CHALLENGING ASSUMPTIONS ON SMOKING; RESEARCH QUESTIONS EFFECT OF RESTRICTIONS.

Byline: Associated Press 

Would health costs go down if everyone stopped smoking? Does cracking down on underage cigarette sales make teen-agers smoke less?

If the answer to both questions seems like an obvious ``yes,'' think again.

Two new studies support the contrary view.

One looked at the economic impact if every smoker went cold turkey tomorrow. The conclusion: Health care costs would drop for a while but would then inexorably rise for the simple reason that nonsmokers live longer.

The other study found that even with strict - and seemingly effective - enforcement of laws against selling cigarettes to anyone under 18, teen-agers can still get them easily, and they smoke just as much, if not more.

Both works challenge simple assumptions about the causes and consequences of smoking. They were published in today's issue of the New England Journal of Medicine.

An estimated 3,000 minors take up cigarettes each day in the United States. Making cigarettes harder to buy is the cornerstone of a new effort by the Food and Drug Administration to keep them out of the hands of teen-agers.

The FDA rules, which went into effect in February, require stores to get photo identification from anyone who looks younger than 27. A federal goal is to have at least 80 percent of stores obey the laws.

Nevertheless, such rules - which already existed in many communities - have received little testing to make sure they work. So a team led by Dr. Nancy A. Rigotti of Massachusetts General Hospital set out to compare high school students' access to cigarettes in six Massachusetts towns - three where state or local tobacco sales laws were beginning to get strict enforcement, and three where the laws were not enforced, even though underage sales were still illegal.

``It looks like keeping teen-agers from buying cigarettes will be more difficult than was first expected,'' Rigotti said. ``Even when 80 percent of merchants obeyed the law, young people said they had little trouble buying.''

The study was conducted from 1994 to 1996. In the enforcement towns, stores were barred from selling to youngsters under 18. But they did not have to ask for an ID from everyone who looked young.

The researchers tested compliance by sending 16-year-old girls into stores to buy cigarettes. The girls could not lie about their age or show fake IDs.

By the study's end, 18 percent of the stores in the towns with enforcement were still selling cigarettes to the decoys, compared with 55 percent in the other towns.