Systematic review of the utility of the frailty index and frailty phenotype to predict all-cause mortality in older people

Table 1 Characteristics of included studies by study size and details of the frailty index used

Author (year)	Country (name of study)^a	Size (% male)	Age, years mean (SD)	Follow-up (years)	Study quality (SIGN^b checklist)	No. of items	Details of the frailty index used in individual studies
							Domains included
							Energy	Physical activity	Weight loss or BMI	Strength^c	Gait ^d	No. of other domains^e
Chao (2018) [32]	USA (HRS)	FP: 1642 (n/s); FI: 7713 (n/s)	n/s (aged ≥65)^f	7	+	24	✓					8
Romero-Ortuno and Soraghan (2014) [33]	Europe - various (SHARE)	7058 (43.3%)	M: 80.4 (4.6); F: 81.1 (4.9)	5	++	70	✓	✓		✓	✓	12
Ding (2017) [34]	England (ELSA)	4638 (44.6%)	74.0 (6.3)	2	0	30	✓			✓	✓	6
Woo (2012) [35]	China	4000 (50%)	n/s (aged ≥65)	4	+	47		✓	✓	✓	✓	8
Li (2015) [36]	Europe, North America and Australia (GLOW)	3985 (0%)	69.4 (8.9)	3	++	34	✓	✓	✓	✓	✓	7
Zucchelli (2019) [37]	Sweden (SNSACK)	3363 (35.1%)	74.7 (11.2)	3 to 5	+	45					✓	10
Widagdo (2015) [38]	Australia (ALSA)	2087 (n/s)	n/s (aged ≥65)	3	0	39				✓	✓	8
Thompson (2019) [39]	Australia (NWAHS)	909 (45%)	74.4 (6.2)	1 to 10	++	34	✓	✓	✓	✓	✓	8

^aStudy names are as follows: SHARE, The Survey of Health, Ageing and Retirement in Europe; HRS, The Health and Retirement Study; ELSA, The English Longitudinal Study of Ageing; GLOW, The Global Longitudinal Study of Osteoporosis; SNSACK, The Swedish National Study on Ageing and Care in Kungsholmen; ALSA, The Australian Longitudinal Study of Ageing; NWAHS, The North West Adelaide Health Study
^bSIGN, Scottish Intercollegiate Guidelines Network. ⁺⁺all or most of the criteria in the SIGN checklists have been fulfilled, ⁺some of the criteria have been fulfilled, ⁰few or no criteria fulfilled
^cItems like grip strength and difficulty lifting weights over 10 lbs
^dItems like gait speed, can walk 100m, difficulty with moving around, and usage of walking stick
^eSee Additional file 1: Table S6 for full list of domains (18 domains: energy, physical activity, weight loss/BMI, strength, gait, cognition, mood, activities of daily living, self-reported health, hearing and vision, incontinence, medication, sleep, hospitalisation, comorbidities, symptoms, social support and falls)
^fHRS includes aged 50 or older participants at baseline but the author limits the analysis to those aged 65 and older

ISSN: 2046-4053