Figure 1From: Response shift masks the treatment impact on patient reported outcomes (PROs): the example of individual quality of life in edentulous patients SEIQoL Index scores at baseline (T 1 ) and after three months (T 2 ). 1The traditional reported treatment effect = post-test minus pre-test score 2The response shift effect = pre-test minus then-test score 3The actual treatment effect = post-test minus then-test scoreBack to article page