International psychometric validation of the Living with Chronic Illness Scale in Spanish-speaking patients with chronic obstructive pulmonary disease.

Objectives: To validate the Living with Chronic Illness (LW-CI) Scale in patients with chronic obstructive pulmonary disease (COPD).

Design: Observational, cross-sectional validation study with retest. Acceptability, reliability, precision and construct validity were tested.

Setting: The study took place in primary and secondary specialised units of public and private hospitals of Spain and Colombia.

Participants: The study included 612 patients with COPD assessed from May 2018 to May 2019. A consecutive cases sampling was done. Inclusion criteria included: (A) patients with a diagnosis of COPD; (B) native Spanish speaking; (C) able to read and understand questionnaires; and (D) able to provide informed consent. Exclusion criteria included: (A) cognitive deterioration and (B) pharmacological effect or disorder that could disrupt the assessment.

Results: The LW-CI-COPD presented satisfactory data quality, with no missing data or floor/ceiling effects, showing high internal consistency for all the domains (Cronbach's alpha for the total score 0.92). Test-retest reliability was satisfactory (intraclass correlation coefficient=0.92). The LW-CI-COPD correlated 0.52-0.64 with quality of life and social support measures. The scale demonstrated satisfactory known-groups validity, yielding significantly different scores in patients grouped according to COPD severity levels.

Conclusions: This has been the first validation study of the LW-CI-COPD. It is a feasible, reliable, valid and precise self-reported scale to measure living with COPD in the Spanish-speaking population. Therefore, it could be recommended for research and clinical practice to measure this concept and evaluate the impact of centred-care interdisciplinary interventions based on the patients' perspective, focused on providing holistic and comprehensive care to patients with COPD.