Predictive properties of different multidimensional staging systems in patients with chronic obstructive pulmonary disease

Frailty and Exacerbation of Chronic Obstructive Pulmonary Disease: Is There Any Association?

Purpose

This study investigated if individuals with chronic obstructive pulmonary disease (COPD) and frailty are more likely to have acute exacerbations of COPD or require hospitalization for exacerbation than those without frailty.

Patients and Methods

Data on 135 outpatients with stable COPD were analyzed with the Cox proportional hazards model to assess the risk of future events. The Kihon Checklist was administered at baseline to classify the participants as robust, pre-frail, or frail. The follow-up period was a maximum of six and a half years.

Results

In all, 76 patients (56.3%) experienced an exacerbation and 46 (34.1%) were hospitalized due to it. Multivariate Cox proportional hazards analysis that accounted for FEV1 and sex showed that the frail group was more likely to face future risks of COPD exacerbations [Hazard ratio 1.762 (95% CI 1.011-3.070), p=0.046] and hospitalizations for exacerbation [2.238 (1.073-4.667), p=0.032] than the robust group. No significant differences were observed when comparing robust patients to those who were pre-frail or pre-frail to frail either in exacerbations or hospitalizations. When comparing the C-indices for frailty and FEV1, the former index (exacerbation 0.591 and hospitalization 0.663) did not exceed the latter (0.663 and 0.769) in either analysis.

Conclusion

Frail COPD patients have a more unfavorable future risk of acute exacerbations of COPD and hospitalizations for exacerbation than robust patients. However, no significant differences were observed when comparing robust patients to those who were pre-frail or pre-frail to frail, suggesting that the future risk for COPD patients with frailty is only higher compared to those who are considered robust. Additionally, FEV1 was found to be a more reliable predictor of future events than measures of frailty.

Cost-utility analysis of transitional care services for older inpatients with chronic obstructive pulmonary disease (COPD) in Korea

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with a high readmission rate and poses a significant disease burden. South Korea initiated pilot projects on transitional care services (TCS) to reduce readmissions. However, evidence from cost-effectiveness analyses remains undiscovered. This study aimed to evaluate the cost-effectiveness of TCS in patients with COPD from the healthcare system' perspective.

METHOD

A cost-utility analysis was conducted using a Markov model containing six components of possible medical use after discharge. Transition probabilities and medical costs were extracted from the National Health Insurance Service Senior Cohort (NHIS-SC), and utility data were obtained from published literature. Sensitivity analyses were performed to test the robustness of the results.

RESULTS

Conducting TCS produced an incremental quality-adjusted life years gain of 0.231, 0.275, 0.296 for those in their 60s, 70s, and 80s, respectively, and cost savings of $225.16, $1668, and $2251.64 for those in their 60s, 70s, and 80s, respectively, per patient over a 10-year time horizon. The deterministic sensitivity analysis indicated that the TCS cost and the cost of readmission by other diseases immensely impact the results. The probabilistic sensitivity analyses showed that the probability that the incremental cost-effectiveness ratio is below $23,050 was over 85%, 93%, and 97% for those in the 60s, 70s, and 80s, respectively.

CONCLUSIONS

TCS was the dominant option compared to usual care. However, it is advantageous to the healthcare budget preferentially consider patients aged over 70 years with severe TCS symptoms. In addition, it is essential to include the management of underlying comorbidities in TCS intervention.

TRIAL REGISTRATION

Clinical Research Information Service (CRIS), KCT0007937. Registered on 24 November 2022.

The Role of the Cumulative Illness Rating Scale (CIRS) in Estimating the Impact of Comorbidities on Chronic Obstructive Pulmonary Disease (COPD) Outcomes: A Pilot Study of the MACH (Multidimensional Approach for COPD and High Complexity) Study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a heterogeneous systemic syndrome that often coexists with multiple comorbidities. In highly complex COPD patients, the role of the Cumulative Illness Rating Scale (CIRS) as a risk predictor of COPD exacerbation is not known.

OBJECTIVE

The objective of this study was determine the effectiveness of the CIRS score in detecting the association of comorbidities and disease severity with the risk of acute exacerbations in COPD patients.

METHODS

In total, 105 adults with COPD (mean age 72.1 ± 9.0 years) were included in this prospective study. All participants at baseline had at least two moderate exacerbations or one leading to hospitalization. The primary outcome was a composite of moderate or severe COPD exacerbation during the 12 months of follow-up.

RESULTS

The CIRS indices (CIRS total score, Severity Index and Comorbidity Index) showed a positive correlation with modified Medical Research Council (mMRC), COPD assessment test (CAT) and a negative correlation with forced expiratory volume in the first second (FEV1), Forced Vital Capacity (FVC), and FEV1/FVC. The three CIRS indices were able to predict the 12-month rate of moderate or severe exacerbation (CIRS Total Score: Hazard Ratio (HR) = 1.12 (95% CI: 1.08-1.21); CIRS Severity Index: HR = 1.21 (95% CI: 1.12-1.31); CIRS Comorbidity Index = 1.58 (95% CI: 1.33-1.89)).

CONCLUSIONS

Among patients with COPD, the comorbidity number and severity, as assessed by the CIRS score, influence the risk in moderate-to-severe exacerbations. The CIRS score also correlates with the severity of respiratory symptoms and lung function.

Tidal volume expandability and ventilatory efficiency as predictors of mortality in Taiwanese male patients with chronic obstructive pulmonary disease: A 10-year follow-up study - Is V̇O2peak or FEV1% the gold standard?

