Pharmacy data reveals impact of smoking ban

HELEN PEARSON

Sales peaks of patches only last for a couple of weeks. © Corbis

Tax hikes and a ban on public smoking prompted New Yorkers to try quitting the habit, public-health officials revealed last week. The finding is part of intelligence churned out by the health-surveillance systems springing up across the United States.

Researchers are increasingly tracking doctors' visits, pharmacy sales, absentee rates and even death certificates, hoping to pick up unusual spikes in activity. These might be early warning signs of a bioterror attack or spreading foreign disease, they reason.

The New York City Department of Health and Mental Hygiene, for example, receives daily streams of data about hospital diagnoses and drugstore purchases. Health official Kristi Metzger and colleagues examined how sales of nicotine patches and pills from more than 100 outlets in New York changed over the past two years.

Sales of nicotine-replacement therapies shot up with the advent of virtuous New Year's resolutions, Metzger told the 2003 National Syndromic Surveillance Conference in New York last week. A small recurring peak suggests that "people may be more likely to quit on Mondays", she added.

A July 2002 hike in the New York state tax on cigarettes, from 8 cents to $1.50 per pack, also sent sales of nicotine therapies soaring. So too did the Smoke-Free Air Act, which came into force on 30 March this year and bans smoking in all indoor New York workplaces, including bars and restaurants. But people's resolve rapidly crumbled: the sales boosts lasted only a week or two.

Such data might one day inform public-health policy, Metzger suggested. For example, it could have given health officials a heads-up after August's East Coast blackout. Retrospectively, officials reported a spike in people visiting hospitals with diarrhoea brought on by spoiled food.

Watchful eye

Prompted by the US anthrax attacks of October 2001, most of the new surveillance systems are designed to pick up early warning signs of a bioterror attack, such as a hike in fevers or rashes. They use sophisticated algorithms to filter computerized health data for unusual peaks.

But the systems are untested as yet by bioterror agents - so researchers are teasing other information from them. "These data have all sorts of uses," says Julie Pavlin, an expert in preventive medicine at the Walter Reed Army Institute of Research in Silver Spring, Maryland.

We're realising these data have all sorts of uses Julie Pavlin Walter Reed Army Institute

Pavlin told the New York meeting of her efforts to mine doctors' data on families of those in the military. She probed computer codes that describe patients' main diagnoses after a clinic visit, as well as prescription logs. This information has been collated since 1997, partly as a means of budgeting, Pavlin explained.

Pavlin saw an anticipated peak in patient numbers visiting doctors with depression or anxiety around the time that US forces invaded Iraq in March. Such information might warn doctors to set up support networks or classes in the future, Pavlin suggested. "They can help track the mental health of the community," she added.

© Nature News Service / Macmillan Magazines Ltd 2003