Peak flow meters: are they monitoring tools or training devices?

Patient compliance with assessing and monitoring of asthma

BACKGROUND

The current asthma guidelines encourage use of a diary for assessing and monitoring symptoms and airway function. However, patient compliance and acceptability are usually poor owing to the burden of frequent and prolonged assessment.

OBJECTIVE

We investigated whether better patient compliance could be ensured if a study was more relevant to patient convenience and had less impact on their daily life.

METHODS

A total of 106 patients with symptomatic asthma underwent a fixed-time thrice-daily assessment schedule for a period lasting 2 weeks, and they were assigned to a doctor visit after the assessment. Symptoms and medication use were recorded in a booklet (paper diary) and airway function measured by a portable spirometer (electronic diary).

RESULTS

Of 4,452 expected entries, the paper diary yielded 3,186 compliant entries and the electronic diary yielded 3,557 compliant entries; 71% of patients completed at least 30 compliant entries in the paper diary and 79% in the electronic diary. Use of an electronic device was associated with better compliance compared with paper technique (80.0% vs. 71.7%, p < 0.0001). Patient compliance decreased in the second week compared with the first week of diary keeping for both types of diaries (paper diary: 68.6% vs. 74.8%, p < 0.0001; electronic diary: 76.7% vs. 83.4%, p < 0.0001). The morning compliance was the least good, the afternoon better, and the evening best (paper diary: 68.2% vs. 71.0% vs. 75.9%, p < 0.0001; electronic diary: 77.2% vs. 79.0% vs. 83.9%, p < 0.0001). Among demographics and clinical factors, higher anxiety levels were linked to lower patient compliance.

CONCLUSION

Good patient compliance and acceptability can be achieved when a study takes into account patient convenience, uses user friendly electronic devices, and is less disruptive to patients' daily life.

Home monitoring in asthma self-management

Peak flow monitoring of asthma came into vogue with the advent of asthma self-management programs. Because it offered an objective way to gauge asthma severity, it promised improvement in the accuracy of asthma monitoring over that attainable by symptom monitoring. This promise has not been fulfilled. The ensuing years have witnessed a debate concerning the relative merits of symptom and peak flow monitoring. The debate has focused both on the degree to which peak flow and symptom scores are related to one another and on the relative effectiveness of symptom and peak flow monitoring for asthma control. We review research relating to these topics. The work shows that the strength of the relationship between peak flow and symptoms is low to moderate and varies between individuals and that benefits of peak flow monitoring in asthma self-management provide, at best, no more than a small increment in effectiveness beyond that afforded by symptom monitoring.

A randomized clinical trial of peak flow versus symptom monitoring in older adults with asthma

OBJECTIVE

To determine whether peak flow monitoring has value above and beyond symptom monitoring when used as part of an asthma management plan.

METHODS

From a large managed-care organization, 296 adults, aged 50-92 yr, were recruited and randomly assigned in equal numbers to either use of symptoms or peak flow rate (twice daily or "as needed") for asthma monitoring, and monitored every 6 mo for 2 yr. Interventions were delivered in four 90-min small-group classes and included a personalized action plan and coaching in proper use of asthma inhalers.

RESULTS

We found no significant differences between peak flow rate and symptom monitoring, or between twice-daily and as-needed peak flow monitoring in the primary or secondary study outcomes: health care utilization (acute, nonacute, or total asthma visits), Asthma Quality-of-Life Questionnaire (AQLQ) scores, and lung function. AQLQ scores and prebronchodilator FEV1 increased significantly for both groups between baseline and 6 mo (AQLQ: mean, 0.4 units; 95% confidence interval, 0.3, 0.5; p < 0.0001; FEV1% predicted: mean, 4%). Inhaler technique improved substantially in both groups.

CONCLUSIONS

Peak flow monitoring has no advantage over symptom monitoring as an asthma management strategy for older adults with moderate-severe asthma when used in a comprehensive asthma management program. Improved outcomes in both groups suggest that understanding proper medication use, regular monitoring of asthma status, and understanding how to respond to changes are of primary importance.

