Subjective symptomatology of asthma in an outpatient population

Cognitive behavioural therapy (CBT) for adults and adolescents with asthma

BACKGROUND

People with asthma have a higher prevalence of anxiety and depression than the general population. This is associated with poorer asthma control, medication adherence, and health outcomes. Cognitive behavioural therapy (CBT) may be a way to improve the quality of life of people with asthma by addressing associated psychological issues, which may lead to a lower risk of exacerbations and better asthma control.

OBJECTIVES

To assess the efficacy of CBT for asthma compared with usual care.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP). We also searched reference lists of all primary studies and review articles and contacted authors for unpublished data. The most recent searches were conducted in August 2016.

SELECTION CRITERIA

We included parallel randomised controlled trials (RCTs) comparing any cognitive behavioural intervention to usual care or no intervention. We included studies of adults or adolescents with asthma, with or without comorbid anxiety or depression. We included studies reported as full text, those published as abstract only, and unpublished data.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently screened the search results, extracted data, and assessed included studies for risk of bias. We analysed dichotomous data as odds ratios (ORs) and continuous data as mean differences (MDs) or standardised mean differences (SMD) where scales varied across studies, all using a random-effects model. The primary outcomes were asthma-related quality of life and exacerbations requiring at least a course of oral steroids. We rated all outcomes using GRADE and presented our confidence in the results in a 'Summary of findings' table.

MAIN RESULTS

We included nine RCTs involving 407 adults with asthma in this review; no studies included adolescents under 18. Study size ranged from 10 to 94 (median 40), and mean age ranged from 39 to 53. Study populations generally had persistent asthma, but severity and diagnostic measures varied. Three studies recruited participants with psychological symptomatology, although with different criteria. Interventions ranged from 4 to 15 sessions, and primary measurements were taken at a mean of 3 months (range 1.2 to 12 months).Participants given CBT had improved scores on the Asthma Quality of Life Questionnaire (AQLQ) (MD 0.55, 95% confidence interval (CI) 0.17 to 0.93; participants = 214; studies = 6; I2 = 53%) and on measures of asthma control (SMD -0.98, 95% CI -1.76 to -0.20; participants = 95; studies = 3; I2 = 68%) compared to people getting usual care. The AQLQ effect appeared to be sustained up to a year after treatment, but due to its low quality this evidence must be interpreted with caution. As asthma exacerbations requiring at least a course of oral steroids were not consistently reported, we could not perform a meta-analysis.Anxiety scores were difficult to pool but showed a benefit of CBT compared with usual care (SMD -0.38, 95% CI -0.73 to -0.03), although this depended on the analysis used. The confidence intervals for the effect on depression scales included no difference between CBT and usual care when measured as change from baseline (SMD -0.33, 95% CI -0.70 to 0.05) or endpoint scores (SMD -0.41, 95% CI -0.87 to 0.05); the same was true for medication adherence (MD -1.40, 95% CI -2.94 to 0.14; participants = 23; studies = 1; I2 = 0%).Subgroup analyses conducted on the AQLQ outcome did not suggest a clear difference between individual and group CBT, baseline psychological status, or CBT model. The small number of studies and the variation between their designs, populations, and other intervention characteristics limited the conclusions that could be drawn about these possibly moderating factors.The inability to blind participants and investigators to group allocation introduced significant potential bias, and overall we had low confidence in the evidence.

AUTHORS' CONCLUSIONS

For adults with persistent asthma, CBT may improve quality of life, asthma control, and anxiety levels compared with usual care. Risks of bias, imprecision of effects, and inconsistency between results reduced our confidence in the results to low, and evidence was lacking regarding the effect of CBT on asthma exacerbations, unscheduled contacts, depression, and medication adherence. There was much variation between studies in how CBT was delivered and what constituted usual care, meaning the most optimal method of CBT delivery, format, and target population requires further investigation. There is currently no evidence for the use of CBT in adolescents with asthma.

Lifelong opioidergic vulnerability through early life separation: a recent extension of the false suffocation alarm theory of panic disorder

The present paper is the edited version of our presentations at the "First World Symposium On Translational Models Of Panic Disorder", in Vitoria, E.S., Brazil, on November 16-18, 2012. We also review relevant work that appeared after the conference. Suffocation-False Alarm Theory (Klein, 1993) postulates the existence of an evolved physiologic suffocation alarm system that monitors information about potential suffocation. Panic attacks maladaptively occur when the alarm is erroneously triggered. The expanded Suffocation-False Alarm Theory (Preter and Klein, 2008) hypothesizes that endogenous opioidergic dysregulation may underlie the respiratory pathophysiology and suffocation sensitivity in panic disorder. Opioidergic dysregulation increases sensitivity to CO2, separation distress and panic attacks. That sudden loss, bereavement and childhood separation anxiety are also antecedents of "spontaneous" panic requires an integrative explanation. Our work unveiling the lifelong endogenous opioid system impairing effects of childhood parental loss (CPL) and parental separation in non-ill, normal adults opens a new experimental, investigatory area.

Cognitive behavioural intervention for adults with anxiety complications of asthma: prospective randomised trial

BACKGROUND

High levels of asthma-related fear and panic exacerbate asthma symptoms and complicate the management of asthma. Asthma-specific fear may be reduced by a cognitive behavioural intervention. We aimed to test if there is a reduction in asthma-specific fear after cognitive behavioural intervention compared with routine treatment.

METHODS

Adults with asthma registered with family doctors in Sheffield UK were screened for anxiety and 94 highly anxious patients were randomly allocated to receive either a cognitive behavioural intervention to improve self-management of their anxiety (n = 50) or routine clinical care (n = 44). Asthma-specific fear at the end of treatment and at six month follow up were the primary endpoints. Service usage in the six months prior to and six months following the intervention was monitored to allow estimation of costs. Data were analysed by intention to treat.

