Phases of clinical trials

摘要: Researchers assessed the efficacy of nortriptyline when combined with nicotine replacement for smoking cessation. A randomised controlled trial was performed. Participants were included if they trying to stop smoking. In total, 445 participants and 456 control (placebo plus replacement). The primary outcome prolonged confirmed abstinence at six months.1 Nortriptyline is an antidepressant, although time study it not licensed cessation, had shown benefit in previous trials. Nicotine cessation most commonly used drug this setting. The proportion people who achieved months greater those using than placebo, difference statistically significant (16% v 12%; relative risk 1.34, 95% confidence interval 0.97 1.86). authors concluded that are effective drugs treatment no more either alone. Which one following options best describes phase above clinical trial?