Medication-related harm in older adults following hospital discharge: development and validation of a prediction tool

OBJECTIVES

To develop and validate a tool to predict the risk of an older adult experiencing medication-related harm (MRH) requiring healthcare use following hospital discharge.

DESIGN, SETTING, PARTICIPANTS

Multicentre, prospective cohort study recruiting older adults (≥65 years) discharged from five UK teaching hospitals between 2013 and 2015.

PRIMARY OUTCOME MEASURE

Participants were followed up for 8 weeks in the community by senior pharmacists to identify MRH (adverse drug reactions, harm from non-adherence, harm from medication error). Three data sources provided MRH and healthcare use information: hospital readmissions, primary care use, participant telephone interview. Candidate variables for prognostic modelling were selected using two systematic reviews, the views of patients with MRH and an expert panel of clinicians. Multivariable logistic regression with backward elimination, based on the Akaike Information Criterion, was used to develop the PRIME tool. The tool was internally validated.

RESULTS

1116 out of 1280 recruited participants completed follow-up (87%). Uncertain MRH cases ('possible' and 'probable') were excluded, leaving a tool derivation cohort of 818. 119 (15%) participants experienced 'definite' MRH requiring healthcare use and 699 participants did not. Modelling resulted in a prediction tool with eight variables measured at hospital discharge: age, gender, antiplatelet drug, sodium level, antidiabetic drug, past adverse drug reaction, number of medicines, living alone. The tool's discrimination C-statistic was 0.69 (0.66 after validation) and showed good calibration. Decision curve analysis demonstrated the potential value of the tool to guide clinical decision making compared with alternative approaches.

CONCLUSIONS

The PRIME tool could be used to identify older patients at high risk of MRH requiring healthcare use following hospital discharge. Prior to clinical use we recommend the tool's evaluation in other settings.

Medication-related harm: a geriatric syndrome

The WHO Global Patient Safety Challenge: Medication Without Harm recognises medication-related harm (MRH) as a global public health issue. Increased life-expectancy coupled with multimorbidity and polypharmacy leads to an increased incidence of MRH, especially in older adults: at a cost of approximately £400 million to the National Health Service (NHS) in England. Harm from medicines has long been recognised by geriatricians, and strategies have been developed to mitigate harm. In general, these have focused on the challenges of polypharmacy and appropriateness of medicines, but impact on the quality of life, clinical and economic outcomes has been variable and often disappointing. The problem of MRH in older adults will continue to grow unless a new approach is adopted. Emerging evidence suggests that we need to take a broader approach as described in our conceptual model, where well-recognised physiological changes are incorporated, as well as other rarely considered psychosocial issues that influences MRH. Parallels may be drawn between this approach and the management of geriatric syndromes. We propose there must be a greater emphasis on MRH, and it, of itself, should be considered as a geriatric syndrome, to bring the spotlight onto the problem and to send a clear signal from geriatric experts that this is an important issue that needs to be addressed using a co-ordinated and tailored approach across health and social care boundaries. This requires a more proactive approach to monitor and review the medicines of older adults in response to their changing need.