Elisabeth Ståhl

Health-related quality of life is related to COPD disease severity

BackgroundThe aim of this study was to evaluate the association between health-related quality of life (HRQL) and disease severity using lung function measures.MethodsA survey was performed in subjects with COPD in Sweden. 168 subjects (70 women, mean age 64.3 years) completed the generic HRQL questionnaire, the Short Form 36 (SF-36), the disease-specific HRQL questionnaire; the St Georges Respiratory Questionnaire (SGRQ), and the utility measure, the EQ-5D. The subjects were divided into four severity groups according to FEV1 per cent of predicted normal using two clinical guidelines: GOLD and BTS. Age, gender, smoking status and socio-economic group were regarded as confounders.ResultsThe COPD severity grades affected the SGRQ Total scores, varying from 25 to 53 (GOLD p = 0.0005) and from 25 to 45 (BTS p = 0.0023). The scores for SF-36 Physical were significantly associated with COPD severity (GOLD p = 0.0059, BTS p = 0.032). No significant association were noticed for the SF-36, Mental Component Summary scores and COPD severity. Scores for EQ-5D VAS varied from 73 to 37 (GOLD I-IV p = 0.0001) and from 73 to 50 (BTS 0-III p = 0.0007). The SGRQ Total score was significant between age groups (p = 0.0047). No significant differences in HRQL with regard to gender, smoking status or socio-economic group were noticed.ConclusionThe results show that HRQL in COPD deteriorates with disease severity and with age. These data show a relationship between HRQL and disease severity obtained by lung function.

A randomised trial to evaluate the self-administered standardised chronic respiratory questionnaire

The original chronic respiratory questionnaire (CRQ), one of the most widely used measures of health-related quality of life (HRQL) in chronic respiratory disease (CRD), is traditionally interviewer administered (IA) and includes an individualised dyspnoea domain. The present authors studied the impact of self-administered (SA) and standardised dyspnoea questions on CRQ measurement properties. In a factorial design multicentre trial, 177 patients with CRD (mean age 67.7 yrs; mean forced expiratory volume in one second per cent predicted 44.6%) were randomised to CRQ-IA (n = 86) or CRQ-SA (n = 91), and to initially complete the standardised or individualised items before and after respiratory rehabilitation. While maintaining validity, the CRQ-SA proved more responsive to changes in HRQL than the CRQ-IA in all domains. Compared with the standardised dyspnoea domain, the individualised dyspnoea domain indicated greater responsiveness. The correlations of baseline scores and change scores with other HRQL instruments indicated good validity of the CRQ-SA. In conclusion, self-administration and standardisation of the chronic respiratory questionnaire maintains validity and responsiveness relative to the interviewer-administered chronic respiratory questionnaire. These results challenge the assumption that interviewer-administered questionnaires are superior to self-administered questionnaires in older patients with chronic respiratory disease.

Psychometric and utility-based measures of health status of asthmatic patients with different disease control level

AbstractObjective: To explore the relationship between asthma control level and healthrelated QOL (HR-QOL), and to understand the role of various psychometric and utility-based methods in studying this relationship. Methods: Two hundred and twenty-eight consecutive adult outpatients and inpatients at four sites participated in the study. Physicians identified the level of disease control according to the Global Initiative for Asthma (GINA) classification system. Patients filled in three different HR-QOL questionnaires (EuroQol 5-D [EQ-5D], Short-Form 36-item health survey [SF-36], and St George’s Respiratory Questionnaire [SGRQ]) and a direct time trade-off question. The Short Form- 6D (SF-6D) was used to derive utility values from SF-36 data. Results: All patient-reported evaluation methods could discriminate between patients with different disease control levels, and both generic and diseasespecific instruments strongly correlated to each other. The magnitude of differences in HR-QOL between groups with different disease control levels was clinically meaningful. All three HR-QOL measures reflected a relationship between disease control level and HR-QOL, but the actual pattern of the relationship depended on the instrument used. Utilities gained from the EQ-5D index, compared with the SF-6D index, had higher values in the patient group with the best disease control and lower values in the patient group with poor disease control. Conclusions: When choosing an instrument to measure the health status of asthmatic patients in clinical studies, the severity range of the study population should be considered. Researchers might prefer to use the EQ-5D in asthma patients with severe disease or poor disease control and the SF-6D in patients with mild disease or good disease control.

