Original Study Heterogeneity of Different Tools for Detecting the Prevalence of Frailty in Nursing Homes: Feasibility and Meaning of Different Approaches N. Martínez-Velilla MD, PhD a, b, c, *, Pablo Aldaz Herce MD, PhD d , Álvaro. Casas Herrero MD, PhD a, b, c , Marta Gutiérrez-Valencia PharmD a, b , Mikel López Sáez de Asteasu MSc e , Alberto Sola Mateos MD f , Ana Conde Zubillaga MD g , Berta Ibáñez Beroiz PhD, MSc h, i , Arkaitz Galbete Jiménez PhD, MSc h, i , Mikel Izquierdo PhD b, c, e a Servicio de Geriatría, Complejo Hospitalario de Navarra, Pamplona, Navarra, España b Instituto de Investigación Sanitaria Navarra (IdiSNA), Pamplona, Navarra, España c Centro de Investigación Biomédica en Red (CIBER) en Fragilidad y Envejecimiento Saludable, Spain d Centro de Salud de San Juan, Pamplona, Spain e Department of Health Sciences, Public University of Navarre, Pamplona, Spain f Agencia Navarra para la dependencia, Pamplona, Spain g Residencia La Vaguada Nursing Home, Pamplona, Spain h Navarrabiomed-Departamento de Salud-Universidad Pública de Navarra, Pamplona, Spain i Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Spain Keywords: Frailty nursing homes aging diagnosis disability multimorbidity abstract Background and objective: The identification of frail individuals has been recognized as a priority for the effective implementation of healthy aging strategies. Only a limited number of studies have examined frailty in nursing homes, and there is a big heterogeneity in the methods used. The primary objective of this study was to determine the prevalence and feasibility of different frailty screening tools in nursing homes as well as its relationship with multimorbidity and disability. Design, setting, and participants: Cross-sectional analysis from a concurrent cohort study, which included 110 participants aged over 65 years and with different degrees of disability at 2 nursing homes. Measurements: The study used 4 different frailty scales: The Fried frailty criteria, the imputed Fried frailty criteria, the Rockwood clinical frailty scale, and the frailty in nursing home scale, and we analyzed their relationship with disability and multimorbidity. Results: The mean age of the study population was 86.3 years (standard deviation 7.3), and 71.8% were female. Most residents had a high percentage of cognitive and functional impairment, multimorbidity, and risk of malnutrition. The following prevalence rates for frailty were determined: 71.8% (62.8, 79.4), 42.7% (33.9, 52.1), and 36.4% (23.8, 51.1) as per according to the Rockwood clinical frailty scale, frailty in nursing home scale, and Fried index (95% confidence interval), respectively. In the case of the Fried index, the prevalence of frailty is based on the percentage of patients meeting the criteria, which is 40% due to the large number of missing values. After the imputation of variables with the multivariate imputation by chained equation software, the prevalence of frailty increased to 66.4% (57.1, 74.5). We observed different statistically significant associations between the frailty scales and the clinical and demographic variables, and also with disability and multimorbidity. Conclusions: Most residents of nursing homes are likely to be frail, but there is no single operational definition of frailty. Although all measures of frailty had similar associations with the clinical variables of This project has been funded by the TransPyrenean Biomedical Research Network (REFBIO) for the establishment of a network of stable collaboration among biomedical research centers in the Pyrenees Area (European Program INTERREG IV POCTEFA-A; REFBIO13/BIOD/002). The authors also are indebted the Spanish Net on Aging and frailty; (RETICEF)] (ISCIII, FEDER) and Centro de Investigación Biomédica en Red (CIBER) en Fragilidad y Envejecimiento Saludable (CIBERFES; CB16/10/ 00315) del Instituto de Salud Carlos III, (FEDER), respectively. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors declare no conflicts of interest. * Address correspondence to Nicolás Martínez-Velilla, MD, PhD, Department of Geriatrics, Complejo Hospitalario de Navarra, Pamplona, Spain. E-mail address: nicolas.martinez.velilla@cfnavarra.es (N. Martínez-Velilla). JAMDA journal homepage: www.jamda.com http://dx.doi.org/10.1016/j.jamda.2017.06.016 1525-8610/Ó 2017 AMDA e The Society for Post-Acute and Long-Term Care Medicine. JAMDA 18 (2017) 898.e1e898.e8