Table 2.
Unadjusted median time [days (95% CI)] of the time required for BLLs to drop below 10 μg/dL by analysis type and selected covariates, among a cohort of children tested for blood lead in Vermont and North Carolina, 1996–1999.
| Qualifying blood lead level (μg/dL)
|
|||||
|---|---|---|---|---|---|
| Type of analysis | 10–14 | 15–19 | 20–24 | 25–29 | ≥ 30 |
| Central (n = 996) | 237 (211–284) | 424 (362–479) | 659 (593–774) | 954 (750–1,057) | 1,083 (917–1,083) |
| Excluding censored children (n = 588) | 191 (175–216) | 267 (224–301) | 463 (352–598) | 750 (479–954) | 723 (151–917) |
| Interpolated time to end point (n = 996) | 125 (103–151) | 340 (292–401) | 564 (483–684) | 762 (606–992) | NA |
| Central, black children (n = 399) | 265 (211–306) | 479 (378–636) | 659 (593–863) | 957 (750–1,057) | NA |
| Central, white children (n = 397) | 230 (194–306) | 377 (305–502) | 686 (363–823) | 1,075 (460–1,075) | 1,083 (932–1,083) |
| Central, male children (n = 540) | 258 (201–306) | 427 (377–566) | 598 (559–788) | 825 (750–1,057) | NA |
| Central, female children (n = 452) | 232 (195–288) | 370 (294–476) | 686 (509–798) | 1,056 (525–1,198) | 917 (754–932) |
| Central, rural address (n = 546) | 269 (220–316) | 440 (355–602) | 774 (659–823) | 818 (525–957) | 1,083 (854–1,083) |
| Central, urban address (n = 450) | 214 (182–266) | 386 (294–479) | 509 (332–598) | 1,056 (750–1,198) | NA |
NA, not available