Table 2:
Study Cohort Attribution and Clinical Characteristics, 2009–2017
| Any Mental Illness | Bipolar, Schizophrenia, or other Psychotic Disorders | Depression w/o Bipolar, Schizophrenia, or other Psychotic Disorders | |
|---|---|---|---|
| N | 5,157,533 | 1,993,853 | 2,215,837 |
| Year first attributed to ACO provider, % | |||
| 2009 to 2011 (prior to first ACO contract) | 38.0 | 40.3 | 37.1 |
| 2012 | 4.8 | 4.9 | 4.8 |
| 2013 | 5.8 | 5.9 | 5.9 |
| 2014 | 4.6 | 4.4 | 4.7 |
| 2015 | 4.0 | 3.7 | 4.2 |
| 2016 | 3.5 | 3.0 | 3.7 |
| 2017 | 2.8 | 2.3 | 2.9 |
| Average duration of first ACO attribution (for those ever in ACO), years | 2.3 | 2.3 | 2.4 |
| Clinical condition, % (ever in study period) | |||
| Behavioral health conditions | |||
| Anxiety | 54.4 | 55.2 | 48.9 |
| Bipolar Disorder | 21.7 | 56.2 | 0.0 |
| Depression | 69.7 | 69.2 | 100.0 |
| Schizophrenia and other psychotic disorders | 26.5 | 68.5 | 0.0 |
| Other Mental Illness | 16.8 | 10.4 | 11.5 |
| Substance Use Disorder | 10.1 | 14.9 | 7.9 |
| Physical health conditions | |||
| Coronary Artery Disease | 15.5 | 13.2 | 17.6 |
| Vascular Disease | 35.9 | 35.0 | 38.8 |
| Polyneuropathy | 2.0 | 1.9 | 2.3 |
| Cardio-Respiratory Failure and Shock | 23.1 | 22.4 | 24.8 |
| End Stage Renal Disease | 2.3 | 1.9 | 2.6 |
| Renal Failure (non-acute) | 3.8 | 2.7 | 4.6 |
| Diabetes | 40.8 | 39.3 | 44.0 |
| Cancer | 13.9 | 11.6 | 15.6 |
| Chronic Obstructive Pulmonary Disease | 34.0 | 33.6 | 36.0 |
| Congestive Heart Failure | 31.5 | 27.5 | 35.8 |
| 3 or more HCCs | 64.6 | 66.8 | 67.4 |
| Died during study period | 26.3 | 24.6 | 28.4 |
SOURCE: Authors’ analysis of Medicare claims and enrollment data for 2009–2017. NOTES: HCC=Hierarchical Condition Category. Mental Illness conditions required 1 inpatient or 2 outpatient diagnoses 7 days apart, within year. “Other Mental Illness” includes phobias, personality disorders (see appendix for specific codes), as well as combinations of single outpatient diagnoses of anxiety, depression, bipolar disorder and schizophrenia that total two or more. Non-mental illness conditions are based on HCC flags, version 22. “Any Mental Illness” column includes some beneficiaries who are represented in neither the “Bipolar, Schizophrenia, or other Psychotic Disorders” nor the “Depression w/o Bipolar, Schizophrenia, or other Psychotic Disorders” columns. Average duration refers to consecutive years attributed to same ACO as first ACO to which first attributed (rather than across all ACOs).