Institutional review board approval was not required for this study since all information was freely available online. For the purposes of this study, we defined an “article” as being any piece of published writing excluding personal blogs, editorials, and commentaries (Figure 1).

GT has been widely used to capture the most popular queries searched by the public, providing important information regarding emerging patterns. Prior studies have supported the use of GT to monitor COVID-19 incidence and public attention, especially within countries lacking proper diagnostic tools [11,12]. To prevent location bias, online articles were collected using a location-disabled search on Google.com/ncr on April 30, 2020. Using GT, we used the “Explore” option and applied the parameters “United States,” “Custom date range 2/29/20 to 4/30/20,” “Health,” and “Web search.” A start date of February 29, 2020, was chosen because this was associated with the first Centers for Disease Control and Prevention–reported death from COVID-19 in the United States [13] and marks an increase in Google searches for the word “coronavirus.” From here, we sorted the search queries by “Top” and then collected the top five search queries that had an increased level of Google search frequency (Figure 2.1). These were “coronavirus,” “corona,” “corona virus,” “symptoms,”and “coronavirus update.” We then used each of these terms and searched them on GT using the aforementioned methodology. Along with the original five terms, we collected the top five related search queries (including the initially searched word) and excluded any repeat search queries. This resulted in 25 unique health-related search phrases (Figure 2.2). Of note, multi-word keywords were searched using quotations marks, and a comparative analysis of search volume without quotes was not performed.

Next, between April 30 and May 2, 2020, we searched each keyword phrase and collected all articles (writing that includes more than 100 words) from the first 3 pages of the Google search; this resulted in approximately 10 articles per page (Figure 3). Prior research has shown that internet users tend not to view past these first 3 pages on Google [14]. When queries yielded articles that overlapped, we excluded the repeated articles from analysis. For each article, we collected the Google page number, order on the page, article link, website name, category of website, article title, author, date of publication, and number of references.

Three separate authors scored all articles individually using each of the 7 QUEST questions and associated point values (Textbox 1). Each article’s individual sections were then combined into a score between 0 and 28, where 28 was the highest quality article possible. The final score for each article was an average of the three independent scorers’ analyses. Interrater consensus was determined using Fleiss’s kappa metric.

Excel (Microsoft Corporation) was used to conduct the statistical analysis and generate figures for this study. In addition to determining general descriptive metrics (mean, median, etc), we coined the metric search order product to examine if there was any statistical difference in quality between articles toward the beginning and end of the results. Equal to the results page number on Google multiplied by the order of article on that page, the search order product encompasses the article’s hierarchy in search results. For example, if an article was second on the third page of the results on Google, its search order product would be 6. A low search order product indicates an earlier appearing article once its associated phrase is searched (meaning increased public exposure), while a high search order product is characteristic of a later-appearing article (decreased public exposure). Comparative t tests and Pearson correlation analyses were conducted to stratify scores by variables. The Benjamini-Hochberg false detection rate correction for multiplicity was applied to appropriately adjust P values.

Readability analysis was performed using Readability Studio Professional Edition Version 2015 (Oleander Software, Ltd), applying nine validated formulas to quantify article readability: Coleman-Liau Index [15], Flesch-Kincaid Grade Level [16], FORCAST formula [17], Fry graph [18], Gunning Fog Index [19], New Dale-Chall [20], New Fog Count [16], Raygor Reading Estimate [21], and SMOG (Simple Measure of Gobbledygook) [22]. Nine different readability scales were used to minimize the bias that comes with using only one scale. We subsequently calculated the reading level for each article by averaging estimates derived from all nine scales. These were then compared to the American Medical Association–recommended reading level of sixth grade for health education materials [9]. A 10th readability formula, the Flesch Reading Ease (FRE) [23], was applied separately as it calculates reading level on a different scale. FRE scores of 0 to 30 indicate very difficult, 30 to 50 difficult, 50 to 60 fairly difficult, 60 to 70 standard, 70 to 80 fairly easy, 80 to 90 easy, and 90 to 100 very easy.

A total of 709 Google results listings were initially examined. After excluding repeated articles (n=405), nonarticles (n=92), unrelated articles (n=7), broken links (n=1), and paid sites (n=9) from the analysis, 195 individual articles were scored using QUEST (Figure 3).