FINDINGS

At the end of treatment, there was a significantly greater reduction in asthma-specific fear for people in the CBT group compared with controls. At six months after treatment the reduction in asthma-specific fear in the CBT group was increased and the difference between treatment and control group was statistically significant. Service use costs were not reduced in the CBT group.

INTERPRETATION

A brief cognitive behavioural intervention was found to have efficacy in reducing asthma-specific panic fear immediately after treatment and at 6 months follow up. There was no cost advantage to cognitive behavioural treatment.

Measuring asthma-specific quality of life: structured review

Measuring quality of life (QoL) has become an increasingly important dimension of assessing patient well-being and drug efficacy. As there are now several asthma QoL questionnaires to choose from, it is important to appreciate their strengths and weaknesses. To assist in this choice, we have reviewed the existing questionnaires in a structured way. Information relating to the conceptual and measurement model, reliability, validity, interpretability, burden, administration format and translations was extracted from the published literature. The instruments differ in almost all criteria considered, and therefore it cannot be assumed that they measure the same thing. We recommend the selection of questionnaires that are designed only for asthma and that do not assess symptoms as part of QoL. Only two of the questionnaires reviewed fulfill these requirements: the Sydney Asthma QoL Questionnaire (AQLQ-S) and the Living with Asthma Questionnaire (LWAQ). However, for multinational studies, it may be convenient or practical to use questionnaires that have been linguistically validated in many languages (AQLQ-J, SGRQ). It remains unclear which of these questionnaires best reflects patient perceptions of QoL. Our review did not involve patients, so for the time being choosing from existing questionnaires requires a compromise based on the rigor of the development process and the target patient group.

Hyperventilation in panic disorder and asthma: empirical evidence and clinical strategies

Sustained or spontaneous hyperventilation has been associated with a variety of physical symptoms and has been linked to a number of organic illnesses and mental disorders. Theories of panic disorder hold that hyperventilation either produces feared symptoms of hypocapnia or protects against feared suffocation symptoms of hypercapnia. Although the evidence for both theories is inconclusive, findings from observational, experimental, and therapeutic studies suggest an important role of low carbon dioxide (CO2) levels in this disorder. Similarly, hypocapnia and associated hyperpnia are linked to bronchoconstriction, symptom exacerbation, and lower quality of life in patients with asthma. Raising CO2 levels by means of therapeutic capnometry has proven beneficial effects in both disorders, and the reversing of hyperventilation has emerged as a potent mediator for reductions in panic symptom severity and treatment success.

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.

The role of panic-fear in comorbid asthma and panic disorder

We examined mediational models of panic-fear, panic disorder (PD), and asthma outcomes among adult asthma patients. PD was assessed by the Anxiety Disorders Interview Schedule. Twenty-one asthma-PD patients and 27 asthma-only patients completed spirometry and questionnaires. Asthma-PD patients reported greater illness-specific and generalized panic-fear than asthma-only patients, despite no differences in asthma severity or physical symptoms during asthma attacks. Illness-specific panic-fear mediated the relationship between PD and poorer health-related quality of life, including emotional disturbance due to asthma. Illness-specific panic-fear was associated with more primary care office visits for asthma. Asthma-PD patients reported greater irritability during asthma attacks than asthma-only patients. Generalized panic-fear was directly associated with restriction of activities due to asthma and use of rescue medication for asthma. Neither measure of panic-fear was associated with asthma severity. Panic-fear experienced during asthma attacks may be an important area to target for improving health-related quality of life among asthma-PD patients.

The relationship between disease control, symptom distress, functioning, and quality of life in adults with asthma

PURPOSE

The purpose of this study was to evaluate quality of life (QOL) from a multidimensional perspective in relation to asthma control, symptom distress, and functioning in adults with asthma.

METHODS

A cross-sectional, mailing survey design was used. The convenience sample of 172 people diagnosed with asthma participated in this study. QOL, conceptualized as subjective satisfaction with life, was measured by the Quality of Life Index-Pulmonary Version III (QLI-PV III). Functioning was measured with the Living with Asthma Questionnaire (LWAQ). Instruments measuring asthma control and symptom experience have been developed for this study. Multiple regression and path analysis were used to examine the relationships.

RESULTS

The QOL was affected directly by functioning (beta = -0.70). Asthma control and symptom distress were indirectly influencing QOL. Among the predictors, direct paths were found between asthma control and functioning (gamma = 0.20), and between symptom distress and functioning (gamma = 0.57); 51% of the total variation in functioning was explained by symptom distress and asthma control; 48% of the total variation in QOL was explained by functioning.

CONCLUSION

The findings highlight the importance of symptom distress and control of asthma symptoms with respect to functioning and QOL in people with asthma.

Psychological triggers and hyperventilation symptoms in asthma

BACKGROUND

Anecdotal accounts have identified hyperventilation as one route through which psychological factors can trigger bronchoconstriction. However, little is known about the empirical association between psychological and other trigger factors and hyperventilation in asthma exacerbations.

OBJECTIVE

To study the cross-sectional association between perceived triggers and hyperventilation symptoms in 1 British and 1 German sample of patients with asthma who were recruited from the community and from primary care clinics.

METHOD

Patients completed relevant language versions of the Asthma Trigger Inventory and the Asthma Symptom Checklist.

RESULTS

After controlling for demographics and asthma severity, perceived asthma triggers measured by subscales of the Asthma Trigger Inventory explained 12.5% to 37.3% of the variance in Asthma Symptom Checklist hyperventilation-hypocapnia symptoms. Psychological triggers accounted for 10.6% to 26.7% of the variance alone and 4.3% to 11.0% of the variance over and above other trigger factors. In contrast, perceived animal and pollen allergen triggers did not contribute unique variance to the hyperventilation symptom report. Psychological triggers did not explain variance in classic airway obstruction symptoms, thus arguing against a general bias toward inflated symptom reports in patients with psychologically induced asthma.

CONCLUSION

Differences in perceived asthma triggers are substantially associated with hyperventilation symptoms, and patients with more frequent psychological triggers also tend to report that they experience more hyperventilation symptoms during their asthma symptom episodes.

