Cardiac complications associated with short-term mortality in schizophrenia patients hospitalized for pneumonia: a nationwide case-control study.
BACKGROUND
Pneumonia is one of most prevalent infectious diseases worldwide and is associated with considerable mortality. In comparison to general population, schizophrenia patients hospitalized for pneumonia have poorer outcomes. We explored the risk factors of short-term mortality in this population because the information is lacking in the literature.


METHODS
In a nationwide schizophrenia cohort, derived from the National Health Insurance Research Database in Taiwan, that was hospitalized for pneumonia between 2000 and 2008 (n = 1,741), we identified 141 subjects who died during their hospitalizations or shortly after their discharges. Based on risk-set sampling in a 1∶4 ratio, 468 matched controls were selected from the study cohort (i.e., schizophrenia cohort with pneumonia). Physical illnesses were categorized as pre-existing and incident illnesses that developed after pneumonia respectively. Exposures to medications were categorized by type, duration, and defined daily dose. We used stepwise conditional logistic regression to explore the risk factors for short-term mortality.


RESULTS
Pre-existing arrhythmia was associated with short-term mortality (adjusted risk ratio [RR] = 4.99, p<0.01). Several variables during hospitalization were associated with increased mortality risk, including incident arrhythmia (RR = 7.44, p<0.01), incident heart failure (RR = 5.49, p = 0.0183) and the use of hypoglycemic drugs (RR = 2.32, p<0.01). Furthermore, individual antipsychotic drugs (such as clozapine) known to induce pneumonia were not significantly associated with the risk.


CONCLUSIONS
Incident cardiac complications following pneumonia are associated with increased short-term mortality. These findings have broad implications for clinical intervention and future studies are needed to clarify the mechanisms of the risk factors.
Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
Ya-Tang
YT
Liao
Shu-Yu
SY
Yang
Hsing-Cheng
HC
Liu
Wei J
WJ
Chen
Chiao-Chicy
CC
Chen
Yen-Ni
YN
Hung
Chian-Jue
CJ
Kuo
D000328:Adult; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D006331:Heart Diseases / Q000453:epidemiology / Q000209:etiology* / Q000401:mortality*; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000150:complications* / Q000188:drug therapy; D015995:Prevalence; D012307:Risk Factors; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy