Age affects appointment chances
Age, sex and wealth all affect how likely your GP is to refer you for a specialist appointment, a study has concluded.
A UK team analysed data for 130,000 patients, reporting their findings in the British Medical Journal.
Older people were less likely to be referred for three common symptoms, with sex and deprivation also influential.
A charity said the study should raise alarm bells across the NHS.
Michelle Mitchell, Charity Director at Age UK, said: "A doctor's decision to refer patients must be based solely on the patient's clinical need, not their age. Age discrimination in health provision will be unlawful from 2012 and it can't come a moment too soon for older people in need of medical care."
The study from the King's Fund and University College London covered decisions on patients with postmenopausal bleeding, hip pain and heartburn from 326 UK practices across a six-year period.
Once everything else that might influence a doctor's decision to refer - such as smoking, weight, alcohol use and pre-existing conditions - was taken into account, the researchers found significant differences in referral rates between old and young, male and female.
As a guide, the older the patient, the less likely a referral was - in postmenopausal bleeding, someone aged 85 or over was 61% less likely to get a specialist appointment, compared with someone aged 55 to 64.
For patients with hip pain, the difference in referral rates was 32%.
Women were 10% less likely to be referred for hip pain than men, while there was some evidence that coming from a poorer background made a specialist appointment for hip pain and heartburn less likely.
The reasons behind the decisions were not revealed by the study - however, the authors suggested that older patients might be less likely to ask for referral, and that GPs choosing to work in deprived areas might be generally less inclined to refer.
However, they said that the differences could lead to "delays in treatment and poorer outcomes" - and might be an even greater concern if similar patterns emerged in referrals for other common symptoms, some of which could be linked to serious illness.
In an accompanying commentary, Professor Moyez Jiwa, from the Curtin Health Innovation Research Institute in Perth, Australia, said it was hard to know how harmful decisions like this could be.
While some patients might be "denied timely access" to experts, he wrote, others who were referred could be harmed by unnecessary testing and treatment.
He added: "The appropriate referral of cases has economic, quality and safety ramifications that resonate across the health sector and the globe."
Professor Jiwa said that database analysis like this could not help researchers understand why GPs and their patients behaved in a certain way in the consulting room.