How many people really smoke?

This week, a report from the Office of National Statistics reported that the proportion of smokers in the UK has fallen to a record low. In 2006, just 22% of people over the age of 16 smoked cigarettes, down from 27% in the late 1990s.

It’s certainly good news and on the face of it, the Government seem set to meet their target of reducing the proportion of smokers in the UK to 21% by 2010.

However, there’s good reason to be cautious when looking at these stats. They come from the General Household Survey, which in turn depends on people answering questions about their behaviour truthfully. Sadly, we know that they often don’t.

Last year, Robert West, Director of Tobacco Studies at our Health Behaviour Unit revealed the true proportion of smokers in three countries including England. He collected saliva samples from over 6,600 people and measured their levels of cotinine, a chemical created when nicotine is metabolised in the body.

The study showed that surveys like the GHS are off by about 3%, making the true proportion of smokers in the UK larger than estimated.

This hidden 3% had levels of cotinine that were far too high to be explained by passive smoking. They could only have been caused by substantial levels of active smoking.

If this underestimation stays the same over time, then the fall in levels of smoking is still good news. More people may be smoking than we think, but at least the number is going down.

But the report itself says that more and more people may be misrepresenting their smoking habits.

As smoking has become less acceptable as a social habit, some people may have become less inclined to admit how much they smoke – or, indeed, to admit to smoking at all.

So while there’s every reason to be optimistic about the reported decline in smoking, it’s worth remembering that there is a good deal of uncertainty over the numbers.

Even with the ban on smoking in public places, there’s no room for complacency in tobacco control measures. Smoking is, after all, still the single biggest cause of cancer in the world.