The association of comorbid anxiety and depression with asthma-related quality of life and symptom perception in adults

BACKGROUND AND OBJECTIVE

There are limited data on the association and interaction between anxiety and depression comorbidity and asthma-related quality of life (AQOL) and symptom perception. This study evaluated these associations in patients subsequent to an emergency department (ED) visit for asthma.

METHODS

This was a cross-sectional study of 110 (38 male) adult asthma patients (mean age 42 years), who had visited an ED in the previous 18 months. Participants completed the hospital anxiety and depression scale, measures of AQOL and the asthma symptom checklist.

RESULTS

Depression symptoms independently showed a significant negative association with AQOL after controlling for depression/anxiety, age, gender, smoking status and ED visits in the previous 12 months (ED-12). Overall, anxiety and depression symptoms accounted for 28.3% of the variance in AQOL. Greater anxiety was associated with increased perception of asthma-specific panic-fear and hyperventilation symptoms during an asthma attack, irrespective of depression status. Categorical analyses of groups of patients, differentiated by psychometric properties on the hospital anxiety and depression scale (anxiety vs normal, anxiety and depression vs normal depression) confirmed most results. However, for the anxiety group there was a significant association with the AQOL domains of emotional functioning and response to environmental stimuli, after controlling for depression symptoms.

CONCLUSIONS

The negative association of depression symptom scores with AQOL and of anxiety with increased panic-fear and hyperventilation symptoms suggests a potential role for interventions addressing this psychological comorbidity, in order to improve AQOL.

Psychological treatment of comorbid asthma and panic disorder: a pilot study

We evaluated two protocols for treating adults with comorbid asthma and panic disorder. The protocols included elements of Barlow's panic control therapy and elements of Barlow's "panic control therapy" and several asthma education programs, as well as modules designed to teach participants how to differentiate asthma and panic symptoms, and how to apply specific home management strategies for each. Fifty percent of subjects dropped out of a 14-session protocol by the eighth session; however, 83% of patients were retained in an eight-session protocol. Clinical results were mostly equivalent: significant decreases of >50% in panic symptoms, clinically significant decreases in asthma symptoms, improvement in asthma quality of life, and maintenance of clinical stability in asthma. Albuterol use decreased significantly in the 14-session protocol and at a borderline level I the 8-session protocol, while pulmonary function was maintained. A controlled evaluation of this procedure is warranted.

Panic, suffocation false alarms, separation anxiety and endogenous opioids

This review paper presents an amplification of the suffocation false alarm theory (SFA) of spontaneous panic [Klein DF (1993). False suffocation alarms, spontaneous panics, and related conditions. An integrative hypothesis. Arch Gen Psychiatry; 50:306-17.]. SFA postulates the existence of an evolved physiologic suffocation alarm system that monitors information about potential suffocation. Panic attacks maladaptively occur when the alarm is erroneously triggered. That panic is distinct from Cannon's emergency fear response and Selye's General Alarm Syndrome is shown by the prominence of intense air hunger during these attacks. Further, panic sufferers have chronic sighing abnormalities outside of the acute attack. Another basic physiologic distinction between fear and panic is the counter-intuitive lack of hypothalamic-pituitary-adrenal (HPA) activation in panic. Understanding panic as provoked by indicators of potential suffocation, such as fluctuations in pCO(2) and brain lactate, as well as environmental circumstances fits the observed respiratory abnormalities. However, that sudden loss, bereavement and childhood separation anxiety are also antecedents of "spontaneous" panic requires an integrative explanation. Because of the opioid system's central regulatory role in both disordered breathing and separation distress, we detail the role of opioidergic dysfunction in decreasing the suffocation alarm threshold. We present results from our laboratory where the naloxone-lactate challenge in normals produces supportive evidence for the endorphinergic defect hypothesis in the form of a distress episode of specific tidal volume hyperventilation paralleling challenge-produced and clinical panic.

Hyperventilation symptoms are linked to a lower perceived health in asthma patients

BACKGROUND

Hyperventilation symptoms are among the sensations asthma patients tend to report during exacerbations of their disease. However, little is known about their importance for the patients' perceived well-being.

METHOD

We therefore studied the association of reported hyperventilation symptoms (Asthma Symptom Checklist) with perceived physical and mental health (36-item Short-form Health Survey) in a sample of primary care asthma patients (N = 190). We also studied the potential role of perceived control of asthma (Perceived Control of Asthma Questionnaire) in mediating any association between these variables.

RESULTS

In hierarchical multiple regression analyses controlling for demographics, asthma severity, and other asthma symptoms (obstruction, congestion, panic-fear, irritation, and fatigue), hyperventilation symptoms were significantly associated with both physical and mental health status. This association was partially mediated by perceived control of asthma.

CONCLUSION

It is possible that hypocapnia creates symptoms that asthma patients cannot control by using their antiasthmatic medication, thus compromising their perceived control over the management of their asthma, and consequently their perceived health. Behavioral interventions should address the problem of hyperventilation in asthma.

The language of medically unexplained dyspnea

BACKGROUND

Medically unexplained dyspnea (MUD) refers to a condition characterized by a sensation of dyspnea and is typically applied to patients presenting with anxiety and hyperventilation without cardiopulmonary explanations for their dyspnea. The diagnosis is difficult. We investigated whether descriptors of dyspnea and associated symptoms of MUD are differentially diagnostic.

METHODS

A respiratory symptom checklist incorporating 61 spontaneously reported descriptors of dyspnea was administered to 96 patients with MUD and 195 patients with cardiopulmonary diseases. Symptom factors measuring different qualitative aspects of dyspnea were derived by a principal component analysis. The separation of two patient groups in terms of symptom factors was achieved by a discriminant analysis.

