Health status measured with the CRQ does not predict mortality in COPD

Comparison of Predictive Properties between Tools of Patient-Reported Outcomes: Risk Prediction for Three Future Events in Subjects with COPD

BACKGROUND

Patient-reported outcome (PRO) measures must be evaluated for their discriminatory, evaluative, and predictive properties. However, the predictive capability remains unclear. We aimed to examine the predictive properties of several PRO measures of all-cause mortality, acute exacerbation of chronic obstructive pulmonary disease (COPD), and associated hospitalization.

METHODS

A total of 122 outpatients with stable COPD were prospectively recruited and completed six self-administered paper questionnaires: the COPD Assessment Test (CAT), St. George's Respiratory Questionnaire (SGRQ), Baseline Dyspnea Index (BDI), Dyspnoea-12, Evaluating Respiratory Symptoms in COPD and Hyland Scale at baseline. Cox proportional hazards analyses were conducted to examine the relationships with future outcomes.

RESULTS

A total of 66 patients experienced exacerbation, 41 were hospitalized, and 18 died. BDI, SGRQ Total and Activity, and CAT and Hyland Scale scores were significantly related to mortality (hazard ratio = 0.777, 1.027, 1.027, 1.077, and 0.951, respectively). The Hyland Scale score had the best predictive ability for PRO measures, but the C index did not reach the level of the most commonly used FEV₁. Almost all clinical, physiological, and PRO measurements obtained at baseline were significant predictors of the first exacerbation and the first hospitalization due to it, with a few exceptions.

CONCLUSIONS

Measurement of health status and the global scale of quality of life as well as some tools to assess breathlessness, were significant predictors of all-cause mortality, but their predictive capacity did not reach that of FEV₁. In contrast, almost all baseline measurements were unexpectedly related to exacerbation and associated hospitalization.

Patient-reported dyspnea and health predict waitlist mortality in patients waiting for lung transplantation in Japan

BACKGROUND

Waitlist mortality due to donor shortage for lung transplantation is a serious problem worldwide. Currently, the selection of recipients in Japan is mainly based on the registration order. Hence, scientific evidence for risk stratification regarding waitlist mortality is urgently needed. We hypothesized that patient-reported dyspnea and health would predict mortality in patients waitlisted for lung transplantation.

METHODS

We analyzed factors related to waitlist mortality using data of 203 patients who were registered as candidates for lung transplantation from deceased donors. Dyspnea was evaluated using the modified Medical Research Council (mMRC) dyspnea scale, and the health status was determined with St. George's Respiratory Questionnaire (SGRQ).

RESULTS

Among 197 patients who met the inclusion criteria, the main underlying disease was interstitial lung disease (99 patients). During the median follow-up period of 572 days, 72 patients died and 96 received lung transplantation (69 from deceased donors). Univariable competing risk analyses revealed that both mMRC dyspnea and SGRQ Total score were significantly associated with waitlist mortality (p = 0.003 and p < 0.001, respectively) as well as age, interstitial lung disease, arterial partial pressure of carbon dioxide, and forced vital capacity. Multivariable competing risk analyses revealed that the mMRC and SGRQ score were associated with waitlist mortality in addition to age and interstitial lung disease.

CONCLUSIONS

Both mMRC dyspnea and SGRQ score were significantly associated with waitlist mortality, in addition to other clinical variables such as patients' background, underlying disease, and pulmonary function. Patient-reported dyspnea and health may be measured through multi-dimensional analysis (including subjective perceptions) and for risk stratification regarding waitlist mortality.

Validation of the Finnish severe respiratory insufficiency questionnaire

INTRODUCTION

Chronic respiratory insufficiency impacts patients' lives and reduces quality of life. The Severe Respiratory Insufficiency (SRI) questionnaire examines health-related quality of life and is designed specifically for patients receiving home mechanical ventilation (HMV) for chronic respiratory failure (CRF).

OBJECTIVES

The aim of this study was to validate the Finnish version of the SRI and study its reproducibility in patients with CRF.

METHODS

Our 74 patients receiving HMV or long-term oxygen treatment for CRF or both completed the SRI and St George's Respiratory questionnaires (SGRQ) three times (at baseline, and then one week and one month later). Reliability and validity of the questionnaires was analysed with Cronbach's alpha and intraclass correlation coefficient. Patients were prospectively followed up for 5 years, with data collected on their use of hospital services and mortality.

