Background: PubMed is not only the single largest archive of indexed articles’ and abstracts, but also the most widely searched database for use by researchers and professional bodies in all systematic reviews used for framing evidence-based clinical consensus statements and practice guidelines. Objective: The objective of this study was to explore the evidence base provided by PubMed descriptively report the current state of published articles indexed in PubMed. Methods: Descriptive exploratory study through a literature search was done to identify nine time-points in the timeline from 1970-2010, with five-year intervals in order to identify the scientific trend. The number of obtained citations were classified and analyzed under the names of search filters of PubMed namely- text availability, publication date, species, article type, language, gender and subject areas. The numbers for categories and subcategories of search filters were considered for comparison and analysis. Descriptive analysis using frequencies on Microsoft Excel 2010 worksheet was done. Results: There is an exponential increase in number of articles in general over the 40 years. Abstracts and free full text articles were equal in number. Human studies were more than animal studies. Case reports and reviews were more than other article types. More articles were of English language, with equal gender representation. There were more number of articles on cancer than on toxicology and veterinary science. Conclusion: This study found an overall observation that the largest number of articles prevalent in a particular category was also the fastest to increase in number in a 40-year trend. 

Keywords: Evidence-based healthcare; Medical informatics; Medline/PubMed; Literature search.