摘要：We used a structured approach to assess whether active smokers presented with pictorial warnings on cigarette packages (PWCP) had a higher probability of quitting, reducing, and attempting to quit smoking than did unexposed smokers. We identified 21 articles from among nearly 2500 published between 1993 and 2013, prioritizing coverage over relevance or quality because we expected to find only a few studies with behavioral outcomes. We found very large heterogeneity across studies, poor or very poor methodological quality, and generally null or conflicting findings for any explored outcome. The evidence for or against the use of PWCP is insufficient, suggesting that any effect of PWCP on behavior would be modest. Determining the single impact of PWCP on behavior requires studies with strong methodological designs and longer follow-up periods. Smoking and its associated health and mortality risks have been well established. Nearly one fifth of the world’s population smoke, and close to 6 million die each year from tobacco use, 1 a figure estimated to reach 10 million by 2020. 2 In an attempt to curb this trajectory, governments have and continue to implement various tobacco control policies aimed at reducing smoking. Common tobacco control policies include increased taxes, bans or restrictions on advertising, sponsorships, point-of-sale displays, smoking in public places, 3 and, pertaining to this article, health warning labels on cigarette packages. Currently, most countries require warnings to be printed on cigarette packs, though format varies in terms of size, number, and how information is presented, ranging from vague text statements to graphic images alongside the text. 4 Pictorial warnings on cigarette packages (PWCP) were first implemented in 2001. 5 Since then, studies have assessed the perceptions and reactions elicited among smokers and nonsmokers and also the motivation or intention to quit or reduce smoking. 6,7 However, research investigating whether PWCP bring about a change in smoking behavior has been limited.
