Longitudinal trends in vaccination and cancer screening engagement among patients with chronic lymphocytic leukemia: A prospective cohort study and quality improvement initiative (2019–2025)

Abstract

Abstract Patients (pts) with CLL are at increased risk of infections and other cancers. However, the real-world uptake of vaccinations and cancer screenings in these pts is limited. We surveyed pts with CLL annually using a standardized health maintenance questionnaire between June 2019 and March 2025 and provided reminders for recommended vaccinations and age-appropriate cancer screenings. Data collected included vaccination history (influenza, pneumococcal, shingles, COVID-19), primary care visits, and age-appropriate cancer screenings (mammogram, Pap smear, PSA, colonoscopy, skin exams). We used univariate and multivariate logistic regression to examine associations between vaccine/screening uptake and demographic variables (age, sex, race, ethnicity). Survey year and sequence were evaluated using categorical and recurrent event models. Results were reported as rates with 95% confidence intervals (CI) or odds ratios (OR) with 95% CI. A total of 1083 pts with CLL completed at least one yearly survey. Influenza vaccination rates were 92% in 2020 and 95% in 2021, declined to 74% in 2022, 66% in 2023, 62% in 2024 and increased to 67% in 2025 (2025 vs. 2020 OR = 0.18, 95% CI: 0.02–1.51, p = 0.027); pneumococcal vaccination rates were 58% in 2020, 79% in 2021, declined to 63% in 2022, 42% in 2023, 37% in 2024 and 33% in 2025 (2025 vs. 2020 OR = 0.37, 95% CI: 0.09–1.39, p = 0.037); Shingles vaccination started at 20% in 2020, increased to 55% in 2021 (OR = 4.89, p = 0.018), decreased to 47% in 2022, 37% in 2023, 39% in 2024, and 34% in 2025. COVID-19 vaccination was 33% in 2021, peaked at 80% in 2022, declined to 56% in 2023, 48% in 2024 and 2025 (2025 vs. 2022 OR = 0.23, 95% CI: 0.09–0.58, p = 1.9 × 10⁻⁵). Older age was associated with higher vaccine uptake. Sex, race, and ethnicity were not significant. Among pts completing serial surveys, the cumulative rate of at least one influenza vaccine increased from 68% at the 1st survey to 79% by 2nd survey and 82% by the 3rd and 4th surveys. The cumulative rate of receiving at least one COVID-19 vaccine increased from 58% at the 1st survey to 82% by the 2nd and 95% by the 5th survey. Receipt of a second dose rose from 36% by the 2nd survey to 59% by the 3rd, and 86% by the 5th survey. We also evaluated sex and age-appropriate cancer screening rates. Mammography rates were 75% in 2020, 88% in 2021, declined to 58% in 2022 and 50% in 2023, rose to 65% in 2024 and 86% in 2025 (2025 vs. 2023 OR = 6.07, 95% CI: 1.04–35.4, p = 0.0049). Colonoscopy rate declined from 76% in 2020 to 52% in 2021, 61% in 2022, 47% in 2023 (OR = 0.03, 95% CI: 0.07–1.12, p = 0.01), improved to 68% in 2024 and recovered to 100% by 2025 (limited number of patients surveyed). Pap smear rates were 27% in 2020, 22% in 2021, 27% in 2022, 22% in 2023, 29% in 2024 and rose to 42% in 2025 (2025 vs. 2020 OR = 1.94, 95% CI: 0.19–18.9, p = 0.42). PSA screening rates were 29% in 2020, 21% in 2021, increased to 46% in 2022, 48% in 2023, 53% in 2024 and 45% in 2025 (2025 vs. 2020 OR = 1.99, 95% CI: 0.38–10.5, p = 0.25). Dermatology visit rates were 64% in 2020, 53% in 2021, increased to 70% in 2022 (OR vs. 2021 = 2.13, 95% CI: 0.52–8.75, p = 0.14), and remained stable at 63–68% through 2025. Serial survey engagement showed robust gains in completion of cancer screening tests: Mammogram screening rose from 28% at the 1st survey to 32% by the 2nd, and 65% by the 4th; PSA screening increased from 34% at the 1st survey to 40% by the 2nd, 50% by the 4th and dermatologist visit increased from 65% at the 1st survey to 78% by the 2nd and 88% by the 4th. Racial and ethnic disparities were observed in PSA screening: non-Hispanic had higher uptake (OR = 1.9, 95% CI: 1.1–3.4, p = 0.023), while Black (OR = 0.07) and Asian (OR = 0.12) pts had lower odds than White pts (p < 0.01). Primary care visit rates remained consistent: 92% in 2020, 89% in 2021, 86% to 88% between 2022 and 2025. In this prospective cohort study, vaccination and screening rates declined post-pandemic. However, administering repeated yearly surveys was associated with improved uptake over time, including recovery of mammography and colonoscopy rates by 2025 and increased rates of dermatology visits and PSA screening. These findings highlight the importance of longitudinal, quality improvement strategies to optimize preventive care in pts with CLL.