School of Public Health & Health Systems, University of Waterloo, Canada.
Department of Psychology, University of Waterloo, Canada; Ontario Institute for Cancer Research, Canada.
Int J Drug Policy. 2019 Nov;73:24-31. doi: 10.1016/j.drugpo.2019.07.001. Epub 2019 Jul 20.
Health warnings have been shown to increase knowledge and awareness of health risks, influence social norms, and reduce consumption of tobacco products. With the legalization of non-medical cannabis in Canada and other subnational jurisdictions, there is a need for empirical studies to examine the impact of cannabis health warnings on consumer perceptions and behaviour relevant to cannabis.
In October 2017, a between-group experiment was conducted as part of an online survey of Canadians aged 16 to 30 years (N = 870) recruited from a national consumer panel. Participants rated the perceived effectiveness and believability of either text-only or pictorial cannabis health warnings and then completed a message recall task. Participants also reported their level of support for cannabis warnings, and support for including cessation information and a quitline on the warnings.
Pictorial health warnings for cannabis products were perceived as more effective and believable than text-only warnings (p < 0.001), and the superiority of pictorial warnings was found across different warnings: dose (p = 0.039), co-morbid drug use (p = 0.006), and pregnancy (p < 0.001). Pictorial warnings were also rated as more believable (p = 0.048). Overall, 87.7% respondents supported having health warnings on cannabis products, and 84.0% supported the inclusion of a quitline number on cannabis health warnings.
The current study provides the first empirical test of cannabis health warnings, consistent with the considerable body of evidence on the effectiveness of pictorial warnings on tobacco products. There was strong support for the inclusion of picture warnings and the inclusion of resources and quitlines on cannabis packaging.
健康警示已被证明可以提高人们对健康风险的认识和了解，影响社会规范，并减少烟草产品的消费。随着非医用大麻在加拿大和其他国家司法管辖区的合法化，有必要进行实证研究，以检验大麻健康警示对与大麻相关的消费者认知和行为的影响。
2017 年 10 月，作为对年龄在 16 至 30 岁的加拿大在线调查的一部分（参与者来自全国消费者小组），进行了一项组间实验。参与者对文本或图片的大麻健康警示的有效性和可信度进行了评估，然后完成了一个信息记忆任务。参与者还报告了他们对大麻警示的支持程度，以及对在警示中包含戒烟信息和戒烟热线的支持程度。
大麻产品的图片健康警示被认为比纯文本警示更有效和可信（p<0.001），而且在不同的警示中都发现了图片警示的优越性：剂量（p=0.039）、共病药物使用（p=0.006）和妊娠（p<0.001）。图片警示也被认为更可信（p=0.048）。总的来说，87.7%的受访者支持在大麻产品上贴上健康警示，84.0%的受访者支持在大麻健康警示上包含戒烟热线号码。
本研究首次对大麻健康警示进行了实证检验，与大量关于烟草产品图片警示有效性的证据一致。对包含图片警示以及在大麻包装上包含资源和戒烟热线的支持非常强烈。
