Development and validation of the Cancer Knowledge Scale for the general population: An item response theory approach

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.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10552-022-01601-x.

An Item Response Theory to Analyze the Psychological Impacts of Rail-Transport Delay

Questionnaire instruments have been used extensively by researchers in the literature review for evaluation of various aspects of public transportation. Important implications have been derived from those instruments to improve various aspects of the transport. However, it is important that instruments, which are designed to measure various stimuli, meet criteria of reliability to reflect a real impact of the stressors. Particularly, given the diverse range of commuter characteristics considered in this study, it is necessary to ensure that instruments are reliable and accurate. This can be achieved by finding the relationship between the item’s properties and the underlying unobserved trait, being measured. The item response theory (IRT) refers to measurement of an instrument’s reliability by examining the relationship between the unobserved trait and various observed items. In this study, to determine if our instrument suffers from any potentially associated problems, the IRT analysis was conducted. The analysis was employed based on the graded response model (GRM) due to the ordinal nature of the data. Various aspects of the instruments, such as discriminability and informativity of the items were tested. For instance, it was found while the classical test theory (CTT) confirm the reliability of the instrument, IRT highlight some concerns regarding the instrument. Also, the person fit assessment measure, for instance, highlights some concern regarding respondents answering some of the questions due to lack of interest, choosing answers randomly. Not many studies have examined instruments’ reliability in determining the psychological impacts of public transportation on commuters in the way that was performed here.