In 2017 Mary Halter et al.  carried out a systematic review of the contribution physician associates provide in secondary care. It concluded that:
“When PAs were compared with medical staff, reassuringly there was little or no negative effect on health outcomes or cost.” 
A recent study  in 2020 comparing physician associates with foundation year two doctors undertaking emergency medicine consultations in a mixed methods study found that...
“Physician associates in emergency departments in England treated patients with a range of conditions safely, and at a similar level to foundation year two doctors-in-training, providing clinical operational efficiencies.” 
A mixed method multiple case study  in 2018 reviewed the contribution of physician associates in hospital care with the conclusion stating that...
“PAs provided a flexible addition to the secondary care workforce without drawing from existing professions. Their utility in the hospital setting is unlikely to be completely realised without the appropriate level of regulation and authority to prescribe medicines and order ionising radiation within their scope of practice.”