Table 2.

Risk of dementia among HSV and control cohorts

	Matched controls	Matched HSV cohorts			Subgroups of antiherpetic medication cohort by length of treatment
	Non-HSV cohort	Total HSV cohort	No antiherpetic medication	Antiherpetic medication	1–29 days	30–179 days	180 days–1 year	Longer than 1 year
No. of subjects	217,895	87,687	25,911	61,776	21,656	16,049	6218	17,853
No. of dementia cases	17,680	6925	2089	4836	2065	1180	411	1180
Median length (years) of follow-up (IQR)	8.0 (5.2–11.3)	8.9 (6.0–12.2)	7.7 (5.2–10.5)	9.5 (6.4–12.9)	8.7 (5.8–12.1)	9.1 (6.2–12.6)	9.6 (6.4–13.1)	10.6 (7.4–14.0)
Cumulative incidence rate (%)	8.1%	7.9%	8.1%	7.8%	9.5%	7.4%	6.6%	6.6%
IPTW: dementia-free years (95% CI)	Reference	0.91 (0.81, 1.01)	0.35 (0.20, 0.51)	1.15 (1.05, 1.26)	0.79 (0.64, 0.95)	1.14 (0.96, 1.32)	1.07 (0.78, 1.37)	1.67 (1.51, 1.84)
HR (95% CI)	Reference	0.80 (0.78, 0.83)	0.94 (0.88, 0.99)	0.75 (0.72, 0.78)	0.93 (0.87, 0.98)	0.75 (0.70, 0.81)	0.72 (0.63, 0.81)	0.57 (0.53, 0.61)
Tzeng HR (95% CI)a	Reference	0.74 (0.72, 0.77)	1.04 (0.91, 1.19)	0.73 (0.70, 0.75)	0.90 (0.85, 0.96)	0.72 (0.67, 0.78)	0.71 (0.62, 0.81)	0.55 (0.51, 0.60)

^aTzeng HR (95% CI) uses the same dementia and HSV ICD codes and requires at least 3 encounters for HSV during the enrollment year as done by Tzeng et al