Development and psychometric properties of a brief generic cancer knowledge scale for patients (BCKS-10)

PURPOSE: This study aims to introduce the development and psychometric properties of a brief generic cancer knowledge scale for patients (BCKS-10) that includes different elements of knowledge and skills (terminology, diagnosis, treatment, prevention, and numeracy). Although cancer knowledge is a central dimension of cancer literacy, most previous studies either investigated cancer knowledge among the general population, or among patients with a specific cancer diagnosis.

METHODS: Qualitative interviews (n = 11) and a quantitative survey (n = 267) among peer support group leaders were conducted to further develop the BCKS-10 after literature screening. n = 500 patients with cancer were recruited across Germany between October 2020 and February 2021. Construct validity, item discrimination and reliability were tested.

RESULTS: ANOVA revealed no significant differences of the knowledge score between various cancer sites, a significant positive association with education, and a negative association with migration background by trend supporting construct validity. In terms of item discrimination, the corrected item-total correlation of 8 out of 10 items were above the threshold of 0.3. Cronbach's alpha of about 0.68 revealed an acceptable internal consistency as the tool is brief and consists of different dimensions.

CONCLUSION: Overall, the findings show that the BCKS-10 is a suitable tool to briefly assess cancer knowledge among patients independent of cancer site. However, further surveys have to be conducted to validate the psychometric properties and enhance the BCKS-10.