RESULTS

Cronbach's alpha in the SRI ranged from 0.67 to 0.88 and was >0.7 on all subscales except the "attendant symptoms and sleep". On four subscales, Cronbach's alpha was >0.8, and on the summary scale, 0.95. The SRI showed high correlation with SGRQ. Both tests showed good reproducibility. During the 5-year follow-up, 27 (36%) patients died.

CONCLUSIONS

The Finnish SRI proved valid, reliable and reproducible. Its psychometric properties were good and similar to those of the original questionnaire and of other validation studies.

Health-related quality of life measurement in patients with chronic respiratory failure

The improvement of health-related quality of life (HRQL) is an important goal in managing patients with chronic respiratory failure (CRF) receiving long-term oxygen therapy (LTOT) and/or domiciliary noninvasive ventilation (NIV). Two condition-specific HRQL questionnaires have been developed to specifically assess these patients: the Maugeri Respiratory Failure Questionnaire (MRF) and the Severe Respiratory Insufficiency Questionnaire (SRI). The MRF is more advantageous in its ease of completion; conversely, the SRI measures diversified health impairments more multi-dimensionally and discriminatively with greater balance, especially in patients receiving NIV. The SRI is available in many different languages as a result of back-translation and validation processes, and is widely validated for various disorders such as chronic obstructive pulmonary disease, restrictive thoracic disorders, neuromuscular disorders, and obesity hypoventilation syndrome, among others. Dyspnea and psychological status were the main determinants for both questionnaires, while the MRF tended to place more emphasis on activity limitations than SRI. In comparison to existing generic questionnaires such as the Medical Outcomes Study 36-item short form (SF-36) and disease-specific questionnaires such as the St. George's Respiratory Questionnaire (SGRQ) and the Chronic Respiratory Disease Questionnaire (CRQ), both the MRF and the SRI have been shown to be valid and reliable, and have better discriminatory, evaluative, and predictive features than other questionnaires. Thus, in assessing the HRQL of patients with CRF using LTOT and/or NIV, we might consider avoiding the use of the SF-36 or even the SGRQ or CRQ alone and consider using the CRF-specific SRI and MRF in addition to existing generic and/or disease-specific questionnaires.

Development of a Conceptual Model of Disease Progression for Use in Economic Modeling of Chronic Obstructive Pulmonary Disease

BACKGROUND

To develop and validate a new conceptual model (CM) of chronic obstructive pulmonary disease (COPD) for use in disease progression and economic modeling. The CM identifies and describes qualitative associations between disease attributes, progression and outcomes.

METHODS

A literature review was performed to identify any published CMs or literature reporting the impact and association of COPD disease attributes with outcomes. After critical analysis of the literature, a Steering Group of experts from the disciplines of health economics, epidemiology and clinical medicine was convened to develop a draft CM, which was refined using a Delphi process. The refined CM was validated by testing for associations between attributes using data from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE).

RESULTS

Disease progression attributes included in the final CM were history and occurrence of exacerbations, lung function, exercise capacity, signs and symptoms (cough, sputum, dyspnea), cardiovascular disease comorbidities, 'other' comorbidities (including depression), body composition (body mass index), fibrinogen as a biomarker, smoking and demographic characteristics (age, gender). Mortality and health-related quality of life were determined to be the most relevant final outcome measures for this model, intended to be the foundation of an economic model of COPD.

CONCLUSION

The CM is being used as the foundation for developing a new COPD model of disease progression and to provide a framework for the analysis of patient-level data. The CM is available as a reference for the implementation of further disease progression and economic models.

