Functional Measures in Non-COPD Chronic Respiratory Diseases: A Systematic Review

Abstract

Background/Objectives: The extensive range of instruments designed for evaluating functional performance (FP) in chronic respiratory diseases (CRD) other than chronic obstructive pulmonary disease (COPD) presents a challenge in selecting the most appropriate one. Therefore, this systematic review aimed to summarise FP instruments, their measurement properties, their minimum clinically important differences, and their associations with CRD course-related events or prognosis in non-COPD CRD. Methods: Studies employing patient-reported or performance-based instruments to assess FP in non-COPD CRD were systematically identified in the PubMed, PEDro, Embase, and Cochrane Library databases. COPD-exclusive studies or those solely reporting exercise capacity tests were excluded. Examination focused on measurement properties and associations with CRD course-related events or prognosis. The risk of bias was evaluated using the COSMIN, Downs and Black, and PEDro checklists based on the study design. Results: A total of 216 studies across seven CRD categories [asthma, bronchiectasis, cystic fibrosis, interstitial lung disease (ILD), pulmonary arterial hypertension (PAH), pre-/post-lung-transplantation] from various study types were included. Thirty-three instruments were identified, with the SF-36 questionnaire's physical function domain being the most commonly used patient-reported tool. The 1 min sit-to-stand test was the most extensively studied performance-based measure, with its measurement properties frequently reported in non-COPD CRD studies. Associations with events were infrequently documented, primarily in ILD and PAH studies related to mortality. Conclusions: Despite the prevalent use of FP instruments, limited information exists concerning their measurement properties and clinical implications. This review furnishes a concise summary of available evidence, aiding informed clinical decisions when selecting FP tools for non-COPD CRD.

Keywords: functional status; lung disease; physical functional performance; reproducibility of results; systematic review.

Figure 1

Study Flowchart.

Figure 2

Studies using functional performance tests by chronic respiratory disease. Abbreviations: ILD–interstitial lung disease; PAH—pulmonary arterial hypertension; 15steps-C—15-step climbing; CS-PFP—continuous scale physical function performance test; Glittre ADL—Glittre Activities of Daily Living; 8-FUGT—8-foot up-and-go; TUG—timed up-and-go; SPPB—short physical performance battery; 4MGS—four-metre gait speed; 3min-STS—3 min sit-to-stand; 5rep-STS—5-repetition sit-to-stand; 30 s-STS—30 sec sit-to-stand; 1min-STS—1 min sit-to-stand; PPT—physical performance test.

Figure 3

Frequency of patient-reported tools per disease. Abbreviations: ILD—interstitial lung disease; PAH—pulmonary arterial hypertension; pre-LTx—patients with chronic respiratory disease awaiting lung transplantation; post-LTx—patients with chronic respiratory disease who underwent lung transplantation; SF-36—Medical Outcomes Study 36-Item Short Form of Health Survey; SGRQ—Saint’s George Respiratory Questionnaire; WHOfc—World Health Organisation functional class; NYHA—New York Heart Association; AQLQ—Asthma Quality of Life Questionnaire; CFQoL—Cystic Fibrosis Quality of Life; SF-12—Medical Outcomes Study 12-Item Short Form of Health Survey; PROMIS-29—Patient-Reported Outcomes Measurement Information System; LWAQ—Living with Asthma Questionnaire; M-AQLQ—Mini Asthma Quality of Life Questionnaire; CAMPHOR—Cambridge Pulmonary Hypertension Outcome Review; QoL-EPM—Asthma Quality of Life from Escola Paulista de Medicina; MLHFQ—Minnesota Living with Heart Failure Questionnaire; QoL-B—Quality of Life in Bronchiectasis; London ADL—London Activities of Daily Living; FPI—functional performance inventory; SOLQ—Seattle Obstructive Lung Questionnaire; ECOPs—Eastern Cooperative Oncology Performance Status; PROMIS-PF—Patient-Reported Outcomes Measurement Information System Physical Function Short Form 8a; MDHAQ—Multidimensional Health Assessment Questionnaire; HAQ-DI—Health Assessment Questionnaire Disability Index.