Skip to main content

Table 4 Comparison of Simpson's paradox, Lord's Paradox, and suppression

From: Simpson's Paradox, Lord's Paradox, and Suppression Effects are the same phenomenon – the reversal paradox

Type of Reversal Paradox Outcome (illustrated example) Exposure (illustrated example) Covariate/'Confounder' (illustrated example)
Simpson's Paradox Categorical (hypertension) Categorical (birth weight: high vs. low) Categorical (current weight: high vs. low)
Lord's paradox Continuous (blood pressure) Categorical (birth weight: high vs. low) Continuous (current weight)
Suppression Continuous (blood pressure) Continuous (birth weight) Continuous (current weight)