Determinants of health-related quality of life in patients with pulmonary emphysema

Correlation of BODE index with quality of life in stable Chronic Obstructive Pulmonary Disease (COPD) patients - A prospective study

BACKGROUND AND AIMS

Chronic obstructive pulmonary disease (COPD) is characterized by slow progressive deterioration of respiratory function with systemic effects which have a great impact on health-related quality of life (HRQoL). The severity of airflow limitation in COPD, as reflected by forced expiratory volume in one second (FEV1) does not represent the systemic consequences of COPD. Hence, a multidimensional grading system, BODE index (Body mass index, Airflow obstruction, Dyspnea and Exercise capacity) that assessed both the pulmonary and systemic manifestations has recently been proposed to provide useful prognostic information and predict the outcome in COPD patients. The objective of this study was to evaluate the relationship between BODE index and health-related quality of life (HRQOL) in stable COPD patients and its usefulness in predicting the disease exacerbations.

MATERIALS AND METHODS

Sixty stable COPD patients who presented in the out-patient departments of Medicine and Pulmonology were recruited over one year period. We evaluated them by body-mass index, forced expiratory volume in one second (FEV1), Modified Medical Research Council dyspnea scale and six minute walk test (6MWT). BODE index was calculated using these variables. Disease duration, number of exacerbations and hospitalization in the previous year were recorded. We also administered the St. George's Respiratory Questionnaire (SGRQ) to assess the health related quality of life (HRQoL) in these patients. BODE scores were categorized into four quartiles, quartile one to four with scores of 0-2, 3-4, 5-6 and 7-10, respectively.

RESULTS

According to BODE score, (16) 26.7% of patients were BODE 1, (27) 45% BODE 2, (15) 25% BODE 3 and (2) 3.3% were BODE 4. Higher BODE quartiles were associated with higher total SGRQ scores and SGRQ subscale scores (symptom, activity and impact). Very strong correlations were found between BODE quartiles and total SGRQ scores (P < 0.01). Among the components of BODE index, the decrease in the FEV1 (%predicted) and 6MWD, and the increase of MMRC dyspnea grade were associated with worsening of health status (increase in total SGRQ and SGRQ subscales). BODE index also correlated with the acute exacerbations (P < 0.0012) during one year follow-up.

CONCLUSION

BODE index strongly correlated with the HRQoL and also reliably predicted acute exacerbations in stable COPD patients.

Exertional dyspnea associated with chest wall strapping is reduced when external dead space substitutes for part of the exercise stimulus to ventilation

Chest wall strapping has been used to assess mechanisms of dyspnea with restrictive lung disease. This study examined the hypothesis that dyspnea with restriction depends principally on the degree of reflex ventilatory stimulation. We compared dyspnea at the same (iso)ventilation when added dead space provided a component of the ventilatory stimulus during exercise. Eleven healthy men undertook a randomized controlled crossover trial that compared four constant work exercise conditions: 1) control (CTRL): unrestricted breathing at 90% gas exchange threshold (GET); 2) CTRL+dead space (DS): unrestricted breathing with 0.6-l dead space, at isoventilation to CTRL due to reduced exercise intensity; 3) CWS: chest wall strapping at 90% GET; and 4) CWS+DS: chest strapping with 0.6-l dead space, at isoventilation to CWS with reduced exercise intensity. Chest strapping reduced forced vital capacity by 30.4 ± 2.2% (mean ± SE). Dyspnea at isoventilation was unchanged with CTRL+DS compared with CTRL (1.93 ± 0.49 and 2.17 ± 0.43, 0–10 numeric rating scale, respectively; P = 0.244). Dyspnea was lower with CWS+DS compared with CWS (3.40 ± 0.52 and 4.51 ± 0.53, respectively; P = 0.003). Perceived leg fatigue was reduced with CTRL+DS compared with CTRL (2.36 ± 0.48 and 2.86 ± 0.59, respectively; P = 0.049) and lower with CWS+DS compared with CWS (1.86 ± 0.30 and 4.00 ± 0.79, respectively; P = 0.006). With unrestricted breathing, dead space did not change dyspnea at isoventilation, suggesting that dyspnea does not depend on the mode of reflex ventilatory stimulation in healthy individuals. With chest strapping, dead space presented a less potent stimulus to dyspnea, raising the possibility that leg muscle work contributes to dyspnea perception independent of the ventilatory stimulus.

