In the Lifelines study, participants have been asked to specify the sports they engage in (children and adolescents and adults). These self-reported sports were processed using a standardized coding framework at Statistics Netherlands (CBS), resulting in coding of the written sports. (sections: Children & adolescents (Physical activity <18), Lifestyle & environment (Physical activity (SQUASH), and Secondary & Linked variables (SQUASH sum scores)).
The sport codes can be requested in the Lifelines catalogue.

The coding was performed using the Computer Aided Structured Coding Tool (CASCOT) from the University of Warwick. This tool assigns sport codes based on the provided descriptions. It is important to note that only automatic coding was applied to the Lfielines data. In other words, no manual corrections were made.

The sport code list for Dutch sports was developed by CBS in collaboration with theNational Institute for Public Health and the Environment (RIVM). The resulting coding framework categorizes sports into hierarchical groups, assigning each activity a specific code. (see this page)).

The resulting variables include the following:

• Sport code: Assigned sport code based on the sport description.
• Keyword: Primary term used for coding.
• Title group: The categorization label for the sport.
• Score: A score that indicates the quality of the typed results. A score of 71% or more is considered as a corerctly selected sport category. For the Lifelines data, >90% of the data meet this threshold.

The sport codes are used as input to calculate physical activity scores (see SQUASH sum scores). At the moment, these physical activity scores are available for assessment 1A only. For these calculations previously generated coding is used (Ainsworth). At this site, RIVM provides a detailed description regarding the sport codes and syntaxes to calculate physical activity scores yourself.