Development and validation of a Multidimensional Prognostic Index for mortality based on a standardized Multidimensional Assessment Schedule (MPI-SVaMA) in community-dwelling older subjects

Objectives: To develop and validate a Multidimensional Prognostic Index (MPI) for mortality based on information collected by the Multidimensional Assessment Schedule (SVaMA), the recommended standard tool for multidimensional assessment of community-dwelling older subjects in seven Italian regions.

Design: Prospective cohort study.

Participants: Community-dwelling subjects older than 65 years who underwent an SVaMA evaluation from 2004 to 2010 in Padova Health District, Veneto, Italy.

Measurements: The MPI-SVaMA was calculated as a weighted (weights were derived from multivariate Cox regressions) linear combination of the following nine domains: age, sex, main diagnosis, and six scores, ie, the Short Portable Mental Status Questionnaire, the Barthel index (contains two domains: activities of daily living and mobility), the Exton-Smith scale, the Nursing Care Needs, and the Social Network Support by a structured interview. Subjects were followed for a median of 2 years; those who had not died were followed for at least 1 year. The MPI-SVaMA score ranged from 0 to 1 and 3 grades of severity of the MPI-SVaMA were calculated on the basis of estimated cutoffs. Discriminatory power and calibration were further assessed.

Results: A total of 12,020 subjects (mean age 81.84 ± 7.97 years) were included. Two random cohorts were selected: (1) a development cohort, ie, 7876 subjects (mean age 81.79 ± 8.05, %females: 63.1) and (2) a validation cohort, ie, 4144 subjects (mean age: 81.95 ± 7.83, %females: 63.7). The discriminatory power for mortality of MPI-SVaMA was 0.828 (95% CI 0.817-0.838) and 0.832 (95% CI 0.818-0.845) at 1 month and 0.791 (95% CI 0.784-0.798) and 0.792 (95% CI 0.783-0.802) at 1 year in development and validation cohorts, respectively. MPI-SVaMA results were well calibrated showing lower than 10% differences between predicted and observed mortality, both in development and validation cohorts.

Conclusions: The MPI-SVaMA is an accurate and well-calibrated prognostic tool for mortality in community-dwelling older subjects, and can be used in clinical decision making.