The research team, led by Hui Xu and corresponding author Lixin Hao of the National Immunization Program at China CDC, set out to answer a deceptively simple question: among adults with chronic diseases who are under regular medical care, how many actually follow the recommendation to be vaccinated against influenza each year? This question matters because most previous studies of vaccine uptake in China have focused on the general population or on specific groups such as older adults and health care workers. Far less is known about patients with chronic conditions who see their doctors regularly and who might therefore be expected to receive timely vaccination advice as part of routine care.

To investigate, the researchers conducted a questionnaire-based cross-sectional survey in November 2022. The study drew on de-identified data from the China Influenza Vaccination Literacy Evaluation Project, an effort originally carried out by the Chinese Association on Vaccination in 2022 and formally authorized for secondary analysis. The analysis was approved by the Institutional Review Board of China CDC, and all data were anonymized through the removal of direct identifiers and the aggregation of demographic variables to prevent re-identification. Crucially, the survey targeted patients who had been selected by their own physicians and who were being actively managed for chronic diseases as outpatients, meaning that every participant had an established doctor-patient relationship at the time of the survey.

The questionnaire assessed participants’ knowledge about influenza and influenza vaccination, along with a range of demographic, economic, and health-related factors. The primary outcome was patient-reported receipt of the influenza vaccine, which the researchers treated as a measure of compliance with vaccination recommendations. In total, 547 subjects completed the survey. The team used chi-square tests to examine associations between individual factors and vaccination status in univariate analyses, and then applied logistic regression to identify the independent predictors of compliance while adjusting for other variables.

The headline result is sobering. Only 19.6 percent of the 547 outpatients with chronic diseases reported receiving an influenza vaccine annually. In other words, roughly four out of five patients for whom annual influenza vaccination is explicitly recommended were not following that recommendation, despite having regular contact with the health care system. Because these patients were physician-selected and already embedded in ongoing care, the finding suggests that the problem is not simply a matter of hard-to-reach populations. Even patients with consistent medical follow-up are largely missing out on a preventive intervention that could reduce their risk of influenza-related hospitalization and death.

The logistic regression analysis identified three factors that were independently and positively associated with compliance. The strongest was economic: patients with an annual household income of at least 150,000 yuan had more than six times the odds of annual vaccination compared with lower-income patients, with an odds ratio of 6.619 and a 95 percent confidence interval of 2.552 to 17.167. This pronounced income gradient points to cost as a likely barrier, since influenza vaccination in China is generally self-paid for most adults rather than covered by routine public financing. Patients who recalled receiving a recommendation from their doctor were also far more likely to be vaccinated, with an odds ratio of 4.223 (95 percent confidence interval, 2.051 to 8.693), underscoring the persuasive power of a direct physician endorsement.

The third independent predictor was knowledge. Patients who scored higher on the survey’s measure of basic vaccine knowledge had roughly two and a half times the odds of annual vaccination, with an odds ratio of 2.474 (95 percent confidence interval, 1.377 to 4.446). This association suggests that understanding what influenza is, how the vaccine works, and why it matters for people with chronic conditions translates into concrete preventive behavior. Taken together, the three predictors sketch a coherent picture: patients who can afford the vaccine, who hear about it from a trusted clinician, and who understand its value are the ones who get it. Patients lacking any one of these advantages tend to fall through the cracks.

From a technical standpoint, the study’s design has both strengths and limitations worth noting. By restricting the sample to patients with established doctor-patient relationships, the researchers deliberately tested compliance in a setting where the recommendation should be easiest to deliver, which makes the low uptake figure all the more consequential. The reliance on patient-reported vaccination status, rather than verified immunization records, introduces the possibility of recall bias, and the cross-sectional design means the associations identified cannot establish causation. The modest sample size of 547, drawn from a single survey wave in November 2022, also means the results may not generalize to every region or clinical setting in China. Nevertheless, the consistency of the income, physician-recommendation, and knowledge effects with broader vaccine behavior research lends credibility to the central conclusion.

The authors conclude that compliance with influenza vaccination recommendations among outpatients with chronic medical conditions and established doctor-patient relations is suboptimal, and they highlight three corresponding priorities for policy and practice. First, appropriate financing mechanisms are needed so that the cost of influenza vaccination does not fall disproportionately on individuals, given the sixfold advantage observed among higher-income patients. Second, physicians should be encouraged and supported to recommend influenza vaccination to their chronic disease patients during routine visits, since a remembered recommendation roughly quadrupled the odds of uptake. Third, providing clear, accessible information about influenza and influenza vaccination can build the baseline knowledge that appears to underpin informed decisions about prevention.

The implications extend beyond China’s borders. Chronic diseases are rising worldwide, and seasonal influenza continues to exact a heavy toll on vulnerable patients in every health system. The study’s central lesson is that clinical guidelines alone do not change behavior; they must be paired with affordable access, active clinician engagement, and effective health communication. For the roughly 80 percent of Chinese chronic disease outpatients currently going unvaccinated each year, the difference between a routine doctor’s visit that includes a vaccination recommendation and one that does not may ultimately determine whether they spend the influenza season at home or in a hospital bed. The research was funded by the Integrated Disease Prevention and Control program of the Chinese Centre for Disease Control and Prevention, whose funders played no role in data collection, analysis, interpretation, or manuscript preparation, and the article is published open access under a Creative Commons Attribution 4.0 license.

Subject of Research: Influenza vaccination compliance among outpatients with chronic diseases in China

Article Title: Compliance with influenza vaccination recommendations among outpatients with chronic diseases in China in 2022

Article References: Xu, H., Hou, Q., Jia, Y., Yang, Y., Wang, Q., Ma, R., & Hao, L. (2026). Compliance with influenza vaccination recommendations among outpatients with chronic diseases in China in 2022. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14553-3

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14553-3

Keywords: influenza, influenza vaccine, vaccination compliance, chronic disease, outpatients, China, China CDC, cross-sectional study, logistic regression, health policy, immunization, public health