Assessing Frailty with the Tilburg Frailty Indicator (TFI): A Review of Reliability and Validity

Figures & data

Table 1 General Characteristics of the Studies Included

Authors	Year	Country	Setting	Design	n	Age in years, mean ± SD	Prevalence figure
Gobbens et al^Citation1	2010	The Netherlands	community-dwelling	cross-sectional	479	≥ 75 years, 80.3 ± 3.8	47.1%
Metzelthin et al^Citation36	2010	The Netherlands	community-dwelling	cross-sectional	532	≥ 70 years, 77.2 ± 5.5	40.2%
Gobbens et al^Citation42	2012	The Netherlands	community-dwelling	longitudinal	484	≥ 75 years, 80.3 ± 3.8	-
Daniels et al^Citation37	2012	The Netherlands	community-dwelling	longitudinal	430	≥ 70 years, 77.2 ± 5.5	40.2%
Gobbens et al^Citation40	2013	The Netherlands	community-dwelling	cross-sectional	1,031	≥ 65 years, 73.4 ± 5.8	27.7%
Theou et al^Citation46	2013	Eleven European countries, including the Netherlands	community-dwelling	longitudinal	27,527	≥ 50 years, 65.3 ± 10.5	29.2%***
Santiago et al^Citation7	2013	Brazil	community-dwelling	cross-sectional	219	≥ 60 years, sample 1: 69.8 ± 7.8 and sample 2: 71.3 ± 8.0	35.6% (sample 1); 31.7% (sample 2)
Andreasen et al^Citation8	2014	Denmark	community-dwelling*****	cross-sectional****	13; 21	75.9 ± 6.9; 80.6 ± 6.5	-
Uchmanowicz et al^Citation11	2014	Poland	community-dwelling	cross-sectional	100	≥ 60 years, 68.2 ± 6.5	40%
Gobbens & Van Assen^Citation41	2014	The Netherlands	community-dwelling	longitudinal	484	≥ 75 years, 80.3 ± 3.8	-
Mulasso et al^Citation9	2015	Italy	community-dwelling	cross-sectional	267	≥ 65 years, 73.4 ± 6.0	44.6%
Gobbens et al^Citation39	2015	The Netherlands	assisted living facilities	cross-sectional	221	≥ 55 years, 84.8 ± 8.9	76.5%
Coelho et al^Citation10	2015	Portugal	community-dwelling	cross-sectional	252	≥ 65 years, 79.2 ± 7.3	54.8*
Andreasen et al^Citation48	2015	Denmark	community-dwelling******	cross-sectional****	14	≥ 65 years, 80.6	-
Uchmanowicz et al^Citation50	2016	Poland	community-dwelling	cross-sectional	212	≥ 60 years, 70.6 ± 7.2	44.1%
Freitag et al^Citation12	2016	Germany	community-dwelling	cross-sectional	210	≥ 64 years, sample 1: 76.9 ± 5.7 and sample 2: 72.5 ± 5.5	46.7% (sample 1); 32% (sample 2)
Dong et al^Citation13	2017	China	community-dwelling	cross-sectional	917	≥ 60 years, 68.6 ± 6.6	12.4%
Renne & Gobbens^Citation45	2018	The Netherlands	community-dwelling	cross-sectional	241	≥ 70 years, 76.5 ± 5.1	32.8%
Santiago et al^Citation51	2018	Brazil	community-dwelling*******	longitudinal	963	≥ 60 years, 70.5 ± 8.2	44.2%
Vrotsou et al^Citation14	2018	Spain	community-dwelling	cross-sectional	856	≥ 70 years, 78.1 ± 4.9	-
Topcu et al^Citation15	2019	Turkey	geriatrics outpatient clinic	cross-sectional	198	≥ 70 years, 77.7 ± 5.5	63.6%
Op Het Veld et al^Citation44	2019	The Netherlands	community-dwelling	longitudinal	2,420	≥ 65 years, 76.3 ± 6.6	-
Op Het Veld et al^Citation43	2019	The Netherlands	community-dwelling	longitudinal	2,420	≥ 65 years, 76.3 ± 6.6	64.8%**
Alqahtani et al^Citation52	2020	Saudi Arabia	community-dwelling********	cross-sectional	84	≥ 65 years, 72.0 ± 4.7	28.0%
Gobbens et al^Citation38	2020	The Netherlands	community-dwelling	longitudinal	180	≥ 70 years, 76.3 ± 5.1	29.4%
Gobbens & Andreasen^Citation49	2020	Denmark	acutely admitted patients	longitudinal	1,328	≥ 65 years, 76.9 ± 7.5	53.1%
Zhang et al^Citation47	2020	The Netherlands, Spain, Greece, Croatia, United Kingdom	community-dwelling	cross-sectional	2,250	≥ 70 years, 79.7 ± 5.7	-

