title: Activity Theory as a Theoretical Framework for Health Self-Quantification: A Systematic Review of Empirical Studies.
abstract: BACKGROUND
  Self-quantification (SQ) is a way of working in which, by using tracking tools, people aim to collect, manage, and reflect on personal health data to gain a better understanding of their own body, health behavior, and interaction with the world around them. However, health SQ lacks a formal framework for describing the self-quantifiers' activities and their contextual components or constructs to pursue these health related goals. Establishing such framework is important because it is the first step to operationalize health SQ fully. This may in turn help to achieve the aims of health professionals and researchers who seek to make or study changes in the self-quantifiers' health systematically.
  
  
  OBJECTIVE
  The aim of this study was to review studies on health SQ in order to answer the following questions: What are the general features of the work and the particular activities that self-quantifiers perform to achieve their health objectives? What constructs of health SQ have been identified in the scientific literature? How have these studies described such constructs? How would it be possible to model these constructs theoretically to characterize the work of health SQ?
  
  
  METHODS
  A systematic review of peer-reviewed literature was conducted. A total of 26 empirical studies were included. The content of these studies was thematically analyzed using Activity Theory as an organizing framework.
  
  
  RESULTS
  The literature provided varying descriptions of health SQ as data-driven and objective-oriented work mediated by SQ tools. From the literature, we identified two types of SQ work: work on data (ie, data management activities) and work with data (ie, health management activities). Using Activity Theory, these activities could be characterized into 6 constructs: users, tracking tools, health objectives, division of work, community or group setting, and SQ plan and rules. We could not find a reference to any single study that accounted for all these activities and constructs of health SQ activity.
  
  
  CONCLUSIONS
  A Health Self-Quantification Activity Framework is presented, which shows SQ tool use in context, in relation to the goals, plans, and competence of the user. This makes it easier to analyze issues affecting SQ activity, and thereby makes it more feasible to address them. This review makes two significant contributions to research in this field: it explores health SQ work and its constructs thoroughly and it adapts Activity Theory to describe health SQ activity systematically.
authors.affiliation: Health and Biomedical Informatics Centre, Melbourne Medical School, The University of Melbourne, Melbourne, Australia. manal_almalki@hotmail.com.
authors.forename: Manal
authors.identifier: http://orcid.org/0000-0003-1515-1680
authors.initials: M
authors.lastname: Almalki
authors.forename: Kathleen
authors.identifier: http://orcid.org/0000-0003-1616-2170
authors.initials: K
authors.lastname: Gray
authors.forename: Fernando
authors.identifier: http://orcid.org/0000-0002-7312-5707
authors.initials: F
authors.lastname: Martin-Sanchez
mesh_terms: D000203:Activities of Daily Living / Q000145:classification*; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D008962:Models, Theoretical
keywords: activities of daily living; activity theory; diagnostic self-evaluation; human-computer interaction; patient activation; patient participation; personal informatics; quantified self; self-care; self-experimentation; self-management; self-monitoring; self-quantification; self-tracking; user-computer interface