title: The prolongation of length of stay because of Clostridium difficile infection.
abstract: BACKGROUND
  Clostridium difficile infection (CDI) possibly extends hospital length of stay (LOS); however, the current evidence does not account for the time-dependent bias, ie, when infection is incorrectly analyzed as a baseline covariate. The aim of this study was to determine whether CDI increases LOS after managing this bias.
  
  
  METHODS
  We examined the estimated extra LOS because of CDI using a multistate model. Data from all persons hospitalized >48 hours over 4 years in a tertiary hospital in Australia were analyzed. Persons with health care-associated CDIs were identified. Cox proportional hazards models were applied together with multistate modeling.
  
  
  RESULTS
  One hundred fifty-eight of 58,942 admissions examined had CDI. The mean extra LOS because of infection was 0.9 days (95% confidence interval: -1.8 to 3.6 days, P = .51) when a multistate model was applied. The hazard of discharge was lower in persons who had CDI (adjusted hazard ratio, 0.42; P < .001) when a Cox proportional hazard model was applied.
  
  
  CONCLUSIONS
  This study is the first to use multistate models to determine the extra LOS because of CDI. Results suggest CDI does not significantly contribute to hospital LOS, contradicting findings published elsewhere. Conversely, when methods prone to result in time-dependent bias were applied to the data, the hazard of discharge significantly increased. These findings contribute to discussion on methods used to evaluate LOS and health care-associated infections.
authors.affiliation: School of Nursing, Midwifery, and Paramedicine, Australian Catholic University, Canberra, ACT, Australia; Faculty of Nursing and Health, Avondale College for Higher Education, Wahroonga, NSW, Australia. Electronic address: bgmitc001@myacu.edu.au.
authors.forename: Brett G
authors.initials: BG
authors.lastname: Mitchell
authors.affiliation: School of Nursing, Midwifery, and Paramedicine, Australian Catholic University, Canberra, ACT, Australia; National Centre for Clinical Outcomes Research (NaCCOR), Australian Catholic University, Sydney, NSW, Australia.
authors.forename: Anne
authors.initials: A
authors.lastname: Gardner
authors.affiliation: Institute of Health Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors.forename: Adrian G
authors.initials: AG
authors.lastname: Barnett
authors.affiliation: Faculty of Health Science, Australian Catholic University, Melbourne, VIC, Australia.
authors.forename: Janet E
authors.initials: JE
authors.lastname: Hiller
authors.affiliation: Institute of Health Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Graves
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003015:Clostridium Infections / Q000453:epidemiology* / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D003967:Diarrhea / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D062606:Tertiary Care Centers; D055815:Young Adult
keywords: Health care-associated infection; Infection control; Multistate model; Time-dependent bias