Kidney transplantation is the preferred treatment option for most patients with end-stage renal disease. However, the demand for donor kidneys by far exceeds the supply, and the discrepancy is increasing (1, 2). Currently, the more than 70 transplant hospitals participating in the Eurotransplant organ-sharing network have a joint waiting list of approximately 15,000 patients (3), and most of them are waiting for a new kidney. In 2002, 9,623 patients were waiting for a kidney transplant in Germany alone, of whom only 1,882 could undergo transplantation that year. Thus, increasing the possible donor pool is an important public health issue.
One factor that may contribute to this limited availability of donor organs is the lack of knowledge about legal and procedural details of organ donation in the general population, but especially among health care providers. Supposedly, health care providers constitute the group of professionals that should be most knowledgeable in the area of organ donation. Health care professionals are the most critical link in the organ procurement process (1) because they are the first individuals to establish a relationship with the potential donor’s family and to have the opportunity to raise the option of organ donation. It has been suggested that a favorable attitude of health professionals toward organ donation can positively influence a potential donor family’s decision to consent (4–6). Norris found, however, that as many as 61% of the professionals involved in the donation process rate themselves as uncomfortable in approaching donor families (7). Thus, improvements in the knowledge about and attitude toward organ donation may be an appropriate health policy strategy to increase the limited donor pool.
In the present study, it was our aim to assess the knowledge about and the attitude toward organ donation (and kidney transplantation in particular) among medical students and physicians at the University Hospital Freiburg, a large academic health care center in Germany. We hypothesized that knowledge and attitude were associated with higher levels of medical education. Furthermore, we sought to study possible determinants of the decision to hold an organ donor card.
MATERIALS AND METHODS
Study Population
The source population consisted of all residents and fellows of the medical department and all medical students enrolled at the University of Freiburg during the semester of 2002. We excluded students in their final year because those students were spread out across several affiliated hospitals or had gone abroad and thus were hard to keep track of. We also excluded foreign exchange students.
Students
Students were divided into two groups: preclinical and clinical. Preclinical students were defined as those taking preclinical courses (mainly anatomy, biology, physiology, and biochemistry) in the first 2 years of medical school and had not yet passed their first examination (“physikum”). Clinical students were those who had at least passed the first board examination and were taking clinical courses within the hospital and thus having patient contact.
Physicians
The physicians consisted of interns, residents, and fellows exclusively belonging to the department of medicine, which includes the divisions of oncology, cardiology, gastroenterology, nephrology, pneumology, rheumatology, and two medical intensive care units as well as an emergency room. Foreign exchange doctors were excluded from the survey.
Questionnaire Development
The original questionnaire consisted of 28 items: 6 items assessing demographics, 13 items measuring knowledge, and 9 items measuring attitude. The order of items was randomized.
The items regarding knowledge required dichotomous responses (“yes” or “no”). Topics being addressed pertained to waiting list and time, differences between living and cadaveric donors, organ supply, immunosuppression after transplantation, and legal issues about organ donation.
The items regarding attitude used answers on a five-point Likert scale (8), where possible responses range from “strongly agree” to “strongly disagree.” Topics were personal willingness to donate or to receive a transplant, moral objections to donation, and the publicity for organ donation. All items regarding attitude were linearly transformed to a summary score between 0 reflecting the most negative attitude and 100 reflecting the most positive attitude. For the summary scale, the mean of all items was calculated. To ensure face validity, the single items were evaluated regarding medical and legal aspects and approved by an expert panel consisting of two transplant surgeons (head of department and leading attending) and three nephrologists (head of department and two attending physicians).
The questionnaire was pilot-tested on a random sample of medical students and physicians regarding wording and the time needed for completion. To keep compliance high, the time to fill in the questionnaire was not supposed to exceed 8 min. After the pilot testing, two items that were misunderstood by most candidates were dropped from the questionnaire. All participants who filled in the questionnaire for pilot testing were excluded from the following study.