RESULTS

Five factors grouped different attributes of dyspnea: urge to breathe, depth and frequency of breathing, difficulty breathing and phase of respiration, wheezing, and affective dyspnea. The other five factors grouped symptoms of anxiety, tingling, cough and sputum, palpitation, and out of control. A discriminant analysis allowed to separate two patient groups (R(2) = 0.45, p < 0.0001). The presence of urge to breathe, affective dyspnea, anxiety, and tingling pointed to the diagnosis of MUD, whereas the reporting of wheezing, cough and sputum, and palpitation indicated cardiopulmonary diseases. The sensitivity was 85%, and specificity was 88%.

CONCLUSIONS

Descriptors of dyspnea and associated symptoms allows satisfactory separation of patients with MUD from patients with cardiopulmonary diseases. A prospective study will be required to test the validity and predictive values of the descriptor model in another cohort of patients.

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.

Prescription of oral corticosteroids in near-fatal asthma patients: relationship with panic-fear, anxiety and depression

Oral corticosteroids are the most effective drugs for illness management, especially in near-fatal asthma (NFA) patients. Prescription of oral corticosteroids in other groups of asthmatic patients has been shown to be related not only to clinical features of the illness, but also to psychological variables, what suggests the need to investigate this relationship specifically in NFA patients. Forty-two NFA patients aged 18--83 were interviewed to collect data on sociodemographics, clinical features and psychological variables, specifically panic-fear, anxiety and depression; 45.2% had been prescribed oral corticosteroids and 54.8% had not been prescribed this type of medication. Only frequency and severity of symptoms (odds ratio=3.14; 95% confidence interval=1.27-7.79; p=0.013) and state-anxiety (odds ratio=1.03; 95% confidence interval=1.03-1.29; p=0.015) emerged as significant risk indicators for the prescription of oral corticosteroids. These preliminary results in NFA patients confirm previous reports about the relationship between prescription of oral corticosteroids and psychological variables in asthmatic patients. State-anxiety could increase the magnitude of breathing difficulties, and thus imply the need for more effective medications for its management, but further research is necessary to reject other possible explanations.

[Prevalence of hyperventilation syndrome in patients treated for asthma in a pulmonology clinic]

OBJECTIVE

Although the presence of hyperventilation syndrome can affect the symptoms of patients with asthma, there is very little information available regarding its frequency in Spain. The aim of this study was to investigate the prevalence of hyperventilation syndrome in the asthmatic population treated as outpatients and establish its relationship with anxiety disorders.

PATIENTS AND METHOD

We studied 157 consecutive asthmatic patients (61 men and 96 women; mean [SD] age, 45 [17] years; forced expiratory volume in the first second, 84% [21%] of the predicted value) treated in our outpatients clinic. The patients had stable disease with varying degrees of severity. After collecting demographic data and medical histories, we asked the patients to complete the Spanish versions of the Anxiety Sensitivity Index, the Asthma Symptom Checklist, and the Nijmegen questionnaire; in the latter test, a score of 23 or over was considered diagnostic for hyperventilation syndrome. Finally, patients were evaluated to determine whether they had suffered from panic disorder in the last 6 months (according to the criteria of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders).

RESULTS

Hyperventilation syndrome was present in 57 asthmatic patients (36%) and panic disorder in 4 patients (2%). The majority of patients with hyperventilation syndrome were women (78% vs 51%; P=.001) and were older (49 vs 42; P=.01); they displayed more basal dyspnea (1.26 vs 0.89 on the Medical Research Council scale; P=.01), greater sensitivity to anxiety (P=.001), and went to the emergency room more often for exacerbations (P=.002). Patients with hyperventilation syndrome scored significantly higher on all subscales of the Asthma Symptoms Checklist. Finally, the variables introduced in the regression analysis (stepwise) to explain the score on the Nijmegen questionnaire (r(2)=0.57) were basal dyspnea and sensitivity to anxiety.

CONCLUSIONS

Approximately one third of the asthmatic patients treated in a pulmonology clinic also present hyperventilation syndrome. This cannot be explained by comorbidity of asthma with panic disorder, and is only partly linked to the symptoms associated with hyperventilation that appear during an asthma attack.

Respiratory complaints in Chinese: cultural and diagnostic specificities

STUDY OBJECTIVES

We investigated the qualitative components of a wide range of Chinese descriptors of dyspnea and associated symptoms, and their relevance for clinical diagnosis.

MEASUREMENTS

Sixty-one spontaneously reported descriptors were elicited in Chinese patients to make a symptom checklist, which was administered to new groups of patients with different cardiopulmonary diseases, to patients with medically unexplained dyspnea and to healthy subjects.

RESULTS

Test-retest reliability was satisfactory for most of the descriptors. A principal component analysis on 61 descriptors yielded the following eight factors: dyspnea-effort of breathing; dyspnea-affective aspect; wheezing; anxiety; tingling; palpitation; coughing and sputum; and dying experience. Although the descriptors of dyspnea-effort of breathing resembled Western wordings and were shared by patients with a variety of diseases, the descriptors of dyspnea-affective aspect appeared to be more culturally specific and were primarily linked to the diagnosis of medically unexplained dyspnea, whereas wheezing was specifically linked to asthma.

CONCLUSIONS

Three factors of breathlessness were found in Chinese. The descriptors of dyspnea-effort of breathing and wheezing appear to be similar to Western descriptors, whereas the dyspnea-affective aspect seems to bear cultural specificity.

The relationship of perceived self-efficacy to quality of life in chronic obstructive pulmonary disease

From a biomedical perspective, variations in the quality of life of chronic obstructive pulmonary disease (COPD) patients may be attributed to changes in pulmonary function; thus, an increase in lung function should be correlated with an increased score on a health-related quality-of-life measure. However, inconsistent results regarding correlations between various measures of pulmonary function and quality of life have been reported in the literature. The authors evaluated a social cognitive model of quality of life among persons with COPD by analyzing relationships among biomedical measures, self-efficacy measures, and quality-of-life measures in a recursive path model. Path analysis results indicated that the association of pulmonary function and symptoms with quality of life was mediated by perceived self-efficacy for functional activities.

