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Table 1 Reasons given for choice of trial arm

From: Standardisation of information submitted to an endpoint committee for cause of death assignment in a cancer screening trial – lessons learnt from CAP (Cluster randomised triAl of PSA testing for Prostate cancer)

   Phase I (N = 510) Phase 2 (N = 589)
Correct arm Reason given Correct Incorrect Unsure Correct Incorrect Unsure
  1. Factors relating to initial presentation 10% 14% 1% 6% 24% 0%
  a. Asymptomatic, low PSA test result, localised disease, early presentation 10 2 0 6 3 0
  b. Symptomatic, high PSA test result, locally advanced/metastatic disease, late presentation 0 12 1 0 21 0
  2. Study-specific factors 8% 30% 4% 3% 22% 2%
Intervention a. No formal prostate cancer diagnosis 0 3 0 0 2 0
arm b. PSA test not performed 0 21 0 0 11 0
  c. Timing of PSA test, investigations or treatments 4 5 2 1 2 1
  d. Presence of co-morbidities or other cancers 0 0 1 0 4 1
  e. Investigations, treatments received 3 0 0 1 2 0
  f. Other study-specific factors 1 1 1 1 1 0
  3. No reason stated 3% 1% 25% 0% 1% 42%
  (Total for each phase = 100%) 21% 46% 33% 9% 46% 45%
  1. Factors relating to initial presentation 14% 1% 1% 23% 3% 3%
  a. Asymptomatic, low PSA test result, localised disease, early presentation 1 1 1 0 3 1
  b. Symptomatic, high PSA test result, locally advanced/metastatic disease, late presentation 13 0 0 23 0 2
  2. Study-specific factors 50% 1% 4% 20% 2% 1%
Control a. No formal prostate cancer diagnosis 8 0 1 1 0 0
arm b. PSA test not performed 31 0 1 10 0 0
  c. Timing of PSA test, investigations or treatments 6 1 1 2 1 0
  d. Presence of co-morbidities or other cancers 1 0 0 3 0 0
  e. Investigations, treatments received 2 0 0 1 1 1
  f. Other study-specific factors 2 0 1 3 0 0
  3. No reason stated 4% 0% 25% 3% 0% 44%
  (Total for each phase = 100%) 68% 2% 30% 46% 6% 48%
  1. Table 1 shows the reasons reviewers gave for their choice of trial arm, for correct, incorrect and unsure categories; for both phases. Highlighted in bold are the total percentages. Figures have been rounded so may not add up to 100%.