Table 3. Multivariable Analyses: Virologic Failure.
| Patient characteristics | Derivation Set (MGH, n = 712) | Validation Set (BWH, n = 362) | z-test* | ||||||
|---|---|---|---|---|---|---|---|---|---|
| VF Rate | OR | 95% CI | p-value | VF Rate | OR | 95% CI | p-value | p-value | |
| Sub-optimal Adherence | 20.5% | 2.77 | 1.67, 4.58 | <0.0001 | 23.5% | 3.77 | 1.80, 7.96 | 0.001 | 0.499 |
| CD4 count <100/μL | 34.5% | 2.98 | 1.20, 7.42 | 0.019 | 30.8% | 1.22 | 0.26, 5.62 | 0.803 | 0.325 |
| Drug and or Alcohol | 17.0% | 1.89 | 1.14, 3.12 | 0.013 | 17.4% | 1.78 | 0.80, 3.99 | 0.159 | 0.908 |
| Heavily ART experienced | 19.8% | 2.16 | 1.29, 3.60 | 0.003 | 16.7% | 2.00 | 0.92, 4.34 | 0.079 | 0.872 |
| Missed ≥1 Appointment | 17.0% | 1.72 | 1.04, 2.85 | 0.034 | 14.8% | 1.11 | 0.51, 2.45 | 0.788 | 0.361 |
| Prior Virologic Failure | 14.8% | 6.30 | 1.88, 21.07 | 0.003 | 18.8% | 2.61 | 1.14, 5.95 | 0.023 | 0.237 |
| Suppressed <12 months | 18.6% | 1.80 | 1.05, 3.10 | 0.034 | 19.6% | 2.22 | 1.04, 4.72 | 0.039 | 0.662 |
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| Hosmer-Lemeshow test | χ2 = 6.6, p = 0.58 | χ2 = 1.9, p = 0.93 | |||||||
| Discrimination | c-statistic = 0.78 | c-statistic = 0.79 | |||||||
*
z-test - compares the similarity of the two models' beta-coefficients for each predictor