Despite our knowledge of the risk factors for mortality associated with chronic obstructive pulmonary disease (COPD), the mortality rate for this condition continues to increase. This study aimed to investigate the predictive power of physiological variables on all-cause mortality in COPD patients compared to peak oxygen uptake (V ˙ O2peak) and forced expired volume in one second (FEV1). We conducted a retrospective study of 182 COPD patients with complete lung function tests, cardiopulmonary exercise testing (CPET), and survival data. Cox regression analysis was used to estimate the hazard ratios for all-cause mortality. The median follow-up period was 6.8 (IQR 3.9-9.2) years. Out of the 182 patients in our study, sixty-two (34.1%) succumbed to various causes. Of these, 27.4% (n = 17) experienced acute exacerbations, 24.2% (n = 15) had advanced cancer, and 12.9% (n = 8) had cardiovascular disease as the primary cause of death. Another 25.8% (n = 16) passed away due to other underlying conditions, while 6.5% (n = 4) had an unknown cause of death. One patient's demise was attributed to a benign tumor, and another's to a connective tissue disease. The ratio of tidal volume to total lung capacity (VTpeak/TLC) and the ratio of minute ventilation and V ˙ O2 at nadir (V ˙ E/V ˙ O2nadir) (AUR 0.83, 95% CI 0.76-0.91) were superior predictors of all-cause mortality compared to V ˙ O2peak and FEV1%. A mortality prediction formula was derived using these variables. This study highlights the potential of VTpeak/TLC and V ˙ E/V ˙ O2nadir as predictive markers for COPD all-cause mortality in COPD. CPET is an effective tool for evaluating COPD mortality; however, the predictive equation requires further validation.

Value of Cardiopulmonary Exercise Testing in the Prognosis Assessment of Chronic Obstructive Pulmonary Disease Patients: A Retrospective, Multicentre Cohort Study

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is one of the most common chronic diseases associated with high mortality. Previous studies suggested a prognostic role for peak oxygen uptake (VO2peak) assessed during cardiopulmonary exercise testing (CPET) in patients with COPD. However, most of these studies had small sample sizes or short follow-up periods, and despite their relevance, CPET parameters are not included in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) tool for assessment of severity.

OBJECTIVES

We therefore aimed to assess the prognostic value of CPET parameters in a large cohort of outpatients with COPD.

METHODS

In this retrospective, multicentre cohort study, medical records of patients with COPD who underwent CPET during 2004-2017 were reviewed and demographics, smoking habits, GOLD grade and category, exacerbation frequency, dyspnoea score, lung function measurements, and CPET parameters were documented. Relationships with survival were evaluated using Kaplan-Meier analysis, Cox regression, and receiver operating characteristic (ROC) curves.

RESULTS

Of a total of 347 patients, 312 patients were included. Five-year and 10-year survival probability was 75% and 57%, respectively. VO2peak significantly predicted survival (hazard ratio: 0.886 [95% confidence interval: 0.830; 0.946]). The optimal VO2peak threshold for discrimination of 5-year survival was 14.6 mL/kg/min (area under ROC curve: 0.713). Five-year survival in patients with VO2peak <14.6 mL/kg/min versus ≥ 14.6 mL/kg/min was 60% versus 86% in GOLD categories A/B and 64% versus 90% in GOLD categories C/D.

CONCLUSIONS

We confirm that VO2peak is a highly significant predictor of survival in COPD patients and recommend the incorporation of VO2peak into the assessment of COPD severity.

Right ventricular end-diastolic volume and outcomes in exacerbations of COPD

BACKGROUND AND OBJECTIVE

Right ventricular (RV) volumes are crucial outcome determinants in pulmonary diseases. Little is known about the associations of RV volumes during hospitalized acute exacerbations of chronic obstructive pulmonary disease (AECOPD). We aimed to ascertain associations of RV end-diastolic volume indexed to body surface area (RVEDVI) during hospitalized AECOPD and its relationship with mortality in long-term follow-up.

METHODS

This is a prospective observational cohort study (December 2013-November 2019, ACTRN12617001562369) using dynamic retrospective ECG-gated computed tomography during hospitalized AECOPD. RVEDVI was defined as normal or high using Framingham Offspring Cohort values. Cox regression determined the prognostic relevance of RVEDVI for death.

RESULTS

A total of 148 participants (70 ± 10 years [mean ± SD], 88 [59%] men) were included, of whom 75 (51%) had high RVEDVI. This was associated with more frequent hospital admissions in the 12 months before admission (52/75 [69%] vs. 38/73 [52%], p = 0.04) and higher breathlessness (modified Medical Research Council score, 2.9 ± 1.3 vs. 2.4 ± 1.2, p = 0.007). During follow-up, high RVEDVI was associated with greater mortality (log-rank p = 0.001). In univariable Cox regression, increasing RVEDVI was associated with higher mortality (hazard ratio [HR]: 1.02 per ml/m² ; 95% CI: 1.01, 1.03; p = 0.001). In multivariable Cox regression, RVEDVI was independently associated with mortality (HR: 1.01 per ml/m² ; 95% CI: 1.00, 1.03; p = 0.050) at a borderline significance level. Adding RVEDVI to three COPD mortality prediction systems improved model fit (pooled chi-square test [BODE: p = 0.05, ADO: p = 0.04, DOSE: p = 0.02]).

CONCLUSION

In patients with hospitalized AECOPD, higher RV end-diastolic volume was associated with worse acute clinical parameters and greater mortality.

Multidimensional indices in the assessment of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD), a very common disease, is the third leading cause of death worldwide. Due to the significant heterogeneity of clinical phenotypes of COPD there is no single method suitable for predicting patients' health status and outcomes, and therefore multidimensional indices, assessing different components of the disease, were developed and are recommended for clinical practice by international guidelines. Several indices have been widely accepted: BODE and its modifications, ADO, DOSE, CODEX, COTE. They differ in their composition and aim, while they are more accurate and better validated in specific settings and populations. We review the characteristics, strengths and limitations of these indices, and we discuss their role in routine management of patients with COPD, as well as in specific clinical scenarios, such as resuscitation and ceiling of care, or decisions to offer more invasive treatments. This analysis may help clinicians to use those indexes in a more practical and appropriate way.