Notes: *Cut-off for frailty was 6; **This study was conducted among pre-frail and frail individuals; ***This study did not use the original TFI; ****Cross-sectional qualitative research; *****Acutely admitted to hospital; ******Acutely admitted discharged to their own home; *******Users of primary health care services; ********in senior-living facilities, visiting outpatient clinic.

Abbreviation: SD, standard deviation.

Table 2 Internal Consistency Reliability of the TFI

Authors	Internal Consistency Reliability
Gobbens et al^Citation1	Cronbach’s alpha: total 0.73, physical 0.70, psychological 0.63, social 0.34
Metzelthin et al^Citation36	Cronbach’s alpha: total 0.79 Corrected item-total correlations: correlations ranged from 0.18 to 0.58 (mean 0.39)
Gobbens et al^Citation40	Cronbach’s alpha: total 0.71, physical 0.67, psychological 0.54, social 0.51
Santiago et al^Citation7	Cronbach’s alpha: total 0.78, physical 0.79, psychological 0.53, social 0.38
Uchmanowicz et al^Citation11	Cronbach’s alpha: total 0.72 Cronbach’s alpha reliability coefficients after the removal of an item ranged from 0.68 (coping) to 0.73 (anxiety)
Mulasso et al^Citation9	Cronbach’s alpha: total 0.66, physical 0.57, psychological 0.51, social 0.36 Corrected item-total correlations for each item with the domains in general, accepted values, with some exceptions (unexplained weight loss, poor hearing)
Coelho et al^Citation10	KR-20: total 0.78, physical 0.75, psychological 0.48, social 0.49
Uchmanowicz et al^Citation50	Cronbach’s alpha: total 0.74, physical 0.72, psychological 0.37, social 0.59 Corrected item-total correlations: ranged from 0.12 to 0.55
Freitag et al^Citation12	Cronbach’s alpha: total 0.67, physical 0.66, psychological 0.43, social 0.36 Cronbach’s alpha reliability coefficients after the removal of an item ranged from 0.6 (physical tiredness)–0.69 (coping) Corrected item-total correlations ranged from 0.12 (memory problems) to 0.58 (physical tiredness)
Dong et al^Citation13	Cronbach’s alpha: total 0.71, physical 0.71, psychological 0.51, social 0.25
Renne & Gobbens^Citation45	Cronbach’s alpha: total 0.80, physical 0.74, psychological 0.61, social 0.51
Vrotsou et al^Citation14	KR-20: total 0.69, physical 0.64, psychological 0.58, social 0.22
Topcu et al^Citation15	Cronbach’s alpha: total 0.68 Cronbach’s alpha reliability coefficients after the removal of an item ranged from 0.62 (physical tiredness)–0.69 (lack of social relations)Corrected item-total correlations: ranged from −0.05 (living alone) to 0.57 (physical tiredness)
Alqahtani et al^Citation52	KR-20: total 0.70, physical 0.68, psychological 0.57, social 0.42; the KR-20 after the removal of an item ranged from 0.66 (coping)–0.72 (poor hearing, physical tiredness) Corrected item-total correlations ranged from 0.10 (unexplained weight loss) to 0.47 (coping)
Zhang et al^Citation47	Cronbach’s alpha: varied among five countries involved: total 0.70 (Spain)–0.75 (Croatia), physical 0.60 (Spain)–0.73 (The Netherlands), psychological 0.38 (UK)–0.55 (Greece, Croatia), social 0.22 (Greece)–0.43 (The Netherlands)

Abbreviation: KR-20, Kuder–Richardson formula.

