Table 3.
Predicted Outcomes by Health System Type and Insurance Product Ownership
| Variable | Own HMO or PPO: Yes | Own HMO or PPO: No | ||||
|---|---|---|---|---|---|---|
| Health System—Centralized | Health System—Noncentralized | Independent Hospital (Reference) | Health System—Centralized | Health System –Noncentralized | Independent Hospital (Reference) | |
| Cost per discharge ($) | ||||||
| Predicted mean | 11,389 | 11,347 | 11,344 | 11,442 | 11,281 | 11,070 |
| p value | .05 | .87 | .01 | .01 | ||
| Length of stay (days) | ||||||
| Predicted mean | 4.09 | 4.08 | 4.07 | 4.08 | 4.08 | 4.10 |
| p value | <.01 | <.01 | <.01 | <.01 | ||
| AMI mortality (%) | ||||||
| Predicted mean | 2.13 | 2.08 | 2.29 | 2.12 | 2.25 | 2.63 |
| p value | .04 | <.01 | <.01 | <.01 | ||
| Heart failure mortality (%) | ||||||
| Predicted mean | 1.82 | 1.67 | 1.74 | 1.66 | 1.70 | 1.94 |
| p value | .23 | .19 | <.01 | <.01 | ||
| Pneumonia mortality (%) | ||||||
| Predicted mean | 1.84 | 1.69 | 1.84 | 1.64 | 1.79 | 2.07 |
| p value | .98 | <.01 | <.01 | <.01 | ||
| Stroke mortality (%) | ||||||
| Predicted mean | 4.24 | 4.30 | 4.34 | 4.12 | 3.94 | 4.32 |
| p value | .44 | .77 | .03 | <.01 | ||
| Cesarean section probability (%) | ||||||
| Predicted mean | 29.25 | 27.94 | 28.35 | 31.13 | 30.00 | 29.59 |
| p value | <.01 | .04 | <.01 | .01 | ||
Notes. Predicted values from hierarchical linear models (discharges nested within hospitals) measure the relationship between key hospital characteristics (health system affiliation, health maintenance organization [HMO]/preferred provider organization [PPO] ownership, centralization) and outcomes. Predicted means were calculated as though categorical regressor distributions were balanced across the population. Within each level of Own HMO or PPO, p values associated with Health System—Centralized, and Health System—Noncentralized test for significant differences in predicted means against independent hospital. Regression models were measured for each outcome and included year dummies, hospital covariates (hospital ownership type, size, teaching status, patient flow Herfindahl–Hirschman Index, urban, region) and patient covariates (payer, median income quartile of residence, emergency department transfer, comorbidity index, major diagnostic category, surgery flag, sex, age group, and transfer status). Regression models for each of the quality measures included All Patient Refined Diagnosis Related Groups (APR‐DRG) with corresponding severity codes.
Source. Healthcare Cost and Utilization Project State Inpatient Databases data, 2010–2012, linked with American Hospital Association survey data, 2010–2012.