The responsiveness of disease-specific and generic health measures to changes in the severity of asthma among adults

Development and Modification of an Outcome Measure to Follow Symptoms of Children with Sinusitis

OBJECTIVE

To develop a parent-reported Pediatric Rhinosinusitis Symptom Scale (PRSS) that could be used to monitor symptoms of young children with acute sinusitis in response to therapy.

STUDY DESIGN

We developed an 8-item symptom severity scale and evaluated its internal reliability, construct validity, and responsiveness in children 2-12 years of age with acute sinusitis. Parents of 258 children with acute sinusitis completed the PRSS at the time of diagnosis, as a diary at home, and at the follow-up visit at days 10-12. Based on psychometric results and additional parent feedback, we revised the scale. We evaluated the revised version in 185 children with acute sinusitis.

RESULTS

Correlations between the scale and reference measures on the day of enrollment were in the expected direction and of the expected magnitude. PRSS scores at the time of presentation correlated with radiographic findings (P < .001), functional status (P < .001), and parental assessment of overall symptom severity (P < .001). Responsiveness (standardized response mean) and test-retest reliability of the revised scale were good (2.17 and 0.75, respectively).

CONCLUSIONS

We have developed an outcome measure to track the symptoms of acute sinusitis. Data presented here support the use of the PRSS as a measure of change in symptom burden in clinical trials of children with acute sinusitis.

Measuring health-related quality of life in patients with conservatively managed stage 5 chronic kidney disease: limitations of the Medical Outcomes Study Short Form 36: SF-36

PURPOSE

Chronic kidney disease (CKD) negatively affects health-related quality of life (HRQoL), which is often measured using the Medical Outcomes Study Short Form 36 (SF-36) questionnaire. However, the adequacy of SF-36 in this population has not been reported. We aimed to determine floor and ceiling effects and responsiveness to change of SF-36 in patients with conservatively managed stage 5 CKD.

METHODS

SF-36 data were collected prospectively. Floor and ceiling effects were estimated for each SF-36 scale and summary measure based on raw scores. The minimal clinically important difference (MCID) was estimated using a combination of anchor-based and distribution-based methods. Responsiveness to change was assessed by comparing MCID for each scale and summary measure to its smallest detectable change.

RESULTS

SF-36 data were available for 73 of the 74 study participants. Using baseline data, floor and/or ceiling effects were detected for 3 of the 8 SF-36 scales. The anchor-based estimation of MCID based on differences in baseline functional status yielded the most reliable results. For the physical component summary, MCID was estimated at 5.7 points. Whilst the two SF-36 summary measures were responsive to change and free of floor and/or ceiling effects, six of the eight scales were not.

CONCLUSIONS

This small study of patients with conservatively managed stage 5 CKD found that only the summary measures of SF-36 and 2 of its 8 scales can be used to assess changes in HRQoL over time. These findings suggest that in this population, alternative HRQoL assessment tools should be considered for future studies.

Standardizing disease-specific quality of life measures across multiple chronic conditions: development and initial evaluation of the QOL Disease Impact Scale (QDIS®)

BACKGROUND

To document the development and evaluation of the Quality of life Disease Impact Scale (QDIS®), a measure that standardizes item content and scoring across chronic conditions and provides a summary, norm-based QOL impact score for each disease.

METHODS

A bank of 49 disease impact items was constructed from previously-used descriptions of health impact to represent ten frequently-measured quality of life (QOL) content areas and operational definitions successfully utilized in generic QOL surveys. In contrast to health in general, all items were administered with attribution to a specific disease (osteoarthritis, rheumatoid arthritis, angina, myocardial infarction, congestive heart failure, chronic kidney disease (CKD), diabetes, asthma, or COPD). Responses from 5418 adults were analyzed as five disease groups: arthritis, cardiovascular, CKD, diabetes, and respiratory. Unidimensionality, item parameter and scale-level invariance, reliability, validity and responsiveness to change during 9-month follow-up were evaluated by disease group and for all groups combined using multi-group confirmatory factor analysis (MGCFA), item response theory (IRT) and analysis of variance methods. QDIS was normed in an independent chronically ill US population sample (N = 4120).