Exercise Capacity, Ventilatory Response, and Gas Exchange in COPD Patients With Mild to Severe Obstruction Residing at High Altitude

Background

Exercise intolerance, desaturation, and dyspnea are common features in patients with chronic obstructive pulmonary disease (COPD). At altitude, the barometric pressure (BP) decreases, and therefore the inspired oxygen pressure and the partial pressure of arterial oxygen (PaO₂) also decrease in healthy subjects and even more in patients with COPD. Most of the studies evaluating ventilation and arterial blood gas (ABG) during exercise in COPD patients have been conducted at sea level and in small populations of people ascending to high altitudes. Our objective was to compare exercise capacity, gas exchange, ventilatory alterations, and symptoms in COPD patients at the altitude of Bogotá (2,640 m), of all degrees of severity.

Methods

Measurement during a cardiopulmonary exercise test of oxygen consumption (VO₂), minute ventilation (VE), tidal volume (VT), heart rate (HR), ventilatory equivalents of CO₂ (VE/VCO₂), inspiratory capacity (IC), end-tidal carbon dioxide tension (PETCO₂), and ABG. For the comparison of the variables between the control subjects and the patients according to the GOLD stages, the non-parametric Kruskal–Wallis test or the one-way analysis of variance test was used.

Results

Eighty-one controls and 525 patients with COPD aged 67.5 ± 9.1 years were included. Compared with controls, COPD patients had lower VO₂ and VE (p < 0.001) and higher VE/VCO₂ (p = 0.001), A-aPO₂, and V_D/V_T (p < 0.001). In COPD patients, PaO₂ and saturation decreased, and delta IC (p = 0.004) and VT/IC increased (p = 0.002). These alterations were also seen in mild COPD and progressed with increasing severity of the obstruction.

Conclusion

The main findings of this study in COPD patients residing at high altitude were a progressive decrease in exercise capacity, increased dyspnea, dynamic hyperinflation, restrictive mechanical constraints, and gas exchange abnormalities during exercise, across GOLD stages 1–4. In patients with mild COPD, there were also lower exercise capacity and gas exchange alterations, with significant differences from controls. Compared with studies at sea level, because of the lower inspired oxygen pressure and the compensatory increase in ventilation, hypoxemia at rest and during exercise was more severe; PaCO₂ and PETCO₂ were lower; and VE/VO₂ was higher.

Prediction of Mortality Using Different COPD Risk Assessments - A 12-Year Follow-Up

Purpose

A multidimensional approach in the risk assessment of chronic obstructive pulmonary disease (COPD) is preferable. The aim of this study is to compare the prognostic ability for mortality by different COPD assessment systems; spirometric staging, classification by GOLD 2011, GOLD 2017, the age, dyspnea, obstruction (ADO) and the dyspnea, obstruction, smoking, exacerbation (DOSE) indices.

Patients and Methods

A total of 490 patients diagnosed with COPD were recruited from primary and secondary care in central Sweden in 2005. The cohort was followed until 2017. Data for categorization using the different assessment systems were obtained through questionnaire data from 2005 and medical record reviews between 2000 and 2003. Kaplan-Meier survival analyses and Cox proportional hazard models were used to assess mortality risk. Receiver operating characteristic curves estimated areas under the curve (AUC) to evaluate each assessment systems´ ability to predict mortality.

Results

By the end of follow-up, 49% of the patients were deceased. The mortality rate was higher for patients categorized as stage 3–4, GOLD D in both GOLD classifications and those with a DOSE score above 4 and ADO score above 8. The ADO index was most accurate for predicting mortality, AUC 0.79 (95% CI 0.75–0.83) for all-cause mortality and 0.80 (95% CI 0.75–0.85) for respiratory mortality. The AUC values for stages 1–4, GOLD 2011, GOLD 2017 and DOSE index were 0.73, 0.66, 0.63 and 0.69, respectively, for all-cause mortality.

Conclusion

All of the risk assessment systems predict mortality. The ADO index was in this study the best predictor and could be a helpful tool in COPD risk assessment.

Early Predictors of Mortality in Patients with COPD, in Relation to Respiratory and Non-Respiratory Causes of Death - A National Register Study

Background

Both single factors and composite measures have been suggested to predict mortality in patients with chronic obstructive pulmonary disease (COPD) and there is a need to analyze the relative importance of each variable.

Objective

To explore the predictors of mortality for patients with COPD in relation to respiratory, cardiac, and malignant causes, as well as all causes of death.

Methods

After merging the Swedish Respiratory Tract Register (SRTR) and the Swedish Cause of Death Register, patients with respiratory, cardiac, and other causes of death were identified. Demographic and clinical variables from the deceased patients’ first registration with the SRTR were compared. Three univariable and multivariable Cox proportional hazards regression analyses were conducted for different causes of death, with time from first registration to either death or a fixed end date as dependent variable, and variables regarding demographics, respiration, and comorbidities as independent variables.

Results

In the multivariable Cox models, mortality for patients with all causes of death was predicted by older age 1.79 (CI 1.41, 2.27), lower percentage of predicted forced expiratory volume in 1 second (FEV₁ %) 0.99 (CI 0.98, 0.99), lower saturation 0.92 (CI 0.86, 0.97), worse dyspnea 1.48 (CI 1.26, 1.74) (p<0.002 to p<0.001), less exercise 0.91 (CI 0.85, 0.98), and heart disease 1.53 (CI 1.06, 2.19) (both p<0.05). Mortality for patients with respiratory causes was predicted by higher age 1.67 (CI 1.05, 2.65) (p<0.05), lower FEV_1% 0.98 (CI 0.97, 0.99), worse dyspnea 2.05 (CI 1.45, 2.90), and a higher number of exacerbations 1.27 (CI 1.11, 1.45) (p<0.001 in all comparisons). For patients with cardiac causes of death, mortality was predicted by lower FEV_1% 0.99 (CI 0.98, 0.99) (p=0.001) and lower saturation 0.82 (CI 0.76, 0.89) (p<0.001), older age 1.46 (CI 1.02, 2.09) (p<0.05), and presence of heart disease at first registration 2.06 (CI 1.13, 3.73) (p<0.05).

Conclusion

Obstruction predicted mortality in all models and dyspnea in two models and needs to be addressed. Comorbidity with heart disease could further worsen the COPD patient’s prognosis and should be treated by a multidisciplinary team of professional specialists.