The association between health-related quality of life and disease progression in idiopathic pulmonary fibrosis: a prospective cohort study

Background and objective: Generally, a disease-specific health-related quality of life (HRQOL) measurement is more useful than generic measures in assessing perceived physical and mental health characteristic of a particular disease. The idiopathic pulmonary fibrosis (IPF)-specific version of St. George’s Respiratory Questionnaire (SGRQ-I) has been recently developed for patients with IPF. We proposed to evaluate associations between the SGRQ-I and other clinical indices, as well as its prognostic value in patients with IPF. Methods: Fifty-two patients with IPF were recruited in this prospective cohort study. HRQOL was assessed using the SGRQ-I and the Medical Outcomes Study 36-item Short Form, dyspnea using the modified Medical Research Council (mMRC) dyspnea scale, and psychological status using the Hospital Anxiety and Depression Scale (HADS). We then evaluated the relationship between the SGRQ-I and other clinical measures, as well as one-year clinical deterioration defined as a hospital admission due to respiratory exacerbation or all-cause death. Results: Stepwise multiple-regression analyses revealed that the mMRC dyspnea scale, the HADS anxiety or depression, and minimum oxygen saturation during a six-minute walk test significantly contributed to the Total and three components of the SGRQ-I. In multivariate Cox proportional-hazards analyses, the Total score of SGRQ-I predicted clinical deterioration independent of forced vital capacity, the six-minute walk distance, or partial pressure of arterial oxygen on room air. Conclusions: The SGRQ-I is a multidisciplinary instrument representing physical, functional and psychological impairments in patients with IPF. The SGRQ-I is a significant predictor of short-term disease progression independent of physiological measurements. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 226-235)

Self-management and quality of life in chronic obstructive pulmonary disease (COPD): The mediating effects of positive affect

OBJECTIVE

This study aimed to increase our understanding of general self-management (SM) abilities in COPD by determining if SM can predict disease specific quality of life (QoL), by investigating whether specific SM domains are significant in COPD and by exploring the mediating effect of the positive/negative affect in the association between SM and QoL.

METHODS

Cross-sectional study based on 292 patients with COPD. Measures included demographics, lung function, gait speed, health care utilization, positive/negative affect, SM abilities, breathlessness and disease specific QoL. We performed, correlation, multiple regression models and mediation analysis (positive/negative affect being mediator between SM and QoL association).

RESULTS

After controlling for breathlessness, living alone, marital status, hospitalization history, age and lung function, SM related to QoL (p<0.0001). Investment in behaviors (hobbies and social relationships) and self-efficacy are SM domains independently related to QoL in COPD. Positivity measured by the positive/negative affect ratio completely mediates the relationship of SM with QoL.

CONCLUSION

SM is independently associated with disease specific QoL in COPD after adjustment significant covariates but positive/negative affect ratio completely mediates the relationship of SM with QoL.

PRACTICE IMPLICATIONS

Measuring positive/negative affect and addressing investment behavior and self-efficacy are important in implementing COPD-SM programs.

The inspiratory capacity/total lung capacity ratio as a predictor of survival in an emphysematous phenotype of chronic obstructive pulmonary disease

BACKGROUND

Forced expiratory volume in 1 second (FEV1) grades severity of COPD and predicts survival. We hypothesize that the inspiratory capacity/total lung capacity (IC/TLC) ratio, a sensitive measure of static lung hyperinflation, may have a significant association with survival in an emphysematous phenotype of COPD.

OBJECTIVES

To access the association between IC/TLC and survival in an emphysematous phenotype of COPD.

METHODS

We performed a retrospective analysis of a large pulmonary function (PF) database with 39,050 entries, from April 1978 to October 2009. Emphysematous COPD was defined as reduced FEV1/forced vital capacity (FVC), increased TLC, and reduced diffusing capacity of the lungs for carbon monoxide (DLCO; beyond 95% confidence intervals [CIs]). We evaluated the association between survival in emphysematous COPD patients and the IC/TLC ratio evaluated both as dichotomous (≤25% vs >25%) and continuous predictors. Five hundred and ninety-six patients had reported death dates.

RESULTS

Univariate analysis revealed that IC/TLC ≤25% was a significant predictor of death (hazard ratio [HR]: 2.39, P<0.0001). Median survivals were respectively 4.3 (95% CI: 3.8-4.9) and 11.9 years (95% CI: 10.3-13.2). Multivariable analysis revealed age (HR: 1.19, 95% CI: 1.14-1.24), female sex (HR: 0.69, 95% CI: 0.60-0.83), and IC/TLC ≤25% (HR: 1.69, 95% CI: 1.34-2.13) were related to the risk of death. Univariate analysis showed that continuous IC/TLC was associated with death, with an HR of 1.66 (95% CI: 1.52-1.81) for a 10% decrease in IC/TLC.

