Table 2.

Comparison of Quality Composite Measures at Baseline, 12 Months, and 24 Months at Patient-Centered Medical Home (PCMH) and 19 Other Group Health Clinics

Siteb	Period	Quality of care composite measurea
		Patient average (%)	100% Performance (%)	75% Performance (%)	50% Performance (%)
PCMH prototype clinic (n = 1,415)	2006 Rating	69.9	52.8	60.4	78.9
	2007 Rating	71.9	53.9	61.8	81.1
	2008 Rating	78.0	62.5	70.9	85.2
	12-Month difference (2006–2007)c	2.0*	1.1	1.5	2.2
	24-Month difference (2006–2008)c	8.1***	9.8***	10.5***	6.3***
Other clinics (n = 30,067)	2006 Rating	65.7	43.7	53.5	76.4
	2007 Rating	68.1	46.7	56.7	78.3
	2008 Rating	72.2	52.6	62.3	81.3
	12-Month difference (2006–2007)c	2.4***	3.1***	3.3***	1.9***
	24-Month difference (2006–2007)c	6.4***	8.9***	8.8***	4.9***
Difference of changes at 12 months between clinicsd		−0.34	−1.95	−1.77	0.29
Difference of changes at 24 months between clinicsd		1.66	0.86	1.71	1.40

^a Notes: Composites aggregate 22 quality indicators from the Health Care Effectiveness Data and Information Set. The “patient average” is the average of the percentage of qualifying indicators that each patient achieved, “100% performance” is the percentage of patients achieving success on all qualifying indicators, “75% performance” is the percentage of patients achieving success on at least 75% of qualifying indicators, and “50% performance” is percentage of patients achieving success on at least 50% of qualifying indicators.

^bContinuously enrolled patients (2006–2008) who qualified for at least one of the 22 indicators in each year.

^c p Value from paired t test for the average change in percentages between baseline and implementation years across patients qualifying for the measures in the clinic.

^d p Value from two-sample t test assuming unequal variances for the average difference in changes from baseline to implementation years between the prototype and other clinics.

*p < .05. **p < .01. ***p < .001.