Primary care risk stratification in COPD using routinely collected data: a secondary data analysis

Most clinical contacts with chronic obstructive pulmonary disease (COPD) patients take place in primary care, presenting opportunity for proactive clinical management. Electronic health records could be used to risk stratify diagnosed patients in this setting, but may be limited by poor data quality or completeness. We developed a risk stratification database algorithm using the DOSE index (Dyspnoea, Obstruction, Smoking and Exacerbation) with routinely collected primary care data, aiming to calculate up to three repeated risk scores per patient over five years, each separated by at least one year. Among 10,393 patients with diagnosed COPD, sufficient primary care data were present to calculate at least one risk score for 77.4%, and the maximum of three risk scores for 50.6%. Linked secondary care data revealed primary care under-recording of hospital exacerbations, which translated to a slight, non-significant cohort average risk score reduction, and an understated risk group allocation for less than 1% of patients. Algorithmic calculation of the DOSE index is possible using primary care data, and appears robust to the absence of linked secondary care data, if unavailable. The DOSE index appears a simple and practical means of incorporating risk stratification into the routine primary care of COPD patients, but further research is needed to evaluate its clinical utility in this setting. Although secondary analysis of routinely collected primary care data could benefit clinicians, patients and the health system, standardised data collection and improved data quality and completeness are also needed.

The BODE index and inspiratory muscle performance in COPD: Clinical findings and implications

Objectives

The Test of Incremental Respiratory Endurance is a novel testing method that provides a unique examination of one's inspiratory muscle strength, work and endurance. Little is known about the relationship between inspiratory muscle performance and mortality risk in obstructive lung disease. We examined the relationship between the Test of Incremental Respiratory Endurance measures and the Body-mass index, airflow Obstruction, Dyspnea and Exercise index in chronic obstructive pulmonary disease.

Methods

In all, 70 males with mild-to-very severe chronic obstructive pulmonary disease (mean ± standard deviation of 70.2 ± 5.9 years) underwent measurements of body-mass index, spirometry, dyspnea and a 6-min walk test from which the Body-mass index, airflow Obstruction, Dyspnea and Exercise score was calculated. The Test of Incremental Respiratory Endurance provided measures of maximal inspiratory pressure, sustained maximal inspiratory pressure and inspiratory duration.

Results

All Test of Incremental Respiratory Endurance parameters inversely correlated with the Body-mass index, airflow Obstruction, Dyspnea and Exercise score: maximal inspiratory pressure (r = -0.355, p = 0.00), sustained maximal inspiratory pressure (r = -0.426, p = 0.00) and ID (r = -0.278, p = 0.02), with sustained maximal inspiratory pressure displaying the highest correlation. Independent significant correlations were also observed between the sustained maximal inspiratory pressure and all Body-mass index, airflow Obstruction, Dyspnea and Exercise score components, except for body-mass index. Finally, sustained maximal inspiratory pressure was significantly different among the Body-mass index, airflow Obstruction, Dyspnea and Exercise index quartiles.

Discussion

The significant association between the Body-mass index, airflow Obstruction, Dyspnea and Exercise score and inspiratory muscle performance, in particular sustained maximal inspiratory pressure, suggests that these measures may have a potential prognostic value in the evaluation of chronic obstructive pulmonary disease.

Comparison of Multiple Chronic Obstructive Pulmonary Disease (COPD) Indices in Chinese COPD Patients

Background

Chronic obstructive pulmonary disease (COPD) is a serious chronic condition with a global impact. Symptoms of COPD include progressive dyspnea, breathlessness, cough, and sputum production, which have a considerable impact on the lives of patients. In addition to the human cost of living with COPD and the resulting death, COPD entails a huge economic burden on the Chinese population, with patients spending up to one-third of the average family income on COPD management in some regions is clinically beneficial to adopt preventable measures via prudent COPD care utilization, monetary costs, and hospitalizations.

Methods

Toward this end, this study compared the relative effectiveness of six indices in predicting patient healthcare utilization, cost of care, and patient health outcome. The six assessment systems evaluated included the three multidimensional Body mass index, Obstruction, Dyspnea, Exercise capacity index, Dyspnea, Obstruction, Smoking, Exacerbation (DOSE) index, and COPD Assessment Test index, or the unidimensional measures that best predict the future of patient healthcare utilization, cost of care, and patient health outcome among Chinese COPD patients.

Results

Multiple linear regression models were created for each healthcare utilization, cost, and outcome including a single COPD index and the same group of demographic variables for each of the outcomes.

Conclusion

We conclude that the DOSE index facilitates the prediction of patient healthcare utilization, disease expenditure, and negative clinical outcomes. Our study indicates that the DOSE index has a potential role beyond clinical predictions.

Patient Related Outcomes-BODE (PRO-BODE): A composite index incorporating health utilization resources predicts mortality and economic cost of COPD in real life

Multidimensional scores were proposed for defining COPD outcomes, but without any incorporation of the economic COPD cost to clinical indices.

AIM

using mortality as an outcome, the hypothesis that adding total health care cost to the BODE index would better predict mortality in COPD was investigated.

METHODS

275 COPD patients were surveyed. Anthropometrics, lung function, the BODE and the Charlson Comorbidity Index were determined. History of exacerbations, ER visits, hospitalizations and mortality were also determined over the next three years, being their rates graded and added to the BODE index according to a simple algorithm. The novel PRO-BODE index ranged 0-10 points; its relationship to annual total COPD cost and survival was assessed by linear regression analysis.

RESULTS

total COD cost showed the highest relationship with survival (r = -0.58), even higher than that of age and of BODE index (r = -0.28 and r = -0.21, respectively). The integrated Pro-BODE score proved proportional to the cost of care and inversely proportional to the length of survival.

CONCLUSIONS

Pro-BODE is a novel composite index which helps in predicting in real life the impact of COPD over three years, both in terms of patients' survival and of COPD economic burden.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report. GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 report focuses primarily on the revised and novel parts of the document. The most significant changes include: (1) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; (2) for each of the groups A to D, escalation strategies for pharmacologic treatments are proposed; (3) the concept of deescalation of therapy is introduced in the treatment assessment scheme; (4) nonpharmacologic therapies are comprehensively presented; and (5) the importance of comorbid conditions in managing chronic obstructive pulmonary disease is reviewed.

