Revisiting the effect of referral bias on the clinical spectrum of infective endocarditis in adults.


Journal Article

Referral bias occurs because of the clustering of patients at tertiary care centers. This may result in the distortion of observed clinical manifestations of rare diseases. This analysis evaluates the effect of referral bias on the epidemiology of infective endocarditis (IE) in the International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS). This is a prospective multicenter cohort study comparing transferred and non-transferred patients with IE. Factors independently associated with transfer status were evaluated using multivariable logistic regression. A total of 2,760 patients were included in the analysis, of which 1,164 (42.2%) were transferred from other medical centers. Transferred patients more often underwent surgery for IE (odds ratio [OR] = 2.5; 95% confidence interval [CI] 1.9-3.2). They were also more likely to have complications such as stroke (OR = 1.5; 95% CI 1.3-1.9), heart failure (OR = 1.4; 95% CI 1.1-1.6), and new valvular regurgitation (OR = 1.3; 95% CI 1.1-1.6). The in-hospital mortality rates were similar in both groups. Patients with IE who require surgery and suffer complications are referred to tertiary hospitals more frequently than patients with an uncomplicated course. Hospital transfer has no obvious effect on the in-hospital mortality. Referral bias should be taken into consideration when describing the clinical spectrum of IE.

Full Text

Duke Authors

Cited Authors

  • Kanafani, ZA; Kanj, SS; Cabell, CH; Cecchi, E; de Oliveira Ramos, A; Lejko-Zupanc, T; Pappas, PA; Giamerellou, H; Gordon, D; Michelet, C; Muñoz, P; Pachirat, O; Peterson, G; Tan, R-S; Tattevin, P; Thomas, V; Wang, A; Wiesbauer, F; Sexton, DJ

Published Date

  • October 2010

Published In

Volume / Issue

  • 29 / 10

Start / End Page

  • 1203 - 1210

PubMed ID

  • 20549531

Pubmed Central ID

  • 20549531

Electronic International Standard Serial Number (EISSN)

  • 1435-4373

International Standard Serial Number (ISSN)

  • 0934-9723

Digital Object Identifier (DOI)

  • 10.1007/s10096-010-0983-2


  • eng