Health Status in Chronic Obstructive Pulmonary Disease: Measuring the Minimal Clinically Important Difference over Different Periods of Time H.J. Alma, MSc; C. de Jong, PhD; D. Jelusic, MD; M. Wittmann, MD; M. Schuler, PhD; J.W.H. Kocks, MD, PhD; K. Schultz, MD; Prof. T. Van der Molen, MD, PhD Presented by Harma Alma, MD-PhD Student IPCRG 27th of May 2016 Harma Alma, PhD Student IPCRG 27th of May 2016

Statement I have no conflict of interest to declare

Background (1) Health status of major importance in COPD Need to assess clinically relevant changes Minimal (Clinically) Important Difference (MCID) “The smallest difference in score in the domain of interest, which patients perceive as beneficial and which would mandate, in the absence of troublesome side effects and excessive costs, a change in the patient’s management” GOLD, 2016; Jaeschke, 1989

Background (2) Various methods to determine MCID: Anchor-based Global Rating of Change (GRC) – anchor question Clinical event (e.g. exacerbation, hospital admission, doctor’s visit etc. ) Correlated questionnaire/test with known MCID Distribution-based Standard Error of Measurement (SEM) Half Standard Deviation (0,5SD) Beaton, 2002; Copay, 2007; Revicki, 2008

Research question Global Rating of Change (GRC) – anchor question Scores of +/-2 and +/-3 are considered minimal clinical changes Does the length of recall period affect the MCID of various health status tools used in COPD?

Methods Data analysis RIMTCORE Trial RCT on impact of Inspiratory Muscle Training Klinik Bad Reichenhall, Germany Pulmonary rehabilitation, 3 weeks Inclusion: COPD GOLD II-IV, signed IC Exclusion: Respiratory failure, other respiratory co-morbidities, cognitive limitations, CI to IMT training Baseline / 3 wk / 3 / 6 / 9 / 12 months follow-up COPD Assessment Test (CAT), Clinical COPD Questionnaire (CCQ) and St. George’s Respiratory Questionnaire (SGRQ) Change vs. Baseline Global rating of change at follow-up moments SF-36 anchor question at 12 months MCID - mean changes scores (95% CI) for patients reporting a minimal change on the GRC Jones, 1991; Jones, 2009; van der Molen, 2003

Patients (N=451) Table 2: N indicating minimal change 3 weeks + 196 + 196 3 months + 107 36 6 months + 96 42 9 months + 80 37 12 months + 88 43 12 months SF-36 + 81 71 Table 1: Baseline characteristics   Age (years) 57.87 ± 6.56 Gender (% male) 65.0 GOLD II (N (%)) 227 (50.3) GOLD III (N (%)) 176 (39.0) GOLD IV (N (%)) 48 (10.6) Smoking pack years 42.61 ± 23.47

Results - CCQ

Results - CAT

Results - SGRQ

Conclusions MCID ranges found: No specific pattern found CCQ improvement 0,33-0,56 CCQ deterioration 0,42-0,66 CAT improvement 1,40-3,12 CAT deterioration 1,91-4,21 SGRQ improvement 7,58-10,28 SGRQ deterioration 5,01-7,52 No specific pattern found Significant overlap in 95% confidence intervals Recall bias seems of limited influence on the MCID of health status tools.

Questions? Thank you for your attention! E-mail: h.j.alma@umcg.nl

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