Warfarin Treatment and All-Cause Mortality in Community-Dwelling Older Adults with Atrial Fibrillation: A Retrospective Observational Study.

OBJECTIVES: To investigate the relationship between warfarin treatment and different strata of all-cause mortality risk assessed using the Multidimensional Prognostic Index (MPI) based on information collected using the Standardized Multidimensional Assessment Schedule for Adults and Aged Persons (SVaMA) in community-dwelling older adults with atrial fibrillation (AF). DESIGN: Retrospective observational study. SETTING: Older community-dwelling adults who underwent a SVaMA evaluation establishing accessibility to homecare services and nursing home admission from 2005 to 2013 in the Padova Health District, Italy. PARTICIPANTS: Community-dwelling individuals with AF aged 65 and older (N = 1,827). MEASUREMENTS: Participants were classified as being at mild (MPI-SVaMA-1), moderate (MPI-SVaMA-2), or severe (MPI-SVaMA-3) risk of mortality using the MPI-SVaMA, a validated prognostic tool based on age, sex, comorbidity, cognitive status, mobility and functional disability, pressure sore risk, and social support. The association between warfarin treatment and mortality was tested using multivariate- and propensity score-adjusted Cox regression models, controlling for age, sex, all SVaMA domains, concomitant diseases, and drug treatments. RESULTS: Higher MPI-SVaMA scores were associated with lower rates of warfarin treatment and higher 3-year mortality. After adjustment for propensity score quintiles, warfarin treatment was significantly associated with lower 2-year mortality in individuals with MPI-SVaMA-1 (hazard ratio (HR) = 0.64, 95% confidence interval (CI) = 0.50-0.82), MPI-SVaMA-2 (HR = 0.68, 95% CI = 0.55-0.85), and MPI-SVaMA-3 (HR = 0.55, 95% CI = 0.44-0.67). Heterogeneity analyses confirmed that the effect of warfarin treatment was not different between MPI-SVaMA groups (P for heterogeneity = .48). CONCLUSION: Community-dwelling older adults with AF benefitted from anticoagulation in terms of lower all-cause mortality over a mean follow-up of 2 years, regardless of poor health and functional condition. Although this benefit can be ascribed to the treatment, it may also reflect better overall care.

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.