Table 2 Summary of criteria used for Fried Phenotype components

Buttery et al. [34]

Participants with a BMI of less than 23 were considered low weight.

The Timed Up and Go test is used. Participants taking 15 s or more were classified as having a low walking speed.

Isometric grip strength was measured using a hand-held dynamometer Low grip strength was determined using sex and BMI specific cut points specified by Fried.

Measured using a single item from the Medical Outcome SF-36. Participants answering ‘none’ or ‘little of the time’ to the question ‘How much of the time during the past four weeks did you have a lot of energy?’ were classified as having exhaustion.

Participants reporting performing no sports in the previous three months, and no physical activity on any day of the week requiring the person to start to sweat or get out of breath were classified as having low physical activity.

Cakmur [29]

Self-reported unintentional weight greater than 3 kg in the previous 3 months.

Slow gait speed was measured through the 6-meter walking speed test and was adjusted for gender and height.

Muscle weakness was measured with a hand dynamometer, and the average score for the dominant hand, adjusted for gender and BMI, was recorded.

Self-reported exhaustion was evaluated by asking: “Do you feel a lack of energy or fatigue or tiredness?”

The Independence in ADL index was used to evaluate low physical activity.

Castellana et al. [36]

Assessed by the Mini Nutritional Assessment, using a score threshold < 23.5.

Gait speed was evaluated using a 5-m walking test and rated slow if the time recorded was greater than or equal to the cut-off point of 0.6 m/s

The 5-repetitions sit-to-stand test measures the amount of time a patient takes to rise 5 times from a seated position without using his or her arms and was used as a proxy measure of weakness, > 15 s classified as weakness

Modified version of the Berg stool-stepping task

Participants reporting average level of physical activity during the past year, choosing from 6 response categories (from 0 to 5), < 2 classified as having low physical activity

Cheung et al. [27]

10 pounds or greater unintentional weight loss in the last year

Slow walking speed

Grip strength

Self-reported exhaustion

Physical Activity Scale for the Elderly

Closs et al. [38]

4.55 kg or greater unintentional weight loss in the last year

Walking a standard distance course of 4.6 m: ≥ 7 s for men height ≤ 1.73 m or women height ≤ 1.59 m; ≥ 6 s for men height > 1.73 m or women height > 1.59 m

Men: BMI ≤ 24 grip strength ≤ 29; BMI 24.1–26 grip strength ≤ 30; BMI 26.1–28 grip strength ≤ 30; BMI > 28 grip strength ≤ 32

Women: BMI ≤ 23 grip strength ≤ 17; BMI 23.1–26 grip strength ≤ 17.3; BMI 26.1–29 grip strength ≤ 18; BMI > 29 grip strength ≤ 21

Self-reported exhaustion, identified by two questions from the depression scale of CES-D

Minnesota Leisure Time Activity Questionnaire: < 383 kcal for men < 270 kcal for women

Gu et al. [22]

Greater than 4.55 kg or 5 % unintentional weight loss in the last year

Walking speed < 0.8 m/s over a distance of 4.57 m, or needing auxiliary walking equipment or human assistance while walking

Maximum value of grip strength <26 kg in male or <18 kg in female

Answer “Yes” when being asked “whether do you often feel fatigue?“

Defined as “low group” in the short form of international physical activity questionnaire

Herr et al. [33]

Self-reported weight loss of 5 kg during the past year; And/or self-reported weight loss of 3 kg during the past 3 months; And/or body mass index ≤ 18.5 kg/m2

Self-reported slow walking speed And/or difficulty walking up a flight of stairs And/or bedridden or unable to transfer from bed to chair without help

Self-reported difficulty carrying a bag weighting 5 kg

Self-reported fatigue (when moving, resting,or all the time)

No regular exercise or outdoor activity (self-reported); And/or bedridden or unable to transfer from bed to chair without help

Kamil et al. (2014) [31]

5 % or greater unintentional weight loss in the last year or body mass index less than 18.5 kg/m.

20-foot gait speed in the lowest sex-adjusted quintile.

