Psychological defensiveness among heart transplant candidates

This study examined the utility of the K-correction procedure (i.e., raw sc ore weights added to scales 1, 4, 7, 8, 9) to adjust for a defensive respon se set on the MMPI. The sample consisted of 51 patients with end-stage hear t disease undergoing psychosocial evaluation for transplantation. Participa nts were separated into "defensive" and "nondefensive" groups using a media n split on the K scale (defensive defined as T-score greater than or equal to 59). The MMPI was scored once in the standard manner and then rescored o mitting all K-scale items from the clinical scales. As hypothesized, raw sc ore analysis after omitting K-scale items showed the defensive group endors ed significantly fewer items on three of the five clinical scales involving K-correction (scales 1, 7, 8). In contrast, analysis of K-corrected T-scor es using standard procedures showed a significant group difference only on scale 4, with a higher T-score found among the defensive group. The defensi ve and nondefensive groups were not significantly different on numerous dem ographic, medical, and psychiatric characteristics, suggesting that the ten dency to respond in a defensive manner is the major characteristic that dis tinguishes the two groups. Given this assumption, the K-correction procedur e appears to appropriately adjust for a defensive response set on scales 1, 7, 8, and 9, whereas K-correction may overadjust on scale 4.