Prediction of Poor Short-Term Prognosis and Unmet Needs in Advanced Chronic Obstructive Pulmonary Disease: Use of the Two-Minute Walking Distance Extracted from a Six-Minute Walk Test

OBJECTIVES

Prognostic challenges hinder the identification of patients with advanced chronic obstructive pulmonary disease (COPD) for timely palliative interventions. We postulate that a two-minute derivative (two-minute walking distance [2MWD]) of a standard six-minute walk test (6MWT) can identify frail subjects with poorer survival for early palliative intervention. The primary outcome of interest is mortality at 18 months. Secondary objectives include evaluation of the relationship between the 2MWD and ability to self-care, dyspnea-related disabilities, nutrition, forced expiratory volume in first second (FEV₁), quality of life (QoL), and comorbidity burden.

DESIGN AND SETTING

One hundred twenty-four subjects with stage 3 and 4 COPD were recruited and followed up. Ability to self-care, dyspnea-related disabilities, airflow limitation, nutrition, and QoL were measured by using modified Barthel index (MBI), Modified Medical Research Council (MMRC) dyspnea scale, FEV₁ (% predicted), BODE [BMI(B), FEV₁(O), MMRC(D), 6MWT(E)] index, updated ADO [Age(A), MMRC(D), FEV₁(O)] index, Subjective Global Assessment (SGA), and St. George's Respiratory Questionnaire (SGRQ), respectively. Survival data were prospectively collected and analyzed.

RESULTS

The 2MWD correlates highly with BODE and predicts updated ADO independent of age, co-morbidities, long-term oxygen therapy (LTOT), body mass index, and FEV₁. Log-rank test performed with Kaplan-Meier plots demonstrates that 2MWD ≤80 m significantly predicts survival time (p < 0.05). Cox proportional hazard regression shows a 3.6-time greater probability of 18-month mortality (hazard ratio [HR] 3.57; 95% confidence interval [CI] 1.26-10.13; p < 0.05). In addition, 2MWD strongly predicted MBI and MMRC, independent of age, co-morbidities, LTOT, body mass index, and FEV₁. Subjects with 2MWD ≤80 m have a poorer ability to self-care (median MBI 90 vs. 100), lower FEV₁ (32.9% ± 9.8% vs. 38.1% ± 9.4%), poorer QoL (mean SGRQ 46.6 ± 16.2 vs. 36.6 ± 13.3), and greater dyspnea-related disability (mean MMRC 1.7 ± 0.7 vs. 0.9 ± 0.6), and they are more malnourished (40.4% vs. 9.7%; RR 1.51) (all p < 0.001).

CONCLUSION

2MWD ≤80 m identifies subjects with higher mortality, greater functional dependence, poorer in nutrition, greater dyspnea, and lower QoL. Incorporation of 2MWD into composite prognostic indices can enhance predictive accuracy and identify patients requiring early proactive palliative interventions.

Global Strategy for the Diagnosis, Management and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: (i) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; (ii) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; (iii) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; (iv)non-pharmacological therapies are comprehensively presented and (v) the importance of co-morbid conditions in managing COPD is reviewed.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: 1) the assessment of COPD has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; 2) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; 3) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; 4) nonpharmacologic therapies are comprehensively presented and; 5) the importance of comorbid conditions in managing COPD is reviewed.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: 1) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; 2) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; 3) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; 4) nonpharmacologic therapies are comprehensively presented and; 5) the importance of comorbid conditions in managing COPD is reviewed.

End-of-life prognostic indicators in patients with COPD: Part 1

In the UK, chronic respiratory diseases cause 13% of adult disability. The major chronic respiratory disease is chronic obstructive pulmonary disease (COPD), a condition involving chronic airway inflammation that causes airflow obstruction and destruction of lung tissue. This leads to a progressive loss of respiratory membrane, which accounts for the clinical manifestation of COPD, which is difficulty maintaining sufficient gas exchange to meet metabolic demands. The primary cause is smoking, with the vast majority of COPD patients having a past or present history of smoking. However exposure to industrial pollutants is also a contributing factor, as is a rare genetic predisposition to developing COPD.

Demographic, health behavioral, and self-management abilities associated with disease severity among patients with chronic obstructive pulmonary disease: An exploratory study

This study aimed to identify the association between demographic characteristics, health behaviors, self-management abilities, and disease severity among patients with chronic obstructive pulmonary disease (COPD). The study was conducted from January to December 2015 in 4 hospitals in China. The DOSE index was assessed by grade of dyspnea (D), airflow obstruction (O), current smoking status (S), and frequency of exacerbation in the last year (E). Self-management abilities were assessed by the COPD self-management scale. DOSE index associations with demographic characteristics, health behaviors, and self-management abilities were examined with multiple regression analysis. In total, 100 participants were recruited into the study. In univariate analysis, higher symptom management, lower daily life management, and lower self-efficacy in self-management abilities were significantly related to higher DOSE index. In multiple regression analysis, physical activity, body mass index, and gender were negatively related to DOSE index. The study highlighted the importance of physical activity, nutritional status, and gender difference in managing disease severity in COPD. Professional nurses should develop individualized intervention programs and specifically increase physical activity for men and poor nutritional status for patients with COPD.

External validation of multidimensional prognostic indices (ADO, BODEx and DOSE) in a primary care international cohort (PROEPOC/COPD cohort)

BACKGROUND

Due to the heterogeneous and systemic nature of the chronic obstructive pulmonary disease (COPD), the new guidelines are oriented toward individualized attention. Multidimensional scales could facilitate its proper clinical and prognostic assessment, but not all of them were validated in an international primary care cohort, different from the original ones used for model development. Therefore, our main aim is to assess the prognostic capacity of the ADO, BODEx and DOSE indices in primary care for predicting mortality in COPD patients and to validate the models obtained in subgroups of patients, classified by revised Global Initiative for Chronic Obstructive Lung Disease (2011) and updated Spanish Guideline (2014). Besides, we want to confirm that the prognostic capacity of all indices increases if the number of exacerbations is substituted by the interval between them and to assess the impact on health of the patient's lifestyle, social network and adherence to treatment.

