Table 4.
Differential Changes From the Pre‐entry Period to Each Performance Year in the Characteristics of Patients Served by ACOs, as Compared With the Control Group, by Entry Cohort of ACOs a
| Differential Change From Pre‐entry Period to Each Performance Year for ACOs vs. Control Group | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 2012 Entry Cohort | 2013 Entry Cohort | 2014 Entry Cohort | |||||||
| Patient Characteristic | Unadjusted Pre‐entry Sample Mean,b $/Patient | 2013 | 2014 | 2015 | 2013 | 2014 | 2015 | 2014 | 2015 |
| Age (year) | 72.2 | 0.0 | 0.0 | 0.0 | 0.1 | 0.2 | 0.1 | 0.1 | 0.1 |
| Female sex (%) | 58.5 | −0.2 | −0.3 | −0.2 | −0.1 | −0.2 | −0.2 | 0.0 | −0.1 |
| Race or ethnic group c (%) | |||||||||
| Non‐Hispanic white | 83.5 | 0.0 | −0.1 | −0.2 | 0.0 | −0.1 | −0.2 | 0.0 | 0.1 |
| Non‐Hispanic black | 8.5 | −0.1 | 0.0 | 0.2 | 0.0 | 0.0 | 0.2 | −0.1 | −0.2 |
| Hispanic | 4.7 | 0.1 | 0.1 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Other | 3.2 | 0.0 | 0.0 | −0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 |
| Medicaid recipient (%) | 15.3 | −0.2 | −0.2 | −0.2 | −0.1 | −0.3 | −0.1 | −0.1 | 0.1 |
| Disability was original reason for Medicare eligibility (%) | 21.9 | −0.1 | −0.1 | 0.0 | −0.3 | −0.5 | −0.3 | −0.2 | −0.3 |
| End‐stage renal disease (%) | 0.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| CCW conditions,d no. | |||||||||
| Through prior year | 5.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Through 3 years priore | 4.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| History of hip fracture (%) | 2.9 | −0.1 | −0.1 | −0.1 | 0.0 | 0.0 | 0.0 | 0.0 | −0.1 |
| History of myocardial infarction (%) | 4.2 | 0.0 | 0.0 | 0.0 | −0.1 | −0.1 | 0.0 | 0.0 | 0.0 |
| HCC risk scoref | |||||||||
| Based on claims in prior year | 1.23 | 0.00 | 0.00 | 0.00 | 0.00 | 0.01 | 0.02 | 0.00 | 0.00 |
| Based on claims 3 years priore | 1.07 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| ZCTA‐level characteristic | |||||||||
| % below federal policy level | 9.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| % with high school diploma | 75.4 | −0.1 | −0.2 | −0.2 | 0.0 | 0.0 | −0.1 | 0.0 | 0.0 |
| % with college degree | 19.4 | −0.2 | −0.2 | −0.2 | 0.0 | 0.0 | 0.0 | −0.1 | 0.0 |
Means and percentages were adjusted for geography to reflect comparisons within hospital referral regions. ZCTA denotes ZIP Code tabulation area.
In the analyses, the pre‐entry period differed for each entry cohort, but for the purpose of describing the study sample in this table, years 2009–2011 were used to calculate a single mean for each characteristic.
Race or ethnic group was determined from Medicare Master Beneficiary Summary Files.
Chronic conditions from the Chronic Conditions Data Warehouse (CCW) included 27 conditions: acute myocardial infarction, Alzheimer's disease, Alzheimer's disease and related disorders or senile dementia, anemia, asthma, atrial fibrillation, benign prostatic hyperplasia, chronic kidney disease, chronic obstructive pulmonary disease, depression, diabetes, heart failure, hip or pelvic fracture, hyperlipidemia, hypertension, hypothyroidism, ischemic heart disease, osteoporosis, rheumatoid arthritis or osteoarthritis, stroke or transient ischemic attack, breast cancer, colorectal cancer, endometrial cancer, lung cancer, prostate cancer, cataracts, and glaucoma. Analytic models included indicators for all 27 conditions and indicators for the presence of multiple conditions ranging from 2 to 9 or more conditions. Counts of conditions included all conditions except cataracts and glaucoma.
For analyses of CCW condition indicators and hierarchical condition categories (HCC) scores derived from earlier claims, we limited the sample to a subgroup of beneficiaries who were also continuously enrolled in fee‐for‐service Medicare 3 years prior to the study year. The purpose of this was to assess the extent to which any differential changes may have been due to differential changes in coding practices in response to MSSP incentives.
HCC risk scores are derived from demographic and diagnostic data in Medicare enrollment and claims files, with higher scores indicating higher predicted spending in the subsequent year. For each beneficiary in each study year, we assessed the HCC score based on enrollment and claims data in the prior year, two years prior, and three years prior, in each case requiring continuous enrollment in fee‐for‐service Medicare in the study year and the year of claims used to calculate HCC scores.