Discussion
weight loss, KCL-depressive mood
Our findings aim to offer further insights on the TFI structure and provide evidence to improve its use in psychometric terms.The need to confirm the structure of the scale is clear, given the available evidence gaps in some relevant measurement properties [Similarly, in the institutionalized sample, the three-factor solution fit better than the one-factor, but only fit well after depurating the poorly behaving items (2, 5, and 13). To our knowledge, no studies have previously analyzed the adequacy of the TFI in institutionalized older adults.The need to review the TFI model and refine some indicators of the scale has also been suggested by other studies, when analyzing the poor correlations with other items or other similar measures. Among the indicators to be checked, the following have been pointed out: unexplained weight loss (2) [A recent systematic review of the psychometric properties of the TFI [Reliability estimates were not equal in both samples, showing better values for the institutionalized older adults. The CRI values for the physical and psychological domains were good (CRI > 0.70) in the institutionalized sample, while only the physical domain was satisfactory in the community-dwelling older adults. In both cases, social domain reliability estimates were not acceptable. These differences between the two groups may be due to a higher mean age, greater variability in the variables or a larger sample of frail people in the institutionalized group. These findings suggest that the TFI seems to be a good assessment tool to detect physical frailty, as indicated by other authors [In addition, although some authors refer to the adequate reliability of the scale considering the estimates of the total TFI [Convergent and divergent validity for the physical and psychological domains are acceptable given the obtained results, except for some psychological measures whose constructs are similar to the TFI physical domain (KCL-depressive mood and Edmonton mood). These results are in line with several studies in which the construct of alternative psychological measures was related or similar to the TFI physical component [As mentioned before, previous validations have involved community-dwelling older adults. Thus, the use of the TFI in geriatrics still needs to be tested in different settings to explore its potential applications [