The reliability of a frailty index may depend on the deficits included

PURPOSE: Recently, a short version of the TOPICS-MDS questionnaire, the Short Form (SF) was developed. The aim of this study was to assess the validity and reliability of two versions of a frailty index (FI) based on this SF: with or without information on present diseases included. METHODS: This was a clinical, prospective study of geriatric patients. An FI based on the TOPICS-SF items alone (SF-FI) and an FI with the disease information as additional deficits (MDS-FI) were calculated. Criterion and construct validity and reliability were assessed. RESULTS: 95 patients were included. A strong correlation was found between SF-FI and MDS-FI scores (Pearson’s r = 0.92). Data supported four out of six hypotheses for the construct validity. However, a Bland–Altman plot and a regression analysis showed that the SF-FI was generally higher than the MDS-FI. CONCLUSION: This study indicates that the reliability of the TOPICS-SF-FI depends on the presence of disease information.