METHODS

Design: External validation of scales, open and prospective cohort study in primary care.

SETTING

36 health centres in 6 European high, medium and low income countries.

SUBJECTS

477 patients diagnosed with COPD, captured in clinical visit by their General Practitioner/Nurse.

PREDICTORS

Detailed patient history, exacerbations, lung function test and questionnaires at baseline.

OUTCOMES

Exacerbations, all-cause mortality and specific mortality, within 5 years of recruitment.

ANALYSIS

Multivariate logistic regression and Cox regression will be used. Possible non-linear effect of the indices will be studied by using Structured Additive Regression models with penalised splines. Subsequently, we will assess different aspects of the regression models: discrimination, calibration and diagnostic precision. Clinical variables modulated in primary care and the interval between exacerbations will be considered and incorporated into the analysis.

DISCUSSION

The Research Agenda for General Practice/Family Medicine highlights that the evidence on predictive values of prognostic indices in primary care is scarce. A prospective cohort like that of PROEPOC/COPD provides good opportunities for research into COPD and make communication easier between family practitioners, nursing staff, pneumologists and other professionals, supporting a multi-disciplinary approach to the treatment of these patients.

TRIAL REGISTRATION

ISRCTN52402811 . Date: 15/01/2015. Prospectively registered.

Multi-component assessment of chronic obstructive pulmonary disease: an evaluation of the ADO and DOSE indices and the global obstructive lung disease categories in international primary care data sets

Suitable tools for assessing the severity of chronic obstructive pulmonary disease (COPD) include multi-component indices and the global initiative for chronic obstructive lung disease (GOLD) categories. The aim of this study was to evaluate the dyspnoea, obstruction, smoking, exacerbation (DOSE) and the age, dyspnoea, obstruction (ADO) indices and GOLD categories as measures of current health status and future outcomes in COPD patients. This was an observational cohort study comprising 5,114 primary care COPD patients across three databases from UK, Sweden and Holland. The associations of DOSE and ADO indices with (i) health status using the Clinical COPD Questionnaire (CCQ) and St George's Respiratory Questionnaire (SGRQ) and COPD Assessment test (CAT) and with (ii) current and future exacerbations, admissions and mortality were assessed in GOLD categories and DOSE and ADO indices. DOSE and ADO indices were significant predictors of future exacerbations: incident rate ratio was 1.52 (95% confidence intervals 1.46-1.57) for DOSE, 1.16 (1.12-1.20) for ADO index and 1.50 (1.33-1.68) and 1.23 (1.10-1.39), respectively, for hospitalisations. Negative binomial regression showed that the DOSE index was a better predictor of future admissions than were its component items. The hazard ratios for mortality were generally higher for ADO index groups than for DOSE index groups. The GOLD categories produced widely differing assessments for future exacerbation risk or for hospitalisation depending on the methods used to calculate them. None of the assessment systems were excellent at predicting future risk in COPD; the DOSE index appears better than the ADO index for predicting many outcomes, but not mortality. The GOLD categories predict future risk inconsistently. The DOSE index and the GOLD categories using exacerbation frequency may be used to identify those at high risk for exacerbations and admissions.

Risk of exacerbation in chronic obstructive pulmonary disease: a primary care retrospective cohort study

Background

The risk of exacerbation in chronic obstructive pulmonary disease (COPD) depends on the severity of disease and other less well known factors. Predictive models of exacerbation are more accurate than the forced expiratory volume in one second (FEV1). The objective was to design a model that predicts the risk of exacerbation in COPD.

Methods

Retrospective cohort study with data from the electronic medical records of patients diagnosed with COPD in the province of Lleida (Spain). A total of 2501 patients were followed during 3 years. The dependent variable was acute exacerbation; independent variables were: clinical parameters, spirometry results, severity of disease, influenza and 23-valent pneumococcal immunisation, comorbidities, smoking and history of exacerbation. The association of these variables with disease exacerbation was measured by the adjusted odds ratio using a logistic regression model.

Results

Mean age at the start of the study was 68.38 years (SD = 11.60) and 74.97 % patients were men; severity of disease was considered mild in 50.82 % of patients, moderate in 35.31 %, severe in 9.44 % and very severe in 4.44 %. During the three year study period up to 83.17 % of patients experienced at least one exacerbation. Predictive factors in the model were age, gender, previous exacerbations, influenza and 23-valent pneumococcal immunisations, number of previous visits to the General Practice and severity (GOLD), with an area under the ROC curve (AUROC) of 0.70.

Conclusions

This model can identify patients at high risk of acute exacerbation. Preventive measures and modification of treatment in these high-risk patients would improve survival.

ALAT-2014 Chronic Obstructive Pulmonary Disease (COPD) Clinical Practice Guidelines: questions and answers

ALAT-2014 COPD Clinical Practice Guidelines used clinical questions in PICO format to compile evidence related to risk factors, COPD screening, disease prognosis, treatment and exacerbations. Evidence reveals the existence of risk factors for COPD other than tobacco, as well as gender differences in disease presentation. It shows the benefit of screening in an at-risk population, and the predictive value use of multidimensional prognostic indexes. In stable COPD, similar benefits in dyspnea, pulmonary function and quality of life are achieved with LAMA or LABA long-acting bronchodilators, whereas LAMA is more effective in preventing exacerbations. Dual bronchodilator therapy has more benefits than monotherapy. LAMA and combination LABA/IC are similarly effective, but there is an increased risk of pneumonia with LABA/IC. Data on the efficacy and safety of triple therapy are scarce. Evidence supports influenza vaccination in all patients and anti-pneumococcal vaccination in patients <65years of age and/or with severe airflow limitation. Antibiotic prophylaxis may decrease exacerbation frequency in patients at risk. The use of systemic corticosteroids and antibiotics are justified in exacerbations requiring hospitalization and in some patients managed in an outpatient setting.

