Diagnostic errors in fatal medical malpractice cases in Shanghai, China: 1990-2015

Medical disputes remain unabated in China. Previous studies have shown the changes of diagnostic discrepancy over time in developed countries, but diagnostic discrepancy remains understudied in China, especially in the setting of medical disputes. We sought to describe the year-based changes of diagnostic discrepancies in medical disputes, and to identify factors associated with classes of diagnostic discrepancy.

We conducted a retrospective cohort study of all medically disputed cases from 1990 through 2015 in Shanghai, China, with use of necropsy as the gold standard for diagnosis. Cases were grouped based on national legislative eras. Diagnostic discrepancy was classified as major errors (class I and II), minor errors (class III and IV), no discrepancy (class V) and undetermined (class VI) based on discrepancy severity.

There were 482 medical disputes. Cases were predominantly males (male: female = 1.6:1) and concentrated in patients less than 10 years old or between 50 and 70 years. Major and minor discrepancy accounted for 51.7 and 34.8%, respectively. Fifty-five cases (11.2%) were non-discrepant (Class V). The dispute rate remained high before the first round of legislation (mean 0.31 per 1 million patients) but declined dramatically afterwards (R² = - 0.82, p < 0.001 for time trends). Over the national legislative eras, the annual number of cases with diagnostic errors declined steadily. Incidence rates of discrepancy decreased significantly for class I (R² = - 0.73, p = 0.024), II (R² = - 0.48, p = 0.013), III (R² = - 0.69, p < 0.0001), IV (R² = - 0.69, p < 0.0001) and V discrepancy (R² = - 0.58, p = 0.0018). Diseases from the respiratory system had significantly lower risks of any diagnostic errors (OR = 0.48, 95% 0.24-0.95, p = 0.036). A neoplasm carrier increased by 92% the risk of any diagnostic error (OR = 1.92; 95%CI 1.18-3.14; p = 0.009) and hypertension reduced by 78% the risk of minor errors (OR = 0.22, 95%CI 0.06-0.91, p = 0.036). Severity of discrepancy relieved over years and associated with ageing in patients with cardiovascular diseases (p = 0.01).

The rate of fatal medical disputes and diagnostic discrepancy declined after stepwise legislations in China. Respiratory diseases, neoplasm carrier and hypertension could be independent predictors for assessing diagnostic errors.