RESULTS

MGCFA confirmed a 1-factor model, justifying a summary score estimated using equal parameters for each item across disease groups. In support of standardized IRT-based scoring, correlations were very high between disease-specific and standardized IRT item slopes (r = 0.88-0.96), thresholds (r = 0.93-0.99) and person-level scores (r ≥ 0.99). Internal consistency, test-retest and person-level IRT reliability were consistently satisfactory across groups. In support of interpreting QDIS as a disease-specific measure, in comparison with generic measures, QDIS consistently discriminated markedly better across disease severity levels, correlated higher with other disease-specific measures in cross-sectional tests, and was more responsive in comparisons of groups with better, same or worse evaluations of disease-specific outcomes at the 9-month follow-up.

CONCLUSIONS

Standardization of content and scoring across diseases was shown to be justified psychometrically and enabled the first summary measure of disease-specific QOL impact normed in the chronically ill population. This disease-specific approach substantially improves discriminant validity and responsiveness over generic measures and provides a basis for better understanding the relative QOL impact of multiple chronic conditions in research and clinical practice.

Testing item response theory invariance of the standardized Quality-of-life Disease Impact Scale (QDIS(®)) in acute coronary syndrome patients: differential functioning of items and test

PURPOSE

The Quality-of-life (QOL) Disease Impact Scale (QDIS(®)) standardizes the content and scoring of QOL impact attributed to different diseases using item response theory (IRT). This study examined the IRT invariance of the QDIS-standardized IRT parameters in an independent sample.

METHOD

The differential functioning of items and test (DFIT) of a static short-form (QDIS-7) was examined across two independent sources: patients hospitalized for acute coronary syndrome (ACS) in the TRACE-CORE study (N = 1,544) and chronically ill US adults in the QDIS standardization sample. "ACS-specific" IRT item parameters were calibrated and linearly transformed to compare to "standardized" IRT item parameters. Differences in IRT model-expected item, scale and theta scores were examined. The DFIT results were also compared in a standard logistic regression differential item functioning analysis.

RESULTS

Item parameters estimated in the ACS sample showed lower discrimination parameters than the standardized discrimination parameters, but only small differences were found for thresholds parameters. In DFIT, results on the non-compensatory differential item functioning index (range 0.005-0.074) were all below the threshold of 0.096. Item differences were further canceled out at the scale level. IRT-based theta scores for ACS patients using standardized and ACS-specific item parameters were highly correlated (r = 0.995, root-mean-square difference = 0.09). Using standardized item parameters, ACS patients scored one-half standard deviation higher (indicating greater QOL impact) compared to chronically ill adults in the standardization sample.

CONCLUSION

The study showed sufficient IRT invariance to warrant the use of standardized IRT scoring of QDIS-7 for studies comparing the QOL impact attributed to acute coronary disease and other chronic conditions.

Assessing the validity of the RAND negative impact of asthma on quality of life short forms

BACKGROUND

In response to recommendations from the 2010 National Institutes of Health Asthma Outcomes Workshop, we developed a system for measuring the negative impact of asthma on quality of life (QoL), which was referred to as the RAND Negative Impact of Asthma on Quality of Life (RAND-IAQL) item bank. The bank contains 65 items that focus on the patient's perception of the impact or bother of asthma on his or her life.

OBJECTIVE

Evidence for the validity of 2 short forms, the RAND-IAQL 4-item and 12-item Short Forms, from the bank is presented.

METHODS

Using a sample of 2032 adults with asthma, we validated our short forms against the Asthma Quality of Life Questionnaire-Marks (AQLQ-M), the Asthma Control Test, and generic measures of QoL developed by the Patient-reported Outcomes Measurement Information System (PROMIS). Discriminant validity was examined by comparing scores of respondents who differed according to multiple health indicators.

RESULTS

Our sample ranged in age from 18 to 99 years (mean, 43 years), with 14% Hispanic, 11% Asian, 19% African American, and 56% non-Hispanic white race/ethnicity. Men had a significantly worse impact of asthma on QoL than women. The impact of asthma on QoL was greatest in African American and Hispanic subjects compared with that seen in non-Hispanic white subjects. Our measures correlated highly with the AQLQ-M and more strongly with the PROMIS global physical than mental scales. They differentiated between adults with asthma according to their perceived severity, level of control, presence or absence of exacerbations, and physical comorbidity.

CONCLUSION

The RAND-IAQL item bank, measuring the impact of asthma on QoL, will complement other patient-reported outcomes, such as measures of asthma symptoms, functioning, and control.

Patient-reported outcomes in clinical trials of inhaled asthma medications: systematic review and research needs

PURPOSE

To assess the diversity, application, analysis and interpretation of patient-reported outcomes (PROs) in asthma clinical trials.

METHODS

We critically appraised the use of asthma-specific PROs in 87 randomised controlled trials (RCTs) of inhaled asthma medications published during 1985-2006.

RESULTS

A total of 79 RCTs reported PROs, of which 78 (99%) assessed symptom scores and seven (9%) assessed asthma quality of life scores. Only eight (10%) used validated instruments and five (6%) provided clinical interpretation of scores. Due to heterogeneity in the reporting of symptom measures, it is not possible to determine how many discrete symptom assessment instruments have been used. Only 26 (33%) of the RCTs that measured symptom scores reported the scores for follow-up. Limited improvement occurred over time: fewer than 30% of the RCTs used validated PRO measures in any individual year.

CONCLUSION

Numerous validated PRO instruments are available but it is unclear why few are used in asthma clinical trials. Problems include poor reporting, and uncritical analysis and interpretation of PRO scores. Research needs include identifying and recommending a set of PROs for use in asthma clinical research and providing guidance for researchers on the application, analysis and interpretation of PRO measures in clinical trials.

Assessing the responsiveness of the Asthma Quality of Life Questionnaire with pharmaceutical care

OBJECTIVE

To assess the responsiveness of the Asthma Quality of Life Questionnaire (AQLQ) in the context of pharmaceutical care delivery New Zealand community pharmacy setting.

SETTING

Community pharmacy practices in three locations in the Otago and Southland region of New Zealand.

METHOD

About 62 patients with asthma (17-80 years of age) were recruited in five community pharmacies in the Otago and the Southland region of New Zealand. Patients were randomly assigned to two groups (Group 1 and Group 2). The AQLQ and a study-specific outcomes questionnaire were administered to both groups at baseline (T1), then again (with an additional global Self-Assessment of change question) 3 months later (at T2) after providing the service to Group 1. Responsiveness of the AQLQ was assessed by measuring the ability of the AQLQ to detect within-subject change in patients who subjectively indicated change, and to distinguish between two groups of patients: those who indicated change and those who indicated no change. Additionally, the correlation between the change of the AQLQ scores at T2 and the patients' self-assessment of change at T2 was estimated and used as means for assessing the AQLQ responsiveness.

MAIN OUTCOME MEASURE

Asthma-specific quality of life as measured by the AQLQ and change in quality of life as perceived by participants.

RESULTS

The results supported the responsiveness of three out of the four domains of the Asthma Quality of Life Questionnaire. The fourth domain, Environmental stimuli, showed weaker responsiveness, and the reasons of this were discussed.

CONCLUSION

This study provided data supporting the responsiveness of the AQLQ when used in the context of pharmaceutical care. However, while the AQLQ's Activity Limitation, Symptoms and Emotional domains reflected adequate sensitivity to change in QoL over time, its Environmental domain was less sensitive. Researchers conducting longitudinal studies utilising the AQLQ in pharmaceutical care interventions should bear this in mind, and should consider the possible reasons for this apparent lack of responsiveness, and its implications.

