Characterization of Comments About bioRxiv and medRxiv Preprints.

Importance: Preprints have been increasingly used in biomedical science, and a key feature of many platforms is public commenting. The content of these comments, however, has not been well studied, and it is unclear whether they resemble those found in journal peer review. Objective: To describe the content of comments on the bioRxiv and medRxiv preprint platforms. Design, Setting, and Participants: In this cross-sectional study, preprints posted on the bioRxiv and medRxiv platforms in 2020 were accessed through each platform's application programming interface on March 29, 2021, and a random sample of preprints containing between 1 and 20 comments was evaluated independently by 3 evaluators using an instrument to assess their features and general content. Main Outcome and Measures: The numbers and percentages of comments from authors or nonauthors were assessed, and the comments from nonauthors were assessed for content. These nonauthor comments were assessed to determine whether they included compliments, criticisms, corrections, suggestions, or questions, as well as their topics (eg, relevance, interpretation, and methods). Nonauthor comments were also analyzed to determine whether they included references, provided a summary of the findings, or questioned the preprint's conclusions. Results: Of 52 736 preprints, 3850 (7.3%) received at least 1 comment (mean [SD] follow-up, 7.5 [3.6] months), and the 1921 assessed comments (from 1037 preprints) had a median length of 43 words (range, 1-3172 words). The criticisms, corrections, or suggestions present in 694 of 1125 comments (61.7%) were the most prevalent content, followed by compliments (n = 428 [38.0%]) and questions (n = 393 [35.0%]). Criticisms usually regarded interpretation (n = 286), methodological design (n = 267), and data collection (n = 238), while compliments were mainly about relevance (n = 111) and implications (n = 72). Conclusions and Relevance: In this cross-sectional study of preprint comments, topics commonly associated with journal peer review were frequent. However, only a small percentage of preprints posted on the bioRxiv and medRxiv platforms in 2020 received comments on these platforms. A clearer taxonomy of peer review roles would help to describe whether postpublication peer review fulfills them.

Worldwide dietary patterns and their association with socioeconomic data: an ecological exploratory study.

BACKGROUND: Dietary patterns are associated with health outcomes and environment sustainability, having socioeconomic drivers. This ecological study aims to identify dietary patterns in food availability data at the global level using multivariate statistical methodology, to associate the identified dietary patterns with socioeconomic data and to analyze the adequacy of the applied multivariate statistical methods for this purpose. METHODS: Principal Component Analysis was applied to median values of times series of food availability data of 172 UN registered countries available at FAOSTAT database in Food Balance Sheets section in a sectional manner, after calculating median values of time series for each food group and country. Principal Components were associated with socioeconomic data available from the World Bank database. Sensitivity analyses were realized to verify the stability of dietary patterns through five different times. RESULTS: Five principal components were identified in the median values of each time series, each characterizing a possible dietary pattern. The first one, a westernized dietary pattern, was composed of energy-dense and processed foods, foods of animal origin, alcoholic beverages, but also, albeit less, by vegetables, fruits and nuts, being associated with income, urbanization and trade liberalization. This westernized pattern was characterized more animal origin and processed foods, such as vegetable oils, alcoholic beverages and stimulants yet preserving unprocessed and regional foods. The other dietary patterns were three agricultural patterns characterized more by regional foods, especially starchy staples, and one coastal dietary pattern composed of fish and seafoods, being associated with GINI index, poverty, and female labor force. Sensitivity analyses demonstrated the stability of dietary patterns. CONCLUSIONS: Principal Component Analysis was adequate to identify dietary patterns in food availability data. A westernized dietary pattern was identified, being associated with income, urbanization, and trade liberalization. This association did not occur for the remain of the dietary patterns identified, these being less driven by economic development.