Table 1.
MA plan characteristicsa
| Mean (SD) or % | |
|---|---|
| Dependent variables | |
| Premium | 46.09 (53.71) |
| % Zero premium plan | 32.9 |
| % High‐quality plan: Summary score | 42.1 |
| % High‐quality plan: Process measuresb | 35.4 |
| % High‐quality plan: Satisfaction measuresc | 36.6 |
| Independent variables | |
| Mean 2010 MA HHId | 3274.5 (1058.9) |
| Mean 2010 Hospital HHIe | 3607.8 (1931.0) |
| Mean 2010 County‐level Hospital beds per 1000 pop. | 2.6 (1.0) |
| Mean 2010 County‐level MDs per 1000 pop. | 2.3 (0.9) |
| Mean MA benchmark payment rate relative to average FFS Medicare spending | 1.16 (0.09) |
| Mean 2010 Log county‐level population over 65 | 10.7 (1.2) |
| Mean 2010 County median income | 49 447 (9150) |
| Mean 2010 County‐level proportion of Medicare beneficiaries in fair or poor health | 36.4 (8.7) |
| % HMO plans | 61.1 |
| % PPO plans | 29.9 |
| % PFFS plans | 9.0 |
| % For‐profit plans | 66.5 |
| n | 1232 |
The unit of analysis is the MA plan level. In the above table, most variables have been enrollment‐weighted and aggregated to the plan level to calculate the mean value across each plan's service area. Premiums, plan quality, plan type (HMO, PPO, PFFS), and plan profit status are consistent across the service area so these variables were not enrollment‐weighted.
A high‐quality score on process measures is operationalized as a total score of 4 stars or higher for both of the two categories “Staying Healthy: Screening, Tests and Vaccines” and “Managing Chronic (Long Term) Conditions.”
A high‐quality score on satisfaction measures is operationalized as a total score of 4 stars or higher for each of the three categories “Ratings of Health Plan Responsiveness and Care,” “Health Plan Members’ Complaints and Appeals,” and “Health Plans’ Telephone Customer Service.”
MA HHI is Medicare Advantage health insurance market concentration, as measured by the Herfindahl‐Hirschman Index (HHI), with counties serving as the relevant geographic market and each insurance company's county‐level MA enrollment serving as the measure of market share. MA HHI was enrollment‐weighted and aggregated to the plan level to calculate mean MA HHI across each plan's service area.
Hospital market concentration was measured by calculating HHIs with geographic markets set at the core‐based statistical area (CBSA) level and with market shares defined using each hospital's total annual Medicare days. As above, hospital HHI was enrollment‐weighted and aggregated to the plan level to calculate mean hospital HHI across each plan's service area.