TABLE 1.

Enrollee Characteristics: BCBSMA 2008–2012

	N			%
Person-years	1 182 847			100
Unique enrollees	458 168			39
Age, y
0–1	110 973			9
2–6	261 104			22
7–12	355 119			30
13–17	323 591			27
18–19	132 060			11
Male	604 204			51
No. of chronic conditionsa
0	636 687			54
1	340 363			29
2	135 700			11
≥3	70 097			6
Health plan typeb
Employer insured	807 966			68
Self-insured	374 881			32
Basic benefit designc
Health maintenance organization	868 809			73
Preferred provider organization	253 040			21
Point of service	60 998			5
Geocoded socioeconomic background via the ABSMd
High (ABSM >1 SD above enrollee mean)	181 350			15
Medium	850 804			72
Low (ABSM <1 SD below enrollee mean)	150 693			13
Proportion with any spending in category	1 143 293			97
Outpatient	1 136 404			96
Prescription medications	671 109			57
ED	173 227			15
Inpatient	72 326			6
Per person annual, $	N	Median	Mean	SD	Min	Max
Annual plan payments	1 182 847	795	2607	13 828	0	3 225 485
Outpatient	1 182 847	644	1616	6949	0	2 191 095
Prescription medications	1 182 847	6	263	1751	0	467 969
ED	1 182 847	0	39	154	0	14 793
Inpatient	1 182 847	0	689	10 523	0	3 211 813

^aPer the Agency for Healthcare Research and Quality Chronic Condition Indicator for the International Classification of Diseases, Ninth Revision, Clinical Modification.³⁹

^bEmployer sponsored is when the employer purchases health insurance from a health plan on behalf of employees, and the insurer takes the financial risk. Self-insured means that the employer designs and funds his or her own health plan for employees; the employer takes the financial risk and may pay health plan fees to administer the health plan (eg, process claims).

^cHealth maintenance organization and point of service benefit designs typically require enrollees to designate a primary care provider who directs care within a designated network for which there are no or limited patient out-of-pocket costs; out-of-pocket costs rise if patients seek out-of-network care. In health maintenance organizations, patients must involve their primary care providers in directing care to a greater extent than in point of service plans. In preferred provider organization plans, primary care providers are not required to direct care, and enrollees typically pay some out-of-pocket amounts for the care they seek.

^dAs a continuous variable, ABSM has a mean of 3.4 and an SD of 6.7.