Translating the Behaviour Change Technique Taxonomy v.1 to other languages: the approach used in European Portuguese (BCTTv1-PT)

Background: The Behaviour Change Techniques Taxonomy v1 (BCTTv1) is the most widely used classification of behaviour change techniques (BCTs), contributing to the accurate report and evaluation of behaviour change interventions and accumulation of evidence. Purpose: This study reports a structured approach to adapt the BCTTv1 into European Portuguese (BCTTv1-PT).Methods: A collaborative and iterative approach was used. The translation process encompassed four phases: (1) independent forward translation by two native Portuguese speakers proficient in English, (2) forward translation reconciliation, (3) expert consultation by involving seven experts in behaviour change to collect feedback on the draft version of the taxonomy through a structured online form; and (4) feedback analysis and improvement of the BCTTv1-PT. Results: Independent forward translations and a reconciled version of the BCTTv1-PT were produced. All experts agreed with the groupings designation (100%). Recommendations were made to improve BCTs labels, definitions and/or examples in all groupings, except for Feedback and monitoring. Experts disagreed with the translated definitions in 40.9% of the BCTs (38/93), with examples in 21.5% (20/93) and with labels in 11.8% (11/93). Recommendations were made for all instances where there was disagreement (n = 69) and were enacted entirety, yielding the final version (BCTTv1-PT).Conclusion: Researchers, educators, students and health and other professionals will be able to standardise terminology and have a common language, contributing to the impact of the BCTTv1-PT. This study presents a systematic and rigorous approach for the adaptation of the BCTTv1 and similar taxonomies, which may guide others.