Question: How to quit smoking. Nicotine patches are often used to help smokers quit. Does giving medicine to fight depression help? A randomized double-blind experiment assigned 244 smokers who wanted to stop to receive nicotine patches and another 245 to receive both a patch and the anti-depression drug bupropion. After a year, 40 subjects in the nicotine patch group and 87 in the patch-plus-drug group had abstained from smoking. Give a 99% confidence interval for the difference (treatment minus control) in the proportions of smokers who quit.