Current perspectives on symptom perception in asthma: a biomedical and psychological review

Symptom perception in patients with asthma is often inadequate. Patients may fail to perceive serious airway obstruction or suffer from breathlessness without objective cause. These extremes are associated with fatal asthma and excessive use of medicines, respectively. This article covers symptom perception in a multidisciplinary perspective. A presentation of current definitions and methods for studying symptom perception in asthma is followed by a summary of theories on the origin of breathlessness. Next, biomedical and psychological factors influencing symptom perception are examined. Preliminary biomedical research emphasizes neural pathway impairment, but causal factors remain inconclusive, particularly regarding the overperception of symptoms. Psychological studies suggest that the accuracy of symptom perception is influenced by (a) competition between asthmatic and nonasthmatic sensory information, (b) negative emotions, and (c) acquired response tendencies (e.g. habituation to symptoms, repression of symptoms, selective perception, and false interpretation of symptoms). These factors may favor either blunted perception or overperception. Empirical data in support of psychological factors are still insufficient. Methodological problems and procedures to improve symptom perception are discussed.

Advancing the science of perceptual accuracy in pediatric asthma and diabetes

OBJECTIVES

To review research on perceptual accuracy in pediatric asthma and diabetes and to provide recommendations for future research efforts and clinical applications of the construct in these populations.

METHODS

A literature search was conducted using Medline and PsychInfo databases as well as the bibliographies of relevant articles.

RESULTS

Children and adolescents with asthma or diabetes evidence considerable variability in perceptual accuracy and frequently make clinically relevant errors that have the potential to affect self-management behavior.

CONCLUSIONS

Recommendations for future research include studying distinct types of perceptual errors, empirically supporting the relationship between perceptual accuracy and relevant outcomes, identifying factors related to perceptual inaccuracy, and conducting longitudinal research and intervention studies. Recommendations for applying the construct in clinical practice include adopting an individualized approach to symptoms to guide patient education and management, identifying patients prone to making clinically relevant errors, and developing and implementing interventions to improve accuracy.

Symptom perception and respiratory sensation: clinical applications

This article has described symptom perception and its relation to asthma management. Underestimation of airway obstruction in persons with asthma is a common and serious problem that is linked to fatalities in persons with asthma. Strategies to identify and manage the poor perceiver have been suggested.

Symptom perception in childhood asthma: how accurate are children and their parents?

Accurate symptom perception on the part of the patient is a critical component of asthma management. Limited data are available about how accurate children and their parents are in evaluating asthma symptoms. This study was designed to determine the symptom perceptual accuracy of families and to identify risk factors associated with inaccurate symptom perception. One hundred children (6-19 years) and their parents evaluated symptoms using subjective (visual analog scales) as well as objective (peak expiratory flow rates) measures of symptom severity. Accuracy was evaluated by comparing the match in zones (based on NHLBI clinical practice guidelines) indicated on the subjective measure with the objective measure. Children and parents were inaccurate about one-third of the time overall. Poor and minority families initially appeared to be less accurate; however, when we adjusted for the child's illness severity, these sociodemographic features were no longer significant risk factors. Children were as accurate as parents. When we evaluated symptom accuracy at "sick times" (when the child's peak flow reading was <80% personal best) accuracy decreased markedly to only about one-third of the episodes being correctly evaluated.

Psychological aspects of asthma

Asthma can be affected by stress, anxiety, sadness, and suggestion, as well as by environmental irritants or allergens, exercise, and infection. It also is associated with an elevated prevalence of anxiety and depressive disorders. Asthma and these psychological states and traits may mutually potentiate each other through direct psychophysiological mediation, nonadherence to medical regimen, exposure to asthma triggers, and inaccuracy of asthma symptom perception. Defensiveness is associated with inaccurate perception of airway resistance and stress-related bronchoconstriction. Asthma education programs that teach about the nature of the disease, medications, and trigger avoidance tend to reduce asthma morbidity. Other promising psychological interventions as adjuncts to medical treatment include training in symptom perception, stress management, hypnosis, yoga, and several biofeedback procedures.

Effect of asthma severity on symptom perception in childhood asthma

Individual ability to perceive airway obstruction varies substantially. The factors influencing the perception of asthma are probably numerous and not well established in children. The present study was designed to examine the influence of asthma severity, use of preventive medication, age and gender on the association between respiratory symptoms (RS) and peak expiratory flow (PEF) rates in asthmatic children. We followed 92 asthmatic children, aged 6 to 16 years, for five months. Symptom scores were recorded daily and PEF was measured twice a day. The correlations among variables at the within-person level over time were analyzed for each child and for the pooled data by multivariate analysis. After pooling the data, there was a significant (P<0.05) correlation between each symptom and PEF; 60% of the children were accurate perceivers (defined by a statistically significant correlation between symptoms and PEF across time) for diurnal symptoms and 37% for nocturnal symptoms. The accuracy of perception was independent of asthma severity, age, gender or the use of preventive medication. Symptom perception is inaccurate in a substantial number of asthmatic children, independently of clinical severity, age, gender or use of preventive medication. It is not clear why some asthmatic patients are capable of accurately perceiving the severity of airway obstruction while others are not.