Self-reported weakness (some or much difficulty lifting or carrying an object as heavy as 10 pounds or unable to do).

Self-reported exhaustion (some or much difficulty walking from one room to another or unable to do).

Self-reported low physical activity (participant report of being less active than individuals of the same age).

Liljas et al. [28]

Weight loss was defined as loss of 10 % or more of body weight in the last 4 years or a current BMI of less than 18.5 kg/m2.

Slow walking speed was measured as the mean time of two measurements taken to complete an 8-foot walk at usual pace.

Assessed using a dynamometer with the maximum handgrip strength measure out of three attempts on each side used for analysis. Weak grip was classified as being in the lowest quintile of the sex- and BMI-adjusted distribution.

Self-reported exhaustion identified by two questions (items 7 and 20) from the CES-D scale. Exhaustion was defined as a positive response to either of the two statements from the CES-D (items 7 and 20).

Based on three questions about the frequency with which participants undertook vigorous, moderate, and mild exercise.

Lorenzo-López et al. [30]

Unintentional weight loss greater than 4.5 kg in previous year.

The walking time (in seconds) over a distance of 4.57 m, adjusting for gender and height.

Muscle weakness was measured with a hand dynamometer in the dominant hand, results adjusted for gender and BMI.

Self-reported exhaustion, identified by two questions (items 7 and 20) from the CES-D scale.

Measured by the weighted score of kilocalories expended per week, calculated based on the Minnesota Leisure Time Activity Questionnaire, based on each participant’s report, and adjusting for gender.

Mohd Hamidin et al. [23]

Greater than 4.5 kg or 5 % unintentional weight loss in the last year

Walking a standard distance course of 4.6 m: ≥ 7 s for men height ≤ 1.73 m or women height ≤ 1.59 m; ≥ 6 s for men height > 1.73 m or women height > 1.59 m

Participants who cannot carry out the muscle strength test, or who recorded less than 18.0 kg of grip strength for male and 12.5 kg for female, were classified as positive for grip strength criterion.

Self-reported exhaustion was defined as a positive response to either of the two statements from the CES-D (items 7 and 20).

Assessed according to self-report of frequency, duration and intensity of usual activities based on the Rapid Assessment of Physical Activity questionnaires

Naharci et al. [32]

Unintentional loss of 10 or more pounds in the last six months.

Participants were asked to walk without assistance for 25 feet, and the time was measured for the intermediate 15 feet. Cut-offs stratified by gender and height were used, and slow walking speed was defined according to Fried criteria.

Grip strength was measured using dynamometers on the dominant hand. The average of two attempts was used, and the cut-offs were stratified by gender and BMI quartiles. The lowest quartile in each gender group was considered weak for the frailty criteria.

Self-reported exhaustion identified by two questions (items 7 and 20) from the CES-D scale. Exhaustion was defined as a positive response to either of the two statements from the CES-D (items 7 and 20).

Participants were asked how often they engaged in vigorous, moderate and mild activities [17], and were classified as having low physical activity if they answered ‘hardly ever or never’ or ‘one to three times a month’ to all three of the questions.

Ng et at [37]

BMI of less than 18.5 kg/m2 and/or unintentional weight loss of 10 pounds (4.5 kg) or more in the past 6 months.

Using the 6-meter fast gait speed test, using the average of 2 measurements, and the lowest quintile values stratified for gender and height to classify participants as slow.

Leg muscle strength was determined using dominant knee extension, using the average value from 3 trials in kilograms, standardized on gender and BMI strata. Participants with knee extension strengths in the lowest quintiles were classified as weak.

Measured with 3 questions on vitality domain in the Medical Outcomes Study SF-12: “Did you feel worn out?” “Did you feel tired?” “Did you have a lot of energy?” with total summed scores ranging from 3 to 15, and a higher score indicating more energy. A score of less than 10 was used to denote exhaustion.

Physical activities were assessed based on self-reported time (in hours) spent doing light, moderate, and vigorous activities on weekdays and the weekend. The total amount of time spent on performing moderate and vigorous activities per week and activity time below the gender-specific lowest quintile was used to denote frailty.