Level and Determinants of Willingness to Donate Organs Among the General Public: A Cross-Sectional Survey in China

Background: This study aims to assess the level and determinants of the general public’s willingness to organ donation. Methods: We conducted a population-based cross-sectional study of 4261 participants in China. The primary outcome was the willingness to donate organs. Logistic regression modelling was used to determine the factors that affect willingness to donate organs. Results: Overall, the proportion of participants who showed a willingness to donate organs was 47.45% (95%CI: 0.46, 0.49) in this study. Logistic regression modelling showed participants from Western (OR=1.35, 95%CI=1.13-1.62) and Eastern China (OR=1.54, 95%CI=1.20-1.66) were more willing to donate organs compared with those from Central China. The odds of being willing to donate organs was higher in females than males (OR=1.34, 95%CI=1.17-1.55); and was higher in those participants with experience of organ donation (OR=1.57, 95%CI=1.12-2.20), experience of caring for organ transplant patients (OR=1.47, 95%CI=1.03-2.10), and those undertaking related voluntary activities (OR=1.68, 95%CI=1.45-1.94), than those without. Conclusion: The general public’s level of willingness to organ donation was not high in China. Geographical region, gender, experience of organ donation related activities, taking care of organ transplant patients and volunteering in related activities were independently associated with participants’ willingness to donate organs.


Background
Since the 1950s, organ transplantation has been considered the most effective life-saving therapeutic option to treat patients who suffer from organ failure 1-2 . Globally, there is a severe imbalance between supply and demand, the need for organs dramatically exceeds the number of donated organs available for transplantation 3 . Countries around the world attempt to increase the number of organs donors to meet the demand. Rate of organ donation per million population (pmp) is higher in Western countries. In the United States, registration rates for organ donation range from 20-60% 4 , and in 2019, Spain was the world leader in organ donation, with 48.9 pmp deceased organ donors 5 . In Europe, Greece has the fewest organ donations; with 5.5 of donors pmp 5,6 . Previous studies have shown that organ donation rates in Asia tend to be lower than in Western countries 7-9 . In 2019, the organ donation rate in Iran was 11.26 pmp, 0.75 pmp in Japan, and 4.43 pmp in China 5 . Thus, increasing the rate of organ donation in Asian populations represents a significant public health challenge.
In China, The Organ Transplantation Program began in the 1960s, and has been successful in saving the lives of thousands of patients with advanced organ diseases. Although  From the perspective of engaging the general public and improving the rate of organ donation it is essential to understand the characteristics of organ donors. Previous studies have shown that a potential organ donor was characterized as being highly educated, well informed and enthusiastic about donation and would have had a discussion with family members regarding this issue 13-14 . Some studies have provided insight into the status and determinants of organ donation 14-17 . However, these studies have certain limitations: For example, in one study only 1074 effective questionnaires were returned by the participants, indicating a small sample size 15 . Further, other studies comprised of specific populations only, such as, medical students and health professionals, 16,17 . In addition, individuals who had undergone renal transplantation showed a positive attitude towards deceased donation than their caregivers in Hunan 14 . Another limitation of these studies was the geographic areas chosen to conduct the studies were specific regions and cities of China, and not representative of the country as a whole.
This study aims to explore the level and determinants of willingness towards organ donation by using a large national sample obtained from Eastern, Central and Western China. The results will provide important information for scientists and policymakers to implement targeted measures to improve the organ donation rate in China.

Data Source
Due to the cost-effectiveness, a multistage stratified sampling method was applied to sample the research sites. The sampling method was divided into four stages, comprised of different sampling units. For the first stage we selected a province from each of three regions of China: Zhejiang province in the East, Henan province in the Centre and Shaanxi province in the West. Next, we selected the capital city of each province: Hangzhou, Zhengzhou and Xi'an, respectively. Subsequently, a convenience sampling method was used to select a community in the city or town in the city suburbs. Participants from the selected city or town were recruited during the final stage of sampling. According to the results of a previous study, the rate of willingness towards organ donation was 49% 17 . Therefore, the sample size was calculated as 1334 for each site with a permissible error of δ = 3%, a type I error of α = 0.05 and an expected 20% nonresponse rate. We recruited a total of 4305 participants: 1409, 1408 and 1488 participants from Western, Central and Eastern China respectively from October to December 2019. During the survey, a structured questionnaire that included questions relating to willingness to donate organs was administered individually to each participant (Additional file 1). Forty-four participants failed to answer questions relating to willingness to donate and have been excluded from the analysis. We undertook a statistical analysis of the remaining 4261 participant questionnaires.

