Hospital readmissions related to adverse drug withdrawal events in older adults: a pilot study

Drug-related hospitalisations are common and approximately 50% are preventable. They can be caused by adverse drug reactions, therapeutic failures, and Adverse Drug Withdrawal Events (ADWEs). ADWEs include any clinically significant set of symptoms caused by the cessation or dose reduction of a medication, including physiological withdrawal reactions or return of the underlying medical condition; few studies have examined the prevalence and characteristics of ADWEs.

To conduct a pilot study to determine the proportion of hospital readmissions caused or contributed to by ADWEs in older adults, explore the characteristics of these events, and test the method of assessment of ADWEs.

A retrospective case note review included patients that were admitted to geriatric units with two hospital admissions within a three month period. Participants were screened for deprescribing events, defined as medication cessation, dose reduction, or substitution. Two assessors then independently reviewed the data to determine if an ADWE had occurred and assessed its contribution to a readmission.

Ten participants experienced 33 deprescribing events during their first hospital admission, or between admissions. A total of seven out of the 33 deprescribing events (affecting six participants) were assessed to have likely led to an ADWE (21%). Of these, six were assessed as likely contributing to the readmission. Of the total 12 readmissions examined (across 10 participants), five readmissions (five participants) were assessed as likely being contributed to by an ADWE (41.6%). The most common medications that were assessed as likely to have contributed to an ADWE-related hospital admission were cardiac medications, particularly diuretics, which were implicated in four out of six ADWEs assessed as likely to have contributed to hospital readmission.

ADWEs are potentially common in complex older adults and their potential contribution to hospital readmissions highlights the need for further research on how to identify and ultimately prevent them.