title: Epidemiology of appendicitis and appendectomy for the low-income population in Taiwan, 2003-2011.
abstract: BACKGROUND
  Although numerous epidemiological studies on appendicitis have been conducted worldwide, only a few studies have paid attention to the effect of socioeconomic status on appendicitis, particularly studies focusing on the low-income population (LIP).
  
  
  METHODS
  We analyzed the epidemiological features of appendicitis in Taiwan using data from the National Health Insurance Research Database from 2003 to 2011. All cases diagnosed as appendicitis were enrolled.
  
  
  RESULTS
  Between 2003 and 2011, 2,916 patients from the LIP and 209,206 patients from the normal population (NP) were diagnosed with appendicitis. Our finding revealed that the ratios of comorbidities, complicated appendicitis, and readmissions in LIP patients were slightly higher than those of NP patients. LIP patients were more likely to live in suburban and rural areas, and hence a higher proportion of them were hospitalized in a district or regional hospital compared with NP patients. The crucially finding was that the overall incidence ratios of appendicitis, acute appendicitis, and perforated appendicitis in the LIP were substantially higher than those in the NP (36.25%, 35.33%, and 37.28%, respectively). The mean LOS in LIP patients was longer than that of NP patients. The overall case-fatality ratio of appendectomy in the LIP was higher when compared with the NP (0.41% versus 0.12%, p < 0.05). We also observed that appendicitis was occurred frequently in male patients, with a higher incidence for those aged 15-29 years in both the LIP and NP. The incidences of incidental appendectomy showed a decreasing trend in both the LIP and NP. Finally, a valuable discovery was that the total hospital cost was comparable between the laparoscopic appendectomy (LA) and open appendectomy (OA) (1,178 ± 13 USD versus 1,191 ± 19 USD, p < 0.05) in LIP patients because they saved more hospitalization costs than NP patients when the previous one chose the LA.
  
  
  CONCLUSIONS
  This study confirmed that a lower socioeconomic status has significantly negative impact on the occurrence and treatment of appendicitis and appendectomy. In terms of hospital costs and LOS, LIP patients benefit more from the LA approach than they do from the OA approach in the treatment of appendicitis.
authors.affiliation: School of Computer & Information Engineering, Xiamen University of Technology, Xiamen, 361024, China. kblin@xmut.edu.cn.|Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, 32003, Taiwan. kblin@xmut.edu.cn.
authors.forename: Kai-Biao
authors.initials: KB
authors.lastname: Lin
authors.affiliation: Department of Information Management, Yuan Ze University, Taoyuan, 32003, Taiwan. clchan@saturn.yzu.edu.tw.|Innovation Center for Big data and Digital Convergence, Yuan Ze University, Taoyuan, 32003, Taiwan. clchan@saturn.yzu.edu.tw.
authors.forename: Chien-Lung
authors.initials: CL
authors.lastname: Chan
authors.affiliation: Management Center, Keelung Hospital, Ministry of Health and Welfare, Keelung City, Taiwan. yang.nanping@gmail.com.|Institute of Public Health, National Yang-Ming University, Taipei, Taiwan. yang.nanping@gmail.com.
authors.forename: Nan-Ping
authors.initials: NP
authors.lastname: Yang
authors.affiliation: Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, 32003, Taiwan. krlai@cs.yzu.edu.tw.|Innovation Center for Big data and Digital Convergence, Yuan Ze University, Taoyuan, 32003, Taiwan. krlai@cs.yzu.edu.tw.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Lai
authors.affiliation: Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, 32003, Taiwan. y60130@ms26.hinet.net.|Innovation Center for Big data and Digital Convergence, Yuan Ze University, Taoyuan, 32003, Taiwan. y60130@ms26.hinet.net.|Section of Cardiology, Cardiovascular Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan. y60130@ms26.hinet.net.
authors.forename: Yuan-Hung
authors.initials: YH
authors.lastname: Liu
authors.affiliation: School of Computer & Information Engineering, Xiamen University of Technology, Xiamen, 361024, China. szzhu@xmut.edu.cn.
authors.forename: Shun-Zhi
authors.initials: SZ
authors.lastname: Zhu
authors.affiliation: Innovation Center for Big data and Digital Convergence, Yuan Ze University, Taoyuan, 32003, Taiwan. Pan@51donate.com.
authors.forename: Ren-Hao
authors.initials: RH
authors.lastname: Pan
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001062:Appendectomy / Q000191:economics / Q000401:mortality / Q000706:statistics & numerical data*; D001064:Appendicitis / Q000150:complications / Q000453:epidemiology* / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D017721:Hospital Costs / Q000706:statistics & numerical data; D006767:Hospitals, District / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D010535:Laparoscopy / Q000191:economics; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data; D011203:Poverty / Q000706:statistics & numerical data*; D012424:Rural Population / Q000706:statistics & numerical data; D012737:Sex Factors; D013383:Suburban Population / Q000706:statistics & numerical data; D013624:Taiwan / Q000453:epidemiology; D014505:Urban Population / Q000706:statistics & numerical data; D055815:Young Adult