Table 2 Description of the hypothesis testing

1

shorter length of stay managed care

mean length of stay for the managed care and the non-managed care group are compared

2

less variation length of stay managed care

variation in length of stay for the managed care and the non-managed care group are compared

3

influence managed care at physician level

the variation for the managed care group and the non-managed care group at physician level is compared to the variation for both groups at hospital level

4

shorter length of stay, less variation when more managed care patients per physician

the regression coefficient for the proportion of managed care patients per physicians is examined as well as the covariance between this proportion and the variation in length of stay; both are expected to be negative

5

shorter length of stay, less variation when more managed care patients per hospital

the regression coefficient for the proportion of managed care patients per hospital is examined as well as the covariance between this proportion and the variation in length of stay; both are expected to be negative.

6

fewer insurers per physician, less variation in length of stay

the covariance between the number of insurers per physician and the variation in length of stay is examined and expected to be positive.

7

fewer insurers per hospital, less variation in length of stay

the covariance between the number of insurers per hospital and the variation in length of stay is examined and expected to be positive.

8

fewer different hospitals per physician, less variation in length of stay

the covariance between the number of hospitals per physician and the variation in length of stay is examined and expected to be positive.

9

DRGs that can be standardized show less variation

variation for all DRGs is compared, most variation is expected in medical DRGs and DRGs with complications