Multidimensional Prognostic Index in Association with Future Mortality and Number of Hospital Days in a Population-Based Sample of Older Adults: Results of the EU Funded MPI_AGE Project

<div><p>Background</p><p>The Multidimensional Prognostic Index (MPI) has been found to predict mortality in patients with a variety of clinical conditions. We aimed to assess the association of the MPI with future mortality and number of in-hospital days for the first time in a population-based cohort.</p><p>Methods</p><p>The study population consisted of 2472 persons, aged 66–99 years, from the Swedish National Study on Aging and Care in Kungsholmen, Sweden, who underwent the baseline visit 2001–4, and were followed up >10 years for in-hospital days and >12 years for mortality. The MPI was a modified version of the original and aggregated seven domains (personal and instrumental activities of daily living, cognitive function, illness severity and comorbidity, number of medications, co-habitation status, and nutritional status). The MPI score was divided into risk groups: low, medium and high. Number of in-hospital days (within 1, 3 and 10 years) and mortality data were derived from official registries. All analyses were age-stratified (sexagenarians, septuagenarians, octogenarians, nonagenarians).</p><p>Results</p><p>During the follow-up 1331 persons (53.8%) died. Laplace regression models, suggested that median survival in medium risk groups varied by age from 2.2–3.6 years earlier than for those in the corresponding low risk groups (p = 0.002-p<0.001), and median survival in high risk groups varied by age from 3.8–9.0 years earlier than for corresponding low risk groups (p<0.001). For nonagenarians, the median age at death was 3.8 years earlier in the high risk group than for the low risk group (p<0.001). The mean number of in-hospital days increased significantly with higher MPI risk score within 1 and 3 years for people of each age group.</p><p>Conclusion</p><p>For the first time, the effectiveness of MPI has been verified in a population-based cohort. Higher MPI risk scores associated with more days in hospital and with fewer years of survival, across a broad and stratified age range.</p></div

Median Time to Death in Years, by Multidimensional Prognostic Index (MPI) Status and Age.

<p>Multidimensional Prognostic Index (MPI) aggregated six domains (personal and instrumental activities of daily living, cognitive function, illness severity and comorbidity, the number of medications, co-habitation status). Age 66 excluded because too few had died to estimate median time to death. Mortality data until 2014-06-26. Analysis used Laplace regression.</p><p>Median Time to Death in Years, by Multidimensional Prognostic Index (MPI) Status and Age.</p

Characteristics of the Study Cohort.

<p>*Multidimensional Prognostic Index (MPI) aggregated six domains (personal and instrumental activities of daily living, cognitive function, illness severity and comorbidity, the number of medications, co-habitation status).</p><p>ǂA total follow-up time for mortality of a maximum of 12.8 years and for number of in-hospital days of a maximum of 10.8 years.</p><p>Characteristics of the Study Cohort.</p

Mean Number of In-Hospital Days within 1, 3 and 10 Years Since Baseline, by Multidimensional Prognostic Index (MPI) Status and Age.

<p>Multidimensional Prognostic Index (MPI) aggregated six domains (personal and instrumental activities of daily living, cognitive function, illness severity and comorbidity, the number of medications, co-habitation status). Age group 66 with high risk MPI omitted, due to only one participant in this category.</p><p>Mean Number of In-Hospital Days within 1, 3 and 10 Years Since Baseline, by Multidimensional Prognostic Index (MPI) Status and Age.</p

Pre-matching baseline characteristics of community-dwelling older patients with diabetes mellitus according to statin use.

<p>VCOG: cognitive status; VIP: Nursing Care Needs; VPIA: pressure sores risk; VADL: activities of daily living; VMOB: mobility; VSOC: social support; MPI: Multidimensional Prognostic Index</p><p>MPI-SVaMA: Multidimensional Prognostic Index based on the Standardized Multidimensional Assessment Schedule for Adults and Aged Persons</p><p>* Number of all medications prescribed within one year before patient’s enrollment</p><p>Pre-matching baseline characteristics of community-dwelling older patients with diabetes mellitus according to statin use.</p

Summary of the methodological constructs of the four frailty indexes compared.

<p>FI-SOF: Frailty Index derived from the Study of Osteoporotic Fractures;</p><p>FI-CD: Frailty Index based on cumulative deficits;</p><p>FI-CGA: Frailty Index based on a Comprehensive Geriatric Assessment;</p><p>ADL: activities of daily living;</p><p>IADL: instrumental activities of daily living;</p><p>SPMSQ: Short Portable Mental Status Questionnaire;</p><p>CIRS: Cumulative Illness Rating Scale;</p><p>MNA: Mini Nutritional Assessment;</p><p>ESS: Exton-Smith Scale;</p><p>MPI: Multidimensional Prognostic Index.</p

Risk of one-month and one-year all-cause mortality according to the four frailty instruments in hospitalized older patients.

<p>*continuous variables.</p><p>**p-values obtained fitting univariate proportional hazard regression models, accounting for clustering due to centre effect.</p><p>HR: hazard ratio; CI: confidence intervals; FI-SOF: Frailty Index derived from the Study of Osteoporotic Fractures; FI-CD: Frailty Index based on cumulative deficits; FI-CGA: Frailty Index based on a Comprehensive Geriatric Assessment; MPI: Multidimensional Prognostic Index.</p

Comparison of the areas under the receiver operating characteristic (ROC) curves of the four frailty instruments compared.^*

<p>AUC: areas under curve; SE: standard error; CI: confidence interval; MPI: Multidimensional Prognostic Index; FI-SOF: Frailty Index derived from the Study of Osteoporotic Fractures; FI-CD: Frailty Index based on cumulative deficits; FI-CGA: Frailty Index based on a Comprehensive Geriatric Assessment.</p><p>*AUCs were assessed by crude and adjusted logistic regression models, accounting for clustering due to centre effect.</p

Baseline characteristics of community-dwelling older patients with diabetes mellitus divided according to their Multidimensional Prognostic Index (MPI) grade based on the Standardized Multidimensional Assessment Schedule for Adults and Aged Persons (SVaMA).

<p>VADL: activities of daily living; VCOG: cognitive status; VIP: Nursing Care Needs; VMOB: mobility; VPIA: pressure sores risk; VSOC: social support</p><p>* Number of all medications per month, taken before the patient’s enrollment</p><p>^ ev/py: events/person-years, ir%: incidence rate (number of events per 100 person-years)</p><p>Baseline characteristics of community-dwelling older patients with diabetes mellitus divided according to their Multidimensional Prognostic Index (MPI) grade based on the Standardized Multidimensional Assessment Schedule for Adults and Aged Persons (SVaMA).</p

Subgroups of hospitalized older patients where different frailty indexes showed a significant different predictive discriminatory power for one-year all-cause mortality.^*

<p>AUC: areas under curve; SE: standard error; CI: confidence interval; ADL: activities of daily living; MPI: Multidimensional Prognostic Index; FI-SOF: Frailty Index derived from the Study of Osteoporotic Fractures; FI-CD: Frailty Index based on cumulative deficits; FI-CGA: Frailty Index based on a Comprehensive Geriatric Assessment; IADL: instrumental activities of daily living; SPMSQ: Short Portable Mental Status Questionnaire; CIRS: Cumulative Illness Rating Scale;</p><p>MNA: Mini Nutritional Assessment.</p><p>*AUCs were assessed by crude and adjusted logistic regression models, accounting for clustering due to centre effect.</p