Reliability and validity of functional health status and health-related quality of life questionnaires in children with recurrent acute otitis media

In this study the reliability and validity of generic and disease-specific questionnaires has been assessed focusing on responsiveness. This is part of a study on the effects of recurrent acute otitis media (rAOM) on functional health status (FHS) and health-related quality of life (HRQoL) in 383 children with rAOM participating in a randomized clinical trial. The following generic questionnaires were studied: 1. RAND general health rating index, 2. Functional Status Questionnaire (FSQ Generic and FSQ Specific), 3. TNO-AZL Infant Quality of Life (TAIQOL), and the following disease-specific questionnaires: 1. Otitis Media-6 (OM-6), 2. Numerical rating scales (NRS) for child and caregiver (NRS Child and NRS Caregiver), and 3. a new Family Functioning Questionnaire (FFQ). Reliability was good to excellent (Cronbach’s α range 0.80–0.90, intraclass correlation coefficient range 0.76–0.93). Moderate to strong correlations were found between the questionnaires as well as between questionnaires and relevant clinical indicators (r = 0.29–0.49), demonstrating construct validity. Discriminant validity for children with few versus frequent episodes of acute otitis media per year was good for most questionnaires (P < 0.004) but poor for the otitis media-related subscales of the TAIQOL (P = 0.10–0.97) and both NRS (P = 0.22 and 0.48). Except for the TAIQOL subscales, change scores were significant (P < 0.003) for generic and disease-specific questionnaires. Effect sizes were somewhat higher for disease-specific compared to generic questionnaires (0.55–0.95 versus 0.32–0.60) except for the TAIQOL subscales, which showed very poor sensitivity to change. Anchor-based methods resulted in a somewhat larger range of estimates of MCID than distribution-based methods. Combining distribution-based and anchor-based methods resulted in similar ranges for the minimally clinical important differences for generic and disease-specific questionnaires: 2–15 points on a 0–100 scale. Apart from the generic TAIQOL subscales, both generic and disease-specific questionnaires used in this study showed good psychometric qualities and responsiveness for use in clinical studies on children with rAOM.

Associations of patient health-related problem solving with disease control, emergency department visits, and hospitalizations in HIV and diabetes clinic samples

BACKGROUND

Patient problem solving and decision making are recognized as essential to effective self-management across multiple chronic diseases. However, a health-related problem-solving instrument that demonstrates sensitivity to disease control parameters in multiple diseases has not been established.

OBJECTIVES

To determine, in two disease samples, internal consistency and associations with disease control of the Health Problem-Solving Scale (HPSS), a 50-item measure with 7 subscales assessing effective and ineffective problem-solving approaches, learning from past experiences, and motivation/orientation.

DESIGN

Cross-sectional study.

PARTICIPANTS

Outpatients from university-affiliated medical center HIV (N = 111) and diabetes mellitus (DM, N = 78) clinics.

MEASUREMENTS

HPSS, CD4, hemoglobin A1c (HbA1c), and number of hospitalizations in the previous year and Emergency Department (ED) visits in the previous 6 months.

RESULTS

Administration time for the HPSS ranged from 5 to 10 minutes. Cronbach's alpha for the total HPSS was 0.86 and 0.89 for HIV and DM, respectively. Higher total scores (better problem solving) were associated with higher CD4 and fewer hospitalizations in HIV and lower HbA1c and fewer ED visits in DM. Health Problem-Solving Scale subscales representing negative problem-solving approaches were consistently associated with more hospitalizations (HIV, DM) and ED visits (DM).

CONCLUSIONS

The HPSS may identify problem-solving difficulties with disease self-management and assess effectiveness of interventions targeting patient decision making in self-care.

The European DISABKIDS project: development of seven condition-specific modules to measure health related quality of life in children and adolescents

Background

The European DISABKIDS project aims to enhance the Health Related Quality of Life (HRQoL) of children and adolescents with chronic medical conditions and their families. We describe the development of the seven cross-nationally tested condition-specific modules of the European DISABKIDS HRQoL instrument in a population of children and adolescents. The condition-specific modules are intended for use in conjunction with the DISABKIDS chronic generic module.

Methods

Focus groups were used to construct the pilot version of the DISABKIDS condition-specific HRQoL modules for asthma, juvenile idiopathic arthritis, atopic dermatitis, cerebral palsy, cystic fibrosis, diabetes and epilepsy. Analyses were conducted on pilot test data in order to construct field test versions of the modules. A series of factor analyses were run, first, to determine potential structures for each condition-specific module, and, secondly, to select a reduced number of items from the pilot test to be included in the field test. Post-field test analyses were conducted to retest the domain structure for the final DISABKIDS condition-specific modules.