Questionnaire Distribution
Between January and May 2002, the questionnaire was distributed among the physicians and medical students at the beginning of classes and grand rounds and collected immediately. Only mandatory classes were chosen to avoid selection bias. Students who still did not attend those mandatory classes had a second chance to fill in the questionnaires at the dean’s office while picking up their semester certificates. Physicians were asked to fill in the questionnaire during grand rounds of the individual departments, and questionnaires were collected immediately afterward.
The survey was approved by the university’s ethics committee and permission was obtained from all department heads who were assured that confidentiality would be maintained and ethical principles would be followed. Before the questionnaires were distributed, background and reason for the survey were explained, and possible participants were encouraged to participate without any undue pressure.
Statistical Analysis
The internal consistency reliability for the attitude items was evaluated using Cronbach’s α coefficient. Values higher than 0.7 are considered to be sufficiently reliable for use in group comparisons (9).
Descriptive data are presented with mean±SD after testing for normal distribution. Differences between groups were assessed using chi-square tests. All statistical tests were two-sided, and an α level of 0.05 was considered to indicate statistical significance. We used logistic regression to explore the association between all covariates and the likelihood of the respondent holding an organ donor card. We calculated univariate and multivariable adjusted odds ratios (OR) and their corresponding 95% confidence intervals (CI). All statistical calculations were performed using SPSS 9.0 (SPSS, Inc., Chicago, IL) for Windows 98/NT (Microsoft Corp., Redmond, WA).
RESULTS
Demographics and Response Rate
The study population consisted of 1,645 participants. One thousand one hundred thirty-six questionnaires were returned, 26 of which had missing information on educational level and 2 of which had missing information about gender. Those 28 people were deleted, leaving 1,108 participants for the analysis: 496 were preclinical students, 457 were clinical students, and 155 were medical residents or fellows of the University Hospital of Freiburg, Germany. The response rate was 77.5% among the preclinical medical students, 54% among the clinical students, and 93% among the physicians.
Table 1 shows the baseline characteristics of the study participants. The mean age was 21±3.0 years (±SD) for the preclinical students, 24±2.3 years for the clinical students, and 33±4.5 years for the physicians. Fifty-three percent of the entire study population consisted of women: 58.3% among the preclinical students, 46.6% among the clinical students, and 30.3% among physicians. Overall, 34.9% had organ donor cards: 23.6% among preclinical students, 43.6% among clinical students, and 45.7% among physicians. Less than 10% percent (9.4%) had a relative or friend who suffered from chronic kidney disease, was treated with dialysis, or was a renal transplant patient. Only 8% perceived themselves specifically trained to approach relatives of brain-dead patients about the matter of organ donation, the highest rate being 14.2% among the physicians.
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Table 1: Baseline characteristics among the survey participants (n = 1,108) by their educational level
Knowledge about Organ Donation and Transplantation
Abbreviated descriptions of the single knowledge items and the item difficulties are presented in Figure 1. Most items about knowledge were of intermediate-range difficulty, although a few items were answered correctly by almost everybody or almost nobody. The item difficulty was higher than 0.85 for two items but lower than 0.15 for one item. Because we intended to cover the full range of possible questions, we purposely refrained from eliminating such items with a difficulty higher than 0.85 or lower than 0.15. For further analysis, items answered correctly were added to form a single summary score. Table 2 shows the knowledge summary score by level of education and gender. The numbers of items answered correctly increased significantly with higher level of education (P <0.01) but were not significantly different by gender.
