This review of peer-reviewed literature combined with advisory group interpretation suggests the introduction of PAs into primary care may maintain the quality of referrals and diagnostic tests needed to support cancer diagnosis. It also highlights the lack of research on several aspects of PAs’ roles, including outcomes of the diagnostic process.
Strengths and limitations
This review, the first of its kind to focus on cancer diagnosis, provides timely insights into the contribution of PAs in an important sphere of activity at a time of rapid expansion of the physician associate profession in England. It also addresses some of the limitations of the last major systematic review in 2013 examining the contribution of PAs to primary care, which reported the quality of evidence was weak with few studies comparing performance with other professionals.12 There are important limitations, however.
Most (13/15) studies came from USA, which limit the transferability of findings to other healthcare systems. In particular, in the US the role of primary care professionals in cancer diagnosis may be different; they are not always required for referral to specialists but they are often central in organising cancer screening (a task led by cancer screening hubs in England). Studies undertaken in other countries (Netherlands, Israel, Germany) were identified but excluded because PAs were not deployed in primary care settings. However, eligible studies from the UK and Canada – where access to specialist care is normally via a family physician37 - provided corroborative and complementary insights to those from USA. Moreover, US-based studies have relevance internationally for two other key reasons. Firstly, the drivers for the introduction of PAs have been experienced globally, i.e. shortages in primary care providers amid increasing patient demand, and shifts to multidisciplinary models of primary care teams to provide care.3 Secondly, they give some indications of how PAs that are regulated and integrated into the healthcare system might perform on processes such as ordering of ionizing radiation that are not currently permitted in the UK.
None of the studies sought specifically to investigate the impact of PAs on cancer diagnosis. Some excluded cases with ‘red flag’ symptoms which might exclude cases where cancer was suspected. However, red-flag symptoms are present in only a minority of cancer diagnoses, and UK guidance specifically recommends investigation of a wide range of symptoms.35 Five studies presented only aggregated data for NPs and PAs. Numbers of PAs may be smaller than NPs, so there is a risk that findings are driven by NPs rather than PAs. This aggregation, therefore, may miss important differences in care. Where sub-analyses had disaggregated data, PAs data was often more similar to primary care physicians than NPs. To inform workforce decisions, in future studies PA and NP performance needs to be reported separately.
Most studies considered PAs’ impact from the perspective of other clinical professionals only; views of patients and non-clinical practice staff were absent from 12/15 studies. As others have reported, patients are open to seeing PAs and experience with them is largely positive when the role is explained.3839 Studies so far have focused on preferences and degree of satisfaction with PAs. As Box 1 comments indicate, given the potential difference in status and duration of training, patients may develop a different relationship, and communicate in different ways with PAs than with primary care physicians.
The streamlining of review methods did result in findings within a relatively short period of time that could be shared to influence practice (e.g. with preceptorship scheme in North London). Streamlining review methods may have resulted in missing relevant papers, particularly due to narrowness of the search (restricted to English paper and since 2009). However, a systematic review conducted in 2013, identified major gaps in the literature at this point so extending the search to find papers published earlier than 2009 would be unlikely to yield further insights.
Comparison with existing literature
Our principal finding – that in most studies PAs performed similarly to physicians – is largely in line with findings from other studies.12 In the UK a suite of studies examining the impact of PAs in primary care at micro, meso and macro levels in 2014 reported PAs were acceptable, effective and efficient in complementing the work of GPs.32 25 40 At this time, however, there were just 25 PAs working in primary care, with around half trained outside of the UK, which may limit the transferability of this study to a context where most PAs have been trained in the UK and their presence is the norm, not the exception. As others have noted, this finding does not mean that PAs and physicians deliver equivalent care in general. Indeed, in common with other studies, the profile of patients seen by PAs often differed from those of primary care physicians, and generally seemed to be healthier.40 The findings may indicate, however, that there are circumstances in which the additional clinical acumen amongst primary care physicians gained by more training and experience may not be required.41
In common with the wider literature, this review also highlighted that PAs’ deployment varied between (and within) settings. 32; 2842 Limits on their role, due to lack of regulation and prescribing rights, is understood as a significant barrier in the UK.43 However, aside from regulation, there are other barriers to delegation. In particular, there is evidence of some resistance and hostility from other health care professionals where there is perceived role overlap or competition for training opportunities.42 This resistance appears to lessen when there is greater understanding of the role.43 For PA skills to be utilised appropriately, the whole primary care team need to be clear about and accept the role of PAs in their setting. This role clarity is also required by non-clinicians also to ensure that patients are triaged to the most appropriate clinician.4445 Role clarity does not mean uniformity; evidence from our review and advisory group stakeholders (Box 1) suggested that the flexibility and adaptiveness of the PA role in general can enable PAs to develop in different ways as required by their particular healthcare system.
Conclusions and implications for research, policy and practice
This review suggests that the expansion of PAs working in primary care may maintain the quality of care needed to support cancer diagnosis. This is important, given concerns that PAs might provide poorer quality of care.16192428 It is also important to guide deployment of PAs in contexts like the UK, where, following regulation, their roles could be expanded to cover tasks like ordering of ionizing radiation. The review also highlights important gaps in the evidence base, particularly how primary care workforce changes may impact on the timeliness of cancer diagnosis. For research to explore the impact of new professions on the timeliness of diagnosis, amendments research and monitoring are needed to collect data on consultations with a range of professionals other than physicians.
Although we discovered no adverse outcomes from the introduction of PAs, it is clear that PAs need to be actively integrated into their working environments. Integration of PAs may require strategies for the whole practice. For example, support for clinical supervisors could enable them to maximise safe delegation to PAs. Support to primary care leaders could promote PAs’ integration into wider team, through clarifying respective clinical roles.
The context of primary care has altered significantly since the studies in this review were conducted. International guidance on the role of primary care in cancer acknowledges the planned structural shift away from a model of the lone practitioner, but provides no insight into the potential role of PAs.3 In addition, routes to cancer diagnosis have been affected in unforeseen ways by the Covid pandemic. These include, but are not limited to, patients’ reluctance to consult primary care when they experience possible cancer symptoms, a switch to remote instead of face-to-face consultations which may decrease clinicians’ capacity to spot subtle symptoms, and a delay in diagnostics referrals due to lockdown backlogs and decreased capacity in order to maintain social distancing.46 Further studies should examine the impact of emerging professions such as PAs on timely cancer diagnosis in this new context of primary care.