Thresholds for clinically important deterioration versus improvement in COPD health status:results from a randomised controlled trial in pulmonary rehabilitation and an observational study during routine clinical practice

OBJECTIVES: Chronic Obstructive Pulmonary Disease (COPD) is a progressive disease. Preventing deterioration of health status is therefore an important therapy goal. (Minimal) Clinically Important Differences ((M)CIDs) are used to interpret changes observed. It remains unclear whether (M)CIDs are similar for both deterioration and improvement in health status. This study investigates and compares these clinical thresholds for three widely-used questionnaires. DESIGN AND SETTING: Data were retrospectively analysed from an inhouse 3-week pulmonary rehabilitation (PR) randomised controlled trial in the German Klinik Bad Reichenhall (study 1), and observational research in Dutch primary and secondary routine clinical practice (RCP) (study 2). PARTICIPANTS: Patients with COPD aged ≥18 years (study 1) and aged ≥40 years (study 2) without respiratory comorbidities were included for analysis. PRIMARY OUTCOMES: The COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ) and St George's Respiratory Questionnaire (SGRQ) were completed at baseline and at 3, 6 and 12 months. A Global Rating of Change scale was added at follow-up. Anchor-based and distribution-based methods were used to determine clinically relevant thresholds. RESULTS: In total, 451 patients were included from PR and 207 from RCP. MCIDs for deterioration ranged from 1.30 to 4.21 (CAT), from 0.19 to 0.66 (CCQ), and from 2.75 to 7.53 (SGRQ). MCIDs for improvement ranged from -3.78 to -1.53 (CAT), from -0.50 to -0.19 (CCQ), and from -9.20 to -2.76 (SGRQ). Thresholds for moderate improvement versus deterioration ranged from -5.02 to -3.29 vs 3.89 to 8.14 (CAT), from -0.90 to -0.72 vs 0.42 to 1.23 (CCQ), and from -15.85 to -13.63 vs 7.46 to 9.30 (SGRQ). CONCLUSIONS: MCID ranges for improvement and deterioration on the CAT, CCQ and SGRQ were somewhat similar. However, estimates for moderate and large change varied and were inconsistent. Thresholds differed between study settings. TRIAL REGISTRATION NUMBER: Routine Inspiratory Muscle Training within COPD Rehabilitation trial: #DRKS00004609; MCID study: #UMCG201500447

Investigating sensitivity, specificity, and area under the curve of the Clinical COPD Questionnaire, COPD Assessment Test, and Modified Medical Research Council scale according to GOLD using St George's Respiratory Questionnaire cutoff 25 (and 20) as reference

Background: In the GOLD (Global initiative for chronic Obstructive Lung Disease) strategy document, the Clinical COPD Questionnaire (CCQ), COPD Assessment Test (CAT), or modified Medical Research Council (mMRC) scale are recommended for the assessment of symptoms using the cutoff points of CCQ >= 1, CAT >= 10, and mMRC scale >= 2 to indicate symptomatic patients. The current study investigates the criterion validity of the CCQ, CAT and mMRC scale based on a reference cutoff point of St George's Respiratory Questionnaire (SGRQ) >= 25, as suggested by GOLD, following sensitivity and specificity analysis. In addition, areas under the curve (AUCs) of the CCQ, CAT, and mMRC scale were compared using two SGRQ cutoff points (>= 25 and >= 20). Materials and methods: Two data sets were used: study A, 238 patients from a pulmonary rehabilitation program; and study B, 101 patients from primary care. Receiver-operating characteristic (ROC) curves were used to assess the correspondence between the recommended cutoff points of the questionnaires. Results: Sensitivity, specificity, and AUC scores for cutoff point SGRQ >= 25 were: study A, 0.99, 0.43, and 0.96 for CCQ >= 1, 0.92, 0.48, and 0.89 for CAT >= 10, and 0.68, 0.91, and 0.91 for mMRC >2; study B, 0.87, 0.77, and 0.9 for CCQ >1, 0.76, 0.73, and 0.82 for CAT >10, and 0.21, 1, and 0.81 for mMRC >= 2. Sensitivity, specificity, and AUC scores for cutoff point SGRQ >= 20 were: study A, 0.99, 0.73, and 0.99 for CCQ >= 1, 0.91, 0.73, and 0.94 for CAT >= 10, and 0.66, 0.95, and 0.94 for mMRC >= 2; study B, 0.8, 0.89, and 0.89 for CCQ >= 1, 0.69, 0.78, and 0.8 for CAT >= 10, and 0.18, 1, and 0.81 for mMRC >= 2. Conclusion: Based on data from these two different samples, this study showed that the suggested cutoff point for the SGRQ (>25) did not seem to correspond well with the established cutoff points of the CCQ or CAT scales, resulting in low specificity levels. The correspondence with the mMRC scale seemed satisfactory, though not optimal. The SGRQ threshold of >= 20 corresponded slightly better than SGRQ >= 25, recently suggested by GOLD 2015, with the established cutoff points for the CCQ, CAT, and mMRC scale

