TY - JOUR
T1 - Positive Impact of [18F]FDG-PET/CT on Mortality in Patients With Staphylococcus aureus Bacteremia Explained by Immortal Time Bias
AU - van der Vaart, Thomas W.
AU - Prins, Jan M.
AU - van Werkhoven, Cornelis H.
AU - ten Doesschate, Thijs
AU - Soetekouw, Robin
AU - van Twillert, Gitte
AU - Veenstra, Jan
AU - Herpers, Bjorn L.
AU - Rozemeijer, Wouter
AU - Jansen, Rogier R.
AU - Bonten, Marc J. M.
AU - van der Meer, Jan T. M.
N1 - Funding Information: Financial support. This work was funded by the Amsterdam University Medical Centres and the University Medical Centre Utrecht. Publisher Copyright: © 2023 The Author(s).
PY - 2023/7/1
Y1 - 2023/7/1
N2 - Background: Several studies have suggested that in patients with Staphylococcus aureus bacteremia (SAB) [18F] fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) improves outcome. However, these studies often ignored possible immortal time bias. Methods: Prospective multicenter cohort study in 2 university and 5 non-university hospitals, including all patients with SAB. [18F]FDG-PET/CT was performed on clinical indication as part of usual care. Primary outcome was 90-day all-cause mortality. Effect of [18F]FDG-PET/CT was modeled with a Cox proportional hazards model using [18F]FDG-PET/CT as a time-varying variable and corrected for confounders for mortality (age, Charlson score, positive follow-up cultures, septic shock, and endocarditis). Secondary outcome was 90-day infection-related mortality (assessed by adjudication committee) using the same analysis. In a subgroup-analysis, we determined the effect of [18F]FDG-PET/CT in patients with high risk of metastatic infection. Results: Of 476 patients, 178 (37%) underwent [18F]FDG-PET/CT. Day-90 all-cause mortality was 31% (147 patients), and infection-related mortality was 17% (83 patients). The confounder adjusted hazard ratio (aHR) for all-cause mortality was 0.50 (95% confidence interval [CI]:. 34-.74) in patients that underwent [18F]FDG-PET/CT. Adjustment for immortal time bias changed the aHR to 1.00 (95% CI. 68-1.48). Likewise, after correction for immortal time bias, [18F]FDG-PET/CT had no effect on infection-related mortality (cause specific aHR 1.30 [95% CI. 77-2.21]), on all-cause mortality in patients with high-risk SAB (aHR 1.07 (95% CI. 63-1.83) or on infection-related mortality in high-risk SAB (aHR for 1.24 [95% CI. 67-2.28]). Conclusions: After adjustment for immortal time bias [18F]FDG-PET/CT was not associated with day-90 all-cause or infection-related mortality in patients with SAB.
AB - Background: Several studies have suggested that in patients with Staphylococcus aureus bacteremia (SAB) [18F] fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) improves outcome. However, these studies often ignored possible immortal time bias. Methods: Prospective multicenter cohort study in 2 university and 5 non-university hospitals, including all patients with SAB. [18F]FDG-PET/CT was performed on clinical indication as part of usual care. Primary outcome was 90-day all-cause mortality. Effect of [18F]FDG-PET/CT was modeled with a Cox proportional hazards model using [18F]FDG-PET/CT as a time-varying variable and corrected for confounders for mortality (age, Charlson score, positive follow-up cultures, septic shock, and endocarditis). Secondary outcome was 90-day infection-related mortality (assessed by adjudication committee) using the same analysis. In a subgroup-analysis, we determined the effect of [18F]FDG-PET/CT in patients with high risk of metastatic infection. Results: Of 476 patients, 178 (37%) underwent [18F]FDG-PET/CT. Day-90 all-cause mortality was 31% (147 patients), and infection-related mortality was 17% (83 patients). The confounder adjusted hazard ratio (aHR) for all-cause mortality was 0.50 (95% confidence interval [CI]:. 34-.74) in patients that underwent [18F]FDG-PET/CT. Adjustment for immortal time bias changed the aHR to 1.00 (95% CI. 68-1.48). Likewise, after correction for immortal time bias, [18F]FDG-PET/CT had no effect on infection-related mortality (cause specific aHR 1.30 [95% CI. 77-2.21]), on all-cause mortality in patients with high-risk SAB (aHR 1.07 (95% CI. 63-1.83) or on infection-related mortality in high-risk SAB (aHR for 1.24 [95% CI. 67-2.28]). Conclusions: After adjustment for immortal time bias [18F]FDG-PET/CT was not associated with day-90 all-cause or infection-related mortality in patients with SAB.
KW - Staphylococcus aureus bacteraemia
KW - [18F]FDG-PET/CT
KW - immortal time bias
KW - mortality
UR - http://www.scopus.com/inward/record.url?scp=85164237268&partnerID=8YFLogxK
U2 - https://doi.org/10.1093/cid/ciad112
DO - https://doi.org/10.1093/cid/ciad112
M3 - Article
C2 - 36869816
SN - 1058-4838
VL - 77
SP - 9
EP - 15
JO - Clinical Infectious Diseases
JF - Clinical Infectious Diseases
IS - 1
ER -