Table 5.
Odds ratios for end-of-study biopsy adherence for men never prompted for a biopsy
| n=11126 at risk, n=6868 events | ||
|---|---|---|
| Odds ratio (95% CI) | P-value | |
| Model 1 | ||
| DEMOGRAPHICS | ||
| Age ≤ 68a at year 6 | 1.19 (1.08, 1.31) | 0.0005 |
| Married | 1.32 (1.14, 1.53) | 0.0002 |
| GENERAL ADHERENCE | ||
| Adherent to study drug at year 6 | 2.75 (2.38, 3.18) | <.0001 |
| DRE or PSA test done at year 6 | 5.61 (4.18, 7.53) | <.0001 |
| No missed contacts before year 5 | 1.37 (1.19, 1.58) | <.0001 |
| No missed contacts during the previous year | 1.25 (1.03, 1.53) | 0.0234 |
| COMORBIDITIES | ||
| No history of cardiovascular events before year 6 | 1.35 (1.19, 1.52) | <.0001 |
| HEALTH-RELATED QUALITY OF LIFE AT YEAR 6 | ||
| General Health/Health Perception score average or better | 1.62 (1.40, 1.87) | <.0001 |
| SITE CHARACTERISTICS | ||
| Ever received an R&A grant | 1.29 (0.98, 1.71) | 0.0730 |
| ≤200 participants randomized at site | 0.63 (0.47, 0.84) | 0.0016 |
| Poorly performing site | 0.66 (0.46, 0.96) | 0.0300 |
| Model 2 | ||
| Site sizeb and receipt of R&A grant | ||
| Smaller site, received an R&A grant | 1.49 (1.15, 1.94) | 0.0030 |
| Smaller site, no R&A grant | 1.32 (1.03, 1.69) | 0.0288 |
| Larger site, received an R&A grant | 2.69 (2.10, 3.45) | <.0001 |
| Larger site, no R&A grant | 1.00 (reference) | |
| Model 3 | ||
| Age at year 6c and site performance | 0.70 (0.46, 1.06) | 0.0941 |
| Younger participant, poor site performance | 1.24 (1.12, 1.37) | <.0001 |
| Younger participant, acceptable site performance | 0.79 (0.57, 1.10) | 0.1679 |
| Older participant, poor site performance | ||
| Older participant, acceptable site performance | 1.00 (reference) | |
| Model 4 | ||
| Age and adherence to study drug, at year 6 | ||
| Younger participant, adherent | 3.34 (2.77, 4.03) | <.0001 |
| Younger participant, not adherent | 1.28 (1.09, 1.51) | 0.0028 |
| Older participant, adherent | 2.91 (2.43, 3.50) | <.0001 |
| Older participant, not adherent | 1.00 (reference) | |
Interactions obtained by adding each one separately to the main effects model. Model 1 contains only the main effects, Model 2 contains the main effects and the site size/R&A grant interaction, Model 3 contains the main effects and the age/site performance interaction, and Model 4 contains the main effects and the age/study drug adherence interaction.
a
Median age at year 6 for this group
b
Site size is defined as smaller (≤200 participants registered) or larger (> 200 participants registered)
c
Age is defined as younger (≤ 68) and older (> 68)
Abbreviations: DRE = digital rectal examination; PSA = prostate specific antigen; R&A = retention and adherence