There is little economic sense in introducing new charges into the health service, a study from the Office of Health Economics concludes.

Evidence from major industrialised countries shows that patient charges can help to reduce both spending on services and the degree to which they are used, the study says.

But charges are 'an indiscriminate and inefficient instrument' because they reduce both appropriate and inappropriate use of health services.

In addition, there is evidence that charges can have a 'deleterious effect upon health outcomes' and impact disproportionately on poor people.

Authors Ray Robinson and Martin Chalkley conclude that 'it would be unwise to support a major expansion' of patient charges as proposed by some commentators in order to increase revenue for the health service. Charges 'may have a small role to play at the margins' by discouraging frivolous or inappropriate use of NHS services and by raising small amounts of extra money.

But to be efficient, a new system of charges would have to be sensitive enough to distinguish between genuine needs and unnecessary healthcare demands.

'Precisely how this could be done is far from clear,' the study says.

Leaks suggesting that the government may make women pay for the contraceptive pill have provoked outrage among doctors, family planning campaigners and MPs.

British Medical Association chair Sandy Macara said he was 'horrified', and warned that any savings on the prescription bill would be outweighed by the costs to the NHS of unwanted pregnancies and abortions. A Commons early-day motion opposing the imposition of charges, tabled by two backbench Labour MPs, has been signed by 47 MPs from all parties.

Theory and Evidence on Cost Sharing in Health Care: an economic perspective. From OHE, 12 Whitehall, London SW1A 2DY. pounds10.