The correlation between pain and intrinsic capacity in older patients with chronic diseases: a cross-sectional study.

Chronic pain prevalence was 75.3, and 87.0% were classified as having intrinsic capacity decline status.

Locomotor and vitality were the most affected domains.

Age ≥80 years increased the risk of intrinsic capacity decline status, while polypharmacy (≥5 medications) showed a protective effect.

No significant interactions were found between chronic pain and age or polypharmacy.