A combined pulmonary function and emphysema score prognostic index for staging in Chronic Obstructive Pulmonary Disease

Introduction

Chronic Obstructive Pulmonary Disease (COPD) is characterized by high morbidity and mortality. Lung computed tomography parameters, individually or as part of a composite index, may provide more prognostic information than pulmonary function tests alone.

Aim

To investigate the prognostic value of emphysema score and pulmonary artery measurements compared with lung function parameters in COPD and construct a prognostic index using a contingent staging approach.

Material-Methods

Predictors of mortality were assessed in COPD outpatients whose lung computed tomography, spirometry, lung volumes and gas transfer data were collected prospectively in a clinical database. Univariate and multivariate Cox proportional hazard analysis models with bootstrap techniques were used.

Results

169 patients were included (59.8% male, 61.1 years old; Forced Expiratory Volume in 1 second % predicted: 40.5±19.2). 20.1% died; mean survival was 115.4 months. Age (HR = 1.098, 95% Cl = 1.04–1.252) and emphysema score (HR = 1.034, 95% CI = 1.007–1.07) were the only independent predictors of mortality. Pulmonary artery dimensions were not associated with survival. An emphysema score of 55% was chosen as the optimal threshold and 30% and 65% as suboptimals. Where emphysema score was between 30% and 65% (intermediate risk) the optimal lung volume threshold, a functional residual capacity of 210% predicted, was applied. This contingent staging approach separated patients with an intermediate risk based on emphysema score alone into high risk (Functional Residual Capacity ≥210% predicted) or low risk (Functional Residual Capacity <210% predicted). This approach was more discriminatory for survival (HR = 3.123; 95% CI = 1.094–10.412) than either individual component alone.

Conclusion

Although to an extent limited by the small sample size, this preliminary study indicates that the composite Emphysema score-Functional Residual Capacity index might provide a better separation of high and low risk patients with COPD, than other individual predictors alone.

Utility of the combination of serum highly-sensitive C-reactive protein level at discharge and a risk index in predicting readmission for acute exacerbation of COPD

OBJECTIVE

Frequent readmissions for acute exacerbations of COPD (AECOPD) are an independent risk factor for increased mortality and use of health-care resources. Disease severity and C-reactive protein (CRP) level are validated predictors of long-term prognosis in such patients. This study investigated the utility of combining serum CRP level with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) exacerbation risk classification for predicting readmission for AECOPD.

METHODS

This was a prospective observational study of consecutive patients hospitalized for AECOPD at Peking University Third Hospital, in Beijing, China. We assessed patient age; gender; smoking status and history (pack-years); lung function; AECOPD frequency during the last year; quality of life; GOLD risk category (A-D; D indicating the greatest risk); and serum level of high-sensitivity CRP at discharge (hsCRP-D).

RESULTS

The final sample comprised 135 patients. Of those, 71 (52.6%) were readmitted at least once during the 12-month follow-up period. The median (interquartile) time to readmission was 78 days (42-178 days). Multivariate analysis revealed that serum hsCRP-D ≥ 3 mg/L and GOLD category D were independent predictors of readmission (hazard ratio = 3.486; 95% CI: 1.968-6.175; p < 0.001 and hazard ratio = 2.201; 95% CI: 1.342-3.610; p = 0.002, respectively). The ordering of the factor combinations by cumulative readmission risk, from highest to lowest, was as follows: hsCRP-D ≥ 3 mg/L and GOLD category D; hsCRP-D ≥ 3 mg/L and GOLD categories A-C; hsCRP-D < 3 mg/L and GOLD category D; hsCRP-D < 3 mg/L and GOLD categories A-C.

CONCLUSIONS

Serum hsCRP-D and GOLD classification are independent predictors of readmission for AECOPD, and their predictive value increases when they are used in combination.

BODE index or geriatric multidimensional assessment for the prediction of very-long-term mortality in elderly patients with chronic obstructive pulmonary disease? a prospective cohort study

BACKGROUND

a multidimensional approach-the BODE index-has been proposed for prognostic purposes in chronic obstructive pulmonary disease (COPD) and theoretically seems to be well suited for elderly people, but there is a lack of data in this population, especially with respect to long-term survival. The objective of this study is to evaluate whether the BODE index can predict both long (5 years) and very-long (10 and 15 years)-term mortality in an unselected population of elderly people with COPD better than a set of variables commonly taken into account in a geriatric multidimensional assessment (MDA).

METHODS

: this was a multicentre, prospective, population study. We used data from the SaRA study, which included 563 elderly people with COPD whose vital status was ascertained for up to 15 years after enrolment. The discriminative capacity of the BODE index in predicting mortality was derived from Cox proportional hazard models including the components of the BODE index and compared with that of an alternative model based on MDA variables: age, gender, physical disability, cognitive function and mood status.

RESULTS

: at 5 years, the HRs for mortality were 1.04 (95% CI: 0.60-1.79), 1.88 (1.10-3.22) and 3.55 (2.15-5.86) for quartiles 2-4, respectively, compared with quartile 1 of the BODE index. The corresponding figures for 10-year mortality were 1.50 (1.01-2.24), 2.11 (1.39-3.20) and 3.903 (2.62-5.82), and for 15-year mortality were 1.68 (1.19-2.36), 2.08 (1.44-3.01) and 3.78 (2.64-5.41). Similar results were obtained using variables included in the usual MDA.

CONCLUSIONS

: Both the 'classic' MDA and the BODE index are comparably associated with mortality, even at very long term, in elderly people with COPD.