Table 2: Descriptive analysis of knowledge assessmenta
Figure 1: Knowledge items according to item difficulty. Item difficulty (0–1), with lowest values indicating highest difficulty and highest values indicating lowest difficulty. (
1) Median transplant-survival in Germany; (
2) the possibility of a second transplant after a first has failed; (
3) kidney donation in a nonblood relative (e.g., spouse); (
4) cadaveric donors as a bigger source for transplant organs in Germany than living donors; (
5) percentage of listed patients undergoing transplantation by the end of the year; (
6) the median waiting time for transplantation; (
7) lifelong immunosuppression to avoid transplant rejection; (
8) immunosuppressive therapy and pregnancy; (
9) combined kidney and pancreas transplantation in diabetics; (
10) influence on quality of life by immunosuppression vs. dialysis; (
11) legal aspects of organ donation by living donors in a married couple vs. a nonmarried couple; (
12) legal aspects of anonymous living kidney donation; (
13) organ explantation in Germany and presumed consent.
With higher level of education, participants felt more comfortable in approaching relatives of potential organ donors (Table 2). Regression analysis did not appreciably change these results (data not shown).
Attitude Toward Organ Donation and Transplantation
The nine attitude items were analyzed for internal consistency reliability using Cronbach’s α. Three items were deleted from the analysis because these items did not meet the criterion of minimal item-scale correlation of 0.30 (9). The remaining six items were summarized to one summary scale representing the attitude toward organ donation.
The internal consistency using Cronbach’s α coefficient was 0.73 for the attitude summary scale, indicating a high internal consistency reliability. The mean attitude summary score was 72.1 among preclinical students and increased with level of education to 76.5 among clinical students and to 79.5 among physicians (Table 3). Thus, the summary score indicated an increasing openness toward organ donation and transplantation with increasing level of education. This openness toward organ donation was labeled “positive attitude.” Scores were not different by gender or by having relatives on renal replacement therapy. Again, regression analysis did not appreciably change these results (data not shown). Although the Pearson correlation coefficient between knowledge and attitude appeared to be significant with a value of r =0.09, we concluded that significance was a function of the large sample size but was clinically not meaningful.
Table 3: Descriptive analysis of attitude assessment toward organ donation and transplantation by gender and level of educationa
Analysis of Donor Card Holding
As expected, we found that holders of an organ donor card had a more profound knowledge about and a more positive attitude toward organ donation. Results from the multivariable-adjusted analysis of holding a donor card are summarized in Table 4. Compared with physicians, preclinical students had a 61% lower likelihood of holding an organ donor card (OR, 0.39; 95% CI, 0.20–0.77), whereas no difference was found for clinical students (OR, 0.90; 95% CI, 0.50–1.59). Both the attitude and the knowledge scores were found to be positively associated with higher odds of holding an organ donor card. The odds of holding such a card increased by 16% (95% CI, 7%–26%) per unit increase on the 100-unit scale knowledge score and by 3% (95% CI, 2%–4%) on the normalized 100-unit attitude scale. Age, gender, or experience with relatives who had undergone renal replacement therapy or dialysis had no significant influence on the likelihood of holding a donor card (Table 4).
Table 4: Multivariable-adjusted OR and 95% CI of holding an organ donor card
DISCUSSION
This cross-sectional survey study assessed knowledge and attitude regarding organ donation and kidney transplantation among physicians and medical students at the University Hospital of Freiburg, Germany. In this large population sample of health care professionals at various career stages, we found that knowledge increased with medical education level. Similarly, we found that attitude increased with higher medical education. In multivariate analysis, attitude, knowledge, and education level appeared to be independently associated with the likelihood of holding an organ donor card.
Research suggests that the education level of health professionals is positively related to their personal willingness to donate organs (10, 11). The positive effect of educational programs has been studied in various populations and may have a direct influence on attitudes toward organ donation. Weaver and colleagues, for example, provided encouraging evidence that a high school health education program positively affected knowledge about organ donation and that opinions about organ donation were responsive to increases in knowledge (12).
