Rasch analysis of the Mini-Mental Adjustment to Cancer Scale (mini-MAC) among a heterogeneous sample of long-term cancer survivors: A cross-sectional study

• Main Authors: Zucca Alison, Lambert Sylvie D, Boyes Allison W, Pallant Julie F
• Format: Article
• Language: English
• Published: BMC 2012-05-01
• Series: Health and Quality of Life Outcomes
• Subjects: (3–10) Cancer; Psychometrics; Coping; Adjustment; Survivor; Questionnaires; Rasch
• Online Access: http://www.hqlo.com/content/10/1/55

<p>Abstract</p> <p>Background</p> <p>The mini-Mental Adjustment to Cancer Scale (mini-MAC) is a well-recognised, popular measure of coping in psycho-oncology and assesses five cancer-specific coping strategies. It has been suggested that these five subscales could be grouped to form the over-arching <it>adaptive</it> and <it>maladptive</it> coping subscales to facilitate the interpretation and clinical application of the scale. Despite the popularity of the mini-MAC, few studies have examined its psychometric properties among long-term cancer survivors, and further validation of the mini-MAC is needed to substantiate its use with the growing population of survivors. Therefore, this study examined the psychometric properties and dimensionality of the mini-MAC in a sample of long-term cancer survivors using Rasch analysis.</p> <p>Methods</p> <p>RUMM 2030 was used to analyse the mini-MAC data (n=851). Separate Rasch analyses were conducted for each of the original mini-MAC subscales as well as the over-arching adaptive and maladaptive coping subscales to examine summary and individual model fit statistics, person separation index (PSI), response format, local dependency, targeting, item bias (or differential item functioning -DIF), and dimensionality.</p> <p>Results</p> <p>For the fighting spirit, fatalism, and helplessness-hopelessness subscales, a revised three-point response format seemed more optimal than the original four-point response. To achieve model fit, items were deleted from four of the five subscales – Anxious Preoccupation items 7, 25, and 29; Cognitive Avoidance items 11 and 17; Fighting Spirit item 18; and Helplessness-Hopelessness items 16 and 20. For those subscales with sufficient items, analyses supported unidimensionality. Combining items to form the adaptive and maladaptive subscales was partially supported.</p> <p>Conclusions</p> <p>The original five subscales required item deletion and/or rescaling to improve goodness of fit to the Rasch model. While evidence was found for overarching subscales of <it>adaptive</it> and <it>maladaptive</it> coping, extensive modifications were necessary to achieve this result. Further exploration and validation of over-arching subscales assessing <it>adaptive</it> and <it>maladaptive</it> coping is necessary with cancer survivors.</p>