Understanding the medication safety issues for patients with mental illness in primary care: a scoping review

Problem

Medication safety and mental illness are currently two major global health concerns. Whilst there is emerging evidence from mental health hospital settings to identify key medicines safety improvement targets, our understanding of the epidemiology and aetiology of medication safety challenges along with the impact of remedial interventions for those with mental illness in community settings is fragmented despite the majority of patients with mental illness (90%) being managed in primary care. The aim was to collate global evidence concerning the epidemiology, aetiology, and remedial interventions of medication safety challenges across community settings for patients with mental illness.

Approach

Six databases (Embase, Medline, PsycINFO, Cochrane reviews, CINAHL and Web of Science core collection) were searched for studies of medication safety in psychiatric patients in primary care published between January 2000-October 2021. Additional studies were obtained by screening of reference lists of relevant/included studies and searches in Google Scholar. Studies were included if they were set in a primary care/community context, included a study population with a psychiatric diagnosis from which data could be extracted, reported on medication safety challenge epidemiology/aetiology/interventions, and one or more classes of psychotropic or error subtype. Non-English language studies were excluded. Data was extracted by one reviewer with independent extraction by two additional reviewers. Medication safety issues were grouped under the umbrella term of drug-related problems.

Findings

Seventy-nine studies were included of which 77 reported epidemiological data, 25 reported aetiology, and 18 evaluated an intervention. The most common DRP reported on was non-adherence (62/79, 78.5%) followed by Potentially Inappropriate/Hazardous Prescribing (PIP/PHP)/Potentially Inappropriate Medication (PIM) (20/79, 25.3%). The most common primary care setting was general practice (31/79, 39.2%). Of the 25/79 (31.6%) studies reporting aetiology data 19 of these (76.0%) reported on causes of non-adherence. Patient-related factors were reported in 23/25 (92.0%) studies and prescriber-related in 8/25 (32.0%). Eighteen studies evaluated the impact of remedial interventions with most relating to improving adherence rates (11/18, 61.1%). The introduction of specialist pharmacists were the most common intervention (10/18, 55.6%). Interventions had limitations and there were mixed outcomes with 18/18 studies reporting positive outcomes on some medication safety measures however, 6/18 (33.3%) reported little difference on some medication safety measures between groups.

Consequences

Our findings reveal that patients with mental illness may experience a variety of medication safety challenges in community care. To date the available research exploring medication safety in this setting is heavily orientated toward non-adherence and PIP/PIM, with comparatively less attention for other preventable safety outcomes such as medication errors and related harm. Further research is required to explore the epidemiology and aetiology of medication errors and drug-related harm in-depth as this data is currently lacking. This will help inform an intervention as preventable events may be amenable to one.