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Table 1 Predictors identified from the joint multivariate model of MDAS and SDAS

From: Methods for analyzing observational longitudinal prognosis studies for rheumatic diseases: a review & worked example using a clinic-based cohort of juvenile dermatomyositis patients

Predictor Outcome Predictor Estimate Standard Error p
bDAS MDAS 0.0363 0.0316 0.25
SDAS 0.0214 0.0342 0.53
Timea*bDAS MDAS 1.0140 0.1321 <0.0001
SDAS 0.0362 0.1261 0.77
Steroidb MDAS -0.0919 0.0753 0.22
SDAS 0.1211 0.0688 0.08
  1. bDAS Baseline DASm measurement; Time *bDAS denotes the crossing of a time term with bDAS
  2. aThe shapes of the MDAS and SDAS models are defined using 2 time terms each (fractional polynomials). MDAS and SDAS crossed with their common time form (p = –1,) of their respective fractional polynomials (see Additional file 1: Appendix)
  3. bSteroid treatment from 3 months before each occasion of DASm measurement, i.e., it is a time-varying predictor. Significant results have been bolded