Dylan Small writes:

Observational Studies is a peer-reviewed journal that publishes papers on all aspects of observational studies. The journal’s web site is https://obs.pennpress.org/home/. The journal is diamond open access—no charges for readers and no charges for authors.

William Cochran defined an observational study as an empiric investigation in which “the objective is to elucidate cause-and-effect relationships…[in which] it is not feasible to use controlled experimentation, in the sense of being able to impose the procedures or treatments whose effects it is desired to discover, or to assign subjects at random to different procedures.” (1965, JRSS-A). Observational studies are important where randomized experimentation is unethical or infeasible. A particular type of observational study is a “broken randomized experiment,” in which encouragement to take a treatment is randomly assigned but the treatment itself is not imposed by random assignment (e.g., some people may not comply with the random assignment). Furthermore, even when imposing treatment by random assignment is ethical and feasible, observational studies can be useful in providing less expensively obtained preliminary results that can lead to further testing in randomized experiments. Observational studies have played important roles in providing evidence on many topics, for example, providing the key evidence that smoking causes lung cancer.

Several journals deal with observational studies in specific fields, but this is the first journal that is devoted to observational studies across the wide range of fields that make use of them. Topics covered by the journal include, but are not limited to:

• Methodologies for observational studies, including statistical methods for all aspects of observational studies and methods for the conduct of observational studies such as methods for collecting data. In addition to novel methodological articles, the journal welcomes review articles on methodology relevant to observational studies as well as illustrations/explanations of methodologies that may have been developed in a more technical article in another journal.

• Analyses of observational studies. The journal encourages submissions of analyses that illustrate use of sound methodology and conduct of observational studies.

• Study protocols for observational studies. Before examining the outcomes that will form the basis for an observational study’s conclusions, a study protocol should describe the design, exclusion criteria, primary and secondary outcomes, and proposed analyses. In addition to publishing study protocols, the journal will publish comments on the study protocols and allow the authors of the study protocol to respond to the comments.

• Software for observational studies.

• Descriptions of observational study data sets. The journal welcomes descriptions of observational study data sets and how to access them. The goal of the descriptions of observational study data sets is to enable readers to form collaborations, to learn from each other and to maximize use of existing resources. The journal also encourages submission of examples of how a publicly available observational study database can be used.