CONCLUSION

Adjusting for age and sex, IC/TLC ≤25% is related to increased risk of death, and IC/TLC as a continuum, is a significant predictor of mortality in emphysematous COPD patients.

An evaluation of factors associated with completion and benefit from pulmonary rehabilitation in COPD

BACKGROUND

Pulmonary Rehabilitation (PR) is an important treatment for patients with chronic obstructive pulmonary disease (COPD) but it is not established whether any baseline parameter can predict response or compliance.

AIM

To identify whether baseline measures can predict who will complete the programme and who will achieve a clinically significant benefit from a Minimum Clinical Important Difference (MCID) in terms of exercise capacity and health-related quality of life (HRQoL).

METHODS

Data were collected prospectively from patients with COPD at their baseline assessment for an outpatient PR programme in one of eight centres across London. 'Completion' was defined as attending at least 75% of the designated PR visits and return for the follow-up evaluation. The MCID for outcome measures was based on published data.

RESULTS

787 outpatients with COPD (68.1±10.5 years old; 49.6% males) were included. Patients who completed PR (n=449, 57.1%) were significantly older with less severe airflow obstruction, lower anxiety and depression scores, less dyspnoea and better HRQoL. Only baseline CAT score (OR=0.925; 95% CI 0.879 to 0.974; p=0.003) was retained in multivariate analysis. Patients with the lowest baseline walking distance were most likely to achieve the MCID for exercise capacity. No baseline variable could independently predict achievement of an MCID in HRQoL.

CONCLUSIONS

Patients with better HRQoL are more likely to complete PR while worse baseline exercise performance makes the achievement of a positive MCID in exercise capacity more likely. However, no baseline parameter could predict who would benefit the most in terms of HRQoL.

Prognostic assessment in COPD: health related quality of life and the BODE index

RATIONALE

COPD is a debilitating disease with increasing mortality worldwide. The BODE index evaluates disease severity and the St George's Respiratory Questionnaire (SGRQ) measures health status.

OBJECTIVE

To identify the relationship between BODE index and the SGRQ and to test the predictive value of both tools against survival.

METHODS

Open cohort study of 1398 COPD patients (85% male) followed for up to 10 years.

MEASUREMENTS AND MAIN RESULTS

At the time of the inclusion, clinical data, forced spirometry and 6 min walking distance were determined and BODE index and SGRQ were calculated. Vital status and cause of death were documented at the end of follow-up.

RESULTS

The cohort's mean of FEV1% predicted was 46 ± 18%, BODE index was 3.6 ± 2.5, and SGRQ% total score was 49 ± 20. The SGRQ scores increased progressively as severity of COPD increased by BODE quartiles. The correlation between SGRQ and BODE index was good (r = 0.58, p < 0.0001). Both tests correlated with COPD survival (BODE = -0.4 vs. SGRQ = -0.20, p < 0.0001). The area under the curve (AUC) for the BODE index was 0.77 vs. 0.66 for the SGRQ % total score (p < 0.001).

CONCLUSIONS

Health status as measured by SGRQ worsens with disease severity evaluated by the BODE index. Both tools predict mortality and provide complimentary information in the evaluation of patients with COPD.

[Precipitating factors of mortality in chronic obstructive pulmonary disease patients with frequent exacerbations]

OBJECTIVE

To identify the main characteristics in patients with COPD exacerbation, capables to predict the short-term COPD mortality.

MATERIALS AND METHODS

This is a case-control retrospective study of admitted patients with COPD to identify risk factors of mortality. The control group was constituted by alive patients after 6 months. The variables studied were clinical antecedents, comorbility, health and nutritional status, basal dyspnea, dependency, exacerbations, physical examination, pulmonary function, radiology, ECG, microbiology and treatment. Both groups were compared with the Chi-square and the T tests. The predictive capacity was analyzed with logistic regression for which the dependent variable was mortality.

