Table 2.
Characteristics of intervention and control groups before and after matching by age and past utilization
| Characteristics | Before matching | After matching | ||
|---|---|---|---|---|
| Intervention group (%) | Non-intervention group (%) | Intervention group (%) | Control group (%) | |
| Total | 786 | 1951 | 698 | 698 |
| Gender | ||||
| Female | 307 (39) | 706 (40) | 263 (38) | 259 (37) |
| Male | 479 (61) | 1,059 (60) | 435 (62) | 439 (63) |
| Agea | ||||
| 1–2 | NA | NA | 170 (24) | 170 (24) |
| 2–3 | NA | NA | 89 (13) | 89 (13) |
| 3–4 | NA | NA | 77 (11) | 77 (11) |
| 4–5 | NA | NA | 54 (8) | 54 (8) |
| 5–6 | NA | NA | 42 (6) | 42 (6) |
| 6–12 | NA | NA | 199 (29) | 199 (29) |
| 13+ | NA | NA | 67 (10) | 67 (10) |
| Raceb | ||||
| Don’t know | 4 (1) | 17 (1) | 4 (1) | 8 (1) |
| Missing | 0 (0) | 1 (0) | 0 (0) | 1 (0) |
| African American | 354 (45) | 701 (40) | 304 (43) | 247 (35) |
| Hispanic/Latino | 174 (22) | 516 (26) | 156 (22) | 185 (27) |
| White | 70 (9) | 256 (13) | 65 (9) | 108 (15) |
| Native American | 0 (0) | 2 (0) | 0 (0) | 0 (0) |
| Other | 184 (23) | 388 (20) | 169 (24) | 149 (21) |
| Past utilization: Summed hospital daysc | ||||
| 0 | NA | NA | 170 (24) | 170 (24) |
| 1 | NA | NA | 90 (13) | 90 (13) |
| 2 | NA | NA | 192 (28) | 192 (28) |
| 3 | NA | NA | 101 (14) | 101 (14) |
| 4 | NA | NA | 52 (7) | 52 (7) |
| 5 | NA | NA | 36 (5) | 36 (5) |
| 6–8 | NA | NA | 46 (7) | 46 (7) |
| 9+ | 11 (2) | 11 (2) | ||
| Past utilization: Number of ED visitsd | ||||
| 0 | NA | NA | 494 (71) | 494 (71) |
| 1 | NA | NA | 125 (18) | 125 (18) |
| 2 | NA | NA | 42 (6) | 42 (6) |
| 3 | NA | NA | 18 (3) | 18 (3) |
| 4 | NA | NA | 4 (1) | 4 (1) |
| 5+ | NA | NA | 15 (2) | 15 (2) |
| Insurancee | ||||
| Private | 161 (20) | 505 (26) | 144 (21) | 196 (28) |
| Medicaid | 586 (75) | 1352 (69) | 522 (75) | 474 (68) |
| Changed Insurance During Study | 39 (5) | 94 (5) | 32 (5) | 28 (4) |
| Residencef | ||||
| Not Local | 390 (50) | 960 (49) | 349 (50) | 378 (54) |
| Local | 367 (47) | 922 (47) | 333 (48) | 309 (44) |
| Moved during Study | 29 (4) | 69 (4) | 12 (2) | 11 (2) |
aFor the intervention group, age refers to age at time of admission preceding the intervention. For the non-intervention, it refers to the age at the matched admission
bRace and ethnicity were separate variables in the original data. Children with Latino/Hispanic ethnicity were defined as such, regardless of race
cRefers to total number of days spent in the hospital between September 15, 2003 and the date of first intervention, or corresponding matching date. This cannot be calculated prior to matching as there is no reference date for those who were not in the intervention
dRefers to total number of visits to the ED between September 15, 2003 and the date of intervention or corresponding matching date. This cannot be calculated prior to matching as there is no reference date for those who were not in the intervention
eRefers to insurance at time of intervention or corresponding matching date
fRefers to residence at time of intervention or corresponding matching date. “Local” was defined as having a residential ZIP Code in Oakland or neighboring Berkeley