Modification of the asthma quality of life questionnaire (standardised) for patients 12 years and older

BackgroundThe age limit for some adult asthma clinical trials has recently been lowered to 12 years. In this study we have made minor modifications to the standardised version of the adult Asthma Quality of Life Questionnaire (AQLQ(S)) to make it valid for patients 12 years and older (AQLQ12+).MethodsWe have used two clinical trial databases, in which the AQLQ12+ was used, to compare the measurement properties of the questionnaire in patients 12–17 years and patients 18 years and older. A total of 2433 patients (12–75 years), with current asthma and with data that could be evaluated both at randomisation and end of treatment, were included.ResultsThe analysis showed that internal consistency, responsiveness and correlations with other clinical indices were very similar in patients 12–17 years and patients 18 years and older.ConclusionThe measurement properties of the AQLQ12+ are similar in adolescents and adults and therefore the instrument is valid for use in adult studies which include children 12 years and older.

Cost-effectiveness analysis of a dry powder inhaler (Turbuhaler) versus a pressurised metered dose inhaler in patients with asthma.

In an open randomised parallel-group study, 1004 patients with asthma in 7 countries were randomised to receive asthma treatment via 2 different kinds of inhalers: an aerosol pressurised metered dose inhaler (pMDI) and a dry powder inhaler (Turbuhaler). The patients were treated for 52 weeks with inhaled corticosteroids and/or inhaled beta 2-agonists. All patients were considered adequately treated with inhaled corticosteroids and/or inhaled beta 2-agonists via pMDI before inclusion in the study. Healthcare utilisation variables were attached to the case record forms of the patients, thus making an economic analysis possible. Because of the difficulty of comparing costs between countries, each country was analysed separately. Canadian patients constituted the largest subpopulation (445 patients) and were therefore used in this analysis. From the analysis, we concluded that the effectiveness of treatment (measured as the number of exacerbations and days with exacerbation) was significantly better for patients treated via Turbuhaler than via a pMDI (p = 0.03). Furthermore, the total annual costs of treatment were, on average,

Measuring functional performance in patients with COPD: a discussion of patient-reported outcome measures

Can331 less (p < 0.01) for patients using Turbuhaler than for those using a pMDI (mainly due to lower costs for hospitalisation and medication). The cost differences between inhaled corticosteroids and inhaled beta 2-agonists were significantly in favour of treatment via Turbuhaler (p < 0.01). Thus, the results of this study suggest that treatment via Turbuhaler is a cost-effective strategy in patients with asthma in Canada.

A Comparison of Narrative and Table Formats for Presenting Hypothetical Health States to Patients with Gastrointestinal or Pulmonary Disease

ABSTRACT Background: Chronic obstructive pulmonary disease (COPD) is a chronic condition and a major public health concern. Moreover, its prevalence is increasing. COPD commonly affects patient performance of daily activities that people perform in order to meet basic needs, fulfill usual roles, and maintain their health and well-being. What types of activities are affected and to what degree≟ How do these effects change over time? What impact, positive or negative, do various treatments have on the capacity of patients to perform activities? To address these questions, the concept of activity performance must be defined and appropriately measured. Methods: This paper presents a model of function that defines functional performance as distinct but related to physiological impairments and functional capacity. A systematic review of the literature was conducted to locate patient-reported outcome (PRO) instruments that have been used to capture functional performance in clinical studies of COPD and have been validated with patients with COPD. The content of each measure was reviewed to assess depth and breadth of coverage. Results: The systematic review yielded nine validated PROs used to capture functional performance in clinical studies of COPD: three are generic; six were designed specifically for use in patients with COPD. Variability in content coverage occurred across the PROs, with some sacrificing depth for breadth. Few of the PROs covered the full range of content as defined in the model. Limiting selected PROs to those that have been used with patients with COPD, while relevant to this population, may preclude other PRO instruments that can measure functional performance. The relevance of another instrument would, however, need to be confirmed with patients with COPD. Conclusions: Selection of endpoints and instruments for clinical studies of COPD and its treatment must be driven by a clear definition of concepts of interest and the relevance of content areas to patients. Some existing instruments may provide adequate coverage of endpoints or content areas under investigation. Others clearly will not.