RESULTS

125 patients were enrolled (44 exitus and 81 alive) (10 females and 115 males) with mean age of 74+10 years. No significant differences were found between groups in age, sex and disease severity. On the other hand, we found statistically significant differences in basal dyspnea (p<0,01), RCP levels (p<0,007), Hb (p<0,037) and platelets (p<0,041), physic activity (p<0,036), accessory muscles use (p<0,007), positive microbiological culture (p<0,013) and treatment with anticholinergic agents (p<0,029) and digoxin (p<0,039). However, none of these variables was able to predict mortality in the logistic regression analysis.

CONCLUSIONS

The usual data managed in the follow-up of COPD patients are not useful to identify short-term mortality predictors (6 months) during a hospital admittance. Only some variables that would represent a higher chronic inflammation and a lower exercise tolerance showed a statistical tendence in the dead patients group in a exacerbation of COPD.

Measurement Properties and Interpretability of the Chronic Respiratory Disease Questionnaire (CRQ)

The chronic respiratory questionnaire, available as an interviewer and a self-administered instrument, includes 20 items across four domains: dyspnea (5 items), fatigue (4 items), emotional function (7 items), and mastery (4 items). When completing this instrument, patients rate their experience on a 7-point scale ranging from 1 (maximum impairment) to 7 (no impairment). The Chronic Respiratory Questionnaire has demonstrated excellent measurement properties for both discriminative and evaluative purposes and served as a model in numerous methodological studies in chronic airflow limitation and patients with chronic obstructive pulmonary disease. We performed a systematic review of the literature on the chronic respiratory questionnaire to summarize the key qualities of the chronic respiratory questionnaire and to appraise the work regarding the minimal important difference of the chronic respiratory questionnaire. This paper includes a revision of our initial definition of the minimal important difference and a methodological framework for using anchor based approaches to establish the minimal important difference pioneered by Jaeschke and colleagues. Other approaches to evaluate the minimal important difference include distribution-based methods and panel-based methods. Investigators have used all of these approaches to establish the minimal important difference for the chronic respiratory questionnaire and the results are in general agreement with the minimal important difference of 0.5 for the mean domain scores of the chronic respiratory questionnaire. As a result of this literature review and discussion at the workshop, we established several research objectives. These objectives include the exploration of presentation of quality of life information and prospective anchor-based approaches.

Predictors of mortality in patients with stable COPD

OBJECTIVES

To determine which easily available clinical factors are associated with mortality in patients with stable COPD and if health-related quality of life (HRQoL) provides additional information.

DESIGN

Five-year prospective cohort study.

SETTING

Five outpatient clinics of a teaching hospital.

PARTICIPANTS

Six hundred stable COPD patients recruited consecutively.

MEASUREMENTS

The variables were age, FEV(1%), dyspnea, previous hospital admissions and emergency department visits for COPD, pack-years of smoking, comorbidities, body mass index, and HRQoL measured by Saint George's Respiratory Questionnaire (SGRQ), Chronic Respiratory Questionnaire (CRQ), and Short-Form 36 (SF-36). Logistic and Cox regression models were used to assess the influence of these variables on mortality and survival.

RESULTS

FEV(1%)(OR: 0.62, 95% CI 0.5 to 0.75), dyspnea (OR 1.92, 95% CI 1.2 to 3), age (OR 2.41, 95% CI 1.6 to 3.6), previous hospitalization due to COPD exacerbations (OR 1.53, 1.2 to 2) and lifetime pack-years (OR 1.15, 95% CI 1.1 to 1.2) were independently related to respiratory mortality. Similarly, these factors were independently related to all-cause mortality with dyspnea having the strongest association (OR 1.54, 95% CI 1.1 to 2.2). HRQoL was an independent predictor of respiratory and all-cause mortality only when dyspnea was excluded from the models, except scores on the SGRQ were associated with all-cause mortality with dyspnea in the model.

CONCLUSIONS

Among patients with stable COPD, FEV(1%) was the main predictor of respiratory mortality and dyspnea of all-cause mortality. In general, HRQoL was not related to mortality when dyspnea was taken into account, and CRQ and SGRQ behaved in similar ways regarding mortality.

What have we learned from large drug treatment trials in COPD?

