title: Chronic osteomyelitis increases long-term mortality risk in the elderly: a nationwide population-based cohort study.
abstract: BACKGROUND
  The elderly are predisposed to chronic osteomyelitis because of the immunocompromised nature of aging and increasing number of chronic comorbidities. Chronic osteomyelitis may significantly affect the health of the elderly; however, its impact on long-term mortality remains unclear. We conceived this retrospective nationwide population-based cohort study to address this issue.
  
  
  METHODS
  We identified 10,615 elderly patients (≥65 years) comprising 965 patients with chronic osteomyelitis and 9650 without chronic osteomyelitis matched at a ratio of 1:10 by age and gender between 1999 and 2010 from the Taiwan National Health Insurance Research Database. The risk of chronic osteomyelitis between the two cohorts was compared by a following-up until 2011.
  
  
  RESULTS
  Patients with chronic osteomyelitis had a significantly higher mortality risk than those without chronic osteomyelitis [incidence rate ratio (IRR): 2.29; 95 % confidence interval (CI): 2.01-2.59], particularly the old elderly (≥85 years; IRR: 3.27; 95 % CI: 2.22-4.82) and males (IRR: 2.7; 95 % CI: 2.31-3.16). The highest mortality risk was observed in the first month (IRR: 5.01; 95 % CI: 2.02-12.42), and it remained persistently higher even after 6 years (IRR: 1.53; 95 % CI: 1.13-2.06) of follow-up. Cox proportional hazard regression analysis showed that chronic osteomyelitis [adjusted hazard ratio (AHR): 1.89; 95 % CI: 1.66-2.15], advanced age (≥85 years; AHR: 2.02; 95 % CI: 1.70-2.41), male (AHR: 1.34; 95 % CI: 1.22-1.48), and chronic comorbidities were independent predictors of mortality.
  
  
  CONCLUSIONS
  This study demonstrated that chronic osteomyelitis significantly increased the long-term mortality risk in the elderly. Therefore, strategies for prevention and treatment of chronic osteomyelitis and concomitant control of chronic comorbidities are very important for the management of the elderly, particularly for a future with an increasingly aged population worldwide.
authors.affiliation: Department of Emergency Medicine, Chi-Mei Medical Center, Tainan, Taiwan, 901 Zhonghua Road, Yongkang District, Tainan City, 710, Taiwan.|Bachelor Program of Senior Service, Southern Taiwan University of Science and Technology, Tainan, Taiwan.|Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.|Department of Geriatrics and Gerontology, Chi-Mei Medical Center, Tainan, Taiwan.|Department of Occupational Medicine, Chi-Mei Medical Center, Tainan, Taiwan.
authors.forename: Chien-Cheng
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Department of Geriatrics and Gerontology, Chi-Mei Medical Center, Tainan, Taiwan.|Graduate Institute of Medical Sciences, College of Health Sciences, Chang Jung Christian University, Tainan, Taiwan.
authors.forename: Kang-Ting
authors.initials: KT
authors.lastname: Tsai
authors.affiliation: Department of Healthcare Administration and Medical Informatics, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Shih-Feng
authors.initials: SF
authors.lastname: Weng
authors.affiliation: Department of Emergency Medicine, Chi-Mei Medical Center, Tainan, Taiwan, 901 Zhonghua Road, Yongkang District, Tainan City, 710, Taiwan.|Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.|Department of Emergency Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Hung-Jung
authors.initials: HJ
authors.lastname: Lin
authors.affiliation: Department of Emergency Medicine, Chi-Mei Medical Center, Tainan, Taiwan, 901 Zhonghua Road, Yongkang District, Tainan City, 710, Taiwan.|Department of Occupational Medicine, Chi-Mei Medical Center, Tainan, Taiwan.
authors.forename: Hung-Sheng
authors.initials: HS
authors.lastname: Huang
authors.affiliation: Department of Medical Research, Chi-Mei Medical Center, Tainan, Taiwan.
authors.forename: Jhi-Joung
authors.initials: JJ
authors.lastname: Wang
authors.affiliation: Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan.|Department of Occupational and Environmental Medicine, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: How-Ran
authors.initials: HR
authors.lastname: Guo
authors.affiliation: Department of Emergency Medicine, Chi-Mei Medical Center, Tainan, Taiwan, 901 Zhonghua Road, Yongkang District, Tainan City, 710, Taiwan. nych2525@gmail.com.|Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan. nych2525@gmail.com.
authors.forename: Chien-Chin
authors.initials: CC
authors.lastname: Hsu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D002908:Chronic Disease; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009313:National Health Programs; D010019:Osteomyelitis / Q000150:complications / Q000401:mortality*; D016016:Proportional Hazards Models; D012107:Research Design; D012189:Retrospective Studies; D012306:Risk; D016019:Survival Analysis; D013624:Taiwan / Q000453:epidemiology
keywords: Chronic osteomyelitis; Elderly; Long-term mortality