Validity of a self-administered questionnaire version of the Transition Dyspnea Index in patients with COPD

The transition dyspnea index (TDI) is among the most widely used instruments in chronic obstructive pulmonary disease (COPD) patients to measure changes in dyspnea over time. In its original version it is used as guideline for a structured interview to assess the impact of daily activities on dyspnea in the three subdomains: functional impairment, magnitude of task, and magnitude of effort. However, the TDI is sometimes used as a self-administered paper-and-pencil questionnaire. The validity of this questionnaire format has not been tested, which was the aim of the present study. We tested 190 patients with COPD at start and end of a 3-week inpatient pulmonary rehabilitation program (PR). Dyspnea was assessed with the modified Medical Research Council Scale (mMRC), a questionnaire version of the TDI, and an interview version of the TDI. Group means for the TDI questionnaire and interview version were widely comparable for the TDI summary score and the three TDI subdomains. The scores of both TDI versions were strongly correlated and showed comparable, but only weak, correlations with changes during PR in spirometric lung function and mMRC. Improvement in dyspnea after PR was observed in 89% of patients when using the summary score of the questionnaire TDI, but only in 34% of patients when using the mMRC. The results suggest that a self-administered questionnaire format of the TDI is an adequate instrument for assessing changes in activity-related dyspnea during PR in patients with COPD. The responsiveness of this instrument to effects of PR appears greater than the responsiveness of the mMRC.peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=icop20status: publishe

The Impact of Loneliness on Outcomes of Pulmonary Rehabilitation in Patients with COPD

Psychological factors such as negative affect have been demonstrated to impact course and treatment of chronic obstructive pulmonary disease (COPD). However, little is known about the respective impact of social factors. In several other chronic diseases, loneliness has been shown to predict morbidity, but little is known about its impact on COPD. Therefore, this study examined the associations between loneliness and outcome measures of a pulmonary rehabilitation program (PR). Before and after a 3-week inpatient PR program, patients with COPD (N = 104) underwent a 6-min walking test to measure functional exercise capacity. Loneliness was assessed with the Loneliness Scale. The Medical Outcomes Study 36-item short form, 9-item Patient Health Questionnaire, and 7-item General Anxiety Disorder questionnaire were administered as measures of health-related quality of life (HQoL), depression, and anxiety, respectively. Multiple regression analyses showed that at the start of PR, more loneliness was associated with worse levels of functional exercise capacity, HQoL, depression, and anxiety, but with greater improvements in functional exercise capacity and HQoL over the course of PR, even after controlling for age, sex, lung function, and smoking status. Patients with stronger decreases in loneliness from start to end of PR showed stronger improvements in functional exercise capacity and HQoL over the course of PR. The present study shows that subjective loneliness is associated with relevant treatment outcomes in patients with COPD undergoing pulmonary rehabilitation. Therefore, loneliness should be addressed in patients with COPD as it could play a significant role in their disease progression.status: publishe