Exhibit 4.

Differences in the yearly change of avoidable hospitalizations and observation visits by condition and race, 2011–15

Conditions	Baseline Year (2011)a	Latest Year (2015)a	Yearly Change (Slope)b	Difference-in-slopesc	P Value
Overall
Hospitalizations per 10,000 people
Black	674.8	483.9	−46.2	−13.1	<0.001
White	546.7	407.8	−33.2
Observations per 10,000 people
Black	417.9	570.6	39.2	16.0	<0.001
White	378.8	470.6	23.2
Combined hospitalizations and observations per 10,000 people
Black	1074.1	1043.7	−6.3	−3.2	p=0.24
White	920.0	906.8	−3.0
Chronic Conditions
Hospitalizations per 10,000 people
Black	446.3	328.8	−27.6	−10.6	p<0.001
White	294.6	221.5	−17.0
Observations per 10,000 people
Black	331.7	461.4	33.0	15.4	p<0.001
White	260.0	327.7	17.5
Combined hospitalizations and observations per 10,000 people
Black	744.8	756.4	4.8	−0.9	p=0.68
White	553.2	573.5	5.7
Acute Conditions
Hospitalizations per 10,000 people
Black	228.5	155.1	−18.6	−2.5	p=0.001
White	252.1	186.3	−16.1
Observations per 10,000 people
Black	86.2	109.2	6.2	0.5	p=0.61
White	118.8	142.9	5.7
Combined hospitalizations and observations per 10,000 people
Black	329.3	286.3	−11.1	−2.3	p=0.08
White	366.7	333.3	−8.8

Source/Notes: SOURCE: Authors’ analysis of 2011–15 data from 20% Medicare Inpatient and Outpatient Files and Agency for Healthcare Research and Quality’s Prevention Quality Indicators (PQIs) Software

NOTES: These results are from linear regression models and the estimated changes are adjusted for covariates.

^aYearly point estimates are based on a risk-adjusted linear regression model where year is included as a categorical predictor.

^bThe yearly change in each subgroup was estimated from a separate risk-adjusted linear regression model where year was treated as a continuous predictor.

^cThe difference in slopes and its p-value are calculated from the same model as one that determined the yearly change, and it represents the slope in black patients minus the slope in white patients.