Predicting posthospitalization falls in Brazilian older adults: External validation of the Carpenter instrument

Objectives: This study sought to explore and externally validate the Carpenter instrument's efficacy in predicting postdischarge fall risk among older adults admitted to the emergency department (ED) for reasons other than falls or related injuries.

Methods: A prospective cohort study was conducted on 779 patients aged ≥ 65 years from a tertiary hospital in São Paulo, Brazil, who were monitored for up to 6 months post-ED hospitalization. The Carpenter instrument, which evaluates the four risk factors nonhealing foot sores, self-reported depression, inability to self-clip toenails, and prior falls, was utilized to assess fall risk. Follow-up by telephone occurred at 30, 90, and 180 days to identify falls and mortality. Fine-Gray models estimated the predictive power of Carpenter instrument for future falls, considering death as a competing event and sociodemographic factors, frail status, and clinical measures as confounders.

Results: Among 779 patients, 68 (9%) experienced a fall within 180 days post-ED admission, and 88 (11%) died. The majority were male (54%), with a mean age of 79 years. Upon utilizing the Carpenter score, those with a higher fall risk (≥2 points) displayed more comorbidities, greater frailty, and increased clinical severity at baseline. Regression analyses showed that every additional point on the Carpenter score increased the hazard of falls by 73%. Two primary contributors to its predictive potential were identified: a history of falls in the preceding year and an inability to self-clip toenails. However, the instrument's discriminative accuracy was suboptimal, with an area under the curve of 0.62.

Conclusions: While the Carpenter instrument associated with a higher 6-month postadmission fall risk among older adults post-ED visit, its accuracy for individual patient decision making was limited. Given the significant impact of falls on health outcomes and health care costs, refining risk assessment tools remains essential. Future research should focus on enhancing these assessments and devising targeted proactive strategies.