Medicines Management, Medication Errors and Adverse Medication Events in Older People Referred to a Community Nursing Service: A Retrospective Observational Study

Community nursing services play a vital role in helping frail older people to remain living in their own homes. This is the first study to quantify and describe medicines management support and medication-related problems in a representative sample of older people referred to a CNS. It found that CNS clients had a very high prevalence of risk-factors for medication-related problems, including multiple co-morbidities, cognitive impairment, polypharmacy and use of medicines associated with heightened risk. CNS clients used a median of ten medicines, which is higher than the average for community-dwelling older people [23].

In the first week of care most clients were visited on at least 5 days, mainly to administer medicines. In the last week of care, the number of visits was slightly lower and the most common form of support was monitoring medicine-taking. This may reflect the fact that some clients regained independence or semi-independence, or that some of the sickest and frailest individuals, with intensive care needs, were discharged to residential care or died.

The most common form of medication authorisation used by the CNS was medicine lists provided by GPs (usually summaries printed from GPs’ electronic patient records). Medication administration charts were infrequently used, and in some cases multiple medication authorisations were used concurrently. Reliance on GP medicine lists, letters from GPs and specialists and multiple medication authorisations stems from difficulty accessing GPs to obtain and maintain medication charts in the community setting. However, use of these types of authorisation and multiple authorisations is associated with risk of medication errors. It has been reported in several studies that GP medicine lists have a high rate of errors and discrepancies, for a variety of reasons including that the GP is often not the only prescriber and because patient records are not always updated when there are dose-changes and medicines ceased [9, 24, 25]. There were 26 medication errors related to discrepancies between medication authorisations and clients’ medicines (usually pharmacy-packed dose administration aids [DAAs]), which may reflect inaccurate medication authorisations and/or deficiencies in interdisciplinary communication (e.g. GP or other prescriber failing to notify the pharmacy of a medicine change for a DAA client, or GP being unaware of a medicine change initiated by another prescriber).

Multi-compartment DAAs were used by nearly 50 % of CNS clients. Whilst these may simplify medicines management for some older people, they can also increase the cost and complexity of medicines management and there is evidence that they are sometimes used unnecessarily [12, 26]. In this study almost half of the clients who used a DAA were receiving CNS visits 7 days a week, and almost one quarter had their DAA stored in a locked box. It is likely that some of these clients could have been managed without a DAA since they were not self-administering their medicines.

Medication errors were prevalent, with 41 % clients having one or more error identified. Almost three quarters resulted from clients (or carers) missing doses or taking medicines incorrectly. It is not surprising that client/carer errors were common given that CNS clients were older people with functional and/or cognitive decline who were referred for medicines management support, and many continued to have some involvement in taking their medicines (since the CNS could usually visit only once a day and medicines often needed to be taken at other times). However, it is also possible that healthcare providers and their systems contributed to some of the errors attributed to clients. For example, failure to simplify unnecessarily complex medication regimens or to choose the simplest dose-forms sometimes contributed to client errors. It is common practice for CNS nurses to set out the evening doses for clients when they visit in the morning, in order to avoid multiple daily visits, and this practice was sometimes associated with missed doses when the client forgot to take those medicines.

Medication errors caused by CNS staff were uncommon, however this is likely to be an underestimate because these were difficult to detect using retrospective methodology (which was largely reliant on CNS staff identifying and documenting such errors) and with low usage of medication administration charts. In hospitals and residential care settings, using medication chart audits and direct observation of staff administering medicines, much higher error rates have been reported [27, 28].

Missing the occasional dose of a medicine is unlikely to be clinically significant for most medicines, so whilst missed doses were the most common error, many were of minimal clinical importance. However, some errors had potential to cause harm, such as clients double-dosing, often due to confusion associated with the use of DAAs, clients taking an incorrect dose (including cases involving insulin, warfarin and prednisolone), clients potentially receiving incorrect medicines or doses as a result of inaccurate medicine lists, inter-professional communication failures, prescribing errors or dispensing errors and running out of medicines. One-third of errors involved medicines associated with moderate or high risk of AMEs if administered incorrectly.

AMEs requiring medical attention were identified in 13 % of CNS clients, including medication-related hospital admissions in 9 % of clients. This may be an underestimate, as identification of AMEs relied on CNS documentation. It is possible that some AMEs were not recognised or documented by CNS nurses. A majority of AMEs were considered to be potentially preventable, which is consistent with studies in other populations [29, 30].

The most common cause of AMEs was prescribing problems (Table 5). This, plus the high number of medication errors, and in particular errors related to discrepancies between medication authorisations and pharmacy-packed DAAs, suggests that CNS clients could benefit from better interdisciplinary collaboration. Interdisciplinary collaboration is needed to enable a ‘best possible medication history’ and medication reconciliation [31] to occur on admission to the CNS (in order to ensure that the correct medicine regimen is implemented and all members of the healthcare team have access to the same medicine list) [6, 12], to increase the use of medication administration charts (which enable clear documentation of medication administration and improve medication safety), and to facilitate interdisciplinary medication reviews. Despite CNS clients’ high risk of AMEs, and eligibility for government-funded interdisciplinary care services, there was little evidence of formal interdisciplinary collaboration in relation to medicines management.

Interdisciplinary medication reviews such as HMR have been shown to identify and address medicine discrepancies, medication-related problems and inappropriate prescribing, simplify medication regimens and reduce the risk of AMEs [6, 11, 32‐35]. The CNS involved in this study, like most CNSs, does not employ its own pharmacists or medical practitioners, so the only way for an interdisciplinary medication review to occur is if the clients’ GP initiates an HMR (nurses are not able to initiate government-funded HMRs). The low use of HMR in this cohort is consistent with previous Australian studies in high-risk groups such as people referred to Aged Care Assessment Teams or residing in supported accommodation [34, 36]. Efforts to increase the uptake of HMRs, even in high-risk groups such as CNS clients, have had limited success [34, 37], suggesting that alternative methods to facilitate interdisciplinary medicines management are needed. One option is for the CNS to employ clinical pharmacists to work with its nurses to undertake medication reconciliation and medicines reviews, and liaise with clients’ GPs and community pharmacists. A pilot study exploring the role of clinical pharmacists in a CNS is currently underway [38].

A limitation of our study was that it included only one metropolitan CNS. Further studies are warranted to determine the extent to which these findings are generalisable to other CNSs, in particular in rural and regional areas. Retrospective methodology may have led to underestimation of medicine use, medication errors, AMEs and interdisciplinary teamwork. A strength of the study was random selection of subjects to obtain a sample representative of the older people referred for medicines support. Another strength was review of clients’ complete CNS records, including nursing progress notes, to extract data, which is likely to have improved detection of errors and ADRs compared with reliance on spontaneous voluntary reporting by nurses.

Although there has been little previous Australian research in the home nursing setting, research conducted internationally suggests that many of these issues are not unique to Australia. Studies from other countries (mainly the USA) have reported that home nursing clients often have multiple medicines-related risk factors (including polypharmacy, multiple healthcare providers, poor communication between providers and outdated medicine lists) leading to medication errors and AMEs [8‐10, 39‐41]. No Australian or international study has previously recruited a similar random sample and reported the type of medicines management support provided, so it is not possible to compare this data with other studies.