A case study of comorbidities: vocal cord dysfunction, asthma, and panic disorder

The purpose of this case study was to describe the nature of the symptom episodes experienced by a 24-year-old woman diagnosed with VCD, asthma, and panic disorder. A multiple card sort procedure was used to identify the type, order of presentation, and severity of symptoms experienced by the participant during her typical symptom episodes. Seven types of symptom episodes were investigated including VCD, asthma, and panic episodes; and co-occurring or combined episodes of VCD and asthma; VCD and panic; asthma and panic; and VCD, asthma, and panic. The variability and complexity of the participant's symptom episodes, which are described, led to the development of a new VCD/asthma/panic comorbidities symptom classification system.

[Construct validity of the Information and Decisions in Asthma questionnaire]

OBJECTIVE

To establish the construct validity of a new scale based on the Information and Decisions in Asthma (IDEA) questionnaire, which was designed to detect an asthmatic's desire to receive information, active seeking out of information and ability to make decisions about his or her disease.

METHODOLOGY

The IDEA questionnaire containing 31 items in three subscales: desire for information (DI), seeking out information (SI) and decision making (DM) was answered by 120 asthmatic adults (54 men and 66 women; 86 intrinsic and 44 extrinsic) in stable condition and with varying levels of severity of disease. After interviews to take down medical histories (age of onset, years of evolution, visits to the emergency room within the past year), educational level and economic status, all patients completed a battery of tests assessing the following: quality of life (QL), alexithymia (TAS-20), health opinions (HOS), state-trait anxiety (STAI-E/R), asthma symptoms control (ASC), health locus control (HLC), somatosensory amplification (SAS) and personality (NEO-PI).

RESULTS

Although most patients expressed interest in obtaining information, their level of active seeking and decision making were much lower. DI and SI were associated with higher educational levels and economic status, whereas DM correlated with the presence of atopy, age (young patients), sex (women) and few visits to the emergency room. Multiple regression analysis of psychological variables showed that DI and SI were accounted for mainly by the absence of alexithymia, whereas DM depended on an individual's behavioral involvement with his or her disease.

CONCLUSION

The global analysis of these results indicate that the IDEA questionnaire has satisfactory construct validity, given that its dimensions are associated with sociodemographic and psychological characteristics that can be expected given its conceptual content.

Attack context: an important mediator of the relationship between psychological status and asthma outcomes

BACKGROUND

The importance of psychosocial variables in asthma is increasingly recognised, although attempts to relate these to asthma outcomes often produce only weak relationships. This study aimed to identify whether such relationships might be obscured by the effects of recent asthma experience on psychological status.

METHODS

An adult community sample of 37 patients who had suffered a recent attack of asthma and 37 with stable asthma were given measures of panic fear and control confidence. The relationship with subsequent emergency service use was examined using two way ANOVA and correlational analyses. Covariate influences (psychiatric morbidity, age, sex, treatment level, asthma duration, social status) were considered.

RESULTS

Control confidence predicted emergency service use in different ways for recent attack and stable asthma patients. This interaction was highly significant (F(1,69) = 10.32, p<0.005) with high confidence relating to an increased risk of an attack in the recent attack group and low confidence relating to increased risk for the stable asthma group. There was also an interaction between panic fear and attack context (F(1,69) = 11.05, p<0.005) with low panic fear resulting in more attacks for recent attack cases.

CONCLUSIONS

Attack context (having a recent attack) is an important mediator of psychological status. Strong cognitive/affective responses to attacks may motivate improved self-care and this represents a window of opportunity for self-care interventions. Weak cognitive/affective responses to attacks may reflect denial and require different intervention approaches. For those with recently stable asthma the relationships are qualitatively and quantitatively different, and the implications for intervention are also discussed.

The structure of symptom report in asthma: a reevaluation

OBJECTIVES

We studied the structure of symptom report in a sample of British asthma patients using the Asthma Symptom Checklist (ASC).

METHODS

The ASC was administered to 193 patients, together with a questionnaire on demographics and asthma-related information and the Perceived Control of Asthma Questionnaire.

RESULTS

Principal Component Analysis yielded evidence for a six-dimensional structure of the ASC, with positively correlated subscales for panic-fear, irritation, obstruction-dyspnea, obstruction-congestion, fatigue, and hyperventilation symptoms. Individual subscales showed good to excellent item characteristics and internal consistencies in individual subscales. Panic-fear and obstruction-congestion were related to self-reported duration of oral corticosteroid intake. Other ASC subscales were positively related to aspects of health care utilization, limitations in daily activity, and lower perceived control of asthma mainly in women. The dyspnea subscale of the ASC showed only little relationship with either of these variables.

CONCLUSION

The ASC can reliably assess the multidimensional structure of asthma symptom report. Its subscales are associated with important aspects of asthma management behavior.

Measurement of fatigue in chronic obstructive pulmonary disease and in asthma

Despite recognition of a high prevalence of fatigue in individuals with chronic airflow obstruction conditions, including chronic obstructive pulmonary disease and asthma, and its importance from a quality of life perspective, no research was found in which fatigue was measured directly in these populations. This may be due to a seeming lack of appropriate instruments for measuring fatigue in these populations. The purpose of this study, therefore, was to pretest an instrument, the Piper Fatigue Scale, which was developed to measure chronic fatigue in clinical populations. The outpatient sample consisted of 17 persons with chronic obstructive pulmonary disease and 19 with asthma. Findings revealed that the visual analogue scale version of the Piper Fatigue Scale may not be appropriate for measuring fatigue in these populations. Instruments with validity and reliability for fatigue in chronic obstructive pulmonary disease and asthma need to be developed.

Relationships between psychological variables relevant to asthma and patients' quality of life

The relationships between health-related quality of life and various psychological variables relevant to the clinical evolution of bronchial asthma were evaluated for 101 asthma patients ages 14 to 72 years. Scores on quality of life exhibited a significant negative correlation with perceived vulnerability, panic-fear personality, and irritability, fatigue, airway obstruction, hyperventilation, and panic-fear during attacks but was not significantly correlated with preventive behaviour, attack-related behaviour, recognition, and control of respiratory function, or quality of care. These results imply that the effects of the former group of variables should be taken into account when assessing asthmatic patients' quality of life.

