Table 2. Incidence of thyroid cancer by sitagliptin exposure.

Sitagliptin use	Case number	Incident thyroid cancer	%	Person-years	Incidence rate
					(per 100,000 person-years)
I. Original sample
Never users	312853	172	0.05	777260.24	22.13
Ever users	58238	28	0.05	95424.71	29.34
Tertiles of cumulative duration of sitagliptin therapy (months)
Never users	312853	172	0.05	777260.24	22.13
<6.53	18287	9	0.05	25343.96	35.51
6.53-14.00	20161	14	0.07	29760.78	47.04
>14	19790	5	0.03	40319.97	12.40
II. Matched sample
Never users	57659	31	0.05	141851.35	21.85
Ever users	57659	28	0.05	94698.12	29.57
Tertiles of cumulative duration of sitagliptin therapy (months)
Never users	57659	31	0.05	141851.35	21.85
<6.53	18066	9	0.05	25104.96	35.85
6.53-14.00	19978	14	0.07	29578.69	47.33
>14	19615	5	0.03	40014.47	12.50