Although the development of effective treatments for patients with chronic obstructive pulmonary disease (COPD) has not been seen as a high priority, the past decade has seen a substantial increase in the number of clinical studies examining different treatments for this disease. Large studies are needed to adequately assess the effectiveness of treatment because of the chronic nature of the disease and the intermittent occurrence of some key outcomes such as exacerbations. Data from randomised controlled trials show that treatment improves exercise performance by increasing lung volume rather than changing expiratory flow. Although assessment of lung function remains the cornerstone of drug assessment, improvements in health status, the number of exacerbations and admissions to hospital are now recognised as important treatment outcomes. Randomised controlled trial data provide the best evidence for treatment efficacy, but results of these studies can be affected by differences in inclusion criteria and patient dropout during the study. Bronchodilator reversibility testing does not reliably define subgroups that will respond to a particular treatment. Carefully done and adequately powered clinical trials continue to inform, not only our views about treatment, but also our understanding of COPD and how it is best assessed and managed. Ensuring that these expensive studies are done objectively to the highest standard is an important goal for the next decade.

Dyspnoea with activities of daily living versus peak dyspnoea during exercise in male patients with COPD

Dyspnoea measurements in chronic obstructive pulmonary disease (COPD) can be broadly divided into two categories: those that assess breathlessness during exercise, and those that assess breathlessness during daily activities. We investigated the relationships between dyspnoea at the end of exercise and during daily activities with clinical measurements and mortality in COPD patients. We examined 143 male outpatients with moderate to very severe COPD. The peak Borg score at the end of progressive cycle ergometry was used for the assessment of peak dyspnoea rating during exercise, and the Baseline Dyspnea Index (BDI) score was used for dyspnoea with activities of daily living. Relationships between these dyspnoea ratings with other clinical measurements of pulmonary function, exercise indices, health status and psychological status were then investigated. In addition, their relationship with the 5-year mortality of COPD patients was also analyzed to examine their predictive ability. Although the BDI score was significantly correlated with airflow limitation, diffusing capacity, exercise indices, health status and psychological status, the Borg score at the end of exercise had non-existent or only weak correlations with them. The BDI score was strongly significantly correlated with mortality, whereas the Borg score was not. Dyspnoea during daily activities was more significantly correlated with objective and subjective measurements of COPD than dyspnoea at the end of exercise. In addition, the former was more predictive of mortality. Dyspnoea with activities of daily living is considered to be a better measurement for evaluating the disease severity of COPD than peak dyspnoea during exercise.

La calidad de vida en los pacientes con enfermedad pulmonar obstructiva crónica: criterios de cuantificación y repercusiones terapéuticas

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent chronica diseases in developed countries. Prognosis of the disease is mainly determined by the degree of air flow obstruction. However, other factors, such as degree of deterioration of the quality of life related with health have been demonstrated to be significantly correlated with morbidity and mortality in COPD. Thus, one of the main objectives of the treatment of COPD is to improve the health condition of the patients, beyond the possible improvement of the lung function. New drugs developed for the treatment of COPD have shown a different impact on the health condition of those affected by COPD.

Analysis of the factors related to mortality in chronic obstructive pulmonary disease: role of exercise capacity and health status

In this study, we analyzed the relationships of exercise capacity and health status to mortality in patients with chronic obstructive pulmonary disease (COPD). We recruited 150 male outpatients with stable COPD with a mean postbronchodilator FEV1 at 47.4% of predicted. Their pulmonary function, progressive cycle ergometry, and health status using the Chronic Respiratory Disease Questionnaire, the St. George's Respiratory Questionnaire (SGRQ), and the Breathing Problems Questionnaire were measured at entry. Among 144 patients who were available for the 5-year follow-up, 31 had died. Univariate Cox proportional hazards analysis revealed that the SGRQ total score and the Breathing Problems Questionnaire were significantly correlated with mortality; however, with the Chronic Respiratory Disease Questionnaire, the total score was not significantly correlated. Multivariate Cox proportional hazards analysis revealed that the peak oxygen uptake and the SGRQ total score were both predictive of mortality, independent of FEV1 and age. Stepwise Cox proportional hazards analysis revealed that the peak oxygen uptake was the most significant predictor of mortality. We found that exercise capacity and health status were significantly correlated with mortality, although different health status measures had different abilities to predict mortality. These results will have a potentially great impact on the multidimensional evaluation of disease severity in COPD.