Article Text

Download PDFPDF

Comparison of count-based multimorbidity measures in predicting emergency admission and functional decline in older community-dwelling adults: a prospective cohort study
  1. Emma Wallace1,
  2. Ronald McDowell1,
  3. Kathleen Bennett2,
  4. Tom Fahey1,
  5. Susan M Smith1
  1. 1HRB Centre for Primary Care Research, Royal College of Surgeons in Ireland (RCSI), Dublin, Ireland
  2. 2Population Health Sciences Division, Royal College of Surgeons of Ireland (RCSI), Dublin, Ireland
  1. Correspondence to Dr Emma Wallace; emmawallace{at}


Objectives Multimorbidity, defined as the presence of 2 or more chronic medical conditions in an individual, is associated with poorer health outcomes. Several multimorbidity measures exist, and the challenge is to decide which to use preferentially in predicting health outcomes. The study objective was to compare the performance of 5 count-based multimorbidity measures in predicting emergency hospital admission and functional decline in older community-dwelling adults attending primary care.

Setting 15 general practices (GPs) in Ireland.

Participants n=862, ≥70 years, community-dwellers followed-up for 2 years (2010–2012). Exposure at baseline: Five multimorbidity measures (disease counts, selected conditions counts, Charlson comorbidity index, RxRisk-V, medication counts) calculated using GP medical record and linked national pharmacy claims data.

Primary outcomes (1) Emergency admission and ambulatory care sensitive (ACS) admission (GP medical record) and (2) functional decline (postal questionnaire).

Statistical analysis Descriptive statistics and measure discrimination (c-statistic, 95% CIs), adjusted for confounders.

Results Median age was 77 years and 53% were women. Prevalent rates ranged from 37% to 91% depending on which measure was used to define multimorbidity. All measures demonstrated poor discrimination for the outcome of emergency admission (c-statistic range: 0.62, 0.65), ACS admission (c-statistic range: 0.63, 0.68) and functional decline (c-statistic range: 0.55, 0.61). Medication-based measures were equivalent to diagnosis-based measures.

Conclusions The choice of measure may have a significant impact on prevalent rates. Five multimorbidity measures demonstrated poor discrimination in predicting emergency admission and functional decline, with medication-based measures equivalent to diagnosis-based measures. Consideration of multimorbidity in isolation is insufficient for predicting these outcomes in community settings.

  • comorbidity
  • hospitalisation
  • frail elderly

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.