Minimal Clinically Important Differences for Patient-Reported Outcome Measures of Fatigue in Patients With COPD Following Pulmonary Rehabilitation

Patrícia Rebelo; Ana Oliveira; Lília Andrade; Carla Valente; Alda Marques

doi:10.1016/j.chest.2020.02.045

Minimal Clinically Important Differences for Patient-Reported Outcome Measures of Fatigue in Patients With COPD Following Pulmonary Rehabilitation

Chest. 2020 Aug;158(2):550-561. doi: 10.1016/j.chest.2020.02.045. Epub 2020 Mar 14.

Authors

Patrícia Rebelo¹, Ana Oliveira², Lília Andrade³, Carla Valente³, Alda Marques⁴

Affiliations

¹ Lab3R-Respiratory Research and Rehabilitation Laboratory, School of Health Sciences, University of Aveiro, Aveiro, Portugal; iBiMED-Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.
² Lab3R-Respiratory Research and Rehabilitation Laboratory, School of Health Sciences, University of Aveiro, Aveiro, Portugal; iBiMED-Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal; West Park Healthcare Centre, Toronto, ON, Canada; School of Rehabilitation Science, McMaster University, Hamilton, ON, Canada.
³ Pulmonology Department, Centro Hospitalar do Baixo Vouga, Aveiro, Portugal.
⁴ Lab3R-Respiratory Research and Rehabilitation Laboratory, School of Health Sciences, University of Aveiro, Aveiro, Portugal; iBiMED-Institute of Biomedicine, Department of Medical Sciences, University of Aveiro, Aveiro, Portugal. Electronic address: amarques@ua.pt.

PMID: 32184112
DOI: 10.1016/j.chest.2020.02.045

Abstract

Background: Fatigue is a burdensome and prevailing symptom in patients with COPD. Pulmonary rehabilitation (PR) improves fatigue; however, interpreting when such improvement is clinically relevant is challenging. Minimal clinically important differences (MCIDs) for instruments assessing fatigue are warranted to better tailor PR and guide clinical decisions.

Research question: This study estimated MCIDs for the Functional Assessment of Chronic Illness Therapy-Fatigue Subscale (FACIT-FS), the modified FACIT-FS, and the Checklist Individual Strength-Fatigue Subscale in patients with COPD following PR.

Study design and methods: Data from patients with COPD who completed a 12-week community-based PR program were used to compute the MCIDs. The pooled MCID was estimated by calculating the arithmetic weighted mean, resulting from the combination of anchor-based (weight, two-thirds) and distribution-based (weight, one-third) methods. Anchors were patients' and physiotherapists' Global Rating of Change Scale, COPD Assessment Test, St. George's Respiratory Questionnaire (SGRQ), and exacerbations. To estimate MCIDs, we used mean change, receiver-operating characteristic curves, and linear regression analysis for anchor-based approaches, and 0.5 × SD, SE of measurement, 1.96 × SE of measurement, and minimal detectable change for distribution-based approaches.

Results: Fifty-three patients with COPD (79% male, 68.4 ± 7.6 years of age, and FEV₁ 48.7 ± 17.4% predicted) were included in the analysis. Exacerbations and the SGRQ-impact and the SGRQ-total scores fulfilled the requirements to be used as anchors. Pooled MCIDs were 4.7 for FACIT-FS, 3.8 for the modified FACIT-FS, and 9.3 for the Checklist Individual Strength-Fatigue Subscale.

Intrpretation: The MCIDs proposed in this study can be used by different stakeholders to interpret PR effectiveness.

Clinical trial registration: ClinicalTrials.gov; No.: NCT03799666; URL: www.clinicaltrials.gov.

Keywords: clinical decision-making; exercise; health status; interpretability; outcome measurement.

Publication types

Observational Study
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Fatigue / diagnosis*
Fatigue / etiology
Fatigue / prevention & control*
Female
Humans
Male
Middle Aged
Minimal Clinically Important Difference*
Patient Reported Outcome Measures*
Predictive Value of Tests
Prospective Studies
Pulmonary Disease, Chronic Obstructive / complications
Pulmonary Disease, Chronic Obstructive / rehabilitation*
Surveys and Questionnaires
Symptom Assessment

Associated data

ClinicalTrials.gov/NCT03799666