Agreement of a Short Form of the Self-Administered Multidimensional Prognostic Index (SELFY-MPI-SF): A Useful Tool for the Self-Assessment of Frailty in Community-Dwelling Older People

BACKGROUND: The Multidimensional Prognostic Index (MPI) is a comprehensive geriatric assessment (CGA)-based tool that has shown excellent accuracy in predicting negative health outcomes in older people. Recently, the self-administered version of MPI (SELFY-MPI) has been validated in a community-dwelling sample, revealing excellent agreement with the original MPI. In the SELFY-MPI, Gijon’s social-familial evaluation scale (SFES) was used to assess socio-relational and economic aspects. Completion of the SELFY-MPI, however, requires a significant amount of time in people aged over 60 years, particularly to fill in the SFES scale. The aim of this study was to validate, in a sample of community-dwelling older people, a short-form version of the SELFY-MPI (SELFY-MPI-SF), in which the SFES scale was replaced by the “co-habitation status” domain, as in the original version of the MPI. METHODS: All participants included in the study completed both versions of the self-administered MPI, which share the following seven domains: 1) basic and 2) instrumental activities of daily living, 3) mobility, 4) cognition, 5) nutrition, 6) comorbidity, and 7) number of medications. Moreover, in the SELFY-MPI-SF, the 8th domain “co-habitation status” (ie living alone, with family or in a residential facility) replaced the SFES scale. The Bland–Altman methodology was applied in order to measure the agreement between the two instruments. Finally, the time to complete the SFES scale and the question on co-habitation was measured. RESULTS: The final study sample was composed of 129 participants (mean age=76.8 years, range=65–93 years, 64.3% women) were enrolled. The mean SELFY-MPI and SELFY-MPI-SF values were 0.221±0.196 and 0.246± 0.188, respectively. The mean difference was clinically irrelevant (−0.025±0.058). None of the 129 observations showed values outside the established 5% limits of agreement. The agreement between SELFY-MPI and SELFY-MPI-SF was excellent (k=0.762; rho=0.924, p<0.0001 for both). Stratified analyses of agreement among subgroups of participants of different ages did not show any significant differences between the two versions. Completion of the SFES required about 7 mins, on average, while the question on habitation status required about 10 s. CONCLUSION: The SELFY-MPI-SF showed strong agreement and precision when compared with the standard SELFY-MPI in people aged 65 and older and can therefore be successfully used as a quicker self-administered frailty instrument in community-dwelling older people.