Factors Influencing Diagnostic Adherence Among High-Risk Populations for Chronic Obstructive Pulmonary Disease in Eastern Rural China: An Analysis Based on the Health Belief Model and Implications for Primary Care Interventions

Background/Objectives: Chronic Obstructive Pulmonary Disease (COPD) is a progressive respiratory disorder imposing massive global mortality and socioeconomic burden, with disproportionately high prevalence and suboptimal diagnostic rates in rural China. This study aimed to identify factors associated with two-dimensional diagnostic adherence—operationalized as a cognitive/psychological dimension (knowledge of diagnostic guidelines, perceived value of early diagnosis, and psychological readiness) and a behavioral dimension (completion of standard diagnostic procedures)—among COPD high-risk populations based on the Health Belief Model (HBM), and to explore the statistical mediating roles of health beliefs and social support. Economic toxicity refers to the financial burden of healthcare, including direct costs (copayments, medications) and indirect costs (transport, lost wages). Methods: A cross-sectional survey was conducted among 248 COPD high-risk individuals recruited via stratified random sampling in Pingdu District, Shandong Province, eastern China. A two-stage screening procedure was employed: first-stage screening at township health centers using portable spirometry, followed by referral for standard diagnostic evaluation at secondary or higher-level hospitals. Validated scales were applied for data collection, including the European Health Literacy Survey Questionnaire-Short Form (HLS-EU-Q16). Analyses included descriptive statistics, reliability/validity testing, Pearson and point-biserial correlations, multiple linear regression (cognitive outcome), multivariable logistic regression (behavioral outcome), and Hayes’ PROCESS macro with 5000 bootstrap samples. Benjamini–Hochberg false discovery rate correction was applied to multiple comparisons. Results: The mean cognitive dimension score was 4.935 ± 2.512, and the behavioral diagnostic completion rate was 42.3%. Independent predictors of cognitive adherence included health literacy (β = 0.286), health beliefs (β = 0.252), COPD knowledge (β = 0.239), living alone (β = −0.157), and economic toxicity (β = −0.108). Predictors of behavioral adherence identified via logistic regression were health literacy (OR = 1.28, 95%CI: 1.15–1.42), social support (OR = 1.12, 95%CI: 1.04–1.21), economic toxicity (OR = 0.82, 95%CI: 0.72–0.94), and medical accessibility (OR = 1.85, 95%CI: 1.12–3.05). Health beliefs statistically mediated 31.4% of the knowledge → cognitive adherence association and 36.9% of the economic toxicity → cognitive adherence association (cognitive outcome; behavioral indirect associations are reported on the log-odds scale with bootstrap confidence intervals). GAD-7 anxiety score was weakly correlated with adherence but not an independent predictor. Conclusions: Health literacy, health beliefs, and COPD knowledge are associated with higher COPD diagnostic adherence in rural high-risk populations in eastern China, while economic toxicity and living alone are associated with lower adherence. Health beliefs mediate the statistical associations between knowledge and economic status and cognitive adherence. Given the cross-sectional design, these findings should be interpreted as associations rather than causal effects. Dual-target interventions covering both cognitive and behavioral barriers are proposed as future strategies to optimize early COPD diagnosis in rural primary care.