ABSTRACT
Patients lost to follow-up (LTFU) are a well-recognized challenge, both in clinical trials and in real clinical practice. PURPOSE: To study the reasons for patients receiving anti-VEGF therapy for «wet¼ age-related macular degeneration (wAMD) in clinical environment to cease monitoring in the clinic. MATERIAL AND METHODS: This retrospective cohort study included patients with wAMD which received anti-VEGF therapy (ranibizumab, aflibercept) in the Ural State Medical University clinic from 2011 to 2019 (n=241). A subgroup of patients continuing treatment (n=90) was compared with a subgroup of lost to follow up patients (LTFU, n=151, 62.7%). Observation lasting less than 12 months was an exclusion criterion. Statistical analysis included a comparison of demographic and clinical data. The reasons for treatment discontinuation were determined using a phone survey. RESULTS: Characteristic for the LTFU subgroup were shorter duration of the follow-up (p<0.0001), lower number of intravitreal injections (p<0.0001), lower baseline (p<0.0001) and final best corrected visual acuity (p<0.0053) as well as higher values of therapy intensity coefficient (the ratio of the number of intravitreal injections to the duration of the follow-up, p<0.0001). According to the results of the phone survey, the following categories of LTFU were identified: ceased regular monitoring/treatment - 83 (55.0% of the LTFU subgroup), continued treatment in another clinic - 14 (9.3%), deceased - 18 (11.9%), status unknown - 36 (23.8%). The most common causes of LTFU were dissatisfaction with treatment results, financial burden and general comorbidities, which were named by 50, 27 and 17 respondents, respectively. CONCLUSION: In accordance with identified reasons for LTFU, we determined the directions for increasing the effectiveness of wAMD treatment: early diagnosis and start of treatment; using the most effective drugs and therapeutic regimens; increasing the availability of anti-VEGF therapy.
