Background Team formulation is a core skill in mental health care, but there is currently no valid tool for assessing the quality of this process.
Aims The aim of this study was to design and evaluate a new scale, the Team Formulation Quality Scale (TFQS), which assesses both structure and content.
Methods Experts were asked to assess the relevance and clarity of each item on the TFQS to measure its content and face validity. Two experienced Clinical Psychologists rated eight audio recorded team formulation sessions and the scores were used to assess the internal consistency and inter-rater reliability of the TFQS.
Results The TFQS demonstrated good content and face validity as experts agreed all twenty-three items were relevant to measuring the quality of team formulation and rated it as understandable and comprehensive. The overall internal consistency of the TFQS was good (alpha = .718). The inter-rater reliability of the TFQS was consistent with individual case formulation quality measures (ICC = .600).
Conclusions We have developed the first scale to measure the quality of team formulation. The TFQS showed good validity and is a reliable tool that can be used in training, clinical practice and research related to team formulations.