NEW & NOTEWORTHY Chest wall strapping was applied to healthy humans to simulate restrictive lung disease. With chest wall strapping, dyspnea was reduced when dead space substituted for part of a constant exercise stimulus to ventilation. Dyspnea associated with chest wall strapping depended on the contribution of leg muscle work to ventilatory stimulation. Chest wall strapping might not be a clinically relevant model to determine whether an alternative reflex ventilatory stimulus mimics the intensity of exertional dyspnea.

Evaluation of correlation of BODE index with health-related quality of life among patients with stable COPD attending a tertiary care hospital

Background:

Chronic obstructive pulmonary disease (COPD) is characterized by progressive deterioration of respiratory function along with systemic effects which have a great impact on health-related quality of life (HRQoL). Classification of severity of airflow limitation in COPD does not represent the clinical consequences of COPD. Hence, combined COPD assessment should be preferred. BODE index (Body mass index, Airflow obstruction, Dyspnea and Exercise capacity) has recently been proposed to provide useful prognostic information.

Objectives:

To find out correlations between the BODE index and HRQoL, and between GOLD classification of COPD severity and HRQoL in stable COPD patients, and to compare between these two correlations.

Materials and Methods:

A longitudinal observational study was carried out with 114 stable COPD patients recruited over 10 months at the outpatient clinic of a tertiary care hospital in Kolkata, India. Patients were classified according to GOLD classification of severity of airflow limitation after performing spirometry. BODE index was calculated for each patient. Saint George's Respiratory Questionnaire (SGRQ) was used to assess the HRQoL.

Results:

BODE scores were categorized into four quartiles, quartile one to four with scores of 0-2, 3-4, 5-6 and 7-10, respectively. Higher BODE quartiles were associated with higher total SGRQ scores and SGRQ subscale scores (symptom, activity and impact). Very strong correlations were found between BODE quartiles and total SGRQ scores (P = 0.914; P < 0.01). In contrast, GOLD classes showed moderate correlation with total SGRQ scores (P = 0.590; P < 0.01).

Conclusions:

BODE index was strongly correlated with the HRQoL in stable COPD patients and it was better than GOLD classes of COPD severity to reflect the health status in patients with stable COPD.

[Factors associated with the quality of life in patients with chronic obstructive pulmonary disease]

OBJECTIVE

To describe the relationship between individual or combined prognostic factors in the multidimensional classifications (BODE and ADO), and health-related quality of life (HRQOL) in patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Cross-sectional descriptive study.

SETTING

Primary care.

PARTICIPANTS

Systematic random sample of 102 patients diagnosed with COPD, excluding those patients with acute exacerbation, dementia, terminal illness or those who receive home care.

MAIN MEASUREMENTS

Demographics variables, smoking habits, body mass index and number of exacerbations. Comorbidity. Degree of dyspnea. Respiratory function tests. Exercise capacity. The BODE index and the ADO index. The EuroQol-5D questionnaire (EQ-5D), and visual analogue scale (VAS).

RESULTS

EQ-5D: mobility: 43.9%; personal care: 13.3%; daily-life activities: 29.6%; pain/discomfort: 55.1%; anxiety/depression: 37.8%, and 34.7% VAS ≤ 60%. Exacerbations: Mobility, OR: 1.85 (95%CI: 1.08-3.20); personal care, OR: 2.12 (95%CI: 1.3-4.76); daily-life activities, OR: 2.35 (95%CI: 1.17-4.71); VAS, regression coefficient: -3.50 (95%CI: 6.31- -0.70). Dyspnea: mobility, OR: 4.47 (95%CI: 1.39-14.42); daily-life activities, OR: 7.71 (95%CI: 2.03-12.34); VAS, regression coefficient: -7.15 (95%CI: 11.71- -2.59). BODE: mobility, OR: 1.53 (95%CI: 1.15-2.02); personal care, OR: 2.08 (95%CI: 1.40-3.11); daily-life activities, OR: 1.97 (95%CI: 1.38-2.80); VAS, regression coefficient: -3.96 (95%CI: -5.51- -2.42). ADO: mobility, OR: 2.42 (95%CI: 1.39-4.20); personal care, OR: 3.21 (95%CI: 1.67-6.18); daily-life activities, OR: 3.17 (95%CI: 1.69-5.93); VAS, regression coefficient: -3.53 (95%CI: -5.57- -1.49).

