People who live in deprived areas get less help from the health service, a study has warned.
The study compared GP cover across the country
Glasgow University researchers found the poorest parts of Scotland's towns and cities had 11% fewer GPs and less access to health promotion programmes.
This was despite evidence of a far higher rate of ill health.
The study, published in the British Medical Journal, was based on a population of 5.35 million people served by 1,050 general practices.
It looked at the availability of primary care according to levels of deprivation.
Ill health was found to be two-and-a-half times greater in the most deprived group compared with the most affluent.
But there were 11% more GPs in the more affluent areas compared with the more deprived half of the population.
The researchers said that although they found larger numbers of practices in the most rural and deprived areas, this reflected the higher proportion of single-handed and small practices in these areas.
They also found that these practices tended to have younger doctors, fewer female doctors and less involvement by GPs in extra voluntary activities compared with affluent areas.
These activities include quality schemes, health service initiatives and training opportunities.
The researchers said that these activities featured about twice as often in practices serving more affluent areas.
"Although there are training and pioneering practices in poor areas, they are exceptions to the general rule," the researchers said.
"These activities are not centrally distributed but are taken up by practices that volunteer.
"Practices serving the most deprived areas are less likely to volunteer, possibly because they are so consumed by dealing with increased levels of morbidity, without increased levels of medical manpower, that they are unable or unwilling to take on additional activities."
Professor Graham Watt, from Glasgow University's Department of General Practice, said the study helped to explain the persistence of health inequalities in the UK, and the under-achievement of the NHS in narrowing the gap.
He said: "The strict rationing of medical manpower, irrespective of need, places a major constraint on what the NHS can deliver in deprived areas.
"It follows that general practitioners in such areas have to ration what they do for patients in the time available.
"Too many NHS agencies have policies and initiatives which fizzle out in the most deprived third of the population.
"There is an urgent need for NHS initiatives and support systems which reach the parts that current approaches fail to reach."