Self-care agency and medication adherence among cancer patients receiving oral chemotherapy: a path analysis study

Oral chemotherapy shifts substantial treatment responsibility to patients and requires sustained engagement in medication use, symptom monitoring, follow-up, and communication with healthcare professionals. This study aimed to determine levels of self-care agency and medication adherence among adults receiving oral chemotherapy and to examine the relationship between adherence-related behaviors and self-care agency.

This descriptive cross-sectional study included 140 adult cancer patients receiving oral chemotherapy at oncology outpatient clinics in Türkiye. Data were collected using a Sociodemographic and Clinical Characteristics Form, the Self-Care Agency Scale (SCAS), and the Oral Chemotherapy Adherence Scale (OCAS). Descriptive statistics, group comparisons, Pearson correlation analysis, and a theory-specified observed-variable mediation path model were used, in which basic conditioning factors (age, gender, education, income, comorbidity, treatment duration, and side effect burden) predicted self-care agency, which in turn predicted the three oral chemotherapy adherence subdimensions; indirect (mediated) effects were tested with 5000 bias-corrected bootstrap resamples.

The mean SCAS total score was 56.78 ± 17.42, which was below the midpoint of the possible scale range (0-140), whereas oral chemotherapy adherence was suboptimal, with the OCAS mean (77.92 ± 10.71) below the developer-defined good-adherence threshold of 84; 78.6% of participants were classified as having suboptimal adherence and 21.4% reached the good-adherence threshold. Total SCAS and OCAS scores were moderately and positively correlated (r = 0.43, p < 0.001). In the mediation path model, the test of the 18 omitted direct paths rejected exact fit (χ²(18) = 43.96, p < 0.001) with mixed approximate fit (CFI = 0.96; TLI = 0.89; RMSEA = 0.102; SRMR = 0.037); self-care agency significantly predicted all three adherence subdimensions (β = 0.36-0.46, all p < 0.001), and income and education exerted positive-and older age and female gender negative-indirect effects on all three subdimensions through self-care agency (all bootstrap 95% CIs excluded zero).

Self-care agency and oral chemotherapy adherence were positively related, and income, education, age, and gender showed significant indirect associations with adherence through self-care agency, indicating that socioeconomic and demographic differences in adherence-related behaviors operate partly through self-care capacity; as cross-sectional associations, these findings do not establish causal mediation. Oncology nursing interventions should therefore combine adherence-support strategies with equity-sensitive education and follow-up approaches, particularly for patients with lower education and income levels.