Sustained reductions in online search interest for communicable eye and other conditions during the COVID-19 Pandemic: An Infodemiology Study (Preprint)

Abstract

At the start of the COVID 19 pandemic, we found reduced numbers of google searches for the term conjunctivitis. We hypothesized that physical distancing during COVID-10 reduced the spread of contagious eye disease. Here we test this hypothesis a year later, expanding to include other communicable conditions.

Determine if reduction in USA searches for terms related to conjunctivitis and other common communicable diseases occurred in spring-winter of the COVID-19 pandemic, and compare this outcome to terms representing non-communicable conditions, COVID-19, and to seasonality.

Weekly relative search frequency volume data from Google trends for 68 search terms in English for the USA, were obtained for the weeks of March 2011 through February 2021. Terms were classified a priori as 16 terms related to COVID-19, 29 terms representing communicable conditions and 23 terms representing control non-communicable conditions. To reduce bias, all analyses were conducted while masked to term names, classifications and locations. To test for the significance of changes during the pandemic, we detrended and compared post-pandemic values to that expected based on pre-pandemic trends, per season, computing 1 and 2 sided P-values. We then compared these P-values between term groups using Wilcoxon rank-sum and Fisher exact tests to assess if non-COVID terms representing communicable disease were more likely to show significant reductions in search in 2020-21 than terms not representing such disease. We also assessed any relationship between a term’s seasonality and reduced search for it in 2020-21 seasons. P-values were subjected to FDR correction prior to reporting. Data were then unmasked.

Terms representing conjunctivitis and other communicable conditions had sustained reduced search in the first 4 seasons of the 2020-2021 COVID-19 pandemic, compared to prior years. In comparison, search for non-communicable condition terms was significantly less reduced (Wilcoxon and Fisher’s Exact Tests, P < 0.001; summer, autumn, winter). A significant correlation was also found between reduced search for a term in 2020-21 and seasonality of that term (Theil-Sen, P < 0.001; summer, autumn, winter). COVID-19 related conditions were significantly elevated compared to prior years, and influenza-related terms were significantly lower than prior years in winter 2020-21 (P < 0.0001).

We demonstrate the low-cost and unbiased use of online search data to study how a wide range of conditions may be affected by large-scale interventions or events such as social distancing during the COVID-19 pandemic. Our findings support emerging clinical evidence implicating social distancing and the COVID-19 pandemic in the reduction of communicable disease. They also agree with elevation of ocular conditions suggested to be linked to COVID-19 infection or behavioral changes such as mask-wearing.

Not applicable