Table 1.

Inclusion and exclusion criteria.

Criterion	Inclusion	Exclusion
Time period	2009–2019	Studies outside these dates
Language	English	Non-english articles
Article Type	Original peer-reviewed research	Research that was not peer-reviewed
Literature focus	Articles reporting on a method or application of Twitter data to address a public health issue. Articles which evaluated the performance of the statistical or machine learning technique used in drawing utility from the Twitter data.	Review articles and other articles not reporting an original contribution. Articles not focused on our above definition of public health but rather concerned with public health in the context of recruitment and outreach, public awareness and communication, information dissemination or opinion mining. Articles which do not make known the statistical or machine learning technique being used. Articles which are works in progress or otherwise do not contain the full-text, such as conference abstracts.