Table 3 Test–Retest Reliability, Inter-Rater Reliability, and Parallel Forms Reliability of the TFI

Authors	Test-Retest Reliability
Gobbens et al^Citation1	Two weeks (Pearson correlation coefficient): total 0.90, physical 0.87, psychological 0.77, social 0.86 One-year period (Pearson correlation coefficient): total 0.79, physical 0.78, psychological 0.67, social 0.76
Santiago et al^Citation7	7–10 days (Pearson correlation coefficient): total 0.88, physical 0.88, psychological 0.67, social 0.89. 7–10 days (simple agreement); items ranged from 0.63 (memory) to 1.00 (live alone, lack of support) 7–10 days (Kappa coefficients): five items had nearly perfect agreement (0.81–1.00), four items had substantial agreement (0.61–0.80) agreement, two items had moderate agreement (0.41–0.60), four items had fair agreement (0.21–0.40)
Coelho et al^Citation10	12–16 days: (Pearson correlation coefficient): total 0.91, physical 0.87, psychological 0.75, social 0.87. 12–16 days (simple agreement): items ranged from 0.78 (depression, anxiety) to 0.97 (living alone) 12–16 days (Kappa coefficients): ranged from 0.52 to 0.95
Uchmanowicz et al^Citation50	10–14 days: (Kappa coefficient): a high level of agreement with regard to items was demonstrated with coefficients ranging from 0.96 to 1.00
Freitag et al^Citation12	20 weeks (ICC): total 0.87, physical 0.85, psychological 0.75, social 0.84
Dong et al^Citation13	10–25 days (ICC): total 0.88, physical 0.80, psychological 0.65, social 0.81
Vrotsou et al^Citation14	7–14 days (simple agreement): item ranged from 0.77 to 0.99, except anxious (0.66) 7–14 days (Kappa coefficient): 0.98 (living alone), 0.23 to 0.34 (physical tiredness, anxious, coping, support) 0.46 to 0.57 (all other items, except unintentional weight loss)
Topcu et al^Citation15	One week (ICC): 0.99
Alqahtani et al^Citation52	One week (ICC): 0.86
Inter-rater reliability
Topcu et al^Citation15	Two observers on the same day (ICC): 0.99
Parallel forms reliability
Theou et al^Citation46	Kappa coefficients: TFI and Frailty Index 0.52, Frailty Index based on Comprehensive Geriatric Assessment 0.52, Clinical Frailty Scale 0.38, Frailty Phenotype 0.37, Edmonton Frail Scale 0.27, FRAIL scale 0.27, Groningen Frailty Indicator (GFI) 0.50
Dong et al^Citation13	Kappa coefficients: ranged for TFI items and alternative measures from 0.12 (hearing problems)–1.00 (living alone)

Abbreviation: ICC, intraclass correlation coefficient.

