Unintended discontinuation of chronic medication following hospitalisation: a retrospective cohort study

Problem

Poor coordination of transitions of care between general practices and hospitals may be associated with discrepancies in medication lists, increasing potential for medication errors of commission and omission. Our aim is to assess whether unintended discontinuation of common, evidence based, long-term medication occurs after hospitalisation; what factors are associated with unintended discontinuation; and whether the absence of documentation of medication at hospital discharge is associated with discontinuity of medication in general practice.

Approach

We performed a retrospective cohort study between 2012 and 2015 examining electronic records and hospital supplied discharge notifications of in 44 Irish general practices of20,488 patients aged 65 years who were receiving prescribed long-term medication for chronic conditions. Continuity of four evidence-based medication drug classes- antithrombotic, lipid-lowering, thyroid replacement drugs and respiratory inhalers in hospitalised versus non-hospitalised patients; patient and health system factors associated with discontinuity; impact of absence of medication in the hospital discharge summary on a patient’s GP prescribing record at six months follow up.

Findings

In patients admitted to hospital, medication discontinuity ranged from 6-11% in the six months post-hospitalisation. Discontinuity of medication is significantly lower for hospitalised patients taking respiratory inhalers, adjusted odds ratio (AOR) 0.63 95%CI 0.49, 0.80, p<0.001 and thyroid medications AOR 0.62 95%CI 0.40, 0.96, p=0.03. There is no association between discontinuity of medication and hospitalisation for antithrombotics, AOR 0.95, 95%CI 0.81, 1.11, p=0.49, or lipid lowering medications AOR 0.92, 95%CI 0.78, 1.08, p=0.29. Older patients and those who paid to see their GP and for their prescriptions were more likely to experience increased odds of discontinuity in all four medicine groups. Between 39.% to 47.4% of patients had medication listed on their discharge summary. Presence of medication on discharge summary is significantly associated with continuity of medication in the GP prescribing record for lipid lowering medications AOR 1.6495% CI 1.15, 2.36, p=0.01 and respiratory inhalers AOR 2.97 95%CI 1.68, 5.25.

Consequences

Discontinuity of evidence-based long term medication is reasonably common. Hospitalisation is not associated with discontinuity in terms of errors of commission. Increasing age and private medical care are independently associated with a higher risk of medication discontinuity. Improvements in discharge medication is likely to help in maintaining medication continuity in general practice.