Department of Pharmacology and Toxicology, Medical University of Lodz, Lodz, Poland.
Centre for Behavioural Medicine, The School of Pharmacy, University College London, London, United Kingdom.
J Med Internet Res. 2021 Apr 21;23(4):e25228. doi: 10.2196/25228.
An accurate understanding of dietary supplements (DS) is a prerequisite for informed decisions regarding their intake. However, there is a need for studies on this understanding among the public based on validated research tools.
This study aims to assess the knowledge about DS among Polish internet users with no medical education and to identify its determinants and design an appropriate predictive model.
The study protocol was prospectively registered with a statistical analysis plan. Polish users of a web-based health service and a social networking service were administered a survey consisting of the recently developed questionnaire on knowledge about DS, the questionnaire on trust in advertising DS, the beliefs about medicines questionnaire, and several other health-related single-item measures and sociodemographic questions. The results were subjected to general linear modeling.
A total of 6273 participants were included. Of the 17 yes or no questions in the questionnaire of knowledge about DS, the mean number of correct responses was 9.0 (95% CI 8.9-9.1). Health service users performed worse than social networking users by 2.3 points (95% CI 2.1-2.5) in an analysis adjusted for potential confounders. Internet users had fewer true beliefs about DS if they presented higher trust in their advertising (adjusted β=-.37; 95% CI -.39 to -.34), used DS (adjusted β=-.14; 95% CI -.17 to -.12), experienced their positive effect (adjusted β=-.16; 95% CI -.18 to -.13), were older or younger than 35 years (adjusted β=-.14; 95% CI -.17 to -.12), expressed interest in the topic of DS (adjusted β=-.10; 95% CI -.13 to -.08), reported getting information about the products from friends (adjusted β=-.13; 95% CI -.15 to -.11), and believed that medicines are harmful (adjusted β=-.12; 95% CI -.15 to -.10). The proposed 5-predictor model could explain 31.2% of the variance in knowledge about DS. The model appeared resistant to overfitting and was able to forecast most of the observed associations.
Polish internet users with no medical education exhibit some false beliefs regarding DS. Trusting the advertising of DS appears to conflict with knowledge about them. There is an urgent need for effective web-based educational campaigns on DS and the promotion of advertising literacy. After the proposed predictive model is externally validated, it may help identify the least informed target audience.
准确了解膳食补充剂（DS）是做出知情摄入决策的前提。然而，需要基于经过验证的研究工具，对公众对此类知识的理解进行研究。
本研究旨在评估波兰无医学教育背景的互联网用户对 DS 的了解程度，并确定其决定因素，设计合适的预测模型。
本研究方案经前瞻性注册，并附有统计分析计划。通过网络健康服务和社交网络服务的波兰用户，对他们进行了一项调查，其中包括最近开发的 DS 知识问卷、DS 广告信任问卷、药物信念问卷以及其他一些健康相关的单项措施和社会人口学问题。结果进行了一般线性建模。
共纳入 6273 名参与者。在 DS 知识问卷的 17 个是/否问题中，正确回答的平均数量为 9.0（95%CI 8.9-9.1）。在调整潜在混杂因素后，健康服务用户的表现比社交网络用户差 2.3 分（95%CI 2.1-2.5）。如果互联网用户对 DS 的广告更信任（调整后β=-.37；95%CI-.39 至-.34）、使用 DS（调整后β=-.14；95%CI-.17 至-.12）、体验到 DS 的积极效果（调整后β=-.16；95%CI-.18 至-.13）、年龄在 35 岁以下或以上（调整后β=-.14；95%CI-.17 至-.12）、对 DS 主题感兴趣（调整后β=-.10；95%CI-.13 至-.08）、从朋友那里获取有关产品的信息（调整后β=-.13；95%CI-.15 至-.11），并认为药物是有害的（调整后β=-.12；95%CI-.15 至-.10），他们对 DS 的真实信念就会减少。提出的 5 个预测因素模型可以解释 DS 知识的 31.2%的方差。该模型似乎能够抵抗过拟合，并且能够预测大部分观察到的关联。
波兰无医学教育背景的互联网用户对 DS 存在一些错误的认识。对 DS 广告的信任似乎与他们对 DS 的了解相冲突。迫切需要开展关于 DS 的有效网络教育活动，并促进广告素养的提高。在对所提出的预测模型进行外部验证后，它可以帮助识别最缺乏信息的目标受众。
