Table 3.
Post hoc analyses in patients who reached a relapse end point
| IVIg withdrawal group | IVIg continuation group | Treatment comparison | |||||||
|---|---|---|---|---|---|---|---|---|---|
| n | Baseline | Mean change | n | Baseline | Mean change | Difference in mean change scores | 95% CI | ||
| iRODS(mean ± SD) Logits | Relapse end point | 17 | 3.3 (3.1) | −1.9 (1.3) | 13 | 3.9 (2.6) | −1.3 (1.0) | 0.54 | −0.33 to 1.42b |
| MCID end pointa | 10 | 3.4 (2.4) | −2.5 (1.2) | 5 | 4.3 (2.7) | −2.2 (0.8) | −0.3 | −1.6 to 1.01 | |
| MRC sum score (median, range) | Relapse end point | 17 | 58 (38–60) | 0 (−10 to −3)c | 13 | 60 (49−60) | −1 (−7 to −0)c | 0d | −1.0 to 2.0d |
| MCID end point | 10 | 58.5 (52–60) | −2 (−10 to −0) | 5 | 60 (52−60) | 0 (−6−0) | 0d | −4.0 to 2.0d | |
| Grip strength (mean ± SD) | Relapse end point | 17 | 79.5 kPa (38.1) | −16.4 (15.4) | 13 | 77.6 kPa (32.7) | −11.6 (17.9) | −4.9 kPa | −17.8 to 8.1 |
| MCID End point | 9 | 87.8 kPa (42.2) | −19.4 (15.2) | 5 | 82.0 kPa (52.8) | −5.6 (9.0) | −13.8 | −30.1 to 2.4 | |
| INCAT-SS (mean ± SD) | Relapse end point | 17 | 5.7 (5.1) | 0.8 (2.2) | 13 | 4.2 (3.5) | 0.5 (2.9) | 0.3 | −1.7 to 2.2 |
| MCID end point | 10 | 5.7 (4.1) | 1.1 (2.3) | 5 | 2.8 (3.0) | 1.8 (2.2) | −0.7 | −3.4 to 2.4 | |
| PI-NRS (mean ± SD) | Relapse end point | 16 | 1.8 (2.0) | 1.8 (2.7) | 11 | 2.0 (2.5) | 1.1 (1.7) | 0.7 | −1.2 to 2.4 |
| MCID End point | 9 | 1.1 (1.7) | 3.1 (2.6) | 5 | 1.2 (2.7) | 1.4 (2.2) | 1.7 | −1.3 to 4.7 | |
| FSS score (mean ± SD) | Relapse end point | 16 | 31.7 (13.1) | −6.0 (6.5) | 11 | 32.3 (13.0) | −4.4 (8.0) | −1.6 | −7. to 1.4 |
| MCID end point | 9 | 37.0 (7.4) | −6.2 (7.0) | 5 | 33.0 (11.5) | −6.6 (4.6) | 0.4 | −9.6 to 10.3 | |
| ALDS (mean ± SD) | Relapse end point | 15 | 81.4 (11.1) | −3.9 (9.6) | 13 | 85.3.8 (9.2) | −2.6 (18.1) | 1.4 | −5.8 to 8.6 |
| MCID end point | 10 | 82.9 (7.9) | −7.1 (9.1) | 4 | 79.8 (11.1) | −7.4 (11.3) | −0.2 | −12.8 to 12.3 | |
| SF-36 (mean ± SD) | |||||||||
| Physical component | Relapse end point | 15 | 38.8 (10.5) | −7.2 (10.1) | 12 | 42.4 (8.6) | −8.0 (8.4) | 0.8 | −6.7 to 8.9 |
| MCID end point | 9 | 41.2 (9.3) | −10.9 (10.0) | 4 | 41.5 (11.3) | −8.8 (9.8) | −2.1 | −15.3 to 11.0 | |
| Mental component | Relapse end point | 15 | 50.9 (10.1) | 0.3 (8.4) | 12 | 47.2 (13.5) | −4.5 (16.6) | 4.8 | −5.3 to 14.9 |
| MCID end point | 9 | 51.4 (10.2) | −0.5 (5.8) | 4 | 44.7 (18.9) | −3.8 (23.0) | 3.2 | −34.2 to 40.7 | |
ALDS = AMC Linear Disability Score; FSS = Fatigue Severity Scale; INCAT-SS = INCAT Sensory Sum Score; PI-NRS = Pain Intensity Numeric Rating Scale; SF 36 = Short Form 36.
Patients who reached a relapse end point based on the MCID on the iRODS. Change of −1.9 logits and −1.3 logits on the iRODS correspond with −12.4 and −8.8 centile points, respectively. Difference in mean change score of 0.54 logits corresponds with 3.6 centile points.
Point estimate and 95% CI were analysed using an independent sample t-test according superiority analysis.
The within-group median change score was calculated as the 50th percentile of all individual differences.
Between-group difference on the MRC expressed in median difference in change scores; point estimate and 95% CI were analysed using the Hodges–Lehmann approach.