Mediating role of inner strength in the relationship between medication literacy and medication adherence among kidney transplant patients.

Objectives: Compared with long-term renal replacement therapy, kidney transplantation is the ideal treatment for end-stage renal disease (ESRD), significantly extending patient life and improving quality of life. Kidney transplant patients need to adhere to lifelong immunosuppressive medication regimens, but their medication adherence is generally poor compared with other organ transplant recipients. Medication adherence is closely related to medication literacy and psychological status, yet related studies are limited. This study aims to investigate the current status of medication adherence, inner strength, and medication literacy in kidney transplant patients, analyze the relationships among these 3 factors, and explore the mediating role of inner strength in the relationship between medication literacy and medication adherence.

Methods: A cross-sectional survey was conducted from March to October 2023 involving 421 patients aged≥18 years who visited kidney transplantation outpatient clinics at 4 tertiary hospitals in Hunan Province. The inner strength, medication literacy, and medication adherence of kidney transplant patients were investigated using the Inner Strength Scale (ISS), the Chinese version of the Medication Literacy Assessment in Spanish and English (MedLitRxSE), and the Chinese version of the Morisky Medication Adherence Scale-8 (C-MMAS-8), respectively. Univariate analysis was performed to examine the effects of demographic and clinical data on medication adherence. Correlation analysis was conducted to explore the relationships among medication literacy, medication adherence, and inner strength. Significant variables from univariate and correlation analyses were further analyzed using multiple linear regression, and the mediating effect of inner strength was explored.

Results: Among the 421 questionnaires collected, 408 were valid, with an effective rate of 96.91%. The scores of C-MMAS-8, MedLitRxSE, and ISS were 6.64±1.16, 100.63±14.67, and 8.47±4.03, respectively. Among the 408 patients, only 86 (21.08%) patients had a high level of medication adherence, whereas 230 (56.37%) patients had a medium level of medication adherence, and 92 (22.55%) patients had poor medication adherence. Univariate analysis indicated that the kidney transplant patients' age, marital status, education levels, years since their kidney transplant operation, number of hospitalizations after the kidney transplant, and adverse drug reactions showed significant differences in medication adherence (all P<0.05). Correlation analysis showed that inner strength positively correlated with both medication literacy (r=0.183, P<0.001) and medication adherence (r=0.201, P<0.001). Additionally, there was a positive correlation between medication adherence and medication literacy (r=0.236, P<0.001). Inner strength accounted for 13.22% of the total effect in the mediating role between medication literacy and medication adherence.

Conclusions: The level of medication adherence among kidney transplant patients needs improvement, and targeted intervention measures are essential. Inner strength mediates the relationship between medication literacy and medication adherence in these patients. Healthcare professionals should focus on enhancing medication literacy and supporting patients' inner strength to improve medication adherence.