Dynamic changes in quality of life in older patients with chronic obstructive pulmonary disease: a 7-year follow up.

PURPOSES: Chronic obstructive pulmonary disease (COPD) is a major cause of the rapid decline of health-related quality of life (HRQoL), associated with accelerated frailty in older populations. This study aimed to analyse the long-term dynamic changes of HRQoL and the predictive factors for the rapid decline of HRQoL in older patients with COPD. METHODS: Overall 244 patients with COPD, aged ≧ 65 years from one medical centre were enrolled between March 2012 and July 2020. Further, we prospectively assessed HRQoL scores with utility values, using EuroQol Five-Dimension (EQ-5D) questionnaires. Additionally, long-term dynamic changes in HRQoL were analysed using the Kernel smoothing method and examined the factors contributing to the deterioration of HRQoL using a linear mixed effects model. RESULTS: Older patients with COPD with forced expiration volume (FEV1) < 50% of prediction entered the phase of rapid and continuous decline of HRQoL ~ 2 years after enrolment, but patients with FEV1 ≥ 50% of prediction without rapidly declined HRQoL during 7 years follow up. Therefore, FEV1 < 50% of prediction is a novel predictor for the rapid decline of HRQoL. The course of rapidly declining HRQoL occurred, initially in the usual activities and pain/discomfort domains, followed by the morbidity, self-care, and depression/anxiety domains ~ 2 and 4 years after enrolment, respectively. The mixed effects model indicated that both FEV1 < 50% of prediction and a history of severe acute exacerbation (SAE) requiring hospitalisation were contributing factors for deterioration in HRQoL . CONCLUSIONS: Both FEV1 < 50% of prediction and exacerbations requiring hospitalisation were contributing factors for the deterioration of HRQoL in long-term follow up. Additionally, FEV1 < 50% of prediction was a novel predictor for patients entering the phase of rapid decline of HRQoL.

Chronic obstructive pulmonary disease trajectory: severe exacerbations and dynamic change in health-related quality of life.

BACKGROUND: The life trajectory of chronic obstructive pulmonary disease (COPD) remains unknown. PATIENTS AND METHODS: We collected data from two populations. In the first cohort, we recruited 375 patients with COPD from our hospital, and 1440 repeated assessments of quality of life (QoL) using the European Quality of Life-5 Dimensions questionnaire from 2006 to 2020. We analysed their dynamic changes using the kernel-smoothing method. The second cohort comprised 27 437 patients from the National Health Insurance (NHI) dataset with their first severe acute exacerbations (AEs) requiring hospitalisation from 2008 to 2017 were analysed for their long-term course of AEs. We employed a Cox hazard model to analyse the predictors for mortality or AEs. RESULTS: Cohorts from our hospital and NHI were male predominant (93.6 and 83.5%, respectively). After the first severe AE, the course generally comprised three phases. The first was a 1-year period of elevated QoL, followed by a 2-year prolonged stable phase with a slowly declining QoL. After the second AE, the final phase was characterised by a rapid decline in QoL. For NHI cohort, 2712 died during the 11-year follow-up, the frequency of the first AE was approximately 5 per 10 000 per day. The median time from the first to the second AE was 3 years, which decreased to less than 6 and 3 months from 4th to 5th and 8th to 9th AE, respectively. The frequency of AE was increased 10-fold and 15-fold and risk of subsequent AE was increased 12-fold and 20-fold after the 6th and the 10th AE, relative to the first. Male gender, heart failure comorbidities were associated with the risk of subsequent AE and death. CONCLUSIONS: The life trajectory of COPD includes the accelerated frailty phase, as well as elevated health and prolonged stable phase after the first AE.

Mapping algorithms for predicting EuroQol-5D-3L utilities from the assessment test of chronic obstructive pulmonary disease.

To predict 3-Level version of European Quality of Life-5 Dimensions (EQ-5D-3L) questionnaire utility from the chronic obstructive pulmonary disease (COPD) assessment test (CAT), the study attempts to collect EQ-5D-3L and CAT data from COPD patients. Response mapping under a backward elimination procedure was used for EQ-5D score predictions from CAT. A multinomial logistic regression (MLR) model was used to identify the association between the score and the covariates. Afterwards, the predicted scores were transformed into the utility. The developed formula was compared with ordinary least squares (OLS) regression models and models using Mean Rank Method (MRM). The MLR models performed as well as other models according to mean absolute error (MAE) and root mean squared error (RMSE) evaluations. Besides, the overestimation for low utility patients (utility ≤ 0.6) and underestimation for near health (utility > 0.9) in the OLS method was improved through the means of the MLR model based on bubble chart analysis. In conclusion, response mapping with the MLR model led to performance comparable to the OLS and MRM models for predicting EQ-5D utility from CAT data. Additionally, the bubble charts analysis revealed that the model constructed in this study and MRM could be a better predictive model.

Life expectancy (LE) and loss-of-LE for patients with chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVES: Prognosis of COPD is usually expressed as a 3-year survival rate, which might not be easily understood by lay people. This study estimates the life expectancy (LE) and loss-of-LE for COPD patients with different GOLD stages and patients with a history of acute exacerbation (AE) requiring hospitalization (severe AE) in the preceding year. METHODS: 532 patients who were diagnosed with COPD according to the GOLD criteria at NCKU hospital between 2006 and 2016 were recruited. Survival was estimated by Kaplan-Meier method, and extrapolated to lifetime to obtain the LE. The loss-of-LE was quantified by subtracting the LE of the COPD cohort from national life tables. The survival of patients with severe AE history was validated by a nation-wide cohort from the National Health Insurance dataset. RESULTS: The survival of patients with severe stage COPD (GOLD grades 3 and 4) was almost the same as those patients with a history of severe AE and the loss-of-LE for the former and the latter were 9.3 (1.1) and 9.4 (1.3) years, respectively. The nation-wide cohort with severe AE history (n = 44,764) showed a loss-of-LE of 8.3 (0.1) years. The loss-of-LE of patients with moderate stage COPD (GOLD grade 2) was 6.2 years, but no reduction in LE was noted for mild stage COPD (GOLD grade 1). CONCLUSIONS: We successfully estimated LE and loss of LE in COPD patients under the GOLD criteria. The survival of severe stage COPD patients is almost the same as those with severe AE history, or about 8-9 years of life lost.

