With increasing public health awareness and the unprecedented global health crisis, consumers' demand for in vitro diagnostic (IVD) reagents is gradually increasing. However, consumer mistrust remains a significant barrier to purchasing and using IVD products. Pharmaceutical companies and governments prioritizing direct-to-consumer (DTC) marketing have recognized the impact of visual packaging elements on consumer perception. Thus, we researched whether visual packaging elements systematically influence consumers' perceived credibility of IVD products' credence attributes, namely, their ability to protect personal and public health. Combining previous related studies, this study was conducted experimentally with rapid diagnostic test (RDT) kits, assuming that the visual elements (i.e., typeface, color, pattern, and information) of packaging can influence consumers' perceived credibility of RDT kits and explored which elements are more credible. Questionnaires were randomly selected and assigned to 216 participants. The results indicated that all four elements influenced the participants' perceived credibility. Specifically, a sans serif typeface, realistic pattern, chromatic color, and more information made the participants feel more credible. Our research results fill a gap in the consumer perception of over-the-counter (OTC) pharmaceutical products by providing new insights into dissecting consumer perceptions. This offers a novel design strategy for online and offline marketing and promotional efforts by different companies and governmental organizations.
