Predictors of treatment adherence in pediatric cancer patients

Leanne Marie Embry

Abstract

Adherence to prescribed treatment regimens has long been recognized as problematic. However, relatively little attention has been paid to the issue of identifying predictors of poor adherence, particularly in pediatric populations. The goal of this study was to examine psychological predictors of treatment adherence in an ethnically diverse group of children and adolescents diagnosed with cancer. The participants in this study were 37 youths (ages 8 to 19 years) who were being treated for cancer, and their parents. Approximately 70% of the children were Hispanic, 27% were Caucasian, and 3% were African American. Adherence was assessed using a 24-hour recall interview, administered separately to children and parents at three different times. Adherence rates were calculated by dividing the number of daily treatment-related behaviors completed by the number of behaviors prescribed (e.g., number of daily medication doses). This allowed for calculation of an overall percentage of adherence, rather than a dichotomous categorization of "adherent" or "nonadherent." The rate of adherence ranged from 25% to 100%, with a mean of 75.4%. There were no differences in adherence rates based on age of the child, diagnosis, ethnic background, gender, socioeconomic status, or family composition. Furthermore, no significant correlations were discovered between adherence rates and a number of the variables examined, including time since diagnosis, complexity of treatment regimen, family adaptability, internalizing behavior problems, anxiety sensitivity, or fears of death and danger. However, family cohesion was positively correlated with adherence, while parental anxiety, child anxiety, and externalizing behavior problems were negatively correlated with adherence. Regression analyses indicated that parental anxiety, child anxiety, and the child's fear of death and danger were significant predictors of adherence, and together accounted for nearly 28% of the variance in adherence rates. These findings highlight the association between treatment adherence and psychological variables, most notably anxiety, in pediatric patients diagnosed with cancer. Results suggest that psychosocial assessment soon after childhood cancer is diagnosed, including evaluation of both parental and child anxiety, may help to identify patients who are at risk for future nonadherence.