The study involved 384,693 patients from five health maintenance organisations in the US and 757,680 patients from the general practice research database in the UK.
About one in three patients in the US were referred to a specialist annually compared with one in seven in the UK. The twofold difference held for the healthiest as well as the sickest patients. The supply of specialists in the US exceeds that in the UK by twofold, and just 1% of US patients wait four months or longer for elective surgery compared with 33% of UK patients.
The low availability of specialists, and resultant long waiting lists, in the UK is an important explanation for these differences, say the authors. Other possible explanations include a less intensive practice style among UK physicians, the common practice of self referral among US patients, and a broader scope of practice among UK physicians.
Given the low rates of referral in the UK relative to the US, it seems unlikely that referral guidelines, which have been proposed as a method to reduce pressure on UK outpatient services, will dramatically enhance specialty capacity by decreasing demand, they conclude.