Greater understanding of changes in the degree of frailty is important for clarifying the natural history of frailty and may help clinical decision-making regarding preventive interventions. The objectives of this study were to explore natural frailty transition rates at 1-year follow-up and to identify the main determinants of such transitions.

This is a prospective longitudinal study covering a representative sample of community-dwelling older adults aged ≥65 years (n = 749) at baseline, and transition information at 1-year follow-up (n = 537).

The assessment of frailty status was based on phenotypic criteria (unintentional weight loss, weakness, exhaustion, slow walking speed, low physical activity). Frailty transitions (progressed, regressed, no change, or death) and associated factors were assessed.

Most participants remained unchanged from their baseline status (57.1% non-frail, 83.4% pre-frail, 66.7% frail). Regarding frailty transitions, 42.9% of non-frail older adults at baseline had progressed to a pre-frail status by the 1-year follow-up, and 7.9% of pre-frail older adults had become frail. Importantly, 33.3% of frail older adults regressed to a pre-frail status and 8.7% of pre-frail adults had regressed to a non-frail status. Non-frail females tended to progress to pre-frailty significantly more than males (p = 0.006), and mortality was higher among participants classified as frail at baseline (10.7%). Logistic regression showed that the main determinants of worsening frailty were hearing impairment (OR 3.180; 95% CI 1.078-9.384), congestive heart failure (OR 10.864; 95% CI 1.379-85.614), and polypharmacy (OR 2.572, 95% CI 1.096-6.037).