Assessing Swedish genetic counselling outcome measures for autism and general use: Rasch findings highlight the need for improved measures

Background Genetic counselling outcome measures are increasingly adapted for diverse clinical contexts. While the Genetic Counselling Outcome Scale (GCOS-24) is available in Swedish, no autism-specific version has been developed. Methods We adapted the Swedish GCOS-24 using the English version of the modified GCOS-24 (mGCOS-24) to create a Swedish autism-specific mGCOS-24. Thereafter, we evaluated both the Swedish autism mGCOS-24 and the Swedish general GCOS-24 using Rasch analysis to assess their psychometric properties. Results Both instruments exhibited structural challenges, including multidimensionality, disordered thresholds, local item dependence, and invariance issues. For the Swedish autism mGCOS-24, we were able to identify subscales with acceptable measurement properties. However, applying the same structure to the Swedish general GCOS-24 did not resolve its broader limitations. Conclusions This study introduces the first Swedish autism‑specific mGCOS‑24 and represents the first Rasch‑based evaluation of any GCOS‑24 or mGCOS‑24 in Swedish. Our findings highlight important opportunities for outcome measure refinement but also indicate that new or more substantially adapted tools may be needed to capture outcomes of genetic counselling in autistic populations.