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Table 6 Estimated associations between baseline predictor and change in health from inappropriate use of change score analyses (i.e. in situations where RTM was assumed to occur)

From: Bias in the study of prediction of change: a Monte Carlo simulation study of the effects of selective attrition and inappropriate modeling of regression toward the mean

Dependency (bdrop) bpred(SE) Coverage of 95% C.I. Diff
Pred. V1 V2    
0 0 0 -.02 (.04) 57% 0.00
.3 .3 0 -.05 (.05) 84% 0.12
.3 .3 .1 -.04 (.05) 77% 0.08
.3 .3 .3 -.02 (.05) 62% 0.00
  1. Dependency is the magnitude (bdrop) of the regression of liability of dropping out on each of the three study variables. Pred = baseline predictor. V1 = the main variable at baseline (baseline health), V2 = the main variable at follow-up (follow-up health). SE = standard error. bpred = regression coefficient from predictor to change in health. Coverage of 95% C.I. = the percentage of the 500 samples with an estimated bpred with a 95% confidence interval containing the true population value. Diff = estimated change score (follow-up health minus baseline health). bpred, SE, and Diff are average results over the 500 generated samples. N in the original samples was 1000. Attrition rate was 50%. The first line shows results when attrition was completely random.
  2. The true population value was bpred = - .10.