Table 3.

Perceived and normative assessment of periodontal health.

Normative Perceived	CPITN 3–4	CPITN 0–2	Total
Bad	TP 46	FP 771	817
Good	FN 118	TN 3520	3638
Total	164	4291	4455

• TP = True Positive • FP = False Positive • FN = False Negative • TN = True Negative • Sensitivity (TP/(TP+FN)) = 0.28 (95%CI 0.21–0.35). • Specificity (TN/(TN+FP)) = 0.83 (95% CI 0.81–0/83). • Positive Predictive Value (TP/(TP+FP)) = 0.05 • Negative Predictive Value (TN/(TN+FN)) = 0.97 • Overall Proportions = 817 participants (18%) reported having bad periodontal health status compared to 164 (3.7%) clinically periodontal disease diagnosed subjects (McNemar test, p = <0.000001).