Coronation Street's Alma had cervical cancer

In the Coronation Street plot, the character Alma Sedgewick developed cervical cancer, dying from the disease in June last year.

Health experts writing in the British Medical Journal (BMJ) estimate around 14,000 extra cervical smear tests were carried out in the North West as a result of the storyline, costing the NHS an estimated �500,000.

They say if that pattern was repeated across England, the storyline could potentially have cost the NHS around �4m in extra smear check costs.

That �4m could have been spent in a different way Dr Andy Howe, Greater Manchester Strategic Health Authority

A helpline run by the charity CancerBACUP received around 300 additional calls per week because of the storyline.

Though it expressed concern some women may have been unnecessarily worried by the storyline, the charity welcomed the fact that awareness of its work rose dramatically during the period it was on screen.

Increased waits

Around 2,000 of the women who came forward in the North West had never had a test, or should have had one sooner.

But the remaining 12,000 were women who were already in the system and came for extra or early tests.

The researchers welcomed the fact that women who might otherwise not have had a smear test came forward, but said the large increase in demand led to a significant strain on local health services.

The extra demand led to increased waiting times for results - potentially increasing women's anxiety.

Writing in the British Medical Journal, the researchers, led by Dr Andy Howe, said: "Television programme makers should realise the power of such stories, not only to achieve maximal viewing figures, but also to cause fear and anxiety, as well as the consumption of scare healthcare resources.

"Those responsible for promoting health need to engage programme makers in a full ethical debate."

'Untapped group'

Dr Howe told BBC News Online: "We saw women who had come who had never had a smear before, and that was a huge benefit of the story."

But he added the demand for extra smears placed a huge burden on the health service.

"The NHS has limited resources. That �4m could have been spent in a different way.

"If we work together better, we could help get to the right women."

Rachel Hardyman of CancerBACUP said TV programmes were an important method of getting messages across.

She wrote in the BMJ: "The trend for giving information at the end of potentially delicate television programmes seems not only responsible but necessary.

"In our study making such information available led to the use of a cancer helpline by a broad and, in part, previously untapped group."

Charcoal burning

Separate research in the BMJ by psychiatrists from the Chinese University of Hong Kong highlights the impact of newspaper reports of suicide rates in Hong Kong.

A 55-year-old woman killed herself by burning charcoal on a barbecue grill in her sealed flat in November 1998.

Two months after details of her death were published, charcoal burning became the third most common form of suicide.

By 2001, it accounted for 25% of suicides in Hong Kong.