma control and argues for PEFMs to be distributed only in conjunction with a self-management plan, and therefore in close association with the patients' medical practitioners. Most patients (75%) appeared to prefer making management decisions based on symptoms rather than on their peak expiratory flow (PEF) and few (16%) performed daily PFM at entry to the study and fewer (6%) nine months later. There was an improvement in the pattern of PFM after education, but the acquisition of a PEFM made no difference to the frequency of ER use or admission.

CONCLUSION

More realistic goals need to be defined in relationship to PFM which may improve patients' acceptance of the strategy, and therefore, hopefully their compliance. Such strategies need to be consistently reinforced over time for them to have an impact on asthma morbidity.