Table 3. Predictors of intensive care/high dependency unit admission and prolonged length of stay in children (< 18 years) and adults with RSV disease, Australia, 2024 (n = 3,998).

Variables	Crude OR	95% CI	p value	Adjusted ORa		95% CI		p value
Predictors of ICU and HDU admission
Children
Age < 6 months	1.79	1.34–2.38	< 0.001		2.71	1.97–3.73				< 0.001
Male sex	1.11	0.84–1.47	0.472		NS
First Nations statusb	1.51	0.91–2.50	0.108		NS
Any underlying medical condition	2.56	1.94–3.40	< 0.001		NS
Preterm birth	2.91	2.10–4.04	< 0.001		2.03		1.34–3.07		0.001
Cardiac disease	4.06	2.67–6.18	< 0.001		1.83		1.13–2.98		0.014
Respiratory disease	2.34	1.67–3.29	< 0.001		NS
Neurological disease	4.44	2.89–6.81	< 0.001		2.27		1.37–3.77		0.001
Genetic disorder	6.51	4.17–10.17	< 0.001		3.69		2.17–6.27		< 0.