Historical trends in publications in the International Journal of Epidemiology

Background: This study aimed to provide a detailed insight into the nature of the content published in the International Journal of Epidemiology (IJE) over its history. Methods: This study reviewed five complete volumes of the IJE at 10-year intervals (1976, 1986, 1996, 2006 and 2016). Information was extracted for 628 articles considered to be most representative of the content of the IJE, with detailed information analysed for 435 articles identified as original research articles. Results: Over time, the number of articles published per issue and per year increased and the number of authors per article increased. Cohort studies were consistently the most common study type. The majority of first authors and two-thirds of the populations studied were from high-income countries, although there was a clear trend over time towards more studies investigating multiple countries. Within original research articles, neoplasms (17%), infectious and parasitic diseases (14%) and diseases of the circulatory system (12%) were the most common disease type studied in original research articles (but the study topics varied between low-income and high-income countries); and socioeconomic factors (17%), environmental factors (15%) and biological factors and behaviours (both 12%) were the most common study factors. The topics of articles generally had good correlation with the global burden of disease, both overall and within geographical regions studied, but mental health and musculoskeletal disorders were notable omissions. Conclusions: Working to increase publications from low-and middle-income groups, and studies covering areas such as mental health and musculoskeletal disorders, should be considered.