Predictors of bronchiectasis among 80 cases and their 160 controls

Unadjusted OR (95% CI)p-valueAdjusted OR (95% CI)p-value
Age#1.01 (0.99–1.03)0.355
Remote residence in adulthood1.25 (0.59–2.65)0.556
Admitted in childhood1.88 (1.06–3.32)0.031
 Childhood2.08 (1.20–3.60)0.0091.90 (0.93–3.86)0.078
 Adulthood2.19 (1.27–3.80)0.005
Number of LRTIs§
 Childhood1.15 (0.95–1.40)0.151
 Adulthood1.24 (1.14–1.36)<0.001
Number of ICU LRTIsƒ1.28 (0.56–2.95)0.558
Severe LRTI##18.63 (5.36–64.77)<0.00117.83 (4.51–70.49)<0.001
HTLV-1 infected¶¶2.23 (1.29–3.86)0.004
HTLV-1 PVL (categorical)++
 Low HTLV-1 PVL1.50 (0.81–2.76)0.1941.92 (0.88–4.19)0.101
 High HTLV-1 PVL7.98 (2.93–21.72)<0.00112.41 (3.84–40.15)<0.001
Sputum cultures
 Yield§§2.23 (1.29–3.87)0.0041.46 (0.65–3.29)0.359
 Haemophilus influenzae1.47 (1.18–1.83)0.0012.07 (1.35–3.16)0.001
 Streptococcus pneumoniae1.56 (1.09–2.24)0.0140.47 (0.21–1.04)0.064
 Pseudomonas aeruginosa2.79 (0.76–10.32)0.124
 NTMƒƒ12.89 (1.52–109.01)0.01944.78 (2.10–952.84)0.015
Eosinophilia###2.88 (1.65–5.03)<0.001
Strongyloides¶¶¶2.23 (1.29–3.89)0.0041.81 (0.80–4.09)0.153
Cellulitis/skin abscess0.81 (0.68–0.99)0.0280.60 (0.45–0.80)0.001
Infective dermatitis+++2.70 (1.28–5.70)0.009
Scabies§§§6.06 (1.93–19.02)0.002
Tobaccoƒƒƒ0.71 (0.40–1.25)0.238
Alcohol####1.15 (0.65–2.03)0.631

LRTI: lower respiratory tract infection; ICU: intensive care unit; HTLV-1: human T-cell leukaemia virus type 1; PVL: pro-viral load; NTM: nontuberculous mycobacteria. #: risk of bronchiectasis per 5 years. : residence >80 km from Alice Springs documented in medical records. +: admitted with any non-severe LRTI prior to diagnosis (cases) or date of recruitment (controls). §: number of admissions with LRTIs prior to diagnosis (cases) or date of recruitment (controls). ƒ: number of ICU admissions for LRTI in childhood and adulthood combined prior to diagnosis for cases or to date of recruitment for controls. ##: severe pneumonia (n=16), severe bronchiolitis (n=4) and pulmonary tuberculosis (n=1) at any age (see Methods); includes one case with combined IgA and IgG deficiency; three controls had severe LRTI (pulmonary tuberculosis n=1, pulmonary abscess n=1, severe pneumonia n=1). ¶¶: HTLV-1 Western blot or HTLV-1c PCR positive. ++: low HTLV-1 PVL, <1000 copies per 105 peripheral blood leukocytes (PBLs); high HTLV-1 PVL, ≥1000 copies per 105 PBLs. §§: the number of pathogens isolated divided by the number of sputum samples collected, calculated once for each admission. ƒƒ: NTM isolated from six cases prior to diagnosis included 1) a novel species that could not be identified together with a scotochromogenic mycobacterium, 2) Mycobacterium avium complex in a patient with pulmonary tuberculosis and 3) Mycobacterium simiae (isolated once from one case and twice from another); mycobacteria were not identified to species level in two cases and one control from which an NTM was isolated only once. ###: eosinophilia recorded on at least two occasions 12 months apart (prior to diagnosis for cases). ¶¶¶: Strongyloides seropositive or larvae identified in stool at any time prior to date of recruitment. +++: infective dermatitis recorded in case notes (cases HTLV-1+ n=10, HTLV-1 n=2; controls HTLV-1+ n=1, HTLV-1 n=5). §§§: clinical diagnosis of scabies recorded in case notes (no case diagnosed by microscopy). ƒƒƒ: any history of tobacco smoking recorded in case notes. ####: any history of harmful alcohol consumption recorded in case notes.