Differences in number of ED visits or total outpatient visits with respect to education and income* †
| Patient characteristic | ED visits | Total outpatient visits |
| Graduated from high school | NS | NS |
| Income US$<40 000 | p value 0.02 | p value 0.01 |
| US$<40K 1.4±3.5 (0) | US$<40K 3.3±6.0 (1) | |
| US$≥40K 1.9±3.5 (1) | US$≥40K 4.6±7.1 (2) |