Comparison of global initiative for chronic obstructive pulmonary disease 2013 classification and body mass index, airflow obstruction, dyspnea, and exacerbations index in predicting mortality and exacerbations in elderly adults with chronic obstructive pulmonary disease.

OBJECTIVES: To examine whether the Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) 2013 revision offers greater predictive ability than the body mass index, airflow obstruction, dyspnea, and exacerbations (BODEx) index in elderly adults with chronic obstructive pulmonary disease (COPD). DESIGN: Prospective cohort study. SETTING: University-affiliated medical center. PARTICIPANTS: Taiwanese outpatients with COPD (N = 354). MEASUREMENTS: Participants were classified as Group A (low risk with mild dyspnea), Group B (low risk with more-severe dyspnea), Group C (high risk with mild dyspnea), and Group D (high risk with more-severe dyspnea) for GOLD 2013 and from Quartile 1 (0-2 points) to 4 (7-9 points) for BODEx score. Ability to predict exacerbations and mortality was compared using logistic regression analysis with receiver operating characteristic (ROC) curve estimations and area under the ROC curve (AUC). RESULTS: Mortality was 14.1% for GOLD Group A, 14.5% for Group B, 6.5% for Group C, and 35.8% for Group D and 15.2% for BODEx Quartile 1, 22.5% for Quartile 2, 28.1% for Quartile 3, and 79.2% for Quartile 4. Risk of exacerbation relative to Group A was 1.7 (95% confidence interval (CI) = 0.6-4.3) for Group B, 14.1 (95% CI = 4.6-43.2) for Group C, and 17.9 (95% CI = 7.6-42.0) for Group D. The AUC for the GOLD classification and BODEx index were 0.65 and 0.67 for mortality (P = .60) and 0.79 and 0.73 for exacerbation (P = .03). CONCLUSION: The GOLD 2013 classification performed well in identifying individuals at risk of exacerbations, and its predictive ability for exacerbations was better than that of the BODEx index, although the predictive ability for mortality in elderly adults with COPD was poor for both indices.

Simulation of late inspiratory rise in airway pressure during pressure support ventilation.

BACKGROUND: Late inspiratory rise in airway pressure (LIRAP, Paw/ΔT) caused by inspiratory muscle relaxation or expiratory muscle contraction is frequently seen during pressure support ventilation (PSV), although the modulating factors are unknown. METHODS: We investigated the effects of respiratory mechanics (normal, obstructive, restrictive, or mixed), inspiratory effort (-2, -8, or -15 cm H2O), flow cycle criteria (5-40% peak inspiratory flow), and duration of inspiratory muscle relaxation (0.18-0.3 s) on LIRAP during PSV using a lung simulator and 4 types of ventilators. RESULTS: LIRAP occurred with all lung models when inspiratory effort was medium to high and duration of inspiratory muscle relaxation was short. The normal lung model was associated with the fastest LIRAP, whereas the obstructive lung model was associated with the slowest. Unless lung mechanics were normal or mixed, LIRAP was unlikely to occur when inspiratory effort was low. Different ventilators were also associated with differences in LIRAP speed. Except for within the restrictive lung model, changes in flow cycle level did not abolish LIRAP if inspiratory effort was medium to high. Increased duration of inspiratory relaxation also led to the elimination of LIRAP. Simulation of expiratory muscle contraction revealed that LIRAP occurred only when expiratory muscle contraction occurred sometime after the beginning of inspiration. CONCLUSIONS: Our simulation study reveals that both respiratory resistance and compliance may affect LIRAP. Except for under restrictive lung conditions, LIRAP is unlikely to be abolished by simply lowering flow cycle criteria when inspiratory effort is strong and relaxation time is rapid. LIRAP may be caused by expiratory muscle contraction when it occurs during inspiration.

Discriminative and predictive properties of multidimensional prognostic indices of chronic obstructive pulmonary disease: a validation study in Taiwanese patients.

BACKGROUND AND OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a pulmonary disease with systemic involvement. Several multidimensional indices have been developed to predict long-term outcomes. However, these indices have not been compared and validated in Taiwanese patients with COPD. METHODS: A prospective, observational, hospital-based study was designed, and a total of 621 patients were recruited from May 2006 to December 2011. Patients followed at least 1 year were enrolled and 594 patients eligible for inclusion. Three prognostic indices--the ADO (age, dyspnoea and airflow obstruction), BODEx (body mass index, airflow obstruction, dyspnoea and exacerbations), and CPI (the COPD Prognostic Index)--were validated and the predictive power of each was analysed. RESULTS: The median follow-up of the 594 patients was 33 months (range 1-72 months), and the mortality rate was 19.2% (114 deaths). All indices were significantly predictive for all-cause mortality in our validation cohort. Furthermore, the C statistics of the three indices, indicating their predictive accuracy, were all >0.7 (area under the curve of the CPI 0.718, P < 0.001, ADO 0.702, P < 0.001, BODEx 0.702, P < 0.001). CONCLUSIONS: ADO, BODEx and CPI scores are useful predictors of all-cause mortality with significantly discriminative properties in Taiwanese patients with COPD.