Psychometric adequacy of the Persian adapted version of the Tilburg Frailty Indicator (P- TFI)

Abstract

Abstract Background: Frailty has been identified as the primary goal of the preventing the various s aging consequences in many studies. Considering frailty help us to plan and train properly. valid and reliable tools are needed. The current study aimed to assess validity and reliability of the Persian adapted version of the Tilburg frailty indicator in Iran. Method: The current study is cross sectional study included three phases: at first phase, the indicator translated to Persian, at the next step, face and content validity was assessed. During the third phase, the P-TFI was sent out for completion to elderlies, who helped assess reliability and construct validity. For construct validity, convergent and divergent validity were used. It was expected that the TFI domain scores would show the highest correlations with their related measures of frailty (convergent construct validity) and the lowest correlations with measures of the other domains (divergent construct validity). Overall, 400 elderlies entered the study as the study population from six health care centers. Results The mean age of the participants was 69.05±7.28 (ranged from 60 to 93) years old. The majority of the participants were female (56.8). More than half of the participants had spouse. The majority had less than twelve years of education (81.5%), and most participants had a modest level of income. an overall of 168 (42%) older people lived with their spouse and child. The mean total score of TFI was 8.26±1.80, and 171 participants (42.75%) were classified frail in terms of the original cut-point of the scale (i.e., the total score ≥5): with the, and considering 6 as the threshold limit for TFI (i.e., The total score ≥6), 89 participants (22.25) were classified as frail. The scores for KR-21 range from 0 to 1, where 0 is no reliability and 1 is perfect reliability. The test-retest reliability for the 14-day interval was 0.88 for the total scale, 0.80 for physical domain, 0.65 for psychological domain and 0.81 for social domain. Mean score of frailty and its dimensions varied from 4.35±1.78, 1.81±1.33,1.69±0.73.0.86±061 for total frailty, physical, psychological and social respectively. The total score of the TFI significantly correlated with each alternate measure as expected. The convergent validity of the TFI was proved by the Cohen’s kappa coefficient between each item of the TFI and corresponding alternate tools. All of the kappa values ranging from.535 to 0.967 were statistically significant.