title: Smartphone Apps for Measuring Human Health and Climate Change Co-Benefits: A Comparison and Quality Rating of Available Apps.
abstract: BACKGROUND
  Climate change and the burden of noncommunicable diseases are major global challenges. Opportunities exist to investigate health and climate change co-benefits through a shift from motorized to active transport (walking and cycling) and a shift in dietary patterns away from a globalized diet to reduced consumption of meat and energy dense foods. Given the ubiquitous use and proliferation of smartphone apps, an opportunity exists to use this technology to capture individual travel and dietary behavior and the associated impact on the environment and health.
  
  
  OBJECTIVE
  The objective of the study is to identify, describe the features, and rate the quality of existing smartphone apps which capture personal travel and dietary behavior and simultaneously estimate the carbon cost and potential health consequences of these actions.
  
  
  METHODS
  The Google Play and Apple App Stores were searched between October 19 and November 6, 2015, and a secondary Google search using the apps filter was conducted between August 8 and September 18, 2016. Eligible apps were required to estimate the carbon cost of personal behaviors with the potential to include features to maximize health outcomes. The quality of included apps was assessed by 2 researchers using the Mobile Application Rating Scale (MARS).
  
  
  RESULTS
  Out of 7213 results, 40 apps were identified and rated. Multiple travel-related apps were identified, however no apps solely focused on the carbon impact or health consequences of dietary behavior. None of the rated apps provided sufficient information on the health consequences of travel and dietary behavior. Some apps included features to maximize participant engagement and encourage behavior change towards reduced greenhouse gas emissions. Most apps were rated as acceptable quality as determined by the MARS; 1 was of poor quality and 10 apps were of good quality. Interrater reliability of the 2 evaluators was excellent (ICC=0.94, 95% CI 0.87-0.97).
  
  
  CONCLUSIONS
  Existing apps capturing travel and dietary behavior and the associated health and environmental impact are of mixed quality. Most apps do not include all desirable features or provide sufficient health information. Further research is needed to determine the potential of smartphone apps to evoke behavior change resulting in climate change and health co-benefits.
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Rachel K
authors.identifier: http://orcid.org/0000-0002-5476-2049
authors.initials: RK
authors.lastname: Sullivan
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Samantha
authors.identifier: http://orcid.org/0000-0001-8129-0350
authors.initials: S
authors.lastname: Marsh
authors.affiliation: Faculty of Medicine, Linköping University, Linköping, Sweden.
authors.forename: Jakob
authors.identifier: http://orcid.org/0000-0001-7545-3758
authors.initials: J
authors.lastname: Halvarsson
authors.affiliation: School of Health and Related Research, Section of Public Health, University of Sheffield, Sheffield, United Kingdom.
authors.forename: Michelle
authors.identifier: http://orcid.org/0000-0001-6028-885X
authors.initials: M
authors.lastname: Holdsworth
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Wilma
authors.identifier: http://orcid.org/0000-0003-0956-178X
authors.initials: W
authors.lastname: Waterlander
authors.affiliation: Department of Human Geography and Spatial Planning, Utrecht University, Utrecht, Netherlands.
authors.forename: Maartje P
authors.identifier: http://orcid.org/0000-0003-4346-4481
authors.initials: MP
authors.lastname: Poelman
authors.affiliation: School of Environment, Faculty of Science, The University of Auckland, Auckland, New Zealand.
authors.forename: Jennifer Ann
authors.identifier: http://orcid.org/0000-0001-5670-7724
authors.initials: JA
authors.lastname: Salmond
authors.affiliation: School of Population Health and Telethon Kids Institute, The University of Western Australia, Perth, Australia.
authors.forename: Hayley
authors.identifier: http://orcid.org/0000-0001-8486-5746
authors.initials: H
authors.lastname: Christian
authors.affiliation: Centre for Energy, Environment and Sustainability, Management School, University of Sheffield, Sheffield, United Kingdom.
authors.forename: Lenny Sc
authors.identifier: http://orcid.org/0000-0001-9957-9355
authors.initials: LS
authors.lastname: Koh
authors.affiliation: Nutritional Epidemiology Group, Schools of Food Science and Nutrition, University of Leeds, Leeds, United Kingdom.
authors.forename: Janet E
authors.identifier: http://orcid.org/0000-0003-3421-0121
authors.initials: JE
authors.lastname: Cade
authors.affiliation: Faculty of Physical Education and Recreation, University of Alberta, Edmonton, AB, Canada.
authors.forename: John C
authors.identifier: http://orcid.org/0000-0001-8485-1336
authors.initials: JC
authors.lastname: Spence
authors.affiliation: Epidemiology and Biostatistics, School of Population Health, The University of Auckland, Auckland, New Zealand.
authors.forename: Alistair
authors.identifier: http://orcid.org/0000-0001-5425-6018
authors.initials: A
authors.lastname: Woodward
authors.affiliation: National Institute for Health Innovation, School of Population Health, The University of Auckland, Auckland, New Zealand.|Institute for Physical Activity and Nutrition, Deakin University, Victoria, Australia.
authors.forename: Ralph
authors.identifier: http://orcid.org/0000-0001-8564-5518
authors.initials: R
authors.lastname: Maddison
keywords: behavior change; carbon footprint; climate change; diet; greenhouse gas emissions; individual; noncommunicable diseases; smartphone apps; travel