The nature and structure of psychological distress in people at high risk for melanoma: A factor analytic study

Objective: This study examined the psychometric properties of two commonly used measures of psychological distress, the Hospital Anxiety and Depression Scale (HADS) and the Impact of Events Scale (IES) in a sample of individuals at high risk of developing melanoma due to strong family history. Methods: One hundred thirty-two individuals with a known family-specific CDKN2A mutation (74% response rate) completed a mailed, self-administered questionnaire including the HADS and the IES. Initial correlational analyses were followed by both exploratory and confirmatory factor analyses, according to a predetermined procedure for order of analyses. Results: Exploratory factor analyses found that neither a two-, three- or four-factor solution satisfactorily accounted for all IES items in the present sample. By contrast, a unidimensional account of the data emerged to best account for all IES items, leaving no items unaccounted for. In contrast, the traditional two-factor (anxiety and depression) structure of the HADS appeared to fit the data well. Conclusions: The traditional, two-factor (intrusion and avoidance) structure of the IES was not borne out within this familial melanoma cohort. Assessment of a single dimension of emotional distress in response to melanoma risk may facilitate more meaningful explorations of psychological adjustment in this context. These findings also raise questions about whether a post-traumatic stress framework is indeed the most appropriate framework to capture the unique nature of melanoma- or cancer-related distress.