CONCLUSIONS

The BODE index and the ADO index showed a significant association with HRQOL. Exacerbations and dyspnea were the best individual factors related to HRQoL.

Use of an Australian quality of life tool in patients with COPD

COPD is a leading chronic disease, increasing globally. Given this condition's irreversible and progressive nature, health-related quality of life (HRQOL) is increasingly a primary end-point in COPD management. We evaluated several HRQOL tools with a primary goals of (1) investigating how the generic Assessment Quality of Life (AQOL) functions compared to the Medical Outcomes Study 36-item Short Form Health Survey (SF36) and the St. Georges Respiratory Questionnaire (SGRQ); and (2) considering the extent to which clinical disease severity, as measured by the BODE index, predicts variation in HRQOL reports.

METHODS

134 consecutive patients entering a pulmonary rehabilitation program were recruited. Participants completed two generic measures of HRQOL (SF36 and AQOL) and one disease specific measure (SGRQ). The clinical severity of COPD was assessed using a composite global COPD severity score, BODE.

RESULTS

Significant associations were demonstrated between AQOL and both the SF36 (r = .68) and SGRQ (r = -.60). BODE significantly predicted AQOL scores (R = -.31); mMRC (R = -.36) and 6MWD (R = .39) were stronger contributors to these predictions than were FEV(1) or BMI.

CONCLUSIONS

This study establishes convergent validity between AQOL, and the SF36 and SGRQ in patients with COPD. For future studies wishing to examine HRQOL from a generic perspective, we have shown that during cross-sectional analyses AQOL performs similarly to the SF36. In addition we identified that the clinical severity of COPD, as assessed by BODE, significantly influences reports of quality of life made using AQOL. The components of BODE that most strongly contributed to predicting HRQOL were dsypnea and exercise tolerance.

Defining patient-reported outcomes in chronic obstructive pulmonary disease: the patient-centered experience

Patients with COPD have reduced HRQOL, and HRQOL worsens as COPD progresses.Although long-term interventions such as smoking cessation, supplemental oxygen therapy for hypoxemia, LVRS, and lung transplantation may save lives, these and other therapies have variable but important effects on PROs. Measures of HRQOL can serve as measures of disease severity and predict outcome. Moreover, these measures are sensitive to change following interventions, and can thus be used as measures of intervention effect. Future research will provide a better understanding of the effects of COPD on HRQOL and the impact of various interventions.

Factors that influence disease-specific quality of life or health status in patients with COPD: a review and meta-analysis of Pearson correlations

BACKGROUND

A major goal in the management of chronic obstructive pulmonary disease (COPD) is to ensure that the burden of the disease for patients with COPD is limited and that patients will have the best possible quality of life.

AIMS

To explore all the possible factors that could influence disease-specific quality of life and health status in patients with COPD.

METHODS

A systematic review of the literature and a meta-analysis were performed to explore the factors that could have a positive or negative effect on quality of life and/or health status in patients with COPD.

RESULTS

Quality of life and health status are determined by certain factors included gender, disease severity indices, lung function parameters, body mass index, smoking, symptoms, co-morbidity, depression, anxiety, and exacerbations. Factors such as dyspnoea, depression, anxiety and exercise tolerance were found to be more correlated with health status than the widely used spirometric values. Forced expiratory volume in one second had a weak to modest Pearson weighted correlation coefficient which ranged from -0.110 to -0.510 depending on the questionnaire used.

CONCLUSIONS

The broad range of determining factors suggests that, in order to reach the management goals, health status should be measured in addition to lung function in patients with COPD.

Relationship between disease severity and quality of life in patients with chronic obstructive pulmonary disease

Few studies have evaluated the relationship between Airways Questionnaire 20 (AQ20), a measure of the quality of life, scores and physiological outcomes or with systemic markers of disease in patients with chronic obstructive pulmonary disease (COPD). The aim of the present study was to investigate the relationship of forced expiratory volume in 1 s (FEV1), body mass index, fat-free mass index, 6-min walk test (6MWT) results, dyspnea sensation and peripheral oxygen saturation (SpO2) with the quality of life of COPD patients. Ninety-nine patients with COPD (mean age: 64.2 +/- 9.2 years; mean FEV1: 60.4 +/- 25.2% of predicted)were evaluated using spirometry, body composition measurement and the 6MWT. The baseline dyspnea index (BDI) and the Modified Medical Research Council (MMRC) scale were used to quantify dyspnea. Quality of life was assessed using the AQ20and the St. George's Respiratory Questionnaire (SGRQ). The Charlson index was used to determine comorbidity. The body mass index/airflow obstruction/dyspnea/exercise capacity (BODE) index was also calculated. AQ20 and SGRQ scores correlated significantly with FEV1, SpO2, 6MWT, MMRC and BDI values as did with BODE index. In the multivariate analyses,MMRC or BDI were identified as predictors of AQ20 and SGRQ scores (P < 0.001 in all cases). Thus, the relationship between AQ20 and disease severity is similar to that described for SGRQ. Therefore, the AQ20, a simple and brief instrument, can be very useful to evaluate the general impact of disease when the time allotted for measurement of the quality of life is limited.

