Ego depletion in cancer: why and how to measure it? The EDIC scale-a measure development research

To develop a measure for ego-depletion in oncology, as a foundational step for research and future interventions to reduce ego-depletion in adults coping with cancer.

Helsinki Ethical approval was granted by the ethics board of the medical centre with which the first author is affiliated. A cross-sectional field test was carried out. Based on the conceptualisation and measurement of ego-depletion, health professionals from a multidisciplinary team at a cancer centre developed items according to the content of ego-depletion and its demonstration in cancer. To validate the measure, we used the Piper Fatigue in Cancer scale, the Emotional and Functional well-being scales from the General Functional Assessment of Cancer Therapy scale, and the Busing self-regulation scale. REDCap, a web-based application, was used to capture data, structure the questionnaire, and distribute it. The final sample comprised 364 respondents.

Descriptive statistics and item characteristics were carried out. Item reduction was performed using partial inter-item correlations and factor analyses. A three-factor structure underlying 27 items on the Ego-Depletion in Cancer Scale (EDIC) was supported. We label the first factor 'Actively Withstanding Ego-depletion,' the second factor 'Ego-depletion Ambivalence,' and the third factor 'Ego Cognitive Exhaustion.' The EDIC significantly correlated with related measures (e.g. fatigue, self-control, and positive emotions; p < .05).

A full EDIC scale, three subscales of the 27 items, is presented. Correlations demonstrated convergent validity and suggested the EDIC is distinct from existing constructs. Implications and applications are discussed. A path analysis demonstrated that the EDIC scale is valid for measuring ego depletion in adults with cancer.