The mean article score was 18.4 (SD 2.6) of 28, with only 7% (14/189) of articles in the top score quartile and 89% (173/189) of articles in the top half of scores. National news outlets published the largest share (70/189, 36%) of the analyzed articles, followed by private health-focused entities (45/189, 23%) and regional news outlets (29/189, 15%; Table 1).

Categorically, global health organization sites had the lowest average score (mean 17.2, SD 1.2) and least dispersive data set (σ²=1.39; Figure 4). Peer-reviewed journals had the most dispersive data set (σ²=10.1) and the highest average QUEST score (mean 22.7, SD 3.18), with significantly higher quality averages as compared to national news outlets (mean 18.3, SD 2.20; P=.002), regional news outlets (mean 17.6, SD 2.24; P=.003), national government sites (mean 17.5, SD 1.81; P=.001), state government sites (mean 17.4, SD 1.65, P=.002), and global health organizations (mean 17.2, SD 1.18; P=.046). In addition, entertainment and cultural outlets (mean 20.6, SD 1.95) also had a significantly higher quality score than regional news outlets (mean 17.6, SD 2.24; P=.009) and state government sites (mean 17.4, SD 1.65; P=.002).

Analysis of the QUEST scores by the search order product showed no significant trends (R=–0.16; P=.75; Figure 5), discrediting any hierarchy by listing order within the sample set. A significant positive correlation (R=0.25; P<.001) existed between the number of references (≥1) in an article and the QUEST diagnostic score. Due to QUEST already allocating points in a binary fashion for containing references, only articles with ≥1 reference were considered.

The readability levels for 187 of 195 articles were collected; 8 articles containing document structure unsuitable for analysis were excluded. The average reading level across all 187 articles was 11.7 (SD 1.9), ranging from 5.4 (fifth grade reading level) to 16.9 (undergraduate senior reading level). There was variability among the readability scales, with New Fog Count scoring the overall lowest mean readability (mean 9.3, SD 2.7) and Fry scoring the overall highest mean readability (mean 14, SD 2.9). FRE scored an overall average of 47.2 (SD 11.4), corresponding to difficult and representative of college-level reading. Based on the averages of the nine readability scales for each article, only 3 (1.6%) articles were written at the recommended sixth grade levels [9], with 44 (23.5%) written beyond a high school level (Figure 6).

This study systematically assessed and determined that articles resulting from the most frequently Google-searched health-related COVID-19 terms in the United States were of higher quality and readability than hypothesized. QUEST proved versatile in synthesizing aggregate data regarding different aspects of literature including authorship, attribution, conflict of interest, currency, complementarity, and tone. Despite the high prevalence of misinformation on the internet, analysis of our data set revealed that 89% of articles scored in the upper quartiles, suggesting that online information in the United States regarding COVID-19 was of a higher quality than anticipated.

With the uptick in news dissemination by national media after the onset of the pandemic, national news outlets were unsurprisingly the largest source of our sample set followed by private health-focused entities. Interestingly, there was less output from global organizations such as the World Health Organization and United Nations; these organizations only had 1% of total article output, contradicting their organizational goals of far-reaching public health campaigns and initiatives [24]. This discrepancy in expected and observed output could be due to organizational choices to frequently update a centralized information page as opposed to generating new articles that would show up as separate listings. Additionally, different categorical sources allocate varying levels of resources and personnel to public-facing operations that would result in searchable online information [25].

The lack of significant trends associated with an increasing search order product value implied a qualitatively homogenous sampling of articles by exposure in our analysis, validating the decision to analyze only the first three pages of each term’s Google search (Figure 5). Using the product of search metrics instead of a direct numerical order of results allowed us to place increased weight on articles listed toward the top of later result pages. Among the sample set, the average quality score of the first articles on the first page (mean 18.7, SD 0.0) was not significantly different from the average quality score of the 10th article on the third page (mean 17.1, SD 1.88) of Google search results.