Do clinical marker states improve responsiveness and construct validity of the standard gamble and feeling thermometer: A randomized multi-center trial in patients with chronic respiratory disease

Traditionally, quality-of-life researchers describe states of health for patients to rate either in narrative form or in table form, but evidence about which format patients prefer is limited. The authors performed 2 randomized studies to test whether patients prefer the table or narrative format and whether the format of presentation influences how patients rate health states. Approximately three-fourths of patients with gastrointestinal disease or chronic airflow limitation preferred the table format. There were no differences in patients’ ratings of 3 described health states or of their own health. Investigators should consider using the table presentation for describing health states to subjects who are not familiar with these states of health.

Formoterol used as needed improves health-related quality of life in asthmatic patients uncontrolled with inhaled corticosteroids

Background: Optimizing the validity and responsiveness of utility measures will enhance their usefulness in randomized trials. We evaluated the impact of clinical marker state (CMS) rating prior to patients’ rating their own health on two utility instruments (feeling thermometer (FT) and standard gamble (SG)) in patients with chronic respiratory disease (CRD). Methods: We randomized 182 patients with CRD to complete the FT (self-administered) and SG with CMS (FT+/SG+, n=91) or without marker states (FT−/SG−, n=91) before and after undergoing respiratory rehabilitation in a multi-center trial. Results: Use of CMS did not influence baseline utility scores. Improvement after therapy on the scale from 0 (dead) to 1.0 (full health) was 0.04 both in FT+ (p=0.03) and FT− (p=0.02; the difference between FT+ and FT− was 0.00, p=0.83). Improvement on the SG was 0.05 in both SG+ (p=0.08) and SG− (p=0.04; difference between SG+ and SG− 0.00, p=0.95). Correlations with other health related quality of life scores were highest for FT+. Conclusion: Administration of CMS did not improve responsiveness of the FT but may have improved construct validity. The SG showed limited construct validity and responsiveness that was not influenced by CMS use.

Measuring symptom response to pharmacological interventions in patients with COPD: a review of instruments used in clinical trials.

Clinical benefits have been shown to occur when using the long-acting beta2-agonist formoterol 4.5 microg for as-needed medication rather than terbutaline 500 microg in patients with unstable asthma taking an inhaled corticosteroid. This study compared their effects on health-related quality of life and the relation with conventional clinical indices in the same population. 362 asthmatics were randomized to use either formoterol 4.5 microg or terbutaline 500 microg as needed, both inhaled via Turbuhaler. The Asthma Quality of Life Questionnaire (AQLQ) was practised at enrolment and completed by 341 patients after randomization and at 4, 8, and 12 weeks. Clinical indices were measured at the same time points. Mean overall AQLQ scores were comparable at baseline, being 4.90 in the formoterol and 4.82 in the terbutaline group and improved during treatment by 0.41 and 0.17 units, respectively (mean difference 0.24, 95% CI 0.08, 0.39, P<0.005). Mean improvement in the symptom domain was 0.49 units when using formoterol. Correlations between changes in clinical indices and changes in AQLQ scores during the 12-week period were weak (maximum r value=0.37). When used for as-needed medication, formoterol 4.5 microg provided an improvement in asthma-specific quality of life and to a somewhat greater extent than the widely used terbutaline 500 microg. The symptom domain in AQLQ showed almost 0.5 units improvement after formoterol, a change that is considered to be clinically relevant.