Table 1.
Cohort characteristics at time of first study PEx
| Variable | Study Participants (N = 3,253) | Inhaled Antibiotic Exposed (n = 678) | Inhaled Antibiotic Nonexposed (n = 2,575) |
|---|---|---|---|
| Demographic variables | |||
| Age, yr, median (IQR) | 12.8 (9.0–16.2) | 13.4 (9.7–16.6) | 12.6 (8.9–16.0) |
| Sex, F, n (%) | 1,774 (55) | 374 (55) | 1,400 (54) |
| Non-Hispanic white, n (%) | 2,535 (78) | 485 (72) | 2,050 (80) |
| Hispanic white, n (%) | 430 (13) | 128 (19) | 302 (12) |
| Other ethnicity, n (%) | 288 (9) | 65 (10) | 223 (9) |
| One class I–III mutation, n (%) | 94 (3) | 17 (3) | 77 (3) |
| Two class I–III mutations, n (%) | 2,647 (81) | 548 (81) | 2,099 (82) |
| Two class IV–V mutations, n (%) | 5 (0) | 0 (0) | 5 (<1) |
| Other genotype, n (%) | 438 (13) | 99 (15) | 339 (13) |
| Missing genotype, n (%) | 69 (2) | 14 (2) | 55 (2) |
| Public insurance, n (%) | 1,929 (59) | 426 (63) | 1,503 (58) |
| Private insurance, n (%) | 1,256 (39) | 233 (34) | 1,023 (40) |
| Other insurance, n (%) | 68 (2) | 19 (3) | 49 (2) |
| Clinical variables | |||
| Baseline ppFEV1*, median (IQR) | 89.0 (74.4–100.8) | 83.8 (69.7–96.3) | 90.2 (75.8–102.1) |
| CF-related diabetes, n (%) | 654 (20) | 166 (24) | 488 (19) |
| Chronic Pa infection†, n (%) | 1,175 (36) | 337 (50) | 838 (33) |
| Intermittent Pa infection‡, n (%) | 620 (19) | 128 (19) | 492 (19) |
| Other/No Pa infection, n (%) | 1,458 (45) | 213 (31) | 1,245 (48) |
| MDR-Pa infection, n (%) | 239 (7) | 80 (12) | 159 (6) |
| MRSA infection, n (%) | 1,224 (38) | 286 (42) | 938 (36) |
| Number of PEx events, n (%) | — | — | — |
| Requiring i.v. antibiotics in prior 12 mo, n (%) | — | — | — |
| — | — | — | |
| 0 | 1,731 (53) | 304 (45) | 1,427 (55) |
| 1 | 971 (30) | 230 (34) | 741 (29) |
| ≥2 | 551 (17) | 144 (21) | 407 (16) |
| Medication, n (%) | |||
| Pancreatic enzymes | 3,152 (97) | 664 (98) | 2,488 (97) |
| Chronic inhaled antibiotic use in prior 12 mo | 2,291 (70) | 613 (90) | 1,678 (65) |
| Azithromycin (during PEx) | 1,480 (45) | 384 (57) | 1,096 (43) |
| Corticosteroid (during PEx) | 824 (25) | 168 (25) | 656 (25) |
| CFTR modulator (during PEx) | 76 (2) | 9 (1) | 67 (3) |
Definition of abbreviations: CF = cystic fibrosis; CFTR = cystic fibrosis transmembrane receptor; i.v. = intravenous; IQR = interquartile range; MDR = multidrug resistant; MRSA = methicillin-resistant Staphylococcus aureus; Pa = Pseudomonas aeruginosa; PEx = pulmonary exacerbation; ppFEV1 = percent predicted forced expiratory volume in 1 second.
*
Defined as the highest ppFEV1 recorded within 6 months before a study PEx.
†
Defined as ≥50% of respiratory cultures Pa positive over the prior 12 months.
‡
Defined as at least one but <50% of respiratory cultures Pa positive over the prior 12 months.