Table A1.
Mixed logit choice model.
| Variable | Mean | Standard deviation | ||
|---|---|---|---|---|
| Est | SE | Est | SE | |
| Change in Oxford Hip Score | 0.130 | 0.008*** | −0.001 | 0.001 |
| 28-day emergency readmission rate (%) | −0.053 | 0.004*** | −0.001 | 0.001 |
| 1-year revision rate (%) | −0.017 | 0.010 | −0.001 | 0.001 |
| 28-day mortality rate (%) | −0.039 | 0.028 | −0.019 | 0.069 |
| Distance (in km) | −0.270 | 0.007*** | ||
| Distance2 | 0.002 | 0.000*** | ||
| Distance3 | 0.000 | 0.000*** | ||
| NHS trust – medium | −0.572 | 0.031*** | ||
| NHS trust – multi-service | −0.663 | 0.096*** | ||
| NHS trust – small | −0.832 | 0.039*** | ||
| NHS trust – specialist | 1.016 | 0.075*** | ||
| NHS trust – teaching | −0.444 | 0.034*** | ||
| Independent sector treatment centre | −1.564 | 0.039*** | ||
| Primary care trust | −1.256 | 0.206*** | ||
| Waiting time (proportion waiting >120 days) | −0.157 | 0.077* | ||
| WTT (OHS change) | 0.899 | 0.056*** | ||
| WTT (Readmission rate) | −0.625 | 0.050*** | ||
| WTT (Revision rate) | −0.067 | 0.041 | ||
| WTT (Mortality rate) | −0.068 | 0.048 | ||
| Number of patients | 170,916 | |||
| Number of providers | 228 | |||
| BIC | 442,785 | |||
Notes: Random coefficient (mixed) multinomial logit model of choice of hospital for elective hip replacement patients treated between April 2010 and March 2013. Waiting time and quality metrics are lagged by one year. Coefficients are marginal utilities. Random coefficients are specified for OHS change, readmission rate, revision rate and mortality rate. WTT is the ratio of the coefficient on the quality variable to the marginal utility of distance evaluated at the average distance to the chosen hospital (in km). Interaction terms with patient characteristics are not reported (available on request). Standard errors are clustered at GP practice level. The mean coefficients do differ from those reported in Table 2 for the conditional logit model if there is less rounding.
p < 0.001; ** p < 0.01;
p < 0.05.