Association between the chance locus of control belief with self-reported occasional nonadherence after heart transplantation: a pilot study.

Nonadherence to immunosuppressant medication after organ transplantation has been found to be as high as 36%, and it has been associated with rejection and graft loss (1, 2). We sought to determine whether locus of control (LOC) had an effect on selfreported nonadherence to immunosuppressantmedication in patients after heart transplantation. Data on 52 participants were collected from July 2009 to December 2011 at the Kaiser Permanente’s Heart Transplant Service in Santa Clara, CA. The Immunosuppressant TherapyAdherence Scale (3) was used to measure adherence, and the Multidimensional Health Locus of Control (4) was used to measure beliefs about control over health outcomes. The following variables were also included in the analysis: age, race, gender, and number of rejection episodes. A score of 12 in the Immunosuppressant Therapy Adherence Scale placed the patient in the adherent group (24 patients), and a score of 11 or less placed the patient in the nonadherent group (28 patients). There were a total of 69.2% men and 30.8% women, among whom 78.8% were white, 11.5% African American, and 9.6% Asian. The mean age was 54.46 years old. The results from the Student’s t-tests and the chi-square tests showed that the chance LOC scores were statistically different in the adherent group versus the nonadherent group (P=0.003). Twenty-six patients (50%) reported missing or forgetting immunosuppressant medication doses 1% to 20% of the times, and two patients (3.8%) reported missing or forgetting medication 21% to 50% of the times in the past 3 months before their participation in the study. The first step of the logistic regressionmodeling identified only change LOC and African American race as significant predictors of nonadherence (P=0.0026). The second step revealed a negative relationship between change LOC and occasional missed doses of immunosuppressant medication (odds ratio, 1.1527; P=0.0071; 95% confidence interval, 1.0394Y1.2792). A receiver operating characteristic curve analysis suggested the same result (area under the curve=0.757; significance P=0.0003 with a 95% confidence interval). Nonadherence is a complex phenomenon characterized by the interplay of several factors. For example, Denhaerynck et al. (5) conducted a literature review and summarized the evidence on the determinants of nonadherence in renal transplant recipients, which included younger age, social isolation, and cognitions (e.g., low selfefficacy and certain health beliefs, such as chance LOC). This review also identified that determinants concerning the health care system seem to have been underinvestigated. Our finding that the chance LOC belief might be one of the factors contributing to occasional nonadherence to immunosuppressant medication is consistent with Raiz et al. (6). Wallston (7) hypothesizes that the chance LOC belief causes the feeling of helplessness and he writes: ‘‘people who feel helpless tend to not engage in positive health behaviors or abandon those behaviors. ’’ Changes in the chance LOC beliefs may offer potential target for nonadherence prevention and early intervention with transplant recipients. The limitations of our study include a relatively small cross-sectional sample of 52 patients and self-report instruments. Additional research with a prospective study design using a larger sample size and longer duration of follow-up is needed to assess the chance LOC’s long-term impact on patient selection, adherence, graft function, and patient survival. Flavio R. Epstein Parag P. Kale Dana M. Weisshaar Heart Transplant Department Kaiser Permanente Santa Clara, CA