Influence of Referral Pathway on Ebola Virus Disease Case-Fatality Rate and Effect of Survival Selection Bias.
Case-fatality rates in Ebola treatment centers (ETCs) varied widely during the Ebola virus disease (EVD) outbreak in West Africa. We assessed the influence of referral pathway on ETC case-fatality rates with a retrospective cohort of 126 patients treated at the Mathaska ETC in Port Loko, Sierra Leone. The patients consisted of persons who had confirmed EVD when transferred to the ETC or who had been diagnosed onsite. The case-fatality rate for transferred patients was 46% versus 67% for patients diagnosed onsite (p = 0.02). The difference was mediated by Ebola viral load at diagnosis, suggesting a survival selection bias. Comparisons of case-fatality rates across ETCs and clinical management strategies should account for potential survival selection bias.
Frauke
F
Rudolf
Mads
M
Damkjær
Suzanne
S
Lunding
Kenn
K
Dornonville de la Cour
Alyssa
A
Young
Tim
T
Brooks
Tom
T
Sesay
Alex P
AP
Salam
Sharmistha
S
Mishra
Merete
M
Storgaard
D004196:Disease Outbreaks; D019142:Hemorrhagic Fever, Ebola / Q000453:epidemiology / Q000401:mortality* / Q000821:virology*; D006801:Humans; D009026:Mortality; D012189:Retrospective Studies; D063728:Secondary Care Centers; D015983:Selection Bias; D012807:Sierra Leone / Q000453:epidemiology; D016019:Survival Analysis; D019562:Viral Load
EVD; Ebola isolation centers; Ebola treatment centers; Ebola virus; Ebola virus disease; Sierra Leone; case-fatality rate; referral pathway; selection bias; viruses; zoonoses