TABLE 3

Predictors of bronchiectasis among 80 cases and their 160 controls

	Unadjusted OR (95% CI)	p-value	Adjusted OR (95% CI)	p-value
Age^#	1.01 (0.99–1.03)	0.355
Remote residence in adulthood^¶	1.25 (0.59–2.65)	0.556
Admitted in childhood	1.88 (1.06–3.32)	0.031
Any LRTI⁺
Childhood	2.08 (1.20–3.60)	0.009	1.90 (0.93–3.86)	0.078
Adulthood	2.19 (1.27–3.80)	0.005
Number of LRTIs^§
Childhood	1.15 (0.95–1.40)	0.151
Adulthood	1.24 (1.14–1.36)	<0.001
Number of ICU LRTIs^ƒ	1.28 (0.56–2.95)	0.558
Severe LRTI^##	18.63 (5.36–64.77)	<0.001	17.83 (4.51–70.49)	<0.001
HTLV-1 infected^¶¶	2.23 (1.29–3.86)	0.004
HTLV-1 PVL (categorical)⁺⁺
Uninfected	Reference		Reference
Low HTLV-1 PVL	1.50 (0.81–2.76)	0.194	1.92 (0.88–4.19)	0.101
High HTLV-1 PVL	7.98 (2.93–21.72)	<0.001	12.41 (3.84–40.15)	<0.001
Sputum cultures
Yield^§§	2.23 (1.29–3.87)	0.004	1.46 (0.65–3.29)	0.359
Haemophilus influenzae	1.47 (1.18–1.83)	0.001	2.07 (1.35–3.16)	0.001
Streptococcus pneumoniae	1.56 (1.09–2.24)	0.014	0.47 (0.21–1.04)	0.064
Pseudomonas aeruginosa	2.79 (0.76–10.32)	0.124
NTM^ƒƒ	12.89 (1.52–109.01)	0.019	44.78 (2.10–952.84)	0.015
Eosinophilia^###	2.88 (1.65–5.03)	<0.001
Strongyloides^¶¶¶	2.23 (1.29–3.89)	0.004	1.81 (0.80–4.09)	0.153
Cellulitis/skin abscess	0.81 (0.68–0.99)	0.028	0.60 (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
Tobacco^ƒƒƒ	0.71 (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.