Laws that end smoking at work and other public places result in significantly fewer hospitalizations for heart attacks, strokes, asthma, and other respiratory conditions, a new analysis performed by researchers at the University of California at San Francisco has found.

The research provides evidence that smoke-free laws that cover workplaces, restaurants, and bars have the biggest impacts on hospitalizations, reduce health care costs and also raise quality of life, the researchers asserted.

The research was published in the latest issue of the American Heart Association journal.

"The public, health professionals, and policy makers need to understand that including exemptions and loopholes in legislation—such as exempting casinos—condemns more people to end up in emergency rooms," said senior author Stanton A. Glantz, a UCSF professor of medicine and director of the Center for Tobacco Control Research and Education located at the university.

"These unnecessary hospitalizations are the real cost of failing to enact comprehensive smoke-free legislation," Glantz said.

For decades, Glantz and his colleagues at UCSF have sought to be at the forefront of tobacco research, disclosing how the tobacco industry manipulated its products and led the public into cigarette addiction, the university said.

In the latest study, the scientists examined the relationship between legislated smoking bans and hospital admissions or death from cardiac, cerebrovascular, and respiratory diseases.

The inquiry consisted of a meta-analysis of 45 studies published prior to Nov. 30, 2011. Altogether, the research covered 33 different smoke-free laws in cities and states around the United States as well as in several countries, including New Zealand and Germany. The laws variously prohibit smoking in such public spots as restaurants, bars, and the workplace.

The authors found that comprehensive smoke-free laws were followed rapidly by significantly lower rates of hospital admissions than before the laws went into force. Examples they cited included a 15 percent drop in heart attack hospitalizations, a 16 percent drop in stroke hospitalizations, and a 24 percent drop in hospitalizations for respiratory diseases including asthma and chronic obstructive pulmonary disease.

Laws that were more comprehensive in scope, meaning that included restaurants and bars as well as workplaces, were followed by larger changes in risk, the authors said. Moreover, the decrease in hospitalizations applied similarly to women and to men, the researchers found.

The authors noted several studies that showed an additional benefit: lower health care costs connected to smoking-related illnesses. The savings reportedly ranged from $302,000 for acute myocardial infarctions in one small Mississippi town, to $6.9 million the first year after smoke-free laws were implemented in one province in Germany.

"Smoke-free legislation...reduces exposure of nonsmokers to secondhand smoke and creates an environment that helps smokers cut down or quit smoking," the authors wrote. "The passage of these laws reflects changes in social norms that also affect smoking behavior; the laws both formalize and accelerate this social change and the associated health benefits."

Crystal E. Tan, the study's first author, is a medical student at UCSF.

The research was supported by National Cancer Institute grants.

UCSF says it's dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.