Development and validation of an electronic frailty index in a national health maintenance organization.

Background: Frailty constitutes a major factor that puts the elderly at risk of health and functional deterioration.

Objectives: To develop and validate an Electronic Frailty Index based on electronic data routinely collected in the HMO.

Study design and setting: A retrospective cohort of the HMO members.

Participants: 120,986 patients, aged 65 years and over at the beginning of 2023.

Predictors: A cumulative frailty index including 36 medical, functional, and social deficits.

Outcomes: One-year all-cause mortality or hospitalization.

Statistical analysis: One-year hazard ratios were estimated for composite outcome of mortality or hospitalization using multivariable hierarchical Cox regression.

Results: The mean EFI score increased with the Social Security Nursing Benefit. Compared to fit patients, mild, moderate, and severe frailty patients had 2.07, 3.35, and 4.4-fold increased risks of mortality or hospitalization, after controlling for covariates.

Conclusions: The findings showed that the Electronic Frailty Index version we created is valid in predicting mortality or hospitalization. In addition, the Electronic Frailty Index converged with an independent measurement produced by National Social Security.