Mandated health insurance increases rates of elective knee surgery

Table 1 Demographic characteristics of the pre- and post-reform cohorts

		Pre-reform (n)	(%)	Post-reform (n)	(%)	P-value
Total		2640		7780
Gender
	Female	1551	59%	4419	57%	0.08
	Male	1089	41%	3361	43%
Race
	White	1592	60%	4997	64%	0.00
	Black	440	17%	1320	17%	0.72
	Asian	98	4%	323	4%	0.32
	Hispanic	208	8%	594	8%	0.69
	Native American	2	0%	8	0%	0.70
	Other	114	4%	242	3%	0.00
	Unknown/Unreported	186	7%	296	4%	0.00
Highest Education
	Unreported	948	36%	398	5%	0.00
	I did not attend school	12	0%	41	1%	0.65
	8th grade or less	61	2%	215	3%	0.21
	Some high school	86	3%	341	4%	0.01
	Graduated from high school or GED	380	14%	1528	20%	0.00
	Some college/vocational/technical pgrm	222	8%	1033	13%	0.00
	Graduated from college, graduate or post	692	26%	3192	41%	0.00
	Other	22	1%	151	2%	0.00
	Patient declined to answer	133	5%	656	8%	0.00
	Patient unavailable to answer	84	3%	225	3%	0.47
BMI
	Unreported	1279	48%	3221	41%	0.00
	Underweight/normal (0-18.49)	20	1%	42	1%	0.21
	Overweight (18.5-24.9)	249	9%	947	12%	0.00
	Obese, Class I (25-29.9)	436	17%	1385	18%	0.13
	Obese, Class II (30-34.9)	319	12%	1107	14%	0.06
	Obese, Class III (35+)	337	13%	1078	14%	0.16
Insurance Type
	Uninsured	199	8%	204	3%	0.00
	Private	1507	57%	4715	61%	0.00
	Government	854	32%	2646	34%	0.12
	Workers' compensation	80	3%	215	3%	0.48
Insurance sub-types
	Medicare	563	21%	1593	20%	0.35
	Medicaid	271	10%	694	9%	0.04
	CommCare	0	0%	240	3%	0.00
	TriCare	20	1%	119	2%	0.00
	Private	1507	57%	4715	61%	0.00
	Workers Comp	80	3%	215	3%	0.48
	Uninsured	199	8%	204	3%	0.00