Twenty-two studies were included (number of participants not reported). Six studies (all RCTs) were classed as good quality. Issues with study quality included selection bias, less than one year’s follow-up, small sample size, high drop-out rate and a lack of detail about the administration of the intervention.
Education (nine studies): Five before-and-after studies used traditional lectures or training sessions to try to improve knowledge of risk factors and diagnostic ability among health professionals. None of these studies were rated as good quality. All involved similar assessments (before and immediately post-test) and showed some improvement in knowledge.
RCTs used various educational interventions that included lectures, videos and an internet triage package, compared to no intervention control groups. Trials were of mixed quality and provided inconsistent evidence. The two RCTs that reported a positive outcome of improved diagnosis and management did not see this improvement maintained to the end of the trial.
Audit and feedback (three studies): One high quality RCT where participants either did or did not receive feedback reported improvement in the recording of clinical information but not in diagnostic accuracy. Low quality before-and-after studies showed significant improvement in outcomes.
Decision support software and guidelines (five studies): Three high quality RCTs evaluated computer-based interventions designed to improve the quality of referrals to secondary care. None of the studies found an improvement in the appropriateness of referrals. One study of a distance learning intervention reported a reduction in urology referrals.
One of two low quality before-and-after studies found that participants made fewer incorrect clinical decisions after using software for the triage of skin lesions and the other found increased use of breast cancer guidelines but no effect on knowledge or attitudes.
Diagnostic and assessment tools (four studies): None of the studies that aimed to improve particular skills or use of equipment to increase diagnostic accuracy were considered to be good quality. One before-and-after study of skin cancer found that dermoscopic teleconsultations led to more relevant referrals than clinical examination. A feasibility study of a clinical prediction rule for colorectal cancer found that uptake of the tool was low.
One RCT gave primary healthcare professionals a one-day training course in a rule for assessing skin cancer and randomised them to assess skin lesions by standard clinical examination or dermoscopy. Dermoscopy improved triage, referral sensitivity and accuracy and led to participants being less likely to miss skin cancers. The other RCT assessed an educational intervention for improving melanoma diagnosis using surface microscopy compared to no training. Participants’ diagnostic ability on clinical photographs improved significantly after microscopy training.
Other skills training: One low quality RCT assessed whether arts-based skill training could improve observational skills. After training by an artist, observational skills improved significantly more than for a control group who received a lecture on skin diseases.