Table 1 Reasons given for choice of trial arm
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% | |