Table 4.
The Effect of Health Information Technology on Selected Emergency Department Utilization Measures
| Time to See a Physician | Length of Visit | Number of Medications Prescribed | Number of Tests Ordered | Number of Images Ordered | |
|---|---|---|---|---|---|
| At least basic system | |||||
| With hospital fixed‐effects | −3.3182 (2.4784) | −2.5130 (3.7204)†† | −0.0171 (0.0430) | 0.0866* (0.0471) | 0.0003 (0.0097) |
| Without hospital fixed‐effects | −1.5142 (2.1507) | 5.8853* (3.4205) | 0.0047 (0.0627) | 0.0915* (0.0539) | 0.0030 (0.0104) |
| Advanced system | |||||
| With hospital fixed‐effects | −5.9904 (2.7930)** , †† | 6.9952 (4.7997) | −0.0126 (0.0431) | 0.1493 (0.0576)*** , † | −0.0144 (0.0123) |
| Without hospital fixed‐effects | 0.2554 (2.6817) | 12.8814*** (4.5204) | −0.0311 (0.0515) | 0.0347 (0.0596) | 0.0040 (0.0114) |
| Mean of dependent variable among visits to EDs without a basic system | 51.76 | 135.96 | 2.02 | 1.60 | 0.56 |
| Mean of dependent variable among visits to EDs without an advanced system | 54.39 | 143.86 | 2.06 | 1.68 | 0.57 |
Estimates for wait time and length of visit are marginal effects from a generalized linear model under a gamma distribution with a log‐link. Estimates for number of medications, tests, and images are marginal effects computed using a zero‐inflated Poisson regression. Sample size is 105,709 visits. Controls included but not shown are age, gender, race, insurance status, whether the patient was discharged home, seen for an injury, seen by a resident, the log of the ED's annual visit volume, number of diagnoses, whether more than 20% of households in the patient's ZIP code were below poverty, immediacy of condition, year effects, and quintile controls for reason for visit. The nonfixed‐effect regressions also include controls for urban and teaching status. Tables S2 and S3 list the full set of marginal effects.
The symbols *, **, *** indicate statistical significance at the 10%, 5%, and 1% levels, respectively. The symbols † and †† indicate a statistically significant difference between the fixed‐effect coefficient and its nonfixed‐effect counterpart at the 10% and 5% levels, respectively.