Overviews reporting guide - 2016 

Overviews are useful to explore a new area, summarize the state of evidence on a broad topic, and provide insight into the progression of a body of research. Because evidence in clinical and public health evolves rapidly, an expert summary and assessment can be extremely valuable. For example, what are the challenges in eliminating pediatric HIV infection^{Footnote 1}? Or what is the current evidence regarding prion disease, which was once thought to be extremely rare, but have now been linked to a much broader group of protein-misfolding disorders that may be more common than previously thought^{Footnote 2}? An overview by an expert in the field can provide a useful introduction to emerging issues as well as a framework to better understand subsequent developments^{Footnote 3}.

Overviews are not underdeveloped systematic reviews. Systematic reviews are best for specific topics ^{Footnote 4}. For example, as systematic review is often used to analyze the evidence on the effectiveness of a specific drug for a specific condition in a specific population. Overviews are best for general topics. A systematic review is research that puts evidence under a microscope; an overview is an evidence-based expert opinion that scans a body of evidence with binoculars.

The potential weakness of an overview is bias. Readers need to be assured that the evidence summarized is fair and accurate, not inappropriately selective. A multi-database literature search with the support of a research librarian can help address this^{Footnote 5} as will a transparent analysis. The goal of an overview is not to provide the highest level of evidence, but rather to summarize, analyze and edify.

Because we are unaware of any reporting guidelines for an overview paper, the Canada Communicable Disease Report (CCDR) has developed a 16-item checklist based on the literature and best practice in scientific communications. This checklist identifies the need to address a topic in a way that is logical, balanced and insightful, including the consideration of contradictory evidence, strengths and limitations, and potential next steps (Table 1).

An overview is generally 1,500 to 2,000 words in length. As with all submissions, check CCDR's Information for authors, published at the beginning of each volume in January of each year for general manuscript preparation and submission requirements^{Footnote 6}.