A total of 109 cases met our inclusion criteria. Most plaintiffs patient were male (83 of 109), and patient age ranged from 44 to 81 years old, the median age was 62 years old (including 1 missing values), and the median length of stay was 25 days. The median responsibility ratio of the cases was 30%, of which 80 patients died, 18 were disabled, 7 were hospitalized longer, and 3 simply increased the cost of treatment (Table 1).

Table 1 Demographic data and characteristics of CABG malpractice claims (Subdivided According to Hospitals with Different Level) (Created by the authors)Characteristics of CABG claims in different level of hospitals

There are different level of hospitals in China. National-level hospitals are usually under the supervision of the National Health Commission directly, or hospitals affiliated with the National Medical Center, or those affiliated to China’s top medical universities. A provincial-level hospital refers to a regional medical center in a province of China. It is a top hospital within the province, which usually registered with the Provincial Center for medical research or medical quality control. Municipal-level hospitals are medical institutions that primarily serve the regional population of a certain city.

There were 27 cases of primary consultation in National-level hospitals, of which 17 were deaths, the median age of patients was 65 years old, the median length of stay was 26 days, and the average proportion of responsibility was 29.6% ± 20.8%. The provincial-level hospitals involved 43 cases, of which 33 cases of death, the median age of the patients was 65.5 years old, the median length of stay was 22 days, and the average responsibility ratio was 28.4% ± 18.0%. While the municipal-level hospitals involved 39 cases, of which 30 cases of death, the median age of patients was 62 years old, the median number of hospital days was 25 days, the average responsibility ratio was 39.5% ± 18.7%. There were statistical differences in the proportion of responsibility for disputes in different levels of medical institutions (p < 0.05), and the proportion of responsibility for related cases in prefecture and municipal medical institutions is higher than that of state-level and provincial medical institutions (Table 1).

Characteristics of cases prosecuted for the patient death

As the majority of the sample cases were caused by the death of patients (73.4%), this study analyzed the characteristics of this kind of cases (Table 2). The indicators of length of stay of deceased patients were analyzed in depth, including the total hospitalization days, preoperative hospitalization days and postoperative death days. The postoperative death days refers to the number of days spent in hospital between the end of surgery and the death of a patient, an indicator that reflected the level and ability of medical institutions to a certain extent. There were statistical differences in the “postoperative death days” in different levels of hospitals (p < 0.05), the median days after surgery to death in prefecture-level hospitals was 5, while that in provincial hospitals was 9 and in national hospitals was 15 days. The median of total hospitalization days of claims with patient death in national hospitals was shorter than that in all types of claims; meanwhile the liability ratio was higher. Furthermore, as with all case data, there were statistical differences in the proportion of compensation in different levels of hospitals in claims with patient death.

Table 2 Characteristics of CABG malpractice claims with patient death in the different levels of hospitals (Created by the authors)Medical issues in CABG malpractice claims

The most common basis for litigation were postoperative management errors, which were involved in 71.6% claims, and the next most common one was preoperative management errors (40.4%), followed by the surgical procedure errors (31.2%), lack of informed consent (12.8%), improper documentation writing (4.6%) and blood transfusions (1.8%). Although this rule of occurrence was basically the same in hospitals at all levels, the relative proportions of each type of medical problem was not exactly the same at different levels of hospitals, with 54% of national hospitals having postoperative management problems, 19% having insufficient preoperative assessment accounts, and 16% having surgical procedures. In provincial-level hospitals, postoperative management problems accounted for 44%, insufficient preoperative assessment for 22%, and improper surgical procedures for 18%. Among municipal-level hospitals, 38% had postoperative management problems, 33% had insufficient preoperative evaluation, and 22% had improper surgical procedures (Fig. 1).

Fig. 1

Distribution of medical issues in different types of hospitals. This figure reveals the distribution characters of each kind of Medical Issues in CABG medical claims occurred in different types of Hospital

The common associated medical issues in these medical procedures were listed in Table 3. Many studies on the medical claims classified the misadventure into some abstract categories (e.g. improper performance of a procedure) [9,10,11], while, this study tied to describe the medical issues as concretely as possible to help reduce such errors in the future. For example, as to the postoperative procedure, the associated medical issues included failure to supervise or monitor a case, failure to recognize or misdiagnose complications, missed or delayed consultation, missed or false clinical examination, delayed treatment, performed when not indicated or contraindicated, medication or enteral nutrition errors, improper nursing care and premature discharged. During the preoperative procedure, failure to examine the following clinical tests could result in patient harm and claims, including the lower extremity vascular status, lung function, renal function, coagulation function, hypertension, and cardiac function examination. Because there were more than one error in a case usually, this study with a limited sample size didn’t not describe the proportion and the liability ratio of each problem.

Table 3 Medical issues in CABG malpractice claims by procedure group (Created by the authors)Analysis of postoperative complications in CABG medical litigations

There were generally four types of patient outcomes involved in CABG medical claims cases: death, disability, prolonged hospitalization, and increased medical costs. In the sample data, only three cases were litigated because of the increase in medical expenses, which was due to transfusions resulting in blood-borne infectious diseases and harmless foreign body residues. Other litigation cases have basically involved the death, disability or prolonged hospitalization of patients due to postoperative complications. Therefore, postoperative complications can be considered as the direct cause of adverse outcome and patient prosecution. Quantitative analysis of the surgical complications involved in litigation cases can help clinicians assess the degree of liability they may bear when a patient develops such complications as a result of medical malpractice. The top 10 postoperative complications in dispute cases were: low cardiac output syndrome, postoperative hemorrhage, non-surgical site infection, surgical site infection, arrhythmia, cerebral infarction, perioperative myocardial infarction, organ injury, peripheral artery embolism, acute kidney injury. Cases distribution of postoperative complications in CABG medical malpractice litigations according to patient outcomes was shown in Fig. 2.

Fig. 2

Cases distribution of postoperative complications in CABG medical claims according to patient outcomes. This figure reveals the number of cases with different patient outcomes (death, disability, extended hospitalization) for each postoperative complication in CABG medical claims

The analysis of the proportion of liability of medical malpractice in the result of patient injury was meaningful to healthcare providers, which could provide clues to the improvement of medical care quality. In this study, the postoperative complication was used as a dimension to group the patient injury. The proportion of liability of medical malpractice for various postoperative complications was shown in Fig. 3. The common postoperative complication related to liability for compensation could be divided into the following categories: (1) Organ injury and postoperative bleeding caused by surgical procedures; (2) Wound management (wound and sternal fixation dehiscence, surgical site infection, etc.); (3) Neurological complications (cerebral hemorrhage, cerebral infarction, hypoxic ischemic encephalopathy); (4) Cardiac correlation (perioperative myocardial infarction, arrhythmia, low cardiac output syndrome, etc.); (5) Complications related to coagulation dysfunction in other systems (venous thrombosis of lower extremity, gastrointestinal bleeding, peripheral arterial embolism, etc.); (6) Acute kidney injury; (7) others. Complications related to insufficient basic operation (such as organ injury, bridge vessels stenosis, bridge vessels occlusion) and insufficient basic postoperative management (such as limb vein thrombosis, surgical site infection, cerebral hemorrhage, hypoxic-ischemic encephalopathy) seemed have a higher proportion of liability for compensation.

Fig. 3

Proportion of liability of medical malpractice for postoperative complications. This figure reveals the Proportion of liability in each type of postoperative complications in CABG medical claims