Table 2.
Risk factors reported at one or more cystic fibrosis clinic visits in the year of enrollment and best FEV1% predicted at age 6–7 years
| Risk Factor | Risk Factor Status as Reported during Baseline Year, n (%)* |
Best FEV1% Predicted at Age 6–7, Mean (SD) |
P Value | |||
|---|---|---|---|---|---|---|
| Participants with Risk Factor | Participants without Risk Factor | Participants with Risk Factor | Participants without Risk Factor | Mean Difference (95% Confidence Interval) | ||
| Frequent or productive cough | 282 (58.3) | 202 (41.7) | 108.4 (16.0) | 109.6 (14.3) | −1.3 (–4.0, 1.5) | 0.36 |
| Less active relative to peers | 73 (15.1) | 393 (81.2) | 108.6 (14.5) | 108.9 (15.4) | −0.3 (–3.9, 3.4) | 0.88 |
| Activity limited by shortness of breath† | 139 (28.7) | 345 (71.3) | 109.0 (15.8) | 108.9 (15.1) | 0.1 (–2.9, 3.2) | 0.93 |
| Wheeze on chest examination | 71 (14.7) | 413 (85.3) | 103.8 (18.7) | 109.8 (14.5) | −5.9 (–10.5, –1.4) | 0.01 |
| Crackles on chest examination | 61 (12.6) | 423 (87.4) | 103.4 (21.2) | 109.7 (14.1) | −6.3 (–11.8, –0.9) | 0.02 |
| Pa-positive culture | 149 (30.8) | 335 (69.2) | 106.5 (16.3) | 110.0 (14.8) | −3.4 (–6.5, –0.4) | 0.03 |
| Methicillin-resistant Staphylococcus aureus–positive culture | 42 (8.7) | 442 (91.3) | 106.0 (16.5) | 109.2 (15.2) | −3.2 (–8.4, 1.9) | 0.22 |
| Oral antibiotics prescribed‡ | 411 (84.9) | 73 (15.1) | 109.1 (15.4) | 107.8 (14.9) | 1.3 (–2.4, 5.0) | 0.49 |
| Inhaled antibiotics prescribed‡ | 146 (30.2) | 338 (69.8) | 108.0 (16.7) | 109.3 (14.7) | −1.3 (–4.4, 1.9) | 0.43 |
| intravenous antibiotics prescribed‡ | 156 (32.2) | 328 (67.8) | 106.0 (16.5) | 110.3 (14.5) | −4.2 (–7.3, –1.2) | 0.006 |
| Dornase alfa prescribed | 225 (46.5) | 259 (53.5) | 109.1 (16.3) | 108.7 (14.4) | 0.4 (–2.3, 3.2) | 0.75 |
| Influenza vaccine received | 408 (84.3) | 67 (13.8) | 109.3 (15.3) | 107.2 (15.6) | 2.0 (–2.0, 6.1) | 0.32 |
| Household member smoked | 159 (32.8) | 323 (66.7) | 107.8 (15.4) | 109.4 (15.3) | −1.6 (–4.6, 1.3) | 0.27 |
| Any smoking exposure | 230 (47.5) | 247 (51.0) | 107.3 (15.0) | 110.6 (15.3) | −3.3 (–6.1, –0.6) | 0.02 |
| Mother smoked while pregnant | 52 (10.7) | 414 (85.5) | 103.3 (15.2) | 109.5 (15.0) | −6.1 (–10.5, –1.8) | 0.006 |
| Wood-burning stove used in home | 44 (9.1) | 437 (90.3) | 107.0 (18.3) | 109.2 (15.0) | −2.3 (–7.8, 3.3) | 0.42 |
| Swimming pool used | 359 (74.2) | 125 (25.8) | 108.4 (15.7) | 110.3 (14.2) | −1.9 (–4.9, 1.1) | 0.21 |
| Hot tub used | 60 (12.4) | 423 (87.4) | 107.9 (13.3) | 109.0 (15.6) | −1.1 (–4.7, 2.6) | 0.56 |
| Others with CF in same home | 77 (15.9) | 406 (83.9) | 106.1 (16.9) | 109.4 (15.0) | −3.3 (–7.3, 0.7) | 0.11 |
| Daycare > 9 h/wk | 221 (45.7) | 253 (52.3) | 107.7 (15.1) | 109.7 (15.4) | −1.9 (–4.7, 0.8) | 0.17 |
| Breastfed§ | 88 (35.6) | 154 (62.3) | 111.2 (13.5) | 109.2 (15.1) | 2.0 (–1.8, 5.7) | 0.30 |
| Palivizumab received§ | 111 (44.9) | 113 (45.7) | 111.6 (13.5) | 108.2 (15.8) | 3.4 (–0.4, 7.3) | 0.08 |
Definition of abbreviations: CF = cystic fibrosis; Pa = Pseudomonas aeruginosa.
Respiratory symptoms, chest examination findings, and associated treatments reflect study-specific encounter data. Culture findings reflect Cystic Fibrosis Foundation National Patient Registry (CFFNPR) culture data. Intravenous antibiotics reflect CFFNPR data on episodes of hospitalization or home intravenous antibiotics for a pulmonary exacerbation. Vaccines, smoking exposures, other environmental exposures, and breastfeeding reflect the most recent family survey collected during the year of enrollment. Participants were considered as having the risk factor if reported at one or more clinic visits or at the most recent family survey during the first year enrolled. All percentages reflect a denominator of 484 participants, with the exception of breastfeeding and palivizumab (which were assessed only in participants < 2 yr of age). Participant numbers (percentages) that sum to less than 484 (100%) indicate that there were missing data. Mean differences and P values reflect simple linear regression models.
Activity limited by at least 1 day/month by shortness of breath or cough.
At least one course reported during the year of enrollment.
Breastfeeding and palivizumab are reported for participants enrolled at age less than 2 years (n = 247). Participant numbers (percentages) that sum to less than 247 (100%) indicate that there were missing data.