Table 4.
Univariable PWP gap models assessing impact of demographic factors/target attainment on ‘severe flare’ and new damage
| Severe flare |
New damage |
|||
|---|---|---|---|---|
| HR (95% CI) | P-value | HR (95% CI) | P-value | |
| Sex (female) | 0.99 (0.80, 1.21) | 0.895 | 1.18 (0.70, 2.00) | 0.532 |
| Disease duration (>1 year) | 0.80 (0.74, 0.86) | <0.001 | 0.95 (0.83, 1.09) | 0.456 |
| Ethnicitya | ||||
| Asian | 0.78 (0.63, 0.98) | 0.031 | 0.92 (0.54, 1.58) | 0.760 |
| White British | 0.79 (0.64, 0.97) | 0.024 | 0.75 (0.44, 1.26) | 0.270 |
| SDI score of ≥1 at study recruitment | 1.13 (1.02, 1.25) | 0.015 | NA2 | NA2 |
| Increasing SDI score during follow-up | 1.10 (1.04, 1.17) | <0.001 | NA2 | NA2 |
| Target state attainment at any time pointb: | ||||
| LLDAS | 0.14 (0.11, 0.19) | <0.001 | 0.24 (0.12, 0.48) | <0.001 |
| LA | 0.31 (0.26, 0.37) | <0.001 | 0.44 (0.29, 0.67) | <0.001 |
| Toronto-LDA | 0.17 (0.12, 0.25) | <0.001 | 0.35 (0.15, 0.83) | 0.017 |
| Remission on-treatment (SLEDAI-defined) | 0.17 (0.13, 0.22) | <0.001 | 0.27 (0.14, 0.50) | <0.001 |
| Remission off-treatment (BILAG-defined) | NA1 | NA1 | 0.10 (0.03, 0.42) | 0.001 |
| Remission off-treatment (SLEDAI-defined) | 0.10 (0.07, 0.16) | <0.001 | 0.33 (0.28, 0.40) | <0.001 |
| Remission off-treatment (BILAG-defined) | NA1 | NA1 | NA3 | NA3 |
| Percentage of the cumulative duration of follow-up in each target stateb,c | NA4 | |||
| LLDAS | 0.962 (0.952,0.973) | <0.001 | ||
| LA | 0.973 (0.967,0.980) | <0.001 | ||
| Toronto-LDA | 0.975 (0.965,0.985) | <0.001 | ||
| Remission on-treatment (SLEDAI-defined) | 0.969 (0.961,0.976) | <0.001 | ||
| Remission on-treatment (BILAG-defined) | 0.951 (0.939,0.963) | <0.001 | ||
| Remission off-treatment (SLEDAI-defined) | 0.974 (0.963,0.984) | <0.001 | ||
| Remission off-treatment (BILAG-defined) | 0.945 (0.927,0.964) | <0.001 | ||
NA1: modelling not possible as pBILAG used to define flare. NA2: modelling not possible as SDI-score used to define damage. NA3: modelling not possible, as no patients who achieved BILAG-defined remission developed new damage. NA4: modelling not possible, small number of patients accruing new damage while in target. Cl: confidence interval; HR: hazards ratio; LA: low activity; LDA: low disease activity; LLDAS: lupus low disease activity state; PWP: Prentice–Williams–Peterson; SDI: SLICC Standardized Damage Index. Significant p-values (p<0.05) are shown in bold text.
African/Caribbean ethnicity is the reference variable.
Target state attainment, and cumulative duration of follow-up in target are time varying covariates.
Models assessed the percentage of the cumulative duration of follow-up in each target state. The HR’s shown are for each 1% cumulative duration of follow-up in each target state.