Factors Associated with Continuous Loss to Follow-up in Cancer Patients

Purpose: This study aimed to identify factors associated with continuous loss to follow-up (LTFU) among outpatient patients with cancer.Methods: A retrospective analysis was conducted using electronic medical records of patients with cancer treated at a university hospital in Seoul between July 1, 2018, and July 30, 2020. LTFU was defined as no clinic visit for at least 12 months after the last visit date. Univariate and multivariable logistic regression analysis was performed between the continuous LTFU group (n=11,028) and the group that returned to our hospital after LTFU (n=56,080).Results: Of the 102,896 patients with cancer, 67,108 were included. Approximately 5 years after the last visit date, 11,028 (16.4%) had not returned to our hospital and were identified as continuous LTFU. Logistic regression showed that the risk of LTFU was 0.83 times lower in women than in men. Patients aged 70 or older had a 1.39-times higher risk of LTFU compared with patients under 70 years old. LTFU risk increased for patients living at a longer distance from Seoul, with the highest risk (1.75 times higher) observed in Jeju. Among cancer types, patients with breast cancer had the highest risk of LTFU at 2.53 times. Patients who received at least one chemotherapy cycle had a 0.82-times lower risk of LTFU compared to those who did not receive it. The risk of LTFU was 0.75 times lower in those receiving radiation therapy compared with that in patients who did not receive radiation therapy; it was also 0.67 times lower in those with comorbidities. Normal blood test parameters (absolute neutrophil count, hemoglobin, glutamic-oxaloacetic transaminase, albumin, Na, K, Creatinine) were independently associated with the risk of LTFU.Conclusion: Gender, age, distance from the hospital, cancer type, treatment, comorbidities, and blood test results were important factors influencing LTFU in patients with cancer. These data can help improve follow-up strategies for cancer care and contribute to improving the quality of care by minimizing LTFU rates.