Adequate Patient Characterization in COPD: Reasons to Go Beyond GOLD Classification

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) serves as a guide to treat and manage different severity classes of patients with COPD. It was suggested that the five categories of FEV₁ % predicted (GOLD 0–4), can be applied for selecting different therapeutic approaches. However, validation of these selective properties is very poor. To determine the relevance of the GOLD staging system for estimating the severity of clinical problems, GOLD 2 (n=70) and GOLD 3 (n=65) patients were drawn from a prospective cohort of patients with COPD and evaluated crosssectionally by a newly developed Nijmegen Integral Assessment Framework (NIAF). The NIAF is a detailed assessment of a wide range of aspects of health status (HS). Significant, though small, differences were found in Static Lung Volumes, Exercise Capacity, Subjective Pulmonary Complaints, Subjective Impairment, and Health-Related QoL, besides Airflow of course. Moreover, overlap between scores of these five HS sub-domains was substantial, indicating small clinical relevance for discernment. No significant differences were found in nine other aspects of HS. It is concluded that GOLD stages do not discriminate in any aspect of HS other than airflow obstruction, and therefore do not help the clinician in deciding which treatment modalities are appropriate.

Natural history of emphysema

Chronic obstructive pulmonary disease (COPD) is a progressive disease with studies of disease progression generally focusing on measures of airflow and mortality. In nonsmokers, maximal lung function is attained around age 15 to 25 years, and after a variable plateau phase, subsequently declines at approximately 20 to 25 ml/year. Smoking may reduce the maximal FEV(1) achieved, shorten or eliminate the plateau phase, and may accelerate the rate of decline in lung function in a dose-dependent manner. Some smokers are predisposed to more rapid declines in lung function than others, and recent reports suggest that females may be at higher risk of lung damage related to smoke exposure than males. Progressive deterioration in dyspnea, functional status, and health-related quality of life (HRQL) in patients with COPD is well known, but the magnitude and rate of decline and its association with severity of airflow obstruction remains poorly defined. Many studies have identified pulmonary function, in particular the FEV(1), as the single best predictor of survival. An impaired diffusing capacity and overall impairment in functional status have also been associated with impaired survival in COPD. The National Emphysema Treatment Trial has provided additional insight into these features in a large, well-characterized group of patients with severe airflow obstruction and structural emphysema.

Factors associated with health-related quality of life in chronic spinal cord injury

OBJECTIVE

An important goal of rehabilitation and treatment after spinal cord injury (SCI) is to improve function and enhance health-related quality of life (HRQoL). However, previous assessments are limited by use of HRQoL instruments not specific to SCI. Although respiratory dysfunction is common in SCI, it has not been possible to assess the association of comorbid medical conditions, including respiratory symptoms and pulmonary function, to HRQoL. Therefore, we assessed whether these factors were associated with HRQoL in SCI using an SCI-specific HRQoL questionnaire.

DESIGN

In our cross-sectional study, 356 participants >or=1 yr post-SCI completed a 23-item SCI-specific HRQoL questionnaire and a detailed health questionnaire, and underwent pulmonary function testing and a neurological exam at VA Boston between 1998 and June 2003.

RESULTS

In a multivariate regression model, age, employment status, motor level and completeness of injury, and ambulatory mode (use of hand-propelled or motorized wheelchair, use of crutches or canes, or walking independently) were independently associated with HRQoL. After adjusting for these factors, chronic cough, chronic phlegm, persistent wheeze, dyspnea with activities of daily living, and lower forced expiratory volume in 1 sec and forced vital capacity were each associated with a lower HRQoL.

CONCLUSIONS

These results provide evidence for the clinical validity of our SCI-specific HRQoL instrument. We also identify potentially modifiable factors that, if addressed, may lead to HRQoL improvement in SCI.

