Diagnostic accuracy of the FRAIL scale plus functional measures for frailty screening: a cross-sectional study.

Background: There is little knowledge of the diagnostic accuracy of screening programmes for frailty in primary care settings.

Aim: To assess a two-step strategy consisting of the administration of the FRAIL scale to those who are non-dependent and aged ≥75 years, followed-up by measurement of the Short Physical Performance Battery (SPPB) or gait speed in those who are positive.

Design & Setting: Cross-sectional and longitudinal cohort study. Analysis of primary care data from the FRAILTOOLS project at five European cities.

Method: All primary care patients consecutively attending were enrolled. They received the index tests, plus the Fried frailty phenotype (FP) and the frailty index to assess their frailty status. Mortality and worsening of dependency in basic and instrumental activities of daily living (BADL and IADL) over 1 year were ascertained.

Results: Prevalence of frailty based on FP was 14.9% in the 362 participants. A FRAIL scale score ≥1 had a sensitivity of 83.3% (95% confidence interval [CI] = 73.1 to 93.6) to detect frailty. A positive result and an SPPB score <11 had a sensitivity of 72.2% (95% CI = 59.9 to 84.6); when combined with a gait speed <1.1 m/s, the sensitivity was 80.0% (95% CI = 68.5 to 91.5). Two-thirds of those screened as positive were not frail. In the best scenario, sensitivities of this last combination to detect IADL and BADL worsening were 69.4% (95% CI = 59.4 to 79.4) and 63.6% (95% CI = 53.4 to 73.9), respectively.

Conclusion: Combining the FRAIL scale with other functional measures offers an acceptable screening approach for frailty. Accurate prediction of worsening dependency and death need to be confirmed through the piloting of a frailty screening programme.