Article Text
Abstract
Purpose Multimorbidity is commonly defined and measured using condition counts. The UK National Institute for Health Care Excellence Guidelines for Multimorbidity suggest that a medication-orientated approach could be used to identify those in need of a multimorbidity approach to management.
Objectives To compare the accuracy of medication-based and diagnosis-based multimorbidity measures at higher cut-points to identify older community-dwelling patients who are at risk of poorer health outcomes.
Design A secondary analysis of a prospective cohort study with a 2-year follow-up (2010–2012).
Setting 15 general practices in Ireland.
Participants 904 older community-dwelling patients.
Exposure Baseline multimorbidity measurements based on both medication classes count (MCC) and chronic disease count (CDC).
Outcomes Mortality, self-reported health related quality of life, mental health and physical functioning at follow-up.
Analysis Sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) adjusting for clustering by practice for each outcome using both definitions.
Results Of the 904 baseline participants, 53 died during follow-up and 673 patients completed the follow-up questionnaire. At baseline, 223 patients had 3 or more chronic conditions and 89 patients were prescribed 10 or more medication classes. Sensitivity was low for both MCC and CDC measures for all outcomes. For specificity, MCC was better for all outcomes with estimates varying from 88.8% (95% CI 85.2% to 91.6%) for physical functioning to 90.9% (95% CI 86.2% to 94.1%) for self-reported health-related quality of life. There were no differences between MCC and CDC in terms of PPV and NPV for any outcomes.
Conclusions Neither measure demonstrated high sensitivity. However, MCC using a definition of 10 or more regular medication classes to define multimorbidity had higher specificity for predicting poorer health outcomes. While having limitations, this definition could be used for proactive identification of patients who may benefit from targeted clinical care.
- multimorbidity
- risk prediction
- chronic diseases
- medications
- polypharmacy
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Footnotes
Patient consent for publication Not required.
Contributors MS, SMS and EW conceptualised the study, MS and FB analysed the data and SS, EW, FB and RM took part in the interpretation of results. MS wrote the original draft and SS, EW, FB, RM, MF and LF contributed to the editing and reviewing of the paper.
Funding The original cohort study was supported by the Health Research Board of Ireland under the Research Training Fellowship for Healthcare Professionals award, grant no. HPF/2012/20 and was conducted as part of the HRB Scholar’s programme in Health Services Research (grant no. PhD/2007/16) at the HRB Centre for Primary Care Research, grant HRC/2007/1. Maxime Sasseville was supported by the Ireland Canada University Foundation (ICUF) for the travel and allocation fees to complete this secondary analysis study.
Competing interests None declared.
Ethics approval Royal College of Surgeons in Ireland (RCSI) Human Research Ethics committee.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement The database from the cohort study is available from Dr EW by local access only. Please contact corresponding author.