The team used Taiwanese National Health Insurance (NHI) hospital-discharge data and compared the likelihood of a ruptured appendix among almost 100,000 people aged 15 and over who were hospitalized for acute appendicitis in Taiwan during the period 1997-2001.

Tsay and colleagues found that a ruptured appendix occurred in 46.7 percent of the schizophrenic patients, in 43.4 percent of the patients with other major mental disorders, and in 25.1 percent of the patients with no major mental diseases. More ruptured cases were found among males and older patients.

After adjusting for age, gender, ethnicity, socioeconomic background, and hospital characteristics, the team found that patients with schizophrenia were still almost three times as likely to suffer a ruptured appendix as the general population. The presence of affective psychoses or other major mental disorders did not, however, remain associated with a significantly increased risk of rupture.