Table 5. Cutoff, sensitivity and specificity values of NC measured in different studies.

Study	Country, year	Age range, years	n	Boys			Girls
				Cutoff	Sensitivity	Specificity	Cutoff	Sensitivity	Specificity
This study	Iran, 2013	6–17	864	27.5–38.3	60.0–88.9	71.4–88.5	26.7–33.4	71.4–78.5	67.7–82.8
Olubukola16	USA, 2010	6–18	1102	28.5-39.0	60.0–100.0	67.9–100	27.0–34.6	60–78.5	55.6–100.0
Hatipoglu7	Turkey, 2010	6–18	976	28.0–38.0	-	-	27.0–34.5	-	-
Lou14	China, 2011	7–12	2874	27.4–31.3	75.5–86.7	73.9–91.7	26.3–31.4	80.0–92.5	74.7–93.3
Atwa15	Egypt, 2012	12–15	2762	29.3–31.7	91.0–96.0	55.0–91.0	28.6–31.4	90.0–96.0	56.0–83.0