Can the levels of toothache-related interests of Google and YouTube users differ between developed and developing countries over the years?

Background: The preferences of Web users can be influenced by distinct factors of populations, such as the ability of obtaining, processing, and understanding health information adequately. In this sense, hypothetically, source-based patterns of health-related Web searches might differ between individuals from developed and developing countries, due to their educational backgrounds. This study aimed to determine the trends of toothache-related searches performed on Google Search and YouTube, regarding differences between developed and developing countries. Methods: This longitudinal study analyzed computational metadata on toothache-related interests of Internet users. Google Trends was accessed to obtain the monthly variation of relative search volume (RSV) of the topic "Toothache-Disease" on Google (G) and YouTube (YT) through 2008 to 2017. Autocorrelation and partial autocorrelation plots, ARIMA models, Kruskal-Wallis, Dunn’s and T tests were performed for evaluating trends, 12-month forecasts and the differences of annual ratios of YT/G searches between developed and developing countries, respectively (P<0.05). Results: Uptrends of RSVs were observed in both country groups over time, although 12-month forecasts tended to plateau. The volumes of searches were larger in developed countries, becoming closer to those observed in developing countries in last years. Independently of country groups, the ratios YT/G remained relatively constant throughout the period, indicating a greater interest in toothache-related information available on Google. Conclusion: In conclusion, toothache-related searches from Google and YouTube increased during the last decade. The preferences of Web users seemed to be influenced by the differences found in the availability and penetration of the Internet, and education levels between developed and developing countries.