Results

The DISABKIDS condition-specific modules were tested in a pilot study of 360 respondents, and subsequently in a field test of 1152 respondents in 7 European countries. The final condition-specific modules consist of an 'Impact' domain and an additional domain (e.g. worry, stigma, treatment) with between 10 to 12 items in total. The Cronbach's alpha of the final domains was found to vary from 0.71 to 0.90.

Conclusion

The condition-specific modules of the DISABKIDS instrument were developed through a step-by-step process including cognitive interview, clinical expertise, factor analysis, correlations and internal consistency. A cross-national pilot and field test were necessary to collect these data. In general, the internal consistency of the domains was satisfactory to high. In future, the DISABKIDS instrument may serve as a useful tool with which to assess HRQoL in children and adolescents with a chronic condition. The condition-specific modules can be used in conjunction with the DISABKIDS chronic generic module.

Health related quality of life in sickle cell patients: the PiSCES project

Background

Sickle cell disease (SCD) is a chronic disease associated with high degrees of morbidity and increased mortality. Health-related quality of life (HRQOL) among adults with sickle cell disease has not been widely reported.

Methods

We administered the Medical Outcomes Study 36-item Short-Form to 308 patients in the Pain in Sickle Cell Epidemiology Study (PiSCES) to assess HRQOL. Scales included physical function, physical and emotional role function, bodily pain, vitality, social function, mental health, and general health. We compared scores with national norms using t-tests, and with three chronic disease cohorts: asthma, cystic fibrosis and hemodialysis patients using analysis of variance and Dunnett's test for comparison with a control. We also assessed whether SCD specific variables (genotype, pain, crisis and utilization) were independently predictive of SF-36 subscales, controlling for socio-demographic variables using regression.

Results

Patients with SCD scored significantly worse than national norms on all subscales except mental health. Patients with SCD had lower HRQOL than cystic fibrosis patients except for mental health. Scores were similar for physical function, role function and mental health as compared to asthma patients, but worse for bodily pain, vitality, social function and general health subscales. Compared to dialysis patients, sickle cell disease patients scored similarly on physical role and emotional role function, social functioning and mental health, worse on bodily pain, general health and vitality and better on physical functioning. Surprisingly, genotype did not influence HRQOL except for vitality. However, scores significantly decreased as pain levels increased.

Conclusion

SCD patients experience health related quality of life worse than the general population, and in general, their scores were most similar to patients undergoing hemodialysis. Practitioners should regard their HRQOL as severely compromised. Interventions in SCD should consider improvements in health related quality of life as important outcomes.

The disabilities of the arm, shoulder and hand (DASH) outcome questionnaire: longitudinal construct validity and measuring self-rated health change after surgery

BACKGROUND

The disabilities of the arm, shoulder and hand (DASH) questionnaire is a self-administered region-specific outcome instrument developed as a measure of self-rated upper-extremity disability and symptoms. The DASH consists mainly of a 30-item disability/symptom scale, scored 0 (no disability) to 100. The main purpose of this study was to assess the longitudinal construct validity of the DASH among patients undergoing surgery. The second purpose was to quantify self-rated treatment effectiveness after surgery.

METHODS

The longitudinal construct validity of the DASH was evaluated in 109 patients having surgical treatment for a variety of upper-extremity conditions, by assessing preoperative-to-postoperative (6-21 months) change in DASH score and calculating the effect size and standardized response mean. The magnitude of score change was also analyzed in relation to patients' responses to an item regarding self-perceived change in the status of the arm after surgery. Performance of the DASH as a measure of treatment effectiveness was assessed after surgery for subacromial impingement and carpal tunnel syndrome by calculating the effect size and standardized response mean.

RESULTS

Among the 109 patients, the mean (SD) DASH score preoperatively was 35 (22) and postoperatively 24 (23) and the mean score change was 15 (13). The effect size was 0.7 and the standardized response mean 1.2.The mean change (95% confidence interval) in DASH score for the patients reporting the status of the arm as "much better" or "much worse" after surgery was 19 (15-23) and for those reporting it as "somewhat better" or "somewhat worse" was 10 (7-14) (p = 0.01). In measuring effectiveness of arthroscopic acromioplasty the effect size was 0.9 and standardized response mean 0.5; for carpal tunnel surgery the effect size was 0.7 and standardized response mean 1.0.

