Developing a smartphone ‘app’ for public health research: the example of measuring observed smoking in vehicles Vimal Patel, 1 Mariusz Nowostawski, 2 George Thomson, 1 Nick Wilson, 2 Hamish Medlin 2 1 Department of Public Health, University of Otago, Wellington, New Zealand 2 Department of Information Science, University of Otago, Dunedin, New Zealand Correspondence to Dr George Thomson, Department of Public Health, University of Otago, Wellington, PO Box 7343, Wellington South, New Zealand; george.thomson@otago.ac.nz Received 24 July 2012 Revised 23 January 2013 Accepted 25 January 2013 Published Online First 26 February 2013 To cite: Patel V, Nowostawski M, Thomson G, et al. J Epidemiol Community Health 2013;67:446–452. ABSTRACT Background We have developed manual methods to gather data on the point prevalence of observed smoking in road vehicles. To enable the widespread international collection of such data, we aimed to develop a smartphone application (app) for this work. Methods We developed specifications for an app that described the: (1) variables that could be collected; (2) transfer of data to an online repository; (3) user interface (including visual schematics) and (4) processes to ensure the data authenticity from distant observers. The app functionality was trialled in roadside situations and the app was made publicly available. Results The smartphone app and its accompanying website were developed, tested and released over a period of 6 months. Users (n=18) who have registered themselves (and who met authentication criteria), have reported no significant problems with this application to date (observing 20 535 vehicles as of 5 July 2012). The framework, methodology and source code for this project are now freely available online and can be easily adapted for other research purposes. The prevalence of smoking in vehicles was observed in: Poland 2.7% (95% CI 2.3% to 3.1%); Australia 1.0% (95% CI 0.7% to 1.3%); New Zealand 2.9% (95% CI 2.6% to 3.2%)—similar to results using preapp methods in 2011 (3.2%, 95% CI 3.1% to 3.3%). Conclusions This project indicates that it can be practical and feasible for health researchers to work together with information science researchers and software developers to create smartphone apps for field research in public health. Such apps may be used to collect observational data more widely, effectively and easily than through traditional (non-electronic) methods. INTRODUCTION Smartphones are mobile phones with enhanced computing ability and interactivity. They are typic- ally equipped with a high-resolution touch-screen and include a number of features such as: global positioning system (GPS), light sensor, accelerom- eter, gyroscope and compass. By the end of 2011, one-third of all mobile phones shipped worldwide were smartphones, 1 and they are owned by at least 43% of all mobile phone subscribers in the USA. 2 Applications (apps) are software programs designed to run on smartphones. They can be used to collect data and transmit it instantaneously via the internet, allowing for international studies at a low cost (compared to non-electronic methods). Additionally, the location of data collection can be quickly and accurately fixed. Systems are being developed to use smartphones for rigorous data collection from distant, relatively untrained obser- vers for a wide range of science domains. 3–5 We have developed and refined manual (non-electronic) methods to gather data on the point prevalence of observed smoking in road vehi- cles. The methods used observation sites with high traffic flows, low traffic speeds and good visibility of vehicle occupants. Observers used a mechanical counter to count the total number of vehicles that fitted the sample frame (regardless of whether smoking was observed or not). They recorded, for vehicles with smoking, the presence of other adults and of children on a preformatted data sheet. 67 In the second project, we observed 149 886 vehicles, with a mean point prevalence of smoking in vehi- cles of 3.2%. Of those vehicles with smoking, 4.1% had children present. 7 The benefits of such data include: (i) providing an objective indicator of exposure to secondhand smoke in confined spaces, as vehicles are uniquely confined and ‘private’ but also publicly observable and (ii) the ability to collect large amounts of data relatively quickly (eg, over 900 events observed per hour). However, limitations in the existing data on observed smoking in vehicles include that it has been explored in few published studies (as of December 2012). These include two in the same setting (Wellington, New Zealand 6 7 ) one in Veneto, Northern Italy, 8 and one in Barcelona, Spain. 9 Given growing international interest in legislating against smoking in vehicles (and the need to evaluate such laws when they are passed), it is desirable to improve on time-consuming and fragmented manual methods of data collection. Hence, we describe here the development of a smartphone app and an accompanying website to enable ongoing data collection of observed smoking in vehicles, and consider its wider applic- ability to public health research. Our project aims were: (1) To develop a free open-source application (app) to enable ongoing data collection of observed smoking in vehicles by many observers internation- ally; (2) to briefly describe the development of this app and an accompanying website and (3) to make the framework and methodology freely available, so that the technology can be used for other research purposes. METHODS A group of three health researchers developed the initial specification and processes for the app and website. These described the planned functions and 446 Patel V, et al. J Epidemiol Community Health 2013;67:446–452. doi:10.1136/jech-2012-201774 Research report