Discussion
In this systematic review, we comprehensively identified 16 patient-related factors (eight non-clinical and eight clinical, respectively) and ten prescriber-related factors of PIPs among primary care older adults. Also, we synthesised four analytical themes of stakeholders’ perceived barrier factors to medicines optimisation and their corresponding recommendations and potential solutions. The results of qualitative studies showed that barriers to medicines optimisation involved factors related to prescribers, patients, environment and technology. The recommended potential solutions were based on each theme of the barriers identified accordingly. The main findings of our study were reviewed and commented on by stakeholders in different areas to strengthen their practicability. Our study expands on previous systematic reviews by mixing quantitative and qualitative findings, which allowed for greater scope and insights into the factors associated with PIPs and barriers and recommendations to medicines optimisation.
A recent systematic review of 22 papers by Nothelle et al14 explored patient, clinician and environmental factors associated with PIM use in community-dwelling older adults in the USA. Their review identified four patient-related associated factors: a higher number of prescribed (reported by 14 studies), female sex (reported by 10 of 16 studies), psychiatric comorbidity (reported by 6 of 8 studies) and geographical region (reported by 7 of 8 studies), which partly coincided with our findings. However, only three studies examining clinician factors were included in their systematic review, and few were statistically significant.12 In two systematic reviews, the number of medications, sex and age were the factors most often associated with PIMs among community-dwelling elderly, and both reviews showed a mixed association between PIMs and sex or age.13 14 Although this result was in line with our findings, the proportion of studies included in our review reporting the positive association was smaller. Similar patient-related factors have been shown in systematic reviews exploring PIPs across different healthcare settings.15 16
Despite many factors that previous reviews and our study had identified, it is vital to note that a greater number of medications were the most consistent risk factors for PIPs in all settings. Alarmingly, the number of medications has been increasing over the years. Qato et al75 reported that 31% of older adults in the USA were taking five or more prescription medications in 2005–2006, rising to 36% in 5 years. These two proportions further increased to 53% and 67% if over-the-counter medications and dietary supplements were included.75 Moriarty et al conducted a repeated cross-sectional study and found that the prevalence of polypharmacy among the elderly (≥65 years) in Ireland increased from 17.8% in 1997 to 60.4% in 2012.32 Therefore, measures to curb the growth trend of medication use, particularly those unnecessary, ineffective and harmful prescribing, should be the priority in reducing medication-related harms.
Two systematic reviews by Anderson et al15 and Reeve et al16 synthesised qualitative studies regarding prescribers’ and patients’ perceived barriers and enablers to minimise PIMs, respectively. Despite differences in the eligibility criteria of participants and healthcare settings, most of the results reported in both reviews were similar to ours. However, one additional barrier described in our study was that PCPs may have no Internet access or computerised decision support systems (CDSSs) owing to underdeveloped infrastructure.61 62 65 67 CDSSs are considered promising solutions to improving medication safety since they can efficiently help PCPs process complex clinical information, increase PCPs’ adherence to guidelines, and improve the quality of prescribing decisions.76 Accordingly, potential solutions were recommended for streamlining the EHR system to help prescribers work efficiently and wisely, such as developing CDSS and online chat systems.67 71 74
A meta-synthesis by Cullinan et al17 described the prescribers’ viewpoints on why PIPs occurred in older patients in detail. They found that prescribers tend to satisfy patients’ requests, partly because some patients became aggressive and demanded their medications. This finding was supported by a factorial experiment revealing that patient requests for a specific medication significantly increase the rate at which physicians prescribe that medication.77 Our study synthesised several practical recommendations to cope with this problem, including patient counselling and education,64 66 74 shared decision making65 and involving caregivers for assistance.67 Furthermore, our findings also added important recommendations regarding deepening cross-disciplinary cooperation among clinical pharmacists, specialists and primary care physicians. However, PCPs’ barriers to and experience in responding to older patients demanding PIPs need to be explored in future studies.
