Hospital follow-up adherence among screen-positive lung cancer utilizing a mobile LDCT in community in Hainan, China: a prospective cohort study

China has the highest global disease burden for both lung cancer and tuberculosis (TB). Mobile low-dose computed tomography (LDCT) screening offers dual detection of early-stage lung malignancies and active TB radiographic manifestations. However, evidence regarding community-based post-screening compliance remains inadequate. This study aimed to evaluate hospital follow-up adherence and its associated factors among individuals who screened positive for lung cancer or TB in a community-based, non-risk-based LDCT screening program. A prospective cohort study was conducted in Dongfang, Hainan Province, from June to September 2024. Permanent residents aged ≥40 years were enrolled in a community-based, non-risk-stratified mobile LDCT screening program. At the time of screening, participants completed a structured questionnaire to capture demographic characteristics, risk factors, and health status. Screening images were interpreted according to established guidelines; individuals with findings indicative of Lung-RADS category 4 (4 A, 4B, 4X) or suspected active pulmonary TB were considered screen-positive. The primary outcome, adherence to hospital-based diagnostic follow-up within six months, was objectively assessed by linking screening records to the provincial medical insurance claims database. Multivariable logistic regression was used to identify factors associated with adherence, stratified by screening finding. Among 22,933 participants (14,134 female and 8799 men), 547 (2.4%) had LDCT findings classified as Lung-RADS 4 and 653 (2.9%) displayed radiological features compatible with TB. Diagnostic follow-up within six months was completed by 303/547 lung-cancer suspects (55.4%) and 336/653 pulmonary TB suspects (51.5%). Among adherent individuals, 98 lung cancers (32.3%) and 95 active pulmonary TB cases (28.3%) were confirmed. In the lung-cancer cohort, respiratory symptoms increased the likelihood of follow-up (adjusted odds ratio aOR 2.47, 95% CI 1.13–5.41), whereas retired status decreased it (aOR 0.52, 0.32–0.85). In the pulmonary TB cohort, female sex was positively associated with adherence (aOR 1.39, 1.02–1.90), while formal employment was negatively associated (aOR 0.53, 0.31 – 0.90). This study highlights the need for targeted interventions to optimize diagnostic follow-up and maximize the clinical and public health impact of integrated lung cancer-TB screening programs.