Table 1

Baseline demographic characteristics

Variables	Treated cohort			Untreated cohort			P values*
Variables	n/mean	%/SD	Median	n/mean	%/SD	Median	P values*
Number of patients	18 549	100%		26 543	100%
Sex, n (%)
Male	11 081	59.7%		13 921	52.5%
Female	7468	40.3%		12 622	47.6%		<0.001
Age
Age (mean, SD, median)	70	±12.2	72	71	±14.3	74	<0.001
Age category, n (%)
18–44	437	2.4%		1215	4.6%
45–54	1542	8.3%		2233	8.4%
55–64	4032	21.7%		4360	16.4%
65–74	4876	26.3%		6157	23.2%
75–79	5575	30.1%		7607	28.7%
80+	2087	11.3%		4971	18.7%		<0.001
Region of residence, n (%)
Northeast	3720	20.1%		3686	13.9%
Midwest	6088	32.8%		10 067	37.9%
South	4685	25.3%		7377	27.8%
West	4056	21.9%		5413	20.4%		<0.001
Medicare plan type, n (%)
Medicare Advantage only	5015	27.0%		4707	17.7%		<0.001
Commercial health plan type, n (%)
HMO	4373	23.6%		4413	16.6%
PPO	13 316	71.8%		20 876	78.7%
Other†	860	4.6%		1254	4.7%		<0.001

*T-test or Wilcoxon rank-sum test was used for continuous variables and Χ² test was used for categorical variables.
†Other plans include consumer directed health plans (CDHP) and indemnity plans.
HMO, health maintenance organisation; PPO, preferred provider organisation.