Table 4 Criterion Validity of the TFI

Authors	Criterion Validity
Gobbens et al^Citation1	Concurrent using correlations: large for total frailty and quality of life domains physical, psychological, environmental, and medium to large for quality of life domain social assessed with the WHOQOL-BREF Concurrent using AUC: excellent for disability and reporting personal care, acceptable for reporting nursing and informal care, poor for reporting visits general practitioner and hospitalization
Metzelthin et al^Citation36	Concurrent using correlations: correlation between TFI and Groningen Frailty Indicator (GFI) was 0.76; the correlation between TFI and Sherbrooke Postal Questionnaire (SPQ) was 0.42
Gobbens et al^Citation42	Predictive, one and two years later, using multiple regression analyses: an increase in predictive accuracy of most adverse outcomes (disability, indicators of health care utilization, and quality of life) Predictive, one and two years later, using AUC: excellent for disability and reporting personal care, acceptable for reporting nursing, informal care, and facilities in residential care, poor for contacts with health care professionals and hospitalization, not significant for visits to a general practitioner
Gobbens et al^Citation40	Concurrent using sequential regression analyses: all components of the TFI together explained the scores on quality of life domains physical health, psychological, social relations, environmental assessed with the WHOQOL-BREF
Daniels et al^Citation37	Predictive, one year later, using OR unadjusted: disability 3.96, 95% CI = 2.48–6.30, mortality 3.08, 95% CI = 1.04–9.13, hospitalization 2.59, 95% CI = 1.36–4.90 Predictive, one year later, using AUC: poor for disability, mortality, and hospitalization
Theou et al^Citation46	Predictive, two and five years later, using AUC: acceptable for mortality
Gobbens and Van Assen^Citation41	Predictive, two and four years later, using sequential regression analyses): the items physical unhealthy, difficulty in walking, difficulty in maintaining balance, physical tiredness, feeling down, and lack of social support predicted quality of life scores assessed with the WHOQOL-BREF
Mulasso et al^Citation9	Concurrent using AUC: excellent for disability, poor for falls and visits to general practitioner
Gobbens et al^Citation39	Concurrent using regression analyses: all three domains (physical, psychological, social) together had an effect on disability, quality of life (physical health, psychological, social relationships, environmental), visits to a general practitioner, and falls; no effects were observed with contacts with health care professionals, hospitalization, receiving personal care, receiving nursing care, receiving informal care, and facilities in nursing home/rehabilitation center
Coelho et al^Citation10	Concurrent using multiple regression analyses: the TFI domains predicted 38.7% and 42.1% of quality of life variance, assessed with EUROHIS-QOL, and WHOQOL-OLD, respectivelyConcurrent using AUC: acceptable for disability in ADL, poor for disability in IADL, and health care utilizationConcurrent using AUC: discriminating ability was excellent regarding identifying frailty by the Groningen Frailty Indicator (GFI) (0.86, 95% CI = 0.85–0.93) and acceptable for frailty assessed with the Frailty Phenotype by Fried et al (0.75, 95% CI = 0.68–0.81)
Dong et al^Citation13	Concurrent using AUC: excellent for depression; acceptable for disability in ADL, and low social support; poor for disability in IADL, and for health care utilization (hospitalization, emergency use) Concurrent using AUC: discriminating ability was excellent regarding identifying frailty by the Frailty Phenotype by Fried et al (0.87, 95% CI = 0.87–0.93) and the Frailty Index (0.86, 95% CI = 0.82–0.91)
Renne and Gobbens^Citation45	Concurrent using sequential multiple linear regression analyses): all fifteen items together explained 36.5% of the variance of the score of quality of life
Santiago et al^Citation51	Predictive, 1 year later, using sequential logistic regression analyses: total frailty predicted mortality, adjusted for sex and age (HR = 2.72, 95% CI = 1.01–7.31); after controlling for sociodemographic variables the frailty domains (physical, psychological, social) improved the prediction of hospitalization (OR = 1.83, 95% CI = 1.10–3.06), falls (OR = 2.08, 95% CI = 1.21–3.58), disability in ADL (OR = 3.03, 95% CI = 1.45–6.29), disability in IADL (OR = 1.51, 95% CI = 1.05–2.17)
Vrotsou et al^Citation14	Concurrent using correlations: the correlation between total and the Frailty Phenotype by Fried et al was 0.49
Op Het Veld et al^Citation44	Predictive, 2 years later: positive predictive value 42.6% and negative predictive value 75.2% for disability in IADL
Op Het Veld et al^Citation43	Predictive, 2 years later, using AUC: poor for mortality, hospitalization, and disability in IADL
Gobbens et al^Citation38	Predictive, 1 year later, using linear and logistic regression analyses: the three frailty domains together predicted disability, visits general practitioner, contacts with health care professionals, receiving nursing; no effects were found on hospitalization, receiving personal care, falls (after controlling for sociodemographic characteristics and multimorbidity) Predictive, 1 year later, using AUC: excellent for total frailty with respect to disability and receiving personal care; poor for receiving nursing, falls, and hospitalization
Gobbens and Andreasen^Citation49	Predictive, 6 months later, using sequential logistic regression analyses: physical and social frailty predicted readmission and mortality; psychological frailty predicted only readmission
Zhang et al^Citation47	Concurrent using AUC: all AUC were excellent for SHARE-FI, and disability; all AUC were acceptable for limited function, poor mental health, and feeling lonely