Our study analysed both quantitative and qualitative studies and identified the consistency between these findings. For instance, quantitative studies have found that patients with a higher number of comorbidities, and specific physical (eg, osteoporosis) or mental diseases (eg, Alzheimer’s disease) were more likely to receive PIPs. This challenge impacts on the qualitative findings of barriers to medicines optimisation, which requires more professional knowledge of physicians, and decreases patient adherence. The challenge could be more severe when the integrated care and applicable guidance were absent. Therefore, many potential solutions have been recommended focusing on improving the ability of PCPs to manage elderly patients with comorbidities, such as shared decision-making and developing guidelines for the management of common comorbidities. In the part of quantitative synthesis, this systematic review demonstrated the associations between PIPs and factors from both patient and prescriber aspects among primary care older adults.
We also identified gaps between the quantitative and qualitative findings. Although prescribers have a greater impact on PIPs, most studies have focused on patient characteristics and clinical information. In contrast, prescriber information has not been adequately investigated, which hampers our ability to identify prescriber-related factors. Many barriers already reported by qualitative studies (eg, patients’ limited understanding and drug dependency) were not included as potential risk factors in quantitative studies to date. A possible reason for this gap was the difficulties in data collection because research solely based on the data of patients’ prescriptions is easier to conduct. Future studies in this area may need to consider relevant qualitative findings and design more practice-based approaches to explore the associated factors.
The results of our thematic synthesis disclosed perceived barrier factors of the prescriber, patient, environment and technology that shape PCPs’ behaviour towards minimising PIPs in routine clinical practice. Several strategies to improve medicines optimisation could be implemented. First, professional training, including screening methods to detect PIPs, drug-related risk stratification and clinical monitoring, and communication skills of medication use, could be provided to PCPs. One example is the academic detailing. Previous systematic reviews demonstrated that the academic detailing was effective at changing PCPs’ prescribing behaviours and improving their capacity for medicines optimisation.78 79 However, there is still room for improvement in the content design, and more high-quality research is needed to examine the acceptability and feasibility of the training programmes.78
Second, patient education on medication use should be integrated into routine clinical practice in primary care settings. A continuous and high-trust therapeutic relationship helps engage patients in self-management of medication. Therefore, PCPs need to understand the motivation of patient use of PIMs and help them make wise decisions. Public health campaigns and advertising are also conducive to patient involvement, apart from direct patient counselling.69 For example, PCPs may give lectures or send health information via social media to the community-dwelling older adults regularly to increase their awareness of medication safety.
Third, policy initiatives and health system reforms should improve PCPs’ working environment of medicines optimisation, such as financial remuneration. Essentially, open channels of information exchange among health professionals are beneficial for developing interprofessional relationships and collaboration. Staff support from pharmacists or nurses can help address difficulties in many ways. They provide reassurance on treatment decisions, contribute to decreased workload and increase patient access to PCPs.80–82 Policies should be made to encourage PCPs to integrate the pharmacists, nurses and other health professionals on the healthcare team to improve the quality of prescribing. Finally, besides advanced electronic health record (EHR) systems and accessible decision support to reduce PIPs, PCPs need concrete and evidence-based medicines optimisation procedures. This again implies an urgent need for high-quality studies involving individualised and complex interventions.
Our study has several limitations. First, it is difficult to quantitatively evaluate the degree of association between PIPs and factors, and compare the results from the included studies because of the heterogeneity of the sample, measurement and analysis methods. Second, since studies involving participants with specific diseases or medications were excluded from our review, the study results may not be generalisable to specific groups. Third, there remained great variations in the terminology used for medicines optimisation, increasing the difficulties in identifying relevant studies. To address this problem, we formulated comprehensive search terms that were applied to multiple databases and manually searched reference lists and related citations. Fourth, a proportion of the studies included in our review were assessed to have a high risk of bias. This may reduce the strength of the evidence presented, and conclusions drawn from these must be treated with caution. However, the research quality was acceptable overall, and all studies could help improve the comprehensiveness of the results. Finally, publications were limited to English and Chinese languages only, which contributed to the potential omission of relevant evidence.