Table 1 Derivation of frailty score components in ELSA

Weight loss

BMI < 18.5 kg/m² OR > 10% weight loss since last wave

Exhaustion

Positive answer to either CES-D question (‘everything I did was an effort’ or ‘I could not get going’

Low grip strength (adjusted for BMI)

Males: Grip adjusted for BMI = Maximum grip – ((BMI-27.6)× 0.31)

Females: Grip adjusted for BMI = Maximum grip – ((BMI-27.9)× 0.07)

Low grip strength was defined as values in the lowest quintile at wave 2, for males and females separately:

M < 31.12 kg

F < 17.60 kg

Low gait speed (adjusted for height)

Males: Gait speed adjusted for BMI = Gait speed – ((height-172)×0.00941)

Females: Gait speed adjusted for BMI = Gait speed – ((height-158)× 0.010)

Low gait speed was defined as values in the lowest quintile at wave 2, for males and females separately.

M < 0.691 m/s

F < 0.619 m/s

Low activity

M < 16.5 activity units

F < 13.5 activity units