title: Time-dependent Cox regression model is superior in prediction of prognosis in primary sclerosing cholangitis.
abstract: More precise prognostic models are needed for prediction of survival in patients with primary sclerosing cholangitis (PSC), particularly for the selection of candidates for liver transplantation. The aim of this study was to develop a time-dependent prognostic model for the calculation of updated short-term survival probability in PSC. Consecutive clinical and laboratory follow-up data from the time of diagnosis were collected from the files of 330 PSC patients from 5 European centers, followed for a median of 8.4 years since diagnosis. Time-fixed and time-dependent Cox regression analyses, as well as the additive regression model, were applied. The reliability of the models was tested by a cross-validation procedure. Bilirubin (on a logarithmic scale), albumin, and age at diagnosis of PSC were identified as independent prognostic factors in multivariate analysis of both the time-fixed and the time-dependent Cox regression models. The importance of bilirubin was more pronounced in the time-dependent model (hazard ratio [HR], 2.84) than in the time-fixed analysis (hazard ratio, 1.51). The additive regression model indicated that once the patients survive beyond the first 5 years, the impact on prognosis of albumin at diagnosis ceases. The time-dependent prognostic model was superior to the time-fixed variant in assigning low 1-year survival probabilities to patients that actually survived less than 1 year. In conclusion, a time-dependent Cox regression model has the potential to estimate a more precise short-term prognosis in PSC compared with the traditional time-fixed models.
authors.affiliation: Medical Department, Rikshospitalet, 0027 Oslo, Norway. kirsten.boberg@rikshospitalet.no
authors.forename: Kirsten Muri
authors.initials: KM
authors.lastname: Boberg
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rocca
authors.forename: Thore
authors.initials: T
authors.lastname: Egeland
authors.forename: Annika
authors.initials: A
authors.lastname: Bergquist
authors.forename: Ulrika
authors.initials: U
authors.lastname: Broomé
authors.forename: Llorenc
authors.initials: L
authors.lastname: Caballeria
authors.forename: Roger
authors.initials: R
authors.lastname: Chapman
authors.forename: Rolf
authors.initials: R
authors.lastname: Hultcrantz
authors.forename: Stephen
authors.initials: S
authors.lastname: Mitchell
authors.forename: Albert
authors.initials: A
authors.lastname: Pares
authors.forename: Floriano
authors.initials: F
authors.lastname: Rosina
authors.forename: Erik
authors.initials: E
authors.lastname: Schrumpf
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001663:Bilirubin / Q000097:blood; D015209:Cholangitis, Sclerosing / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D012709:Serum Albumin / Q000032:analysis; D013997:Time Factors
chemical_list: D012709:Serum Albumin; D001663:Bilirubin