Study variables
The primary outcome of this study was the response of willingness to donate organs, recorded as a binary variable of no (0) or yes (1) in the questionnaires. The proportion of those willing to donate organs was calculated by the number of participants who were willing to organ donation over the total number of participants who responded 18 . Determinants in this study were selected based on previous studies but constrained by the variables collected in the survey 19-21 . They included residence type (urban or rural), geographical location (region), demographic characteristics (gender, age, marital status, education, employment and monthly income) and personal experiences (experience of organ donation, taking care of organ transplant patients, and voluntary related activities).

Quality control
To ensure the high return rate of valid questionnaires and reduce investigator bias, we invited experts from the Wenzhou Medical University, Liverpool School of Tropical Medicine, Hangzhou Normal University, Xi'an Jiaotong University and Zhengzhou University to train the investigators in terms of interviewing skill and operational procedures. Data such as demographics, experiences and willingness to organ donation were collected using structured questionnaires (Additional file 1). The interview process was standardized prior to formal investigation. The entire investigation was conducted under the supervision of senior researchers.

Statistical analyses
A database was established using EpiData 3.1 software (developed by EpiData Association, Odense. Denmark) and data was double entered to ensure data quality. Categorical variables were summarised using number and percentages. Distributions of basic characteristics by residence, and attitude towards organ donation were compared using Chi-square tests. Logistic regression modelling was applied to identify the determinants of participants' willingness to organ donation, controlling for other confounding factors. Odds ratios (ORs) with 95% confidence intervals (CIs) were derived from logistic regression modelling. The statistical results and figures were processed with STATA statistical software version 12.0 (StataCorp LP, College station 77845, USA) software and Excel 2016, respectively. A two-tailed p value < 0.05 was considered statistically significant.

Basic Characteristics
The descriptive statistics of the participants are shown in Table 1. Of the 4261 respondents, 2008 (47.13%) and 2253 (52.87%) lived in urban and rural areas, respectively. Among these participants, 1382 came from the West, 1393 from the Central and 1486 from the East. The respondents were more female than male and had a median age ≤ 30 years old. The overall results showed significant differences in characteristics between urban and rural participants with the p-value < 0.05.  Tables 2 and 3. There were significant differences in the proportions of willingness to donate organs among demographic characteristics and personal experiences ( Table 2). Individuals or relatives and friends of individuals who had experienced organ donation, and individuals taking care of organ transplant patients or undertaking voluntary related activities were more likely to donate an organ ( Table 2). Amongst rural respondents, there was no significant difference in the proportion participants' willingness to donate organs, according to their monthly income P > 0.05 (Table 3).

Determinants of willingness to donate organs
Overall, the results of the logistic regression model in Table 4 show there were no significant difference in the odds of willingness to donate organs between urban and rural participants when adjusting geographical, demographic and personal experience characteristics (OR = 0.93, 95%CI = 0.81-1.07, P = 0.313).  The results for subgroup analysis by rural-urban residence are also presented in Table 4. There were no significant interaction effects (P > 0.05) between residence and any of the characteristics listed in Table 4, suggesting that the determinants of willingness to donate organ are similar for both urban and rural residents.

Main findings
Empirical study plays an essential role in providing key information for experts and policymakers to take targeted measures to improve the number of organ donation registrations. In this study, we found that 47.45% (95% CI: 0.46 to 0.49) of the general public from three regions of China are willing to donate organs, which is similar to the percentage of organ donors in Germany (46.8%) > 10 years ago 22 . Unsurprisingly, it is slightly higher than the percentage of organ donation for brain-dead patients (41.8%) 23 . Our study shows that the proportion of the general population willing to donate organs in the three regions of

Limitations
This study had several limitations. Firstly, this was an observational study in which the determinants of willingness to organ donation included were constrained by the pre-specified variables in the survey questionnaires. As a result, some potential unobserved confounding factors such as policy variables that are likely to have an impact on willingness to organ donation were not considered in the analysis. Presumed consent law and allocation priority were found to be effective measures to increase organ donation, for instance 29-31 . As a result, the observed differences in willingness to organ donation could be subject to possible unobserved confounding factors. Second, we were unable to collect detailed information on people's perceptions about organ donation. Finally, the study was only conducted in three regions (West, East, and Central) of China, therefore the findings may not be representative of other regions in China.

Conclusions
This study has attempted to evaluate the willingness of the general public to donate organs and to assess the influence of social-demographic characteristics and personal experience of determining the willingness of individuals to donate their organs. Overall, approximately half of the respondents were willing to donate organs and was higher in participants in Eastern and West China than in Central China. In addition, gender and personal experiences were independent determinants of an individual's willingness to organ donation. Our results provide valuable information for health experts and policymakers to promote organ donation in China.

Ethics approval and consent to participate
Informed written consent was obtained from all study subjects before participating in the study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of Wenzhou Medical University (No.2019-054).