Abstract
Background
Frailty is an especially problematic expression of population ageing. International guidelines recommend routine identification of frailty to provide evidence-based treatment but currently available tools require additional resource.
Objectives
To develop and validate an electronic frailty index (eFI) using routinely available primary care electronic health record data.
Study design and setting
Retrospective cohort study. Development and internal validation cohorts were established using a randomly split sample of the ResearchOne primary care database. External validation cohort established using THIN database.
Participants
Patients aged 65 to 95, registered with a ResearchOne or THIN practice on 14/10/2008.
Predictors
We constructed the eFI using the cumulative deficit frailty model as our theoretical framework. The eFI score is calculated by the presence or absence of individual deficits as a proportion of the total possible. Categories of fit, mild, moderate and severe frailty were defined using population quartiles.
Outcomes
Outcomes were one, three and five year mortality, hospitalisation and nursing home admission.
Statistical analysis
Hazard ratios (HRs) were estimated using bivariate and multivariate Cox regression analyses. Discrimination was assessed using receiver operating characteristic (ROC) curves. Calibration was assessed using pseudoR2 estimates.
Results
We include data from a total of 931,541 patients. The eFI incorporates 36 deficits constructed using 2,171 CTV3 codes. One year adjusted HR for mortality was 1.92 (95% CI 1.81 to 2.04) for mild frailty, 3.10 (95% CI 2.91 to 3.31) for moderate frailty and 4.52 (95% CI 4.16 to 4.91) for severe frailty. Corresponding estimates for hospitalisation were 1.93 (95% CI 1.86 to 2.01), 3.04 (95% CI 2.90 to 3.19) and 4.73 (95% CI 4.43 to 5.06), and for nursing home admission were 1.89 (95% CI 1.63 to 2.15), 3.19 (95% CI 2.73 to 3.73) and 4.76 (95% CI 2.73 to 3.73), with good to moderate discrimination but low calibration estimates.
Conclusions
The eFI uses routine data to identify older people with mild, moderate and severe frailty, with robust predictive validity for outcomes of mortality, hospitalisation and care home admission. Routine implementation of the eFI could enable delivery of evidence-based interventions to improve outcomes for this vulnerable group.
Frailty is an especially problematic expression of population ageing. International guidelines recommend routine identification of frailty to provide evidence-based treatment but currently available tools require additional resource.
Objectives
To develop and validate an electronic frailty index (eFI) using routinely available primary care electronic health record data.
Study design and setting
Retrospective cohort study. Development and internal validation cohorts were established using a randomly split sample of the ResearchOne primary care database. External validation cohort established using THIN database.
Participants
Patients aged 65 to 95, registered with a ResearchOne or THIN practice on 14/10/2008.
Predictors
We constructed the eFI using the cumulative deficit frailty model as our theoretical framework. The eFI score is calculated by the presence or absence of individual deficits as a proportion of the total possible. Categories of fit, mild, moderate and severe frailty were defined using population quartiles.
Outcomes
Outcomes were one, three and five year mortality, hospitalisation and nursing home admission.
Statistical analysis
Hazard ratios (HRs) were estimated using bivariate and multivariate Cox regression analyses. Discrimination was assessed using receiver operating characteristic (ROC) curves. Calibration was assessed using pseudoR2 estimates.
Results
We include data from a total of 931,541 patients. The eFI incorporates 36 deficits constructed using 2,171 CTV3 codes. One year adjusted HR for mortality was 1.92 (95% CI 1.81 to 2.04) for mild frailty, 3.10 (95% CI 2.91 to 3.31) for moderate frailty and 4.52 (95% CI 4.16 to 4.91) for severe frailty. Corresponding estimates for hospitalisation were 1.93 (95% CI 1.86 to 2.01), 3.04 (95% CI 2.90 to 3.19) and 4.73 (95% CI 4.43 to 5.06), and for nursing home admission were 1.89 (95% CI 1.63 to 2.15), 3.19 (95% CI 2.73 to 3.73) and 4.76 (95% CI 2.73 to 3.73), with good to moderate discrimination but low calibration estimates.
Conclusions
The eFI uses routine data to identify older people with mild, moderate and severe frailty, with robust predictive validity for outcomes of mortality, hospitalisation and care home admission. Routine implementation of the eFI could enable delivery of evidence-based interventions to improve outcomes for this vulnerable group.
| Original language | English |
|---|---|
| Journal | Age and Ageing |
| Early online date | 3 Mar 2016 |
| DOIs | |
| Publication status | E-pub ahead of print - 3 Mar 2016 |