CONCLUSION

The DASH can detect and differentiate small and large changes of disability over time after surgery in patients with upper-extremity musculoskeletal disorders. A 10-point difference in mean DASH score may be considered as a minimal important change. The DASH can show treatment effectiveness after surgery for subacromial impingement and carpal tunnel syndrome. The effect size and standardized response mean may yield substantially differing results.

On assessing responsiveness of health-related quality of life instruments: guidelines for instrument evaluation

A lack of clarity exists about the definition and adequate approach for evaluating responsiveness. An overview is presented of different categories of definitions and methods used for calculating responsiveness identified through a literature search. Twenty-five definitions and 31 measures were found. When applied to a general and a disease-specific quality of life questionnaire large variation in results was observed, partly explained by different goals of existing methods. Four major issues are considered to claim the usefulness of an evaluative health-related quality of life (HRQL) instrument. Their relation with responsiveness is discussed. The confusion about responsiveness arises mostly from a lack of distinction between cross-sectional and longitudinal validity and from a lack of distinction between responsiveness defined as the effect of treatment and responsiveness defined as the correlation of changes in the instrument with changes in other measures. All measures of what is currently called responsiveness can be looked at as measures of longitudinal validity or as measures of treatment effect. The latter ones tell us little about how well the instrument serves its purpose and are only of use in interpreting score changes. We therefore argue that the concept of responsiveness can be rejected as a separate measurement property of an evaluative instrument.

Measuring health-related quality of life in patients with chronic obstructive pulmonary disease in a routine hospital setting: feasibility and perceived value

BACKGROUND

Assessment of health-related quality of life is so far mainly used in specific research settings and not widely accepted in the routine care of patients. Lack of trust in accuracy and reliability and lack of knowledge concerning the questionnaires used, methods, terminology, are just some of the perceived barriers for a more widespread dissemination of these instruments into routine health care. The present study was undertaken in order to test the feasibility of a computerised system for collecting and analysing health-related quality of life in a routine clinical setting and to examine the thoughts and attitudes among physicians concerning the value of these measurements.

METHODS

Seventy-four patients with chronic pulmonary lung disease were asked to assess their health-related quality of life with a computerised version of the SF-36 questionnaire before a regular the visit to a physician. The results were immediately available for the physician during the consultation for comparison of information given by the patients and the physician's evaluation of the patients overall health status. A focus group interview with the physicians was performed before and after the implementation of routine measurements of health-related quality of life.

RESULTS

The systematic assessment concept worked satisfactorily. All patients approached agreed to participate and completed the assessment on the touch screen computer. A weak correlation was found between patients' self-rated health and pulmonary function and between physicians' evaluation and pulmonary function. The physicians appreciated the SF-36 assessments and the value of the patients' perspective although only a few could pinpoint new clinical decisions based upon this new information.

CONCLUSION

Physicians' clinical evaluation and patients' self-rating of health status offer unique and important information that are complementary.

Validity of the St George's respiratory questionnaire at acute exacerbation of chronic bronchitis: comparison with the Nottingham health profile

The purpose of the study is to compare a generic and a specific quality of life (QoL) instrument in the assessment of QoL in chronic bronchitis. Data from 320 patients were collected at acute exacerbation of chronic bronchitis (AECB), and from 230 patients during a subsequent stable phase (non-AECB), utilising both the specific St George's respiratory questionnaire (SGRQ) and the generic Nottingham health profile (NHP). Patients (maximum n = 200) reported significantly poorer QoL at AECB than at non-AECB for all domains except the SGRQ symptom domain (SRM = 0.02). The SGRQ was more sensitive than the NHP to QoL differences between patients. The correlations between the scores across the two assessments were generally higher for the SGRQ, with the correlations between the NHP and SGRQ being lower at AECB, suggesting that the instruments are measuring different constructs at AECB, with the SGRQ being less responsive to QoL change. Indeed, the NHP was generally more responsive to QoL change in terms of 'risk' and clinical factors, with the SGRQ symptom domain appearing particularly non-responsive. In conclusion, this study suggests that the condition-specific SGRQ, and particularly its symptom domain, is less responsive than the generic NHP to QoL change accompanying AECB. This reflects the construct of the symptom domain which measures chronic bronchitis symptoms over the previous year.