Stratification of the QUEST scores by article categorization revealed source-based qualitative differences, in part due to different data-gathering and publishing processes. Output from peer-reviewed journals had the highest average score (mean 22.7, SD 3.18), likely due to their rigorous scientific vetting process prior to publication [26]. Increased variation in this category (σ²=10.1) may be a reflection of the varying requirements set forth by journals and a smaller sample size included in our analysis. Peer-reviewed journals had a significantly increased average QUEST score as compared to national news outlets (mean 18.3, SD 2.20; P=.002), regional news outlets (mean 17.6, SD 2.24; P=.003), national government sites (mean 17.5, SD 1.81; P=.001), state government sites (mean 17.4, SD 1.65; P=.002), and global health organizations (mean 17.2, SD 1.18; P=.046). Unfortunately, the latter categories were marked by the lowest average information quality, though still mostly in the second (7.5-15) and third (14-22.5) score quartiles. Additionally, entertainment and cultural outlets (mean 20.6, SD 1.95) were characterized by significantly higher quality information compared to regional news outlets and state government sites, perhaps reflecting their tendency to target wider audiences [27].

The majority of articles (170/187, 91%) were written well above American Medical Association–recommended reading levels [21] (Figure 6). Results from the readability analysis substantiated our hypothesis that most COVID-19 articles would be too difficult for the average American to read, in line with the results of prior smaller studies [28]. With the overall FRE score representative of college-level reading and categorically falling under “Difficult,” the ability of these most-searched articles to convey accurate information is automatically diminished. Though not directly contributing to misinformation, mismatched comprehension levels lead to knowledge gaps; this may push the public to turn toward other less reliable modalities to stay informed [29]. Ahmed Siddiqui et al [29] specifically discussed the pervasiveness of nonevidence-based medical advice on social media as a “hidden epidemic” considering its ability to transcend geographic and cultural boundaries. Less readable online sources may indirectly facilitate the spread of misinformation regardless of high article quality. This has been affirmed by studies using different criteria from our own including the DISCERN scoring system [6], JAMA benchmarks [30], and even the HONcode system [31]. Additionally, with massive public health awareness efforts underway to encourage COVID-19 vaccination and safe social practices, accurate online media has become increasingly important as a direct source of information for all demographics [32].

Moving forward, publishing sources may benefit from using resources to optimize communication of health information. The Agency for Healthcare Research and Quality updated the second edition of their Health Literacy Universal Precautions Toolkit (HLUPT) recently in September 2020. The document outlines strategies to enhance overall patient understanding, and even contains a section focused on written communication [33]. In a 2015 study, Brega et al [34] determined that applying the sections of the HLUPT pertaining to written materials led to better readability of revised documents. Subjecting patient-facing articles to rigorous quality and literacy guidelines will aide in improving both publishing standards and consumer understanding, both of which are required to best communicate vital information.

The COVID-19 pandemic in the United States was accompanied by an influx of online health information. To investigate the need for quality control of this information, we assessed articles resulting from the most-searched health-related terms in the United States using the QUEST rubric and readability software. Despite the high prevalence and transmission of misinformation during the COVID-19 pandemic, the most frequently searched Google articles had good information quality. Still, the majority of these articles were written above the recommended reading level for the public, diminishing their ability to counteract the spread of misinformation.

The limitations of this study include the small sample size, use of only three raters, and lack of individual comparative analysis when determining search keywords. Although GT was used to identify popular keywords, the search volumes of multi-word keywords were not compared against their results without use of quotations. This likely resulted in some bias of listing order because it excluded results only found if only one of the multi-word terms were searched. Furthermore, Google’s newer quality rating guidelines adopted in 2019 have resulted in increased automatic filtering criteria, likely resulting in higher quality and personalized results than would have otherwise been listed [35].

Only the QUEST scale was used to measure article validity, and there are a range of other evaluation tools in the literature that may provide differing or complementary data. Additionally, the Fleiss’s kappa value of our study was 0.0095, indicating a slight agreement between raters when it came to absolute scores. This may have been due to the subjective nature of the QUEST rubric especially in areas such as attribution, tone, and conflict of interest. Even still, author relative rankings of articles correlated to a greater extent than the absolute score values, indicating a shifted but similarly trending rating among raters. Additionally, facets of QUEST, such as authorship and currency, allocate points for characteristics that do not directly correlate with information accuracy, explaining the lower scores of government and global health organizations due to inherent formatting preferences (ie, omitting authors). The QUEST scale does not address every aspect of misinformation, although it does focus on some aspects such as attribution that is seen in Table 1. Further studies on the spread of misinformation, especially against the backdrop of the COVID-19 pandemic, would benefit from examining media outside articles such as radio, social media, and television.