Re-validating the measurement tool to assess public awareness of cancer - the Cancer Awareness Measure ‘Plus’ (CAM+)

Background: The Cancer Research UK Cancer Awareness Measure (CAM) is a widely used tool informing cancer policy, public health practice, and intervention development. First introduced and validated in 2008, the measure has evolved substantially over time in response to changes in evidence, healthcare delivery, and public understanding of cancer. This study aimed to revalidate the latest version of the measure (CAM+) to ensure its continued reliability, validity, and relevance.

Methods: The revalidation programme comprised four phases conducted in accordance with COSMIN guidance. Phase 1 included: a) a COM-B audit to assess alignment with a behaviour change framework; b) scoping reviews of recent literature; c) face validity assessment with cancer experts and stakeholders; and d) readability assessment using the Hemingway Editor App and the SMOG readability index. Phase 2 assessed content validity using two stages of cognitive interviewing. In Phase 3, factor analysis was conducted to refine the measure and identify redundant items. Phase 4 assessed construct validity, reliability, and responsiveness using known-groups comparisons, test–retest analysis, and sensitivity-to-change assessment following a brief educational intervention.

Results: Phase 1 findings suggested that CAM+ addresses key cancer awareness and behavioural insight needs, while identifying several areas for refinement. The COM-B audit confirmed that CAM+ captures domains relating to capability, opportunity, and motivation relevant to cancer awareness and help-seeking behaviour. Readability assessment led to simplification of several long and complex items to improve clarity and accessibility. Cognitive interviews demonstrated that the revised CAM+ was generally well understood and interpreted as intended, although some response formats required modification. Factor analysis supported refinement of the questionnaire structure and removal of redundant items. Most CAM+ sub-scales demonstrated satisfactory to high internal consistency and good test–retest reliability. Construct validity analyses showed significantly higher CAM+ scores among cancer experts compared with non-cancer experts. Responsiveness analyses demonstrated improved CAM+ scores following exposure to a brief educational intervention.

Conclusions: The revalidated CAM+ demonstrated satisfactory psychometric properties, supporting its reliability and validity as a measure of cancer awareness, attitudes, and help-seeking behaviours in the general population. The updated measure remains a robust tool for informing cancer policy, public health campaigns, and future research, while enabling researchers and practitioners to better understand target populations and tailor interventions to improve cancer awareness and early diagnosis behaviours.