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. 2014 Aug 21;4(3):mmrr2014-004-03-a01. doi: 10.5600/mmrr.004.03.a01

Exhibit 2. Covariate Adjusted Difference in Differences in Mean Annualized Medicare Expenditures between the PGP Intervention Group and the Comparison Group—Demonstration Period Yearly Average.

Estimated Demonstration Savings Standard Error P-Value
Medicare Expenditures, Pooled PGPs –$171 $22 <0.001
Medicare Expenditures by PGP
PGP 1 323 79 <0.001
PGP 2 –188 64 0.003
PGP 3 –229 94 0.015
PGP 4 87 74 0.244
PGP 5 –310 59 <0.001
PGP 6 –818 53 <0.001
PGP 7 –26 102 0.798
PGP 8 –142 69 0.041
PGP 9 21 49 0.675
PGP 10 120 91 0.191
Medicare Expenditures by Cost Components
Inpatient, Facility –228 18 <0.001
Hospital Inpatient –176 16 <0.001
Skilled Nursing Facility –68 8 <0.001
Outpatient/Professional 25 12 0.043
Hospital Outpatient 85 7 <0.001
Physician/Supplier –39 7 <0.001
Home Health –22 3 <0.001
Durable Medical Equipment 0 3 0.934
Medicare Expenditures by Subpopulations
Chronic Conditions
Cancer –181 90 0.044
Congestive heart failure –687 105 <0.001
Diabetes –456 58 <0.001
Chronic obstructive pulmonary disease –522 87 <0.001
Acute ischemic heart disease –602 221 0.006
Stroke –775 190 <0.001
Vascular disease –535 95 <0.001
Any of 7 above conditions –337 39 <0.001
Medicare/Medicaid dual eligibility –90 67 0.177
Aged but originally entitled to Medicare by disability –361 108 0.001
End stage renal disease 497 663 0.454
Currently entitled to Medicare by disability 65 67 0.331
Upper 10% risk score –1,922 190 <0.001
Upper 25% risk score –1,254 100 <0.001
Hospitalized –402 82 <0.001
1

NOTES: Estimates are derived from multivariate regression models, including demographic and geographic covariates, pre-existing trends, and the risk score.

2

Regression estimates are weighted by each person/year’s inverse propensity score and the fraction of each year eligible for Medicare.

3

A negative value for demonstration savings indicates a savings, a positive value a dis-savings.

The Physician/Supplier cost component includes physician/professional expenditures in the inpatient setting.

SOURCE: Authors’ analysis of 2001–2010 Medicare administrative data.