1. Study design and subjects
Using a cross-sectional design, this study was carried out in Zhejiang Province from July to August 2021. Patients diagnosed with various stages of chronic kidney disease (including those receiving hemodialysis and peritoneal dialysis) were invited to participate in a questionnaire in outpatient department, wards or dialysis rooms.The online questionnaire form was designed and distributed via Sojump (Changsha Lanxing Information&Technology, Co., LTD., Hunan Province, China). The quick response (QR) code was generated accordingly. Therefore, the respondents could fill in the questionnaire simply by scanning the QR code.
The present study followed the principles in the Declaration of Helsinki. The protocol was approved by the Ethics Committee of Zhejiang Taizhou Hospital (approval No.: K20210520). All procedures were carried out according to the guiding principles of the institutional ethics committee. All participants were voluntary to engage in the survey, who were also anonymous.
2. Structured questionnaire
The participants were invited to fill in the questionnaire, and the following information was collected: (1) demographics, such as age, gender, residence, educational background, and occupation; (2) COVID-19 booster vaccine willingness. The respondents were asked the following question: “Are you willing to receive a COVID-19 booster vaccine dose?” (Four options: Very willing to, moderately willing to, unwilling to, very unwilling to); (3) perception of COVID-19 vaccine, which included the following questions: “What do you think about safety of COVID-19 vaccine so far (five options: very safe, safe, moderate, unsafe, very unsafe), “What do you think about effectiveness of COVID-19 vaccine” (four options: very effective, effective, barely effective, not effective at all); “What do you think about the risk of COVID-19 infection ?” (five options: very high, high, moderately low, very low); “Have you followed the news about COVID-19 vaccine?”(two options: yes or no); (4) medical history and underlying diseases: “Do you have underlying chronic diseases?” (two options: yes or no), “Which treatment you are currently receiving?” (four options: peritoneal dialysis, hemodialysis, medication treatment, no treatment), “Is the disease properly controlled (two options: yes or no)”; (5) receiving any round of COVID-19 vaccine or not: The following question was asked: “Have you received the first and second rounds of COVID-19 vaccine?” (three options: Not receiving any shot, yes (having received the first round), yes (having received the second round)”. Nearly all problems were closed-ended, and the respondents were provided with multiple answer options.
3. Statistical analysis
Descriptive statistical analysis of the demographics, COVID-19 booster vaccine willingness and perception of COVID-19 vaccine among CKD patients were performed using frequencies, frequency distribution, and mean ± standard deviation. The differences in demographics, cognition and disease situation between patients willing to receive COVID-19 booster vaccine doses and those unwilling to were analyzed by the chi-square test and independent-samples t-test. Binary logistic regression analysis was used to identify the related factors of COVID-19 booster vaccine willingness. The odds ratio (OR) and 95% confidence interval (CI) were calculated. The significant variables identified by the univariate analysis (P < 0.05) were further included as independent variables in the regression model.
All data were analyzed using IBM® SPSS® Statistics V26.0 (SPSS Inc., Chicago, IL, USA). P < 0.05 indicated significant difference.