Fatigue in chronic illness: the experience of individuals with chronic obstructive pulmonary disease and with asthma

Although fatigue has been identified as a major problem for individuals with chronic obstructive pulmonary disease and with asthma, no research was found in which the symptom was directly studied in persons with these conditions. From studies carried out on various patient populations, it appears that fatigue has some specificity to disease state. Thus, it is important to describe the experience of fatigue within patient populations. To expand theoretical understanding of fatigue, qualitative research methods need to be applied. The purpose of this study therefore was to describe and compare the fatigue experiences of persons with chronic obstructive pulmonary disease (n=17) and with asthma (n=19). Data were obtained by use of a semi-structured questionnaire and were content analysed for categories and themes. There were many similarities between the fatigue experiences of the two groups. Fatigue is inextricably linked to laboured breathing. Although it interferes with their ability to carry out meaningful activities, the majority of individuals with chronic obstructive pulmonary disease or asthma cope well with it. The informants identified two types of coping strategies they use to manage their situation, which may be categorized as: problem-focused, including energy conservation, utilization and restoration; and emotion-focused, including being positive, accepting the physical limitations, distracting and normalizing.

Psychological factors associated with emergency room visits among asthmatic patients

This study was designed to investigate physiological and psychological characteristics of subjects with high-frequency emergency room (ER) visits. Asthma status, psychological functioning and predispositions, psychosocial adaptation to asthma, and health behaviors were measured for 30 patients who had two or more ER visits during the last 2 years. These subjects were matched for age, sex, and corticosteroid use with 30 subjects who had no unscheduled ER visits for the same period. No significant differences were found for measures of asthma status. Among the asthma-specific variables, the number of hyperventilation-bronchoconstriction symptoms did not distinguish between the groups. High attenders reported more panic-fear symptoms, lower self-efficacy, and more perceived interference. There were no differences for measures of anxiety/depression, self-focused attention, or health locus of control. However, these variables were found to be significant predictors of panic-fear symptoms, lower self-efficacy, and more perceived interference.

Planning an integrated population-based program

Social, economic, and political pressures demand that hospitals focus on ways to provide cost-effective, population-based care. As a member of the hospital executive staff, nurse administrators need to have a method for analyzing, planning, implementing, and evaluating prospective programs and be able to articulate their potential and relative worth in terms of cost, quality, and value. The author presents a template model for integrated population-based program planning. Children's Home-Based Asthma Management and Prevention Service (CHAMPS) is presented to illustrate application of the model.

Symptom perception in asthma: a multidisciplinary review

Clinical observations and research show that symptom perception in asthma is, at worst, inaccurate or often biased in two directions: (1) blunted perception, (2) overperception (both involving airway obstruction manifested in low or high breathlessness). Theoretically breathlessness occurs during respiratory labor or blood gas changes. However, pathophysiological factors and asthma severity are inconsistently related to perceptual accuracy. Consequently, symptom perception within the biomedical perspective is not well understood. Possible psychological influences, varying from the stimulus level to emotions and high-order reasoning, are discussed.

Subjective symptomatology of asthma: validation of the asthma symptom checklist in an outpatient Spanish population

The objective of this study was to validate the Asthma Symptom Checklist (ASC) so that it could be reliably used to assess the subjective symptomatology of asthma attacks in our context. Subjective symptomatology of asthma was examined in a group of 100 adult Spanish outpatients (57 women, 43 men; 17-69 years of age) with asthma. All of them completed the modified version of the ASC as well as questionnaires of depression, anxiety, and self-management of asthma (self-efficacy expectancies and health care utilization). Data about duration and severity of asthma, as well as dyspnea and %FEV1, were also recorded. The highest reliability Cronbach alpha indexes were for the panic-fear and fatigue scales. The oblique rotation of the ASC revealed five correlated factors (53% of the total variance explained): 1) panic-fear, 2) airways obstruction, 3) airways obstruction and panic-fear, 4) fatigue and irritability, 5) hyperventilation. The structure of factors was revalidated using orthogonal (varimax) rotation. Construct validity was examined by Person product-moment coefficient correlations, ANOVAs (asthma severity x ASC scores), and t-tests (sex by ASC scores). Panic-fear showed the best construct validity, as it was related to the severity of the asthma and the use of high-cost health care resources. There were no differences in ASC scores either on the basis of the asthma severity or on the sex of patients. The ASC factors represent stable components of subjective symptomatology of asthma attacks, especially with regard to the panic-fear and the hyperventilation subscales; however, the structure of the checklist as a whole was not identical to those reported in other studies. Correlations of the ASC with clinical variables related to asthma severity support the construct validity of the instrument and confirm its utility to evaluate the subjective symptomatology of asthma attacks in outpatients.

The Revised Asthma Problem Behavior Checklist: adaptation for use in Spanish asthmatic patients

Behavioral problems associated with asthma management were examined in a group of 100 adult Spanish outpatients with asthma (57 women, 43 men; 17-69 years of age). All of them completed a Spanish version of the Revised Asthma Problem Behavior Checklist (RAPBC). Data about duration, severity, and self-management of asthma (self-efficacy expectancies and health care utilization), as well as dyspnea and FEV1, were also recorded. The highest-reliability Cronbach alpha indices were for the criteria related to emotions and behaviors that could precipitate asthma attacks. Concurrent criterion validity was examined first by Pearson correlations between the RAPBC scores and clinical data about asthma (duration, FEV1, and dyspnea), and second, by examining the differences in RAPBC scores (ANOVAs) among three severity groups of patients. Severe patients reported more behavioral problems associated with poor life-styles and self-management of their asthma and showed more psychological and physical negative consequences related to asthma. In conclusion, while the RAPBC could be considered a valid instrument to assess the behavioral problems associated with asthma in Spanish patients, and shows a good concurrent criterion validity, its reliability (internal consistency) with respect to life-style and self-management behaviors related to asthma should be improved, to ensure its utility as a screening instrument for behavior-related problems in asthmatic Spanish patients.

