However, it praised primary care- based chronic disease clinics for producing health outcomes at least as good as hospital outpatient clinics, being effective in reducing outpatient appointments and improving access to care. But the cost of transferring care in this way was unknown, it said.
The scoping study was carried out by the National Primary Care Research and Development Centre at the University of Manchester and led by Professor Martin Roland.
The study identified patient-initiated follow-up for hospital discharges and direct primary care access to hospital-based tests and treatment as effective changes.
However, it said interventions with good outcomes and improved access, such as telemedicine, GPs with special interests and relocating specialists to primary care clinics, would cost more than hospital clinics.
Referral guidelines had an impact on inappropriate referrals only if they were in the form of structured referral sheets, with prompts to conduct any necessary pre-referral tests or treatments, according to the study. They should also be supplemented with educational outreach by specialists or with in-house second opinions.
However, financial incentives for lowering referral rates were found to be dangerous and feeding back referral rates had no effect.
Using GPs to carry out minor surgery such as removing moles was more expensive and could be dangerous, said the report, especially if there was no consultant supervision.
Professor Roland, said it was dangerous to assume care in the community would always be cheaper and that better access would always be popular if this resulted in the quality of services going down.