In this study, the 71.1% proportion of death certificate with at least one error filled by medical residents is higher than the reported in previous studies. However, our study shows that a simple educational intervention can increase the accuracy rate by more than three-fold. To our knowledge, only four previous groups [9
] have implemented an educational intervention to improve the accuracy of death certification and measured the changes after the intervention. In those studies, the rate of inaccuracies was lower but their study design was very different from ours. Weeramanthri et al [11
] from Australia attempted to change physician behaviour on death certification by means of written guidelines. They sent written educational material as part of the questionnaire and compared rates of errors 1 month before and 1 month after the intervention. Less than 20% of physicians responded the questionnaire and although the proportion of error dropped from 22.4% to 15.1%, this change was not statistically significant. Pain et al [12
] from England evaluated in a randomised controlled fashion the effectiveness of a training video on proper death certification among 185 medical students. The video was shown as an addition to the usual lecture on death certification. Although students assigned to see the video scored slightly better overall, adding this teaching method to the usual lecture had a limited effect on the overall knowledge and skills. Myers et al [9
] from Canada implemented an interactive 75-min seminar on proper completion of death certificates delivered to medical residents rotating in a teaching hospital. The seminar included the discussion of 10 case scenarios accompanied by the correctly completed death certificate reviewed with the help of a coroner. In addition to the seminar, a memorandum was attached reminding residents to avoid the use of mechanisms of death in the Cause of Death section of the death certificate. The audit of 146 death certificates before the seminar for the same case-scenario showed that 32.9% of them contained at least one major error and 84.2% of them had at least one minor error. Although only 83 certificates were completed after the seminar, frequency of major errors dropped to 15.7% but the frequency of minor errors did not change significantly (90.4%). In a randomized fashion, Lakkireddy et al [13
] from USA have recently evaluated in 200 internal medicine residents the impact of two educational interventions: a 45-min interactive workshop or printed instruction material. They used two case simulations that were prepared based on real-life cases, as we did, and found that before the educational intervention, only 15.5% of residents correctly identified the cause of death and 60% incorrectly identified a cardiac cause of death. Although both interventions significantly improved the appropriate completion of death certification, Lakkireddy et al demonstrated that interactive workshops are a better mode of teaching than printed handouts.
The concepts of the "underlying cause of death", the "immediate cause of death" and the "mechanism of death" are often a source of confusion for certifying physicians [14
]. The mechanism of death is a physiologic derangement or biochemical disturbance by which a cause of death exerts its lethal effect. One of the most common errors is attributing the cause of death to respiratory arrest, cardiac arrest, cardiorrespiratory arrest, or asystole in all deaths. Except in heart donors, cardiac arrest is a meaningless term; it is simply a condition to be dead and it must not be used as an underlying cause of death. The underlying cause of death is the disease that triggered the chain of events leading to death, without which death would not have occurred. It should be as etiologically specific as possible. Non specific conditions (e.g. sepsis, haemorrhage, respiratory failure, renal failure) have more than one possible cause and are not acceptable as an underlying cause of death [17
]. The immediate cause of death is the final complication resulting from the underlying cause of death which is occurring closest to the time of death and directly causing death. The certifying physician does not always have enough information to be certain of the immediate cause of death. Therefore, in many cases, an immediate cause of death may not be identifiable and an underlying cause of death can stand alone in part I of the medical section of the death certificate. "Natural causes" may be entered if the manner of death is natural and the physician does not know exactly how the patient died [18
]. Using the phrase "natural causes" is preferable to making a possibly inaccurate guess as to the cause of death.
Experience does not appear to improve death certification practice. Methods to improve standards of practice and performance include early and continuing post-graduate education, and practical accessible guidance on death certification completion. Several authors [7
] have found that most physicians consider accurate death certification important but they feel insufficiently instructed to correctly complete the death certificate. In a recent study, Cirera et al [19
] examined the training need priorities in Spain for proper death certification and found out that the highest priorities were how to accurately declare a death and improve medical training. We think that, for example, an immediate audit of completed death certificate by skilled attending physicians is a valid method. In fact, most physicians have reported that, given that possibility, they would modify the cause of death statement in some circumstances [7
]. On the other hand, pathologists could serve as a better resource for teaching clinicians given their familiarity with the death certification process.
There are some limitations to our study. First, we have used only one method to improve the accuracy of death certification, but as it has been shown by Lakkireddy et al [13
], this type of interactive workshop is perhaps the most effective educational intervention. Second, the information given in the case scenario was simple and clear to exclude the possibility of incorrect clinical diagnoses that very frequently physicians face in their current medical practice. Lastly, the post-educational assessment was done immediately after the seminar and we do not know for how long the residents can keep their abilities over time. We feel that educational interventions to improve accuracy of death certificate should be mandatory not only during the residence programs but as part of the continuing medical education package for attending physicians in community health care centers and teaching hospitals. In the absence of accurate information on death causing diseases, we cannot guarantee that hospital, community or population-based mortalities can be used as a source of information to allocate health care resources and foster research where is needed to improve the health of our citizens.