Health-related quality of life in asthma: a comparison between the St George's Respiratory Questionnaire and the Asthma Quality of Life Questionnaire

The aim of the study is to compare the performance of the Juniper Asthma Quality of Life Questionnaire (AQLQ) and the St George's Respiratory Questionnaire (SGRQ) in a sample of asthmatic patients, representative of a broad spectrum of asthma severity. We studied 116 patients with a mean age (SD) of 42.6 (18.3) year. Patients were assessed twice, at recruitment and after 2 months, to determine the reliability, validity and responsiveness of the AQLQ and the SGRQ. Both questionnaires showed good reliability coefficients (> or = 0.70) which reached the standards for comparison at individual level (> or = 0.90) in the case of activity, impacts and overall SGRQ scores as well as symptoms, activities and overall AQLQ scores. Both AQLQ and SGRQ were able to discriminate among groups of patients based on asthma severity and control and showed, except for the symptoms domain of the SGRQ, large (standardized response means >0.8) and significant changes in the group of patients that improved at follow-up. We conclude that the AQLQ and SGRQ have shown high reliability and validity and, with the exception of the SGRQ symptoms, a high level of responsiveness. In overall terms, not one of these instruments seems to behave better than the other.

The influence of chronic respiratory conditions on health status and work disability

OBJECTIVES

This study examined the impact of asthma and chronic obstructive pulmonary disease (COPD) on health status and work disability.

METHODS

We used data from a population-based sample of 3805 California adults.

RESULTS

Compared with adults with no chronic health conditions, adults with COPD or asthma had a greater risk of self-reported diminished general health (odds ratio [OR] = 10.95; 95% confidence interval [CI] = 6.31, 19.0 and OR = 3.92; 95% CI = 2.31, 6.65, respectively). Respondents with COPD or asthma also had worse mental health status, as indicated by a greater risk of depressive symptoms (OR = 10.05; 95% CI = 5.29, 19.08 and OR = 2.59; 95% CI = 1.33, 5.04). COPD was associated with reduced current employment (OR = 0.41; 95% CI = 0.24, 0.71).

CONCLUSIONS

Asthma and COPD are associated with poor health status and greater work disability.

Patients' and carers' preferences in two models of care for acute exacerbations of COPD: results of a randomised controlled trial

BACKGROUND

Patients with an acute exacerbation of chronic obstructive pulmonary disease (COPD) were randomised to either hospital at home (HaH) or inpatient management, and patient and carer preferred site of management and satisfaction with care received in the two arms was determined.

METHODS

Emergency admissions with an acute exacerbation of COPD were randomised to inpatient care or HaH care. After discharge an independent observer administered a questionnaire to both patients and carers on the preferred site of care and scored satisfaction with the care received.

RESULTS

Of 60 patients recruited, 30 were randomised to receive HaH care. Retrospective patient preference for HaH care was 96.3% in the domiciliary arm and 59.3% in the conventional arm; carer preference figures were 85.7% and 42.9%, respectively. There was a higher preference for domiciliary care by both patients and carers in the HaH arm than in the inpatient arm (p=0.001 and p=0.01, respectively). Patients recorded equal satisfaction with care in the two arms (88.1% in the conventional arm, 91.7% in the domiciliary arm); carer scores were 91.3% and 91.9%, respectively.

CONCLUSIONS

The results of this study show that both patients and carers were significantly more likely to prefer domiciliary care if they were in the HaH arm. Since patients had to be willing to be looked after at home, both patients' and carers' perceptions of the benefits of HaH care were reinforced by their experience. HaH care of acute exacerbations of COPD is the preferred option in suitable patients.

Wheeze not current asthma affects quality of life in young adults with asthma

BACKGROUND

A study was undertaken to investigate quality of life in asthma, defined by differing criteria, to see which may be most appropriate in epidemiological studies.

