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

Abstract

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. 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. 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. 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.