PT  - JOURNAL ARTICLE
AU  - Isabel Fortier
AU  - Nataliya Dragieva
AU  - Matilda Saliba
AU  - Camille Craig
AU  - Paula J. Robson
ED  - ,
TI  - Harmonization of the Health and Risk Factor Questionnaire data of the Canadian Partnership for Tomorrow Project: a descriptive analysis
AID  - 10.9778/cmajo.20180062
DP  - 2019 Apr 01
TA  - CMAJ Open
PG  - E272--E282
VI  - 7
IP  - 2
4099  - http://www.cmajopen.ca/content/7/2/E272.short
4100  - http://www.cmajopen.ca/content/7/2/E272.full
SO  - CMAJ2019 Apr 01; 7
AB  - Background: The Canadian Partnership for Tomorrow Project is a multistudy platform integrating the British Columbia Generations Project, Alberta’s Tomorrow Project, the Ontario Health Study, CARTaGENE (Quebec) and the Atlantic Partnership for Tomorrow’s Health. This paper describes the process used to harmonize the Health and Risk Factor Questionnaire data and provides an overview of the key information required to properly use the core data set generated.Methods: This is a descriptive analysis of the harmonization process that was developed on the basis of the Maelstrom Research guidelines for retrospective harmonization. Core variables (DataSchema) to be generated across cohorts were defined and the potential for cohort-specific data sets to generate the DataSchema variables was assessed. Where relevant, algorithms were developed and applied to process cohort-specific data into the DataSchema format, and information to be provided to data users was documented.Results: The Health and Risk Factor Questionnaire DataSchema (version 2.0, October 2017) comprised 694 variables. The assessment of harmonization potential for the variables over 12 cohort-specific data sets resulted in 6799 (81.6%) of the variables being considered as harmonizable. A total of 307 017 participants were included in the harmonized data set. Through the cohort data portal, researchers can find information about the definitions of variables, harmonization potential, algorithms applied to generate harmonized variables and participant distributions.Interpretation: The harmonization process enabled the creation of a unique data set including data on health and risk factors from over 307 000 Canadians. These data, in combination with complementary data sets, can be used to investigate the impact of biological, environmental and behavioural factors on cancer and chronic diseases.