METHODS

The 426 adults were participants in the follow up phase of the European Community Respiratory Health Survey (ECRHS) in Melbourne. As part of the laboratory visit, participants completed the SF-36 quality of life questionnaire, a detailed respiratory questionnaire, and underwent lung function testing.

RESULTS

Both the physical component summary and the mental component summary scores were significantly worse in those with wheeze in the previous 12 months than in those without wheeze. Only the mental component summary score was significantly worse in those with current asthma than in those without. In contrast, in those with current asthma or bronchial hyperreactivity only, neither of the summary scales was significantly different between cases and controls.

CONCLUSIONS

Quality of life is severely impaired in individuals with wheeze in the previous 12 months while individuals with current asthma or bronchial hyperreactivity alone did not appear to have significantly reduced quality of life.

Development and validation of the ITG Health-Related Quality-of-Life Short-Form measure for use in patients with coronary artery disease. Integrated Therapeutics Group

BACKGROUND

Available coronary artery disease (CAD)-specific health-related quality-of-life (HRQL) measures are not ideally suited for routine clinical practice. We report development of a valid and reliable CAD-specific short-form measure.

HYPOTHESIS

The Integrated Therapeutics Group (ITG) CAD-specific short-form HRQL measure is reliable and valid for assessing the health status of patients with CAD.

METHODS

In all, 409 patients (mean age 62.4 years) completed the 24-item CAD-specific HRQL questionnaire. Factor analysis was used to identify the scaling of the 24 CAD-specific items. Analysis of variance was used to reduce the number of items within each scale, and reliability (Cronbach's alpha), discriminant validity, and ceiling and floor effects of short-form scales were evaluated. Short-form scales were compared with the longer scales using relative validity coefficients. The CAD severity was assessed using New York Heart Association criteria, physician assessment, electrocardiogram results, the number of myocardial infarctions, and the number of CAD-specific medications. Clinical validity of short-form scales was then assessed based on their ability to discriminate across severity levels of these clinical criteria.

RESULTS

Four scales were identified: Extent of Chest Pain, Functioning and Well-Being, Activities Level-Physical, and Activities Level-Social. The 24-item questionnaire was reduced to a 13-item short form, with reliability exceeding 0.70 for all four scales. Relative validity estimates comparing short-form to original scales ranged from 0.68 to 2.58. Mean scores varied significantly (p < 0.05) by clinical severity, supporting the discriminant validity of the ITG CAD short-form scales.

CONCLUSIONS

The ITG CAD short form (used alone or with a general HRQL measure) is valid and practical for assessing patients with CAD.

A new tool for monitoring asthma outcomes: the ITG Asthma Short Form

BACKGROUND

Asthma treatment has broadened from managing clinical markers to incorporate factors that are most meaningful to patients, collectively called health-related quality of life (HQL).

OBJECTIVE

To develop an asthma-specific HQL tool, meeting demands for brevity, usefulness and measurement precision.

METHODS

The 20-item Sydney Asthma Quality of Life Questionnaire (AQLQ) and six additional items were studied using factor analysis, reliability and validity tests among asthma patients 14 and older.

RESULTS

The 15-item Integrated Therapeutics Group Asthma Short Form (ITG-ASF) retains the validity of the AQLQ with improved scaling properties and interpretability. The ITG-ASF yields 6 scores: Symptom-Free Index, Functioning with Asthma, Psychosocial Impact of Asthma, Asthma Energy and Asthma-Confidence in Health and a Total. All items correlated 0.40 or higher with their hypothesized scales and passed discriminant validity tests, with scaling success rates from 75 to 100%. Reliability exceeded the minimum of 0.70 for group comparisons. Ceiling and floor effects were acceptable. Scales were valid in relation to changes in asthma severity and lung function. The best predictor of asthma severity (National Asthma Education and Prevention Program (NAEPP) staging) was the Symptom-Free Index. A Spanish translation is available, Chinese-American is forthcoming. The reading grade level is 4.8.

CONCLUSIONS

Development of the ITG-ASF was a data-driven process maximizing measurement precision and breadth while minimizing burden. The ITG-ASF is a brief, comprehensive and empirically valid tool that complements traditional markers of the outcomes of asthma care.