The Worries About Recurrence or Progression Scale in Cancer (WARPS‐C): A Valid and Reliable Measure to Screen for Fear of Cancer Recurrence

ABSTRACT Objective The Worries About Recurrence or Progression Scale (WARPS) was recently validated in four common chronic illnesses other than cancer, after a rigorous development process based on the COSMIN criteria. Available measures of fear of progression or fear of cancer recurrence (FCR) have been criticised for not meeting all COSMIN criteria. Therefore, this study aimed to explore the psychometric properties of the WARPS in a cancer sample to assess its applicability to measure FCR. Methods We recruited 346 participants living with or beyond cancer for an online survey. The psychometric properties of the WARPS were examined using a confirmatory factor analysis. Convergent validity was assessed against the current gold standard questionnaires and constructs related to FCR. Some participants completed a follow‐up survey 2 weeks later, to assess the test‐retest reliability. Finally, a Receiver Operating Characteristics analysis was conducted to determine clinical cut‐offs for the WARPS. Results Confirmatory factor analysis confirmed that the WARPS has one underlying factor, fear of recurrence or progression (FRP), with adequate model fit. The WARPS demonstrated excellent internal consistency, test‐retest reliability and showed convergent validity. ROC analysis revealed a cut‐off of 54 for moderate, and 65 for severe FCR on the WARPS. Conclusions The WARPS demonstrated good psychometric properties in a cancer sample. It has the capacity to be used as a screening tool to identify clinical levels of FCR. The WARPS was developed consistent with the COSMIN criteria and overcomes some of the limitations of existing measures.