Abbreviations: AUC, area under the curve; CI, confidence interval; ADL, activities of daily living; IADL, instrumental activities of daily living; OR, odds ratio; SHARE-FI, SHARE Frailty Instrument.

Table 5 Construct Validity of the TFI

Authors	Construct Validity
Gobbens et al^Citation1	Convergent and divergent validity using correlations: the 15 single components and three domains correlated as expected with validated measures
Santiago et al^Citation7	Convergent and divergent validity using correlations: the correlations between the items and their corresponding measures were as expected, except the item ‘coping’
Mulasso et al^Citation9	Convergent and divergent validity using correlations: all items correlated with single corresponding frailty measures
Coelho et al^Citation10	Convergent and divergent validity using correlations): physical and social domains correlated as expected with alternative measures; psychological measures showed similar correlations with the psychological and physical domains of the TFI
Freitag et al^Citation12	Convergent and divergent validity using correlations: total frailty was correlated with all alternative measures of frailty. In addition, the domains correlated good with corresponding alternative measures
Dong et al^Citation13	Convergent and divergent validity using correlations: the three domains correlated with alternative measures; however, psychological measures had similar correlations with the psychological and physical domain
Renne & Gobbens^Citation45	Construct validity using correlations: total and all three domains correlated with all six quality of life domains assessed with the WHOQOL-OLD
Vrotsou et al^Citation14	Convergent and divergent validity using correlations: the three frailty domains correlated as expected, except social frailty that had a stronger correlation with the Lawton scale than physical frailty
Alqahtani et al^Citation52	Convergent and divergent validity: correlations as expected between total and six frailty-related measures
Zhang et al^Citation47	Convergent and divergent validity using correlations: validity of physical, psychological and social frailty was supported by all the alternative measures in all five countries

Table 6 Content Validity, Face Validity, Structural Validity, and Known-Groups Validity of the TFI

Authors	Content Validity
Gobbens et al^Citation1	Determined by representatives of professional disciplines and people aged ≥75 years
Theou et al^Citation46	The TFI records items referring to limitations in self-rated health, nutrition, mobility, energy, cognition, mood
Andreasen et al^Citation48	Determined by interviewing frail community-dwelling older people: the majority of important frailty items were covered by the TFI; pain, sleep quality, meaningful activities and spirituality are not present in the TFI
Face Validity
Gobbens et al^Citation1	Checked by participants at geriatric meetings
Andreasen et al^Citation8	A pretest was performed by cognitive interviewing. The TFI was translated and adapted in such a manner that it can be implemented and further tested in clinical practice
Structural Validity
Vrotsou et al^Citation14	Confirmatory factor analysis) (CFA) showed that fit indexes of a second-order model of three factors (frailty domains) were acceptable
Known-Groups Validity
Vrotsou et al^Citation14	Total and physical frailty scores differentiated well between frail and non-frail people defined by the GFST and the SPPB

Abbreviations: GFST, Gérontopôle Frailty Screening Tool; SPPB, Short Physical Performance Battery.

Gobbens RJ, van Assen MA, Luijkx KG, Wijnen-Sponselee MT, Schols JM. The Tilburg Frailty Indicator: Psychometric properties. J Am Med Dir Assoc. 2010;11(5):344–355.20511102

 PubMed Web of Science ®Google Scholar

Metzelthin SF, Daniels R, van Rossum E, de Witte L, van den Heuvel WJ, Kempen GI. The psychometric properties of three self-report screening instruments for identifying frail older people in the community. BMC Public Health. 2010;10:176. doi:10.1186/1471-2458-10-17620353611

