Adesão ao regime medicamentoso dos adolescentes submetidos a transplante hepático: fatores motivacionais.

Introduction: In liver transplantation the immunosuppression is essential for the survival of the graft and of the receiver. Although characteristics of adolescent development may influence medication non-adherence, the literature on the subject is scarce. The high prevalence and consequences of non-adherence makes it essential to identify the non-adherent adolescent with the intention of promoting medication adherence. Methods: The aim of this descriptive cross-sectional study is to characterize adolescents undergoing liver transplantation, and to determine the degree of medication non-adherence, using the Measure Treatment Adherence (MAT) scale and immunosuppression blood values. Moreover, the study seeks to explore the relationship between adherence and motivation - using the Treatment Self-Regulation Questionnaire (TSRQ), and adherence and competency - using Perceived Competence Scale (PCS). Results: The sample consisted of 32 adolescents (Age M=14,44 (SD=2,66); 56,3% (n=18) male) who underwent liver transplantation at a Portuguese pediatric hospital. Adolescents self-reported medication adherence scores in the MAT were significantly higher (100%) than what was expected based on the mean value of the three blood values of tacrolimus obtained within one year prior to completing the questionnaire (66,7%). As a subjective self-reported measure, the MAT is prone to bias and inflated self assessed adherence is commonly found in the literature. On the other hand, the mean value of the three blood levels of tacrolimus obtained widely and considered objective adherences measure, they may individually vary in terms of pharmacokinetic response and absorption. Adolescents showed a predominantly autonomous motivation to fulfill the medication prescription, being that motivation high (TSRQ autonomous motivation subscale presents an average value of 6.5, in a range of 1 to 7). They showed themselves confident and believing in their capacity to follow the medication regimen, due to the high perceived competence (PCS presents an average value of 6.65, in a range of 1 to 7). Opposed to what was postulated by the Self-determination Theory and other investigation's results, motivation and perceived competence are not related to adherence to the medication regimen in this study (rs=,119 p=,523; rs=,283 p=,123, respectively). Thus, perceived competence seems to have a positive influence on the autonomous motivation of these adolescents (rs=,482 p=,006). Conclusion: This study shows that medication adherence when evaluated subjectively scores higher compared to the blood values of immunosuppression. Also, Motivation and Perceived Competence do not seem to influence the adherence to the medication regimen. More multi-centre studies are needed, based on solid theory to examine adherence behaviour more.