The value of assessment tests in patients with acute exacerbation of chronic obstructive pulmonary disease

The aim of our study was to investigate the chronic obstructive pulmonary disease (COPD) assessment test (CAT), serum copeptin, procalcitonin and C-reactive protein (CRP) levels as potential predictive factors for recurrence of acute exacerbation and all-cause mortality in 6 months of COPD inpatients. One hundred fifty-nine patients who met the inclusion criteria were enrolled and followed up for 6 months. The CAT scores, serum copeptin, procalcitonin and CRP levels were measured on admission and 14 days and 3 months later in all patients. The primary endpoint was recurrence of acute exacerbation in 6 months. The secondary endpoint was all-cause mortality after 6 months. The CAT scores, serum copeptin, procalcitonin and CRP levels were significantly elevated on admission and stabilized at 14 days (P < 0.01). In a univariate logistic regression analysis, CAT scores (odds ratio [OR] = 1.10), forced expiratory volume in 1 second % (OR = 1.01), serum copeptin (OR = 1.32) and CRP levels (OR = 1.01) were significantly related to recurrence of acute exacerbation in 6 months (P < 0.05). In a multivariate logistic regression model, increasing CAT scores (OR = 1.10) and serum copeptin levels (OR = 1.29) were still associated with an increased odds of exacerbation (P < 0.05). In a univariate logistic regression analysis, increasing CAT scores (OR = 1.19), forced expiratory volume in 1 second % (OR = 1.05), serum copeptin levels (OR = 1.44) and hospitalization in the previous years (OR = 1.24) were significant determinants of death over a follow-up period of 6 months (P < 0.05). But only serum copeptin (OR = 1.53) and CAT scores (OR = 1.37) were associated with mortality in multivariate logistic regression analysis. Hence, high CAT scores and serum copeptin levels link with recurrence of acute exacerbation and all-cause mortality during 6 months in patients with acute exacerbation of COPD.

Reanalysis of the Japanese experience using the combined COPD assessment of the 2011 GOLD classification

BACKGROUND

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 consensus report proposed a new classification system, incorporating symptoms with future risk, in subjects with chronic obstructive pulmonary disease (COPD). We hypothesized it could be applied to Japanese COPD patients.

METHODS

We previously analyzed clinical factors related to 5-year mortality in 150 male outpatients with COPD. We reviewed the data and reanalyzed the relationships between the new GOLD classification and various outcomes including mortality.

RESULTS

There were 51 (34.0%), 12 (8.0%), 57 (38.0%), and 30 (20.0%) patients in GOLD A (forced expiratory volume in 1s [FEV1] ≥ 50% predicted and modified Medical Research Council [mMRC] 0-1), GOLD B (FEV1 ≥ 50% predicted and mMRC ≥ 2), GOLD C (FEV1<50% predicted and mMRC 0-1), and GOLD D (FEV1 <50% predicted and mMRC ≥ 2), respectively. The GOLD 2011 classification correlated significantly with exercise capacity and multi-dimensional disease staging. Cox proportional hazards analysis revealed that, among several methods categorizing symptoms, the GOLD A-D classification was significantly associated with mortality (p=0.0055).

CONCLUSION

Although the relative number of patients in each category of the combined COPD assessment classification depended on the choice of symptom measures, the categories defined by the mMRC scale (score 0-1 versus ≥ 2) were most useful for future risk assessed as mortality. GOLD A had the lowest mortality, followed by GOLD B and C, and D had the highest mortality. Exercise capacity was also stratified by the new GOLD classification.

Using the DOSE index to predict changes in health status of patients with COPD: a prospective cohort study

Background:

The severity of chronic obstructive pulmonary disease (COPD) should not be based on the level of airflow limitation alone. A multicomponent index such as the DOSE index (dyspnoea score (D), level of airflow obstruction (O), current smoking status (S), and exacerbations (E)) has the potential to predict important future outcomes in patients with COPD more effectively than the forced expiratory volume in one second. Health status deterioration should be prevented in COPD patients.

Aims:

To investigate whether the DOSE index can predict which patients are at risk of a clinically relevant change in health status.

Methods:

A prospective cohort study was performed using data from primary and secondary care. The DOSE score was determined at baseline and the 2-year change in the Clinical COPD Questionnaire (CCQ) score was calculated. Linear regression analysis was performed for the effect of a high DOSE score (≥4) on the change in CCQ score.

Results:

The study population consisted of 209 patients (112 patients from primary care). Overall, a high DOSE score was a significant predictor of a change in CCQ score after 2 years (0.41, 95% CI 0.13 to 0.70), particularly in primary care patients.

Conclusions:

A DOSE score of ≥4 has the ability to identify COPD patients with a greater risk of future worsening in health status.

The Dyspnoea, Obstruction, Smoking, Exacerbation (DOSE) index is predictive of mortality in COPD

BACKGROUND

The Dyspnoea, Obstruction, Smoking, Exacerbation (DOSE) index was designed to assess disease severity and for the clinical management of chronic obstructive pulmonary disease (COPD), but has not been evaluated as a prognostic instrument for mortality in a population including primary care patients.

AIMS

The aim of this study was to investigate the associations of the DOSE index with mortality in primary and secondary care COPD patients.

METHODS

Information was collected from 1,111 COPD patients aged 34-75 years randomly selected from 70 Swedish primary and secondary care centres. Data were obtained using patient questionnaires and record review and the Swedish Board of Health and Welfare provided mortality data. The study population included 562 patients with data on all DOSE index components. The DOSE index was calculated using the MRC dyspnoea scale, forced expiratory volume in 1 second (FEV₁) as percentage of predicted (FEV₁%pred), smoking status, and exacerbation rate. The exacerbation rate over 6 months prior to record review was used to estimate the annual rate. Cox regression analyses estimated survival with adjustment for age, sex, and heart disease.

RESULTS

Over 5 years, 116 patients (20.6%) died. Mortality was higher in patients with DOSE index ≥4 (42.4%) than for lower scores (11.0%) (p<0.0001). Compared with a DOSE index score of 0-3, the hazard ratio for mortality was 3.48 (95% CI 2.32 to 5.22) for a score of 4-5, and was 8.00 (95% CI 4.67 to 13.7) for a score of 6-7.

CONCLUSIONS

The DOSE index is associated with mortality in COPD patients in primary and secondary care and can be used to assess prognosis in addition to other clinically relevant issues.