 PubMed Web of Science ®Google Scholar

Gobbens RJ, van Assen MA, Luijkx KG, Schols JM. The predictive validity of the Tilburg Frailty Indicator: disability, health care utilization, and quality of life in a population at risk. Gerontologist. 2012;52(5):619–631. doi:10.1093/geront/gnr13522217462

 PubMed Web of Science ®Google Scholar

Daniels R, van Rossum E, Beurskens A, van den Heuvel W, de Witte L. The predictive validity of three self-report screening instruments for identifying frail older people in the community. BMC Public Health. 2012;12:69. doi:10.1186/1471-2458-12-6922269425

 PubMed Web of Science ®Google Scholar

Gobbens RJ, Luijkx KG, van Assen MA. Explaining quality of life of older people in the Netherlands using a multidimensional assessment of frailty. Qual Life Res. 2013;22(8):2051–2061. doi:10.1007/s11136-012-0341-123274572

 PubMed Web of Science ®Google Scholar

Theou O, Brothers TD, Mitnitski A, Rockwood K. Operationalization of frailty using eight commonly used scales and comparison of their ability to predict all-cause mortality. J Am Geriatr Soc. 2013;61(9):1537–1551. doi:10.1111/jgs.1242024028357

 PubMed Web of Science ®Google Scholar

Santiago LM, Luz LL, Mattos IE, Gobbens RJ, van Assen MA. Psychometric properties of the Brazilian version of the Tilburg frailty indicator (TFI). Arch Gerontol Geriatr. 2013;57(1):39–45. doi:10.1016/j.archger.2013.03.00123538005

 PubMed Web of Science ®Google Scholar

Andreasen J, Sorensen EE, Gobbens RJ, Lund H, Aadahl M. Danish version of the Tilburg frailty indicator - translation, cross-cultural adaption and validity pretest by cognitive interviewing. Arch Gerontol Geriatr. 2014;59(1):32–38. doi:10.1016/j.archger.2014.02.00724680192

 PubMed Web of Science ®Google Scholar

Uchmanowicz I, Jankowska-Polanska B, Loboz-Rudnicka M, Manulik S, Loboz-Grudzien K, Gobbens RJ. Cross-cultural adaptation and reliability testing of the Tilburg Frailty Indicator for optimizing care of Polish patients with frailty syndrome. Clin Interv Aging. 2014;9:997–1001. doi:10.2147/CIA.S6485325028543

 PubMed Web of Science ®Google Scholar

Gobbens RJ, van Assen MA. The prediction of quality of life by physical, psychological and social components of frailty in community-dwelling older people. Qual Life Res. 2014;23(8):2289–2300. doi:10.1007/s11136-014-0672-124671672

 PubMed Web of Science ®Google Scholar

Mulasso A, Roppolo M, Gobbens RJ, Rabaglietti E. The Italian version of the Tilburg Frailty Indicator: analysis of psychometric properties. Res Aging. 2016;38(8):842–863. doi:10.1177/016402751560619226377805

 PubMed Web of Science ®Google Scholar

Gobbens RJ, Krans A, van Assen MA. Validation of an integral conceptual model of frailty in older residents of assisted living facilities. Arch Gerontol Geriatr. 2015;61(3):400–410. doi:10.1016/j.archger.2015.06.00126293001

 PubMed Web of Science ®Google Scholar

Coelho T, Santos R, Paul C, Gobbens RJ, Fernandes L. Portuguese version of the Tilburg Frailty Indicator: transcultural adaptation and psychometric validation. Geriatr Gerontol Int. 2015;15(8):951–960. doi:10.1111/ggi.1237325255891

 PubMed Web of Science ®Google Scholar

Andreasen J, Lund H, Aadahl M, Gobbens RJ, Sorensen EE. Content validation of the Tilburg Frailty Indicator from the perspective of frail elderly. A qualitative explorative study. Arch Gerontol Geriatr. 2015;61(3):392–399. doi:10.1016/j.archger.2015.08.01726323651

