Table 1 Review eligibility criteria, highlighting changes made following piloting

Population

Physician associates (PAs) or assistants working in primary care in any high-income country [16].

CHANGE: The search terms initially included a range of terms for primary care settings. When articles were retrieved, several potentially relevant ones were missing. The search was amended to remove primary care terms. Instead a paper’s relevance to primary care in the UK was assessed on all retrieved records, where possible at abstract screening or otherwise at full text review.

Intervention/ Exposure:

Actions taken by PAs for patients with any symptom(s) that might be cancer

CHANGE: Although initially planned, the search was not limited to papers with mention of possible cancer symptoms. In practice almost any symptom may be a sign of cancer so it was not feasible to turn this criterion into specific search terms. However, it was possible to exclude papers on abstract screening or full-text review where the symptom or aims of the study was clearly not relevant to cancer diagnosis, e.g. screening for domestic violence, care for multimorbidity.

Comparator:

Any other clinical professional

CHANGE: Following the advice of an expert advisor we included studies where PA data were aggregated with nurse practitioners but excluded studies were PA data were aggregated with other professionals. This was in recognition of the fact that, in many settings, nurse practitioner and PA roles may overlap.

Outcomes:

Quality of symptom recognition and referral where cancer might be suspected

This comprised PA skills, confidence, performance, deployment (activities or decisions undertaken to reach a diagnosis, such as history taking, symptom recognition, referral or investigation, triage and cancer screening referral), satisfaction with care, and adherence to guidance/best practice.

Excluded: Chronic disease management, non-cancer screening or primary prevention.

Study type:

Peer-reviewed papers

Study design: Primary research - qualitative or quantitative

Excluded:

- Editorials, letters or narrative reviews

- Systematic reviews though these were first searched for eligible references.