Relationship Between COPD Progression and Frailty Progression: A Five-year Observation in Real Clinical Practice.

Abstract

Purpose: Although a cross-sectional association between frailty and chronic obstructive pulmonary disease (COPD) has been established, the longitudinal relationship between the progression of both frailty and COPD remains unclear.

Materials and methods: This longitudinal study followed 87 COPD patients over five years, with evaluations conducted every six months. Participants underwent pulmonary function tests and completed the Kihon Checklist, a tool widely used in Japan to assess frailty. Kihon Checklist scores range from 0 (no frailty) to 25 (severe frailty), categorizing participants as robust (0-3), pre-frail (4-7), or frail (8-25). Annual changes were analyzed using linear mixed models.

Results: A significant association was observed between time and worsening frailty classification, with patients transitioning from robust to pre-frail or from pre-frail to frail (odds ratio: 1.224, p = 0.004). However, the GOLD stages (GOLD 1 to GOLD 4) did not exhibit significant progression over five years. The cohort demonstrated significant declines in forced expiratory volume in one second (FEV₁) and increases in Kihon Checklist total scores. FEV₁ decreased by an estimated mean of 28.6 mL per year (95% CI: 18.9-38.4, p < 0.001), while the Kihon Checklist total score increased by 0.30 annually (95% CI: 0.09-0.51, p = 0.006). Estimated FEV₁ declined significantly from baseline after two years in the baseline frail group (p < 0.01), after 3.5 years in the pre-frail group (p < 0.01), and after four years in the robust group (p < 0.05). Although the GOLD 3+4 group showed a significant increase in Kihon Checklist total scores after 3.5 years (p < 0.05), no significant change was observed in the GOLD 1 and GOLD 2 groups.

Conclusion: COPD patients with frailty show a more rapid decline in FEV₁, indicating accelerated COPD progression. These findings suggest frailty is static and only COPD is progressing.