Unadjusted and adjusted associations with severe lung disease in children≥6 years and adults in the South Africa Cystic Fibrosis Registry, 2018

Severe lung disease of FEV1z ≤3.0 (n=292)
Univariable analysis#Multivariable analysis (n=190)
nUnadjusted OR (95% CI)p-valueAdjusted OR (95% CI)p-value
Neonatal bowel obstruction (ref: no)2750.58 (0.28–1.19)0.126NS
Age diagnosis (units: 10 years)2851.26 (0.90–1.76)0.180NS
Current age (units: 10 years)2921.99 (1.55–2.54)<0.001*2.23 (1.50–3.31)<0.001
p.Phe508del (ref: neither record)
 Homozygous2920.77 (0.37–1.57)0.069NS
 Heterozygous2921.45 (0.70–3.01)
Caucasian (ref: other ancestry)2921.50 (0.83–2.72)0.171NS
Ever had P. aeruginosa (ref: no)2794.36 (1.65–11.49)0.001*1.66 (0.34–8.12)0.529
Time since first P. aeruginosa isolate (per 10-year interval)1332.12 (1.38–3.25)<0.001*1.25 (0.85–1.84)0.259
Chronic P. aeruginosa (ref: no)2013.81 (2.08–6.95)<0.001*1.98 (0.90–4.34)0.088
Chronic MSSA (ref: no)1980.57 (0.30–1.10)0.089NS
Ever had MRSA (ref: no)2612.46 (0.98–6.18)0.055NS
Chronic MRSA (ref: no)1988.88 (1.89–41.73)0.001*16.75 (1.74–161.50)0.015
Other fungus or mould (ref: no)2922.19 (1.22–3.93)<0.009*1.31 (0.58–2.93)0.518
ABPA (ref: no)2610.29 (0.06–1.30)0.064NS
Household cigarette smoke exposure/smoker (ref: no)2920.62 (0.30–1.28)0.181NS
CF-related diabetes (ref: no)2863.79 (2.10–6.84)<0.001*1.03 (0.46–2.33)0.939
CF-liver disease with cirrhosis (ref: no)2822.87 (1.15–7.14)0.073NS
Undernutrition+ (ref: no)2923.16 (1.72–5.83)<0.001*5.20 (2.23–12.13)<0.001

FEV1z: forced expiratory volume in 1 s z-score; MSSA: methicillin-sensitive S. aureus; MRSA: methicillin-resistant S. aureus; ABPA: allergic bronchopulmonary aspergillosis; CF: cystic fibrosis; WHZ: weight-for-height z-score; BMIZ: body mass index z-score. Severe lung disease: FEV1z ≤3 in children ≥6 years. #All variables with unadjusted p-values <0.2 in the univariable analyses are tabulated. Refer to supplementary table S3 for full set of univariable results. Included as an interaction term, to apply only to those who have ever had P. aeruginosa. +Undernutrition includes: WHZ ≤1.0, <2 years of age; BMIZ ≤1.0, 2–17 years; or BMI <18.5 kg·m−2, ≥18 years. *Unadjusted p-values are shown; indicated variables had adjusted p-values <0.2 using Holm's method and were thus included in the multivariable regression model.