Symptom monitoring in childhood asthma: a randomized clinical trial comparing peak expiratory flow rate with symptom monitoring

BACKGROUND

Accurate symptom evaluation is a critical component of asthma management. Limited data are available about the accuracy of symptom evaluation by children with asthma and their parents, or the impact of various symptom-monitoring strategies on asthma morbidity outcomes.

OBJECTIVE

The purpose of this randomized clinical trial was to evaluate the effect of three different intensities of symptom monitoring on asthma morbidity outcomes.

METHODS

One hundred sixty-eight children (ages 6 to 19) of diverse racial, geographic, and socioeconomic backgrounds were randomized to 1 of 3 treatment groups (subjective symptom evaluation, symptom-time peak expiratory flow rate (PEFR) monitoring, daily PEFR monitoring) in this longitudinal, clinical trial. Outcome measures included a summary asthma severity score, forced expiratory volume in 1 second, symptom days, and health care utilization.

RESULTS

Children who used PEFR meters (PFMs) when symptomatic had a lower asthma severity score, fewer symptom days, and less health care utilization than children in the other two treatment groups. Minority and poor children had the greatest amount of improvement using PFMs when symptomatic. Results were much less striking in white families. Thirty percent of families in the PFM treatment groups discontinued use entirely by 1 year postexit, whereas the majority of families who continued use (94%) used them only when symptomatic to inform symptom interpretation and management decisions.

CONCLUSIONS

Not every child with asthma needs a PFM. Children and families facing extra challenges as a result of illness severity, sociodemographic, or health care system characteristics clearly benefited most from PFM use.

Perceptions of asthma by adolescents at home

OBJECTIVES

To test symptom perception in asthma under natural circumstances and to establish relationships between changes in airway obstruction as indicated by wheeze, dyspnea, general sensations, and emotional state.

DESIGN

Continuous in vivo monitoring.

METHOD

Symptom perception was tested in 30 adolescents with severe, unstable asthma. They were continuously monitored in their homes for 72 h. Symptom perception was defined as the relation between self-reported dyspnea and airway obstruction as evident from audible wheeze. Tracheal sounds were continuously recorded with wireless telemetry for wheeze assessment. Dyspnea was assessed four times per day on a Likert-type 10-point scale, as well as four times randomly after pager remote command. The subjects kept records of use of medication, daily activities, general symptoms, and mood state in a diary.

RESULTS

There were nine subjects with one or two wheeze episodes, another three subjects with three or four episodes, and one subject with almost continuous wheeze. The presence of wheeze in general related significantly to a rise (from individual baseline) in dyspnea of > 2.5 scale points. Acute wheeze was the best predictor of a rise in dyspnea, but prolonged wheeze correlated significantly with negative mood and general symptoms.

CONCLUSION

Patients with prolonged airway obstruction perceived symptoms less well and were more vulnerable to negative effects of asthma than patients with acute onset airway obstruction.

Objectives, methods and content of patient education programmes for adults with asthma: systematic review of studies published between 1979 and 1998

BACKGROUND

Education programmes for adults with asthma vary widely. Such variability suggests a lack of consensus on what works and what does not. The objectives of this paper are to describe asthma education programmes and assess their variability.

METHODS

A systematic review of reports published between 1979 and 1998 was conducted. Medline, the CINAHL database, the PsycINFO database, the Cochrane collaboration database, the Dissertation Index database, and cross referencing were used to identify educational interventions; 77 projects including 94 interventions that involved 7953 patients were analysed. A standard form was used to record characteristics of studies (design, setting, size, year, and country of publication), projects (theoretical framework, objectives), and education (methods, duration, intensity, educator, and content).

RESULTS

Most reports did not specify the general (56%) and educational objectives (60%) of the intervention. Important training characteristics were often not available: duration of education (45%) and number of sessions (22%), who delivered education (15%), whether training was conducted in groups or was individualised (28%). When this information was available there were wide variations in training methods and content: training duration ranged from 0 (self-education) to 58 hours and the number of sessions from 0 to 36; training tools such as peak flow meters, diary cards or books were used in various proportions of interventions (19%, 27%, and 23%, respectively). The content of education also differed widely between programmes.

