Heatmaps and confusion matrix for the study group ‘Leipzig’. Data were obtained using the study group ‘Leipzig’ (0 control group (CG), six osteoarthritis (OA), 10 rheumatoid arthritis (RA)) as the training set for the rule generation and re-applying the respective rules to the same dataset. (A) Heatmap of the membership weights applying all rules of the primary rule set (α = 0.85; ‘CG’, zero rules; ‘OA’, 72 rules; ‘RA’, four rules) for the prediction of the clinical status of the different samples; dashed red lines indicate the lower limits of the respective pruned lists of rules subsequently applied in (B). (B) Heatmap of the membership weights applying pruned lists of rules (α = 0.85; ‘CG’, zero top-ranked rules; ‘OA’, four top-ranked rules; ‘RA’, four top-ranked rules) for optimized prediction of the clinical status of the different samples. (C) Confusion matrix for the rule set displayed in heatmap (B). TP, true positives; TN, true negatives; FP, false positives; FN, false negatives.