Introduction: Around one third of the world adult population smoke. Due to the recent researches on the smoking addiction and to the use of new drugs, the possibilities to succeed on the attempts to quit smoking have increased remarkably. Purposes: To study the tobacco abstinence in patients under treatment at the Ambulatório de Auxílio ao Abandono do Tabagismo da Pontifícia Universidade Católica do Rio Grande do Sul (AAAT-PUCRS) and to evaluate the role of some variables as risk factors to the chosen outcomes. Patients and methods: In a prospective open clinical trial not randomized we studied all the smokers who attended the AAAT-PUCRS within July 1999 and October 2000. All of them were submitted to the same standard program; the results were analyzed by central tendency measures for quantifying variables, relative risk with a IC95% for the associated factors and the Kaplan Meier's curve for the analyses of the time trend. Results: The study included 169 patients (67.5% women), average age 46 (± 10.4) years old; the most of them smoked 20 cigarettes/day for around 30 years. Even for a very young cohort like this one, it was possible to show that in relation to the outcome success/failure, 49% of the patients quit smoking, 14% remarkably diminished the number of smoked cigarettes and 37% failed completely. For the studied variables, severe dependency to nicotine was the only one associated with an increased risk to failure quitting smoking. Conclusions: It was possible to achieve a reasonable quitting smoking percentage adopting standard procedures described, but adapted for each patient. Pharmacological therapy was associated to a higher percentage of success.

Keywords: Smoking. Treatment. Tobacco use cessation. Ambulatory care.