One hundred years of chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is an increasing health problem and one of the leading causes of morbidity and mortality worldwide, but knowledge about its pathogenesis has increased substantially in recent years. The disease results from interaction between individual risk factors (like enzymatic deficiencies) and environmental exposures to noxious agents, like cigarette smoking, occupational dusts, air pollution and infections in childhood. The main mechanisms that may contribute to airflow limitation in COPD are fixed narrowing of small airways, emphysema and luminal obstruction with mucus secretions. COPD is characterised by a chronic inflammatory process in the pulmonary tissue, with a pattern different from bronchial asthma, associated with extrapulmonary effects and is considered now a complex, systemic disease. Optimal therapeutic targeting of COPD depends on a clear understanding of the precise mechanisms of these complex processes and on early and correct evaluation of disease severity. A combination of pharmacological and non-pharmacological approaches is used to treat COPD. Bronchodilators are the mainstay of COPD treatment and can be combined with inhaled corticosteroids for greater efficacy and fewer side effects. The use of LTOT for hypoxemic patients has resulted in increased survival, and expanded drug therapy options have effectively improved dyspnoea and quality of life. Recent studies have documented the benefits of pulmonary rehabilitation. In addition, non-invasive mechanical ventilation offers new alternatives for patients with acute or chronic failure.

Gender and respiratory factors associated with dyspnea in chronic obstructive pulmonary disease

Rationale

We had shown that COPD women expressed more dyspnea than men for the same degree of airway obstruction.

Objectives

Evaluate gender differences in respiratory factors associated with dyspnea in COPD patients.

Methods

In a FEV₁ % matched population of 100 men and women with COPD we measured: age, MMRC, FEV₁, FVC, TLC, IC/TLC, PaO₂, PaCO₂, D_LCO, P_imax, P_0.1, Ti/Ttot, BMI, ffmi, 6MWD and VAS scale before and after the test, the Charlson score and the SGRQ. We estimated the association between these parameters and MMRC scores. Multivariate analysis determined the independent strength of those associations.

Results

MMRC correlated with: BMI (men:-0.29, p = 0.04; women:-0.28, p = 0.05), ffmi (men:-0.39, p = 0.01), FEV₁ % (men:-0.64, p < 0.001; women:-0.29, p = 0.04), FVC % (men:-0.45, p = 0.001; women:-0.33, p = 0.02), IC/TLC (men:-0.52, p < 0.001; women: -0.27, p = 0.05), PaO₂ (men:-0.59, p < 0.001), PaCO₂ (men:0.27, p = 0.05), D_LCO (men:-0.54, p < 0.001), P_0.1/P_imax (men:0.46, p = 0.002; women:0.47, p = 0.005), dyspnea measured with the Visual Analog Scale before (men:0.37, p = 0.04; women:0.52, p = 0.004) and after 6MWD (men:0.52, p = 0.002; women:0.48, p = 0.004) and SGRQ total (men:0.50, p < 0.001; women:0.59, p < 0.001). Regression analysis showed that P_0.1/P_imax in women (r² = 0.30) and BMI, DL_CO, PaO₂ and P_0.1/P_imax in men (r² = 0.81) were the strongest predictors of MMRC scores.

Conclusion

In mild to severe COPD patients attending a pulmonary clinic, P_0.1/P_imax was the unique predictor of MMRC scores only in women. Respiratory factors explain most of the variations of MMRC scores in men but not in women. Factors other than the respiratory ones should be included in the evaluation of dyspnea in women with COPD.

Is there any treatment other than drugs to alleviate dyspnea in COPD patients?

Patients with chronic obstructive pulmonary disease (COPD) are often limited in their activities by breathlessness. In these patients, exercise training may result in significant improvements in dyspnea, exercise tolerance, and health related quality of life (HRQoL). Further possibilities are to reduce ventilatory demand by decreasing the central respiratory drive or to lessen the perceived breathing effort by increasing respiratory muscle strength through specific respiratory muscle training. Upper limb training may also improve exercise capacity and symptoms in these patients through the modulation of dynamic hyperinflation. Ventilatory assistance during exercise reduces dyspnea and work of breathing and enhances exercise tolerance, although further studies should be required to define their applicability in the routine pulmonary rehabilitation programs. Lung volume resection surgery and lung transplantation in selected patients may control symptoms and improve HRQoL.