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Risk of pleural empyema in patients with schizophrenia: a nationwide propensity-matched cohort study in Taiwan
  1. Te-Chun Shen1,2,
  2. Chia-Hung Chen1,
  3. Yu-Jhen Huang3,
  4. Cheng-Li Lin4,
  5. Ting-Chang Chang5,
  6. Chih-Yen Tu1,6,
  7. Te-Chun Hsia1,
  8. Chuen-Ming Shih1,6,
  9. Wu-Huei Hsu1,6,
  10. Fung-Chang Sung4,7
  1. 1 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
  2. 2 Intensive Care Unit, Chu Shang Show Chwan Hospital, Nantou, Taiwan
  3. 3 Department of Psychiatry, China Medical University Hospital, Taichung, Taiwan
  4. 4 Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan
  5. 5 Department of Business Administration, Asia University, Taichung, Taiwan
  6. 6 School of Medicine, China Medical University, Taichung, Taiwan
  7. 7 Department of Health Services Administration, College of Public Health, China Medical University, Taichung, Taiwan
  1. Correspondence to Professor Fung-Chang Sung; fcsung1008{at}


Objective Thoracic infection and pneumonia are prevalent in patients with schizophrenia; however, it is unclear whether patients with schizophrenia are at an increased risk of developing pleural empyema.

Design A retrospective cohort study with propensity-matched cohorts with and without schizophrenia.

Setting Using the National Health Insurance Research Database of Taiwan.

Participants We identified 55 888 patients with schizophrenia newly diagnosed in 2000–2011 and same number of individuals without schizophrenia as the comparison cohort, frequency matched by propensity scores estimated using age, sex, occupation, income, urbanisation, year of diagnosis and comorbidities.

Primary outcome measures We assessed incident pleural empyema by the end of 2011 and used the Cox proportional hazards model to calculate the schizophrenia cohort to comparison cohort HR of pleural empyema.

Results The overall incidence of pleural empyema was 2.44-fold greater in the schizophrenia cohort than in the comparison cohort (4.39vs1.80 per 10 000 person-years), with an adjusted HR of 2.87(95% CI 2.14 to 3.84). Stratified analyses by age, sex, occupation, income, urbanisation and comorbidity revealed significant hazards for pleural empyema associated with schizophrenia in all subgroups.

Conclusions Patients with schizophrenia are at an increased risk of developing pleural empyema and require greater attention and appropriate support.

  • schizophrenia
  • pleural empyema
  • retrospective cohort study
  • propensity score matched

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  • C-MS and F-CS contributed equally.

  • Contributors T-CS, C-HC, Y-JH, T-CC, C-YT and C-MS conceived and designed the study. T-CH, C-MS and W-HH provided administrative support. T-CS, C-LL, C-MS and F-CS analysed and interpreted the data. T-CS, C-LL, C-MS and F-CS developed and revised the manuscript. All authors were involved in collection and assembly of data. All authors approved the final version of the manuscript to be published.

  • Funding This study is supported in part by Taiwan Ministry of Health and Welfare Clinical Trial and Research Center of Excellence (MOHW107-TDU-B-212-123004); Academia Sinica Taiwan Biobank Stroke Biosignature Project (BM10501010037); NRPB Stroke Clinical Trial Consortium (MOST 105-2325-B-039-003); China Medical University Hospital (DMR-107-192); Tseng-Lien Lin Foundation, Taichung, Taiwan; Taiwan Brain Disease Foundation, Taipei, Taiwan and Katsuzo and Kiyo Aoshima Memorial Funds, Japan. No additional external funding received for this study.

  • Disclaimer The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.

  • Competing interests None declared.

  • Patient consent Not required.

  • Ethics approval This study was approved by the Research Ethics Committee at the China Medical University and Hospital (CMUH-104-REC2-115).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement Datasets of National Health Insurance in Taiwan were used. All investigators should sign an agreement that guarantees patient confidentiality before using the data.