Habituation to prolonged airflow obstruction

The hypothesis that absence of dyspnea during airflow obstruction is caused by habituation to sensory information was tested. Adolescents without respiratory disease breathed through a mouthpiece interrupting airflow analogous to approximately 64% reduction in forced expiratory volume in 1 sec. They were randomly assigned to labored breathing for 1 min, 30 min, or twice 30 min (with a 30-min interval in between). Dyspnea was measured pretest without mouthpiece and posttest with mouthpiece in. Results showed no significant difference in posttest dyspnea between conditions. Dyspnea remained remarkably mild. Severe secondary symptoms (excessive saliva) during the experiment made habituation unlikely and the results were interpreted in favor of the alternative hypothesis: lack of or mild dyspnea is associated with a low-anxiety situation without connotation of suffocation, irrespective of level of airflow obstruction.

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.

Perceived symptoms and discomfort during induced bronchospasm: the role of temporal adaptation and anxiety

Using a mixed within-between design, this study was designed to evaluate the sensorial and cognitive/evaluative aspects of bronchoconstriction induced by progressive methacholine inhalation. 25 asthmatic patients and 15 normal controls were given two consecutive bronchoconstriction tests, inducing a fall of > 30% of the forced expiratory volume in 1 sec (FEV1), which was measured after each inhalation of methacholine. Immediately before each FEV1 measurement, Ss rated perceived bronchial closing, discomfort of breathing and anxiety, as well as the need to use a bronchodilator. In addition to state-anxiety, after each bronchoconstriction test asthma symptoms were evaluated by means of a Free Symptom Report and the Asthma Symptom Checklist. The results show that during the first test, asthmatic patients perceived their symptoms more accurately than non-asthmatic controls. However, during the second test, asthmatic patients became less accurate, while normal controls increased their accuracy of symptom report. These changes were not parallelled for the Free Symptom Report or the Asthma Symptom Checklist. These results suggest that, depending on situational circumstances, patients rely on their cognitive schemata to report asthma symptoms. Need for bronchodilator use was related to perceived discomfort but not to actual or perceived bronchial closing. Clinical implications of this study are discussed.

Asthma, power, and the therapeutic conversation

Previous research has indicated that family therapy may be of use when a child has chronic, uncontrolled asthma. The significant power relations were considered to be those between the child and the parents. In this article, I examine the wider contextual relations that the family encounters when asthma is a problem, and suggest that these relations are unable to be understood without more thoroughly theorizing power. Because of power relations, the meanings of therapeutic encounters for families and health care professionals may not be consensual. The effect may be to hamper adequate asthma management. I suggest that when Foucault's work is examined alongside that of Hoffman, and Anderson and Goolishian, then the processes that distort these understandings are more readily understood. These ideas are illustrated with examples from a research project.

Clinical and symptom measures

We present a review of specific health status measures, including symptoms, physical examination, and laboratory tests (exclusive of lung function tests), in terms of their suitability for assessing the presence and severity of asthma in epidemiologic and clinical research. We focus on the validity, reliability, and responsiveness to clinical intervention of these measures. Several adult questionnaires designed for epidemiologic research include questions on asthma and wheezing that have demonstrated repeatability and validity against concurrent measurements of nonspecific airway responsiveness. The International Union Against Tuberculosis Bronchial Symptoms Questionnaire was designed specifically to detect asthma and airway hyperresponsiveness in adult populations, and its reliability and validity have been well documented. A childhood questionnaire developed by Australian investigators has been demonstrated to provide information on asthma and wheezing that is reliable and valid against the criterion of concurrently measured nonspecific airway responsiveness. Although suitable for epidemiologic research, these questionnaires do not provide sufficient data on the severity of current asthma symptoms (aspects of which include intensity, duration, and frequency of symptoms) to be useful for clinical research involving subjects with established asthma. Many different methods of obtaining and analyzing symptom data have been used in clinical trials, but these have not received the methodologic scrutiny that allow the recommendation of a "best" approach for evaluating symptoms in clinical trials of interventions for asthma. The use of daily symptom diaries in short-term drug trials is common, but the optimal symptom-reporting interval for such studies has not been established. Similarly, a particular approach to integrating different symptoms (wheeze, dyspnea, cough, sputum) and the different aspects of these symptoms (intensity, duration, frequency) cannot be recommended on the basis of available data. Physical examination findings have little utility as asthma outcome measures because they may be normal between symptom episodes, they have relatively poor interobserver reliability, and they are relatively poor predictors of the outcome of emergency room visits for asthma. The finding of an elevated arterial PCO2 has utility as an indicator of a severe asthma attack, but arterial blood gas measurements have little other utility as asthma outcome measures. The chest radiograph is generally normal in patients with asthma and therefore not useful as an asthma outcome measure.(ABSTRACT TRUNCATED AT 400 WORDS)

Measures of life quality, role performance, and functional status in asthma research

Recently a consensus has emerged that health care research should address outcomes important to patients, especially quality of life, role performance, and functional status. The assessment of such outcomes is beset by conceptual and methodological difficulties that may be especially problematic for asthma. Nevertheless, several broad conclusions may be drawn about the use of measures of these outcomes in asthma research. Asthma usually is reasonably well controlled if patients are moderately adherent to their recommended regimens. Consequently, the beneficial impacts of interventions are likely to be small, and large samples are required to detect them. Outcome assessment should combine asthma-specific measures with generic measures applicable to a variety of conditions. Generic measures aimed at severely debilitating disease are less appropriate than measures designed for use in the general population. Asthma-specific measures should emphasize the incidence and impact of such symptoms as coughing, wheezing, sputum production, and shortness of breath. Current procedures for computing utility scores and cost-benefit ratios based on them have serious measurement limitations, and use of such scores should be postponed until those limitations are overcome. These assessment issues should be addressed separately for adults and children.

Scale for assessing functional impairment in adults with asthma

Improved outcome measures for asthma research, especially measures of functional status and quality of life, have become increasingly important. This research describes one such measure, the University of Alabama at Birmingham (UAB) Functional Impairment Scale. This scale consists of eight items to assess the impact of asthma on various aspects of daily living. The psychometric properties of the UAB Scale were assessed in two samples. The coefficient alpha reliabilities were high in both samples (.83 and .84), and the item-total correlations indicated all items were measuring the same trait. The score distributions covered the entire range of possible scores, and the central tendencies and dispersions confirmed the presence of enough variation to detect differences in functional impairment among individuals. Correlations between the UAB Scale and other asthma-related measures support construct validity. All of these results support the potential usefulness of the UAB Scale.

Bronchial asthma and personality dimensions: a multifaceted association

Personality dimensions seem to play an important role in chronic diseases by maintaining or increasing the patient's physical complaints. This study examines in bronchial asthma: (a) the relationships among clinical data, baseline lung function, and personality traits; and (b) the patient's characteristics related to the physician's judgement about his or her asthma severity. Five questionnaires measuring anxiety, depression, self-consciousness, and subjective symptoms were completed by 51 asthmatic patients. Responses to questionnaires and clinical and demographic data were factor-analyzed. Factor analysis revealed that the physician's severity judgement is based on elderly age, high scores on depression, and longer duration of asthma.

Asthma and emotion: a review

This review of the empirical literature on the relationship between asthma and emotion presents an explanatory model of the connection between them. Asthmatics tend to report and display a high level of negative emotion, and asthma exacerbations have been linked temporally to periods of heightened emotionality. Causality may be bidirectional. Hypothesized mediators for the relationship between asthma and emotionality include vagal and alpha-sympathetic hyperreactivity, predominant obstruction in the larger airways, individual response stereotypy, direct effects of emotion-related facial muscle tension on the airways, the emotional effects of asthma medications, heightened respiratory drive, and hyperventilation. Predictions are presented for research on this model of asthma and emotion, and for the psychological treatment of asthma.

Asthma severity: a factor analytic investigation

PURPOSE

Reviewers of the asthma research literature have called for improved questionnaires and other measures, particularly for assessing the severity of asthma. To help meet this need, standard multivariate and psychometric techniques were used with data from asthma patients to develop and evaluate a series of scaled questions. Since there is no "gold standard" for assessing asthma severity, we hope this analysis will help improve our ability to more precisely define these important parameters.

PATIENTS AND METHODS

Data were collected through interviews and review of clinic records for 199 adult patients with asthma from a university clinic population. For evaluating the severity of asthma, eight scales assessed asthma duration, the incidence of asthma symptoms, the extent to which asthma is an inconvenience to patients, the incidence of respiratory diseases, medication regimens, medication side effects, and health care utilization. Forced expiratory volume in 1 second as a percentage of predicted normal was included as an objective measure of pulmonary function. A physician rating scale assessed the severity of the underlying disease, not the severity of a particular episode, as either (1) mild (infrequent attacks with interim symptomatic treatment), (2) moderate (more frequent attacks with continuous daily treatment), and (3) severe (continuous symptom with continuous multiple drug regimen, including some systemic steroids).

RESULTS

In the current analysis of data from adult asthma patients, the scales correlated positively with a physician judgment scale. Factor analysis with an oblique rotation yielded three factors that provided a concise summary of asthma severity. We have named the factors (A) Symptom Intensity, (B) Airflow Impairment, and (C) Management Intensity.

CONCLUSION

Asthma severity appears to be multidimensional rather than unidimensional, including at least three components. The physician rating scale, in combination with measures of the three identified factors, could easily be included in other asthma research protocols to provide a standard, brief assessment of asthma severity and might thus promote greater comparability among studies.

Panic symptoms in asthma and panic disorder: a preliminary test of the dyspnea-fear theory

Ley's (Behaviour Research and Therapy, 27, 549-554, 1989) dyspnea-fear theory was tested on three groups of subjects: 10 with panic disorder, 24 with asthma, and 12 who were nonanxious and nonasthmatic, using measures of pulmonary function, muscle tension; and self-report measures of generalized anxiety, dyspnea, and psychopathology. Results are supportive of dyspnea-fear theory for asthmatics but not for individuals with panic disorder. Differences between groups on panic/fear measures were explained by a combination of general anxiety and dyspnea. Within-group regression analyses showed that only generalized anxiety symptoms contributed significantly to scores on the Asthma Symptom Checklist scale of panic/fear within the panic disorder group; while only dyspnea contributed to panic/fear among asthmatics. Additional results show that panic disorder subjects performed normally on pulmonary function tests but reported respiratory symptoms as severe as did asthmatics. Compared with normal subjects, both patient groups displayed lower correlations between self-rated symptoms of bronchoconstriction and objective pulmonary measures. Panic disorder subjects showed a negative relationship between pulmonary function and hyperventilation symptoms, suggesting a heightened sensitivity to, and discomfort with, sensations associated with normal pulmonary function. Asthmatics displayed a significant relationship between degree of airway obstruction and both trapezius surface EMG and ratings of hyperventilation symptoms.

A scale for assessing quality of life in adult asthma sufferers

The Asthma Questionnaire is a 68-item quality of life scale designed to be sensitive to quality of life changes in clinical trials. The questionnaire covers 11 domains of life experience, the initial domain and item sets being derived from six qualitative focus groups of asthma patients. Psychometric analysis of responses of 101 asthma patients to the initial 101-item set showed the scale to be unidimensional despite being multi-domain, and the finding of unidimensionality was replicated during the further three stages of item refinement using 783 patients. The scale compensates for acquiescence bias as well as allowing a 'not applicable' response category. Validity of the scale was demonstrated by confirmation of expected group differences and the retest reliability was 0.948.