TABLE 2.

Joinpoint regression analysis for trends in incidence rate of thyroid cancer by histologic type

Categories	Trend 1		Trend 2		Trend 3		AAPC (95% CI)
	Years	APC (95% CI)	Years	APC (95% CI)	Years	APC (95% CI)
Men
Overall	1999–2009	26.3 (21.7 to 31.1)*	2009–2012	15.2 (−5.9 to 41.2)	2012–2016	−11.8 (−17.4 to −5.9)*	14.2 (9.8 to 18.8)*
Papillary	1999–2009	29.6 (24.6 to 34.7)*	2009–2012	16.2 (−4.7 to 41.7)	2012–2016	−12.1 (−17.5 to −6.3)*	16.0 (11.6 to 20.7)*
Follicular	1999–2012	7.8 (5.5 to 10.2)*	2012–2016	−9.8 (−18.3 to −0.3)	‐	‐	3.4 (0.7 to 6.1)*
Medullary	1999–2012	8.7 (5. to 12.4)*	2012–2016	−12.4 (−24.7 to 1.8)	‐	‐	3.3 (−0.7 to 7.5)
Anaplastic	1999–2016	0.4 (−1.5 to 2.3)	‐	‐	‐	‐	0.4 (−1.5 to 2.3)
Women
Overall	1999‐2008	26.3 (22.0 to 30.8)*	2008–2012	10.9 (1.7 to 21.0)*	2012–2016	−16.3 (−21.2 to −11.1)*	11.2 (8.2 to 14.3)*
Papillary	1999‐2009	26.1 (22.3 to 30.0)*	2009–2012	9.1 (−8.6 to 30.2)	2012–2016	−16.2 (−21.3 to −10.7)*	11.7 (7.9 to 15.6)*
Follicular	1999‐2012	4.4 (2.6 to 6.1)*	2012–2016	−9.4 (−17.2 to −0.8)	‐	‐	0.9 (−1.3 to 3.2)
Medullary	1999‐2012	8.6 (5.8 to 11.4)*	2012–2016	−19.8 (‐30.0 to −8.2)*	‐	‐	1.1 (−2.3 to 4.6)
Anaplastic	1999‐2016	−1.4 (−3.4 to 0.7)	‐	‐	‐	‐	−1.4 (−3.4 to 0.7)

The age‐standardized incidence rates are calculated as incidence cases per 100,000 people using Segi’s world standard population.

Abbreviations: 95% CI, 95% Confidence intervalAAPC, Average annual percent change; APC, Annual percent change.

^*p‐value <0.05