 PubMed Web of Science ®Google Scholar

Uchmanowicz I, Jankowska-Polanska B, Uchmanowicz B, Kowalczuk K, Gobbens RJ. Validity and reliability of the Polish version of the Tilburg Frailty Indicator (TFI). J Frailty Aging. 2016;5(1):27–32. doi:10.14283/jfa.2015.6626980366

 PubMedGoogle Scholar

Freitag S, Schmidt S, Gobbens RJ. Tilburg frailty indicator. German translation and psychometric testing. Z Gerontol Geriatr. 2016;49(2):86–93. doi:10.1007/s00391-015-0889-925953342

 PubMed Web of Science ®Google Scholar

Dong L, Liu N, Tian X, et al. Reliability and validity of the Tilburg Frailty Indicator (TFI) among Chinese community-dwelling older people. Arch Gerontol Geriatr. 2017;73:21–28. doi:10.1016/j.archger.2017.07.00128734173

 PubMed Web of Science ®Google Scholar

Renne I, Gobbens RJJ. Effects of frailty and chronic diseases on quality of life in Dutch community-dwelling older adults: a cross-sectional study. Clin Interv Aging. 2018;13:325–334. doi:10.2147/CIA.S15611629520132

 PubMed Web of Science ®Google Scholar

Santiago LM, Gobbens RJJ, van Assen M, Carmo CN, Ferreira DB, Mattos IE. Predictive validity of the Brazilian version of the Tilburg Frailty Indicator for adverse health outcomes in older adults. Arch Gerontol Geriatr. 2018;76:114–119.29494871

 PubMed Web of Science ®Google Scholar

Vrotsou K, Machon M, Rivas-Ruiz F, et al. Psychometric properties of the Tilburg Frailty Indicator in older Spanish people. Arch Gerontol Geriatr. 2018;78:203–212. doi:10.1016/j.archger.2018.05.02430007234

 PubMed Web of Science ®Google Scholar

Topcu Y, Tufan F, Kilic C. Turkish version of the Tilburg Frailty Indicator. Clin Inter Aging. 2019;14:615–620. doi:10.2147/CIA.S197512

 Web of Science ®Google Scholar

Op Het Veld LPM, van Rossum E, Kempen G, Beurskens A, Hajema KJ, de Vet HCW. Can the Combined Use of Two Screening Instruments Improve the Predictive Power of Dependency in (Instrumental) Activities of Daily Living, Mortality and Hospitalization in Old Age? J Frailty Aging. 2019;8(4):180–5.

 Google Scholar

Op Het Veld LPM, Beurskens A, de Vet HCW, et al. The ability of four frailty screening instruments to predict mortality, hospitalization and dependency in (instrumental) activities of daily living. Eur J Ageing. 2019;16(3):387–394. doi:10.1007/s10433-019-00502-431543731

 PubMed Web of Science ®Google Scholar

Alqahtani BA, Abdelbasset WK, Alenazi AM. Psychometric analysis of the Arabic (Saudi) Tilburg Frailty Indicator among Saudi community-dwelling older adults. Arch Gerontol Geriatr. 2020;90:104128. doi:10.1016/j.archger.2020.10412832521419

 PubMed Web of Science ®Google Scholar

Gobbens RJ, Boersma P, Uchmanowicz I, Santiago LM. The Tilburg Frailty Indicator (TFI): new evidence for its validity. Clin Interv Aging. 2020;15:265–274. doi:10.2147/CIA.S24323332110005

 PubMed Web of Science ®Google Scholar

Gobbens RJJ, Andreasen J. The prediction of readmission and mortality by the domains and components of the Tilburg Frailty Indicator (TFI): a prospective cohort study among acutely admitted older patients. Arch Gerontol Geriatr. 2020;89:104077. doi:10.1016/j.archger.2020.10407732334333

 PubMed Web of Science ®Google Scholar

Zhang X, Tan SS, Bilajac L, et al. Reliability and Validity of the Tilburg Frailty Indicator in 5 European Countries. J Am Med Dir Assoc. 2020;21(6):772–9.e6. doi:10.1016/j.jamda.2020.03.01932387112

 PubMed Web of Science ®Google Scholar