title: Excess all-cause mortality in the evaluation of a screening trial to account for selective participation.
abstract: OBJECTIVE
  In addition to disease-specific mortality, a randomized controlled cancer screening trial may be evaluated in terms of excess mortality, in which case no patient-specific information on causes of death is needed. We studied the effect of not accounting for attendance on the calculated excess mortality in a prostate cancer screening trial.
  
  
  METHODS
  The numerator of the excess mortality rate related to prostate cancer diagnoses in each study arm equals the excess number of deaths observed in the cancer patients. The estimation of the expected number of deaths in the absence of the prostate cancer diagnoses has to account for the self-selection of those participating in the trial, particularly if the proportion of non-participants is substantial.
  
  
  METHODS
  The European prostate cancer screening trial (ERSPC).
  
  
  RESULTS
  In the screening arm, non-attendees had roughly twice the mortality rate of attendees. Approximately twice as many cancers were detected in the screening arm compared with the control arm, primarily in attendees. Unless attendance is properly accounted for, the expected mortality of prostate cancer patients in the screening arm is overestimated by 0.9-3.6 deaths per 1000 person-years.
  
  
  CONCLUSIONS
  Attendees have a lower all-cause mortality rate (are healthier) and a higher probability of a prostate cancer diagnosis than non-attendees and the men randomized to the control arm. If attendance is not accounted for, the excess mortality and the between-arm excess mortality rate ratio are underestimated and screening is considered more effective than it actually is. These effects may be sizeable, notably if non-attendance is common. Correcting for attendance status is important in the calculation of the excess mortality rate in prostate cancer patients that can be used in conjunction with a disease-specific mortality analysis in a randomized controlled cancer screening trial.
authors: Department of Urology, Erasmus Medical Centre, Rotterdam, The Netherlands and Comprehensive Cancer Center the Netherlands (IKNL), Utrecht, The Netherlands. R.Kranse@iknl.nl
authors: Ries
authors: R
authors: Kranse
authors: Pim J
authors: PJ
authors: van Leeuwen
authors: Timo
authors: T
authors: Hakulinen
authors: Jonas
authors: J
authors: Hugosson
authors: Teuvo L
authors: TL
authors: Tammela
authors: Stefano
authors: S
authors: Ciatto
authors: Monique J
authors: MJ
authors: Roobol
authors: Marco
authors: M
authors: Zappa
authors: Gunar
authors: G
authors: Aus
authors: Chris H
authors: CH
authors: Bangma
authors: Sue M
authors: SM
authors: Moss
authors: Anssi
authors: A
authors: Auvinen
authors: Fritz H
authors: FH
authors: Schröder
mesh_terms: D055088:Early Detection of Cancer / Q000379:methods*; D006801:Humans; D008297:Male; D008403:Mass Screening; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000401:mortality; D015996:Survival Rate
chemical_list: D017430:Prostate-Specific Antigen