Variable Details

Available Studies




Variable Type 


Variable Name 




Frailty (categorical)
Categorical frailty measure - 3 levels

This variable is only available in ROS and MAP.

This variable is a composite indicator of frailty based on 5 dichotomized frailty components:

  1. BMI
  2. Fatigue
  3. Gait
  4. Grip strength
  5. Physical activity

BMI is calculated as weight divided by height. Fatigue is assessed using two questions derived form a modified version of the Center for Epidemiologic Studies - Depression Scale: a) I felt that everything I did was an effort, and b) I could not get “going”. Gait is based on time to walk 8 feet. Grip strength is measured using the Jamar hydraulic hand dynamometer (Lafayette Instruments, Lafayette, IN) and is the average of 4 trials (2 per hand). Physical activity is based on the number of hours per week that participants engage in 5 types of activities: walking, gardening, calisthenics, bicycle riding, and swimming.

BMI below 20, a response of “yes” to one or both questions assessing fatigue, and scores in the lowest quintile of gait (including those unable to ambulate), grip, and physical activity are considered consistent with frailty. The composite measure of frailty is based on the number of frail components (see table below).

Value Coding
0 Not frail - 0 frail components
1 Pre-frail - 1 or 2 frail components
2 Frail - 3 or more frail components