Cross-cultural adaptation of the Genetic Counseling Outcome Scale (GCOS-24) for use in Canada: A qualitative study

The Genetic Counselling Outcome Scale (GCOS)-24 is a patient-reported outcome measure (PROM) developed and validated in the United Kingdom (UK). The aim of this study was to cross-culturally adapt GCOS-24 to Canadian Clinical Genetic Services (CGS). This was achieved through a qualitative study exploring whether the existing GCOS-24 maintains its intended meaning in a Canadian population and assessing whether GCOS-24 items could be better worded to meet the needs of members of families affected by genetic conditions in Canada. Thirteen participants were recruited from Canadian Patient Organizations supporting people and families affected by genetic conditions. Data were collected through semi-structured cognitive interviews, as these allow exploration of participants' comprehension, opinions, thoughts, and feelings regarding GCOS-24's instructions, response options, and the meaning/relevance of each item. Thematic analysis was utilized for data analysis, and an inductive approach to coding was followed to allow for themes to emerge from the data. Themes were organized in respect to their questionnaire item and further classified into their respective Empowerment dimension. The GCOS-24 instructions were found easy to understand by all thirteen participants. Although the response options were also found to be straightforward, the data suggest the questionnaire would benefit from the addition of a "non-applicable" option. Semantic validation of the GCOS-24 showed that items within the Cognitive Control and Emotional Regulation dimensions were found easy to understand by participants. However, items within the Decisional Control, Behavioural Control and Hope dimensions presented semantic difficulties. Participants provided feedback on syntactic changes to support understanding, and this feedback was used to develop a final Canadian-adapted version of GCOS-24, GCOS-Canada. This study provides the first step towards a valid, culturally adapted PROM for use in Canadian CGS service evaluation and research. GCOS-Canada would benefit from psychometric validation to ensure validity, reliability, responsiveness, minimal clinically important difference and internal consistency.