CONCLUSIONS

Insufficient documentation of asthma education programmes for adults precludes their replication. This, together with excessive variability, reduces the possibility of identifying their most effective components. A more systematic description of asthma training programmes should be promoted.

Symptom perception and evaluation in childhood asthma

BACKGROUND

Inaccuracies in symptom perception may contribute to morbidity and mortality in childhood asthma.

OBJECTIVE

To systematically examine the accuracy of symptom perception on the part of children with asthma and their parents, as well as their interpretation and evaluation of the symptoms.

METHOD

Twenty-eight patient/parent pairs from suburban and underserved urban pediatric populations participated in a 5-week protocol tracking subjective assessments of asthma severity (visual analog scales) and peak expiratory flow rates. Relationships between perceptual accuracy and demographic and disease factors were investigated.

RESULTS

Adolescents were more accurate than school-aged children, more accurate children had better morbidity outcomes, and African American parents were more accurate than Caucasian parents. Socioeconomic status did not affect accuracy. Both children and parents missed early symptoms and waited too long prior to intervening in an exacerbation.

CONCLUSIONS

There are multiple opportunities for error in symptom perception and evaluation. Identification of the source of error is critical to the effective utilization of education on self-management.

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.

Randomised comparison of guided self management and traditional treatment of asthma over one year

OBJECTIVE

To compare the efficacy of self management of asthma with traditional treatment.

DESIGN

12 month prospective randomised trial.

SETTING

Outpatient clinics in Finland.

SUBJECTS

115 patients with mild to moderately severe asthma.

INTERVENTIONS

Patient education and adjustment of anti-inflammatory therapy guided by peak flow measurements.

MAIN OUTCOME MEASURES

Unscheduled admissions to hospital and outpatient visits, days off work, courses of antibiotics and prednisolone, lung function, and quality of life.

RESULTS

The mean number of unscheduled visits to ambulatory care facilities (0.5 v 1.0), days off work (2.8 v 4.8), and courses of antibiotics (0.4 v 0.9) and prednisolone (0.4 v 1.0) per patient were lower and the quality of life score (16.6 v 8.4 at 12 months) higher in the self management group than in the traditionally treated group. In both groups admissions for asthma were rare.

CONCLUSIONS

Self management reduces incidents caused by asthma and improves quality of life.

Symptom reporting in asthma patients and insulin-dependent diabetics

In this paper, results from two studies are presented. (1) Sixty-eight diabetics registered their blood glucose levels both as estimated and as measured and they indicated the intensity of 20 symptoms on a symptom checklist. Data were assessed twice a day over a 30-day period. During this period, blood glucose levels decreased slightly, the accuracy of blood glucose estimation improved, and for about half of the subjects specific symptoms could be identified, which covaried closely with blood glucose levels over time. (2) Fifty-three asthmatic patients monitored their peak flow each morning and evening over a period of 30 days. Before measuring peak flow, the patients estimated their peak flow and indicated the intensity of 28 symptoms specific for asthma. For about half of the sample, symptoms were identifiable, which correlated highly with measured peak flow. A substantial increase in the accuracy of estimated peak flow could be observed over time.

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.

Patient, professional, and public education on behavioral aspects of asthma: a review of strategies for change and needed research

Combating increases in asthma morbidity and mortality necessitates an understanding of social and behavioral aspects of the disease. Education for patients, professionals, and the public based on the most current scientific information is required. This paper reviews the existing research on patient education and management of asthma. It discusses physician and family interaction related to asthma management; identifies gaps in the current understanding of relevant patient, professional, and public behavior; outlines needed strategies to improve asthma education; and poses recommendations for further research.

Patient education

Only recently has it been appreciated that the considerable morbidity of asthma can be reduced with tools readily available to every physician who treats children. The pharmacotherapeutic armamentarium has been strengthened by better understanding of the pathogenesis of asthma, the impact of inflammation, and the role of preventive therapy. The task remains to put this expanded knowledge to use to help a larger number of children with asthma and their families to diminish the impact that the disease has on their lives. Concomitant with increased understanding of the pathophysiology of asthma and the medications used to control the process has been a greater appreciation of the role of co-management or self-management. Several programs have been developed to help parents and children with asthma gain better control over the disease, thus decreasing morbidity and significantly improving quality of life. These programs are available to physicians and health care organizations, and it is strongly recommended that asthma education, both as a formal course and in the physician's office, be regularly incorporated into the care plan for every child with asthma.