Table 1.
Demographic and clinical characteristics of young U.S. children with cystic fibrosis from 2003 to 2009, by pathogen acquisition status
| Respiratory Pathogen | ||||||||
|---|---|---|---|---|---|---|---|---|
| MRSA | S. maltophilia | A. xylosoxidans | H. influenzae | |||||
| Acquired (n = 910) |
Negative (n = 3612) |
Acquired (n = 1161) |
Negative (n = 3361) |
Acquired (n = 228) |
Negative (n = 4294) |
Acquired (n = 2148) |
Negative (n = 2374) |
|
| Male (%) | 445(49%) | 1833(51%) | 590(51%) | 1688(50%) | 98(43%) | 2180(51%) | 1062(49%) | 1216(51%) |
| White (%) | 825(91) | 3326(92) | 1065(92) | 3086(92) | 202(89) | 3949(92) | 1984(92) | 2167(91) |
| Hispanic (%) | 72(8) | 427(12)* | 148(13) | 351(10)* | 42(18) | 457(11)* | 208(10) | 291(12)* |
| Identified by newborn screening (%) | 280(31) | 1618(45)* | 423(36) | 1475(44)* | 73(32) | 1825(43)* | 806(38) | 1092(46)* |
| Mean age at diagnosis, months (SD) | 2.9(4.6) | 2.4(4.3)* | 2.6(4.3) | 2.4(4.4) | 3.5(5.3) | 2.4(4.3)* | 2.7(4.5) | 2.3(4.2)* |
| ΔF508 mutation category (%) | ||||||||
| Homozygous | 482(53) | 1553(43)* | 586(50) | 1449(43)* | 108(47) | 1927(45) | 996(46) | 1039(44) |
| Heterozygous | 307(34) | 1437(40) | 390(34) | 1354(40) | 77(34) | 1667(39) | 802(37) | 942(40) |
| Other | 79(9) | 463(13) | 132(11) | 410(12) | 32(14) | 510(12) | 255(12) | 287(12) |
| CFTR functional classa (%) | ||||||||
| Severe | 660(73) | 2284(63)* | 817(70) | 2127(63)* | 150(66) | 2794(65) | 1442(67) | 1502(63)* |
| Residual | 61(7) | 354(10) | 70(6) | 345(10) | 12(5) | 403(9) | 198(9) | 217(9) |
| Unclassified | 189(21) | 974(27) | 274(24) | 889(26) | 66(29) | 1097(26) | 508(24) | 655(28) |
MRSA, methicillin-resistant Staphylococcus aureus; S. maltophilia, Stenotrophomonas maltophilia; A. xylosoxidans, Achromobacter xylosoxidans; H. influenzae, Haemophilus influenzae; SD, standard deviation; CFTR, cystic fibrosis transmembrane conductance regulator
* P < 0.05 based on Student’s t test with unequal variances for continuous variables or χ2 test for categorical variables.
a CFTR functional class is defined as follows: Severe, includes children in which CFTR mutations on both alleles result in minimal CFTR function (class 1, 2, or 3), including ΔF508; Residual, at least one allele with a mutation resulting in partial CFTR function (class 4 or 5); Unclassified, both alleles with unknown functional class, or one allele with minimal CFTR function and the second with unknown functional class