Although our analysis demonstrated that higher education level was associated with greater knowledge and a more positive attitude, it also revealed that knowledge and attitude were only poorly correlated, a fact that could also be observed in an earlier survey by Youngner et al., who stated that increased knowledge alone does not necessarily lead to other cognitive changes among health professionals (13). Sanner, who compared public attitudes toward procedures involving the dead body, could show that in a random sample of Swedish individuals, educational level was only vaguely related to the attitudes toward organ donation (14). She speculated that emotional factors seemed to be decisive and influence one’s attitude rather than general knowledge. Many studies have attempted to determine what factors influence families’ willingness to donate a patient’s organs (15–17). An American survey revealed a profound mistrust in the fairness of organ allocation and the medical profession altogether in people who perceived themselves as not being donors (18). Sensational television reports especially were thought to have a negative impact on public attitudes toward organ donation.
An attitude may be seen as a psychological tendency that is expressed by evaluating a particular entity with some degree of favor or disfavor (19). For the topic of this survey, this implies that an individual is deemed to have a positive or a negative attitude toward the procedure of organ donation. A positive attitude could also be expressed through the signing of an organ donor card, the suggestion here being that it is those individuals who are willing to donate that are also most likely to hold a positive attitude (20).
A positive attitude and the highest knowledge about organ donation are expected from physicians because they are supposed to be role models. To the best of our knowledge, however, no empiric study has compared knowledge and attitudes regarding organ donation between future and present physicians. Conceptual confusion about the identification of potential donors and the donation process may negatively influence their ability and, indeed, willingness to discuss the donation option with families of potential donors.
What was striking to us was the extremely low rate of people who felt well prepared to approach relatives about organ donation, although the percentage of participants feeling comfortable in approaching increased with educational level. It is possible that other factors influencing a doctor’s confidence to interact with relatives are operational beyond the ones that we specifically studied. The fact that our survey was set in a large academic center has even more relevance because a study published recently in the New England Journal of Medicine showed that the highest proportion of potential donors is found in larger hospitals and that resources invested to improve the process of obtaining consent in larger hospitals should maximize the rate of organ recovery (21). Interestingly, having a relative or friend dealing with end-stage renal disease or kidney transplantation did not significantly influence attitude toward organ donation.
One of the strengths of our survey study is the good response rate and thus large sample size of more than 1,000 respondents, which we attribute to the personal distribution and prompt collecting after completion of the questionnaires. We are unaware of any previous survey studies with a better response rate to this topic. In a Canadian survey in which questionnaires were mailed to 2,400 randomly selected physicians, only 34.6% responded, 95% of whom supported organ donation (22).
There are several limitations that should be addressed. First, the distribution of questionnaires at the beginning of classes or grand rounds bears the possibility of a respondent copying answers from his or her neighbor. Although we clearly explained the purpose of the survey and announced that no test was being taken and that everyone should answer the items by themselves, we cannot rule out that answers have been copied. Therefore, the results of the knowledge items should be taken with a hint of caution.
Social desirability is another phenomenon that can be seen as a source of bias, where people tend to answer in a way they think society expects them to answer when confronted with questions that have a moral or ethical impact. Organ transplantation is certainly an issue that can prompt people to feel moral pressure to report socially desirable answers by involuntarily answering “prodonation.” In this case, our survey would rather overestimate a positive attitude toward transplantation among our participants. Because of the homogeneity of the source population of this study, no information on religion, race, or ethnicity was ascertained. Therefore, the results represent the experience of a solely white and Christian population. Finally, it is unclear whether the results of the present survey study can be generalized to other, nonacademic health care settings or to other countries and societies.
CONCLUSION
Our survey study illustrates that medical education positively influences knowledge and attitude toward organ donation and that better knowledge and a more positive attitude were associated with a higher readiness to donate an organ. These findings support the need to expand the content of education and discussion among health professionals about clinical and conceptual aspects of organ recruitment. Further research is needed on other emotional factors that may constitute barriers in maximizing the organ donor pool. Thus, to capitalize on all available organs is an important goal in our attempts to bridge the ever-widening gap between demand and supply of transplantable organs.
Acknowledgments.
The authors thank the participants of the expert panel (G. Walz, M.D., J. Boehler, M.D., H. Pavenstaedt, M.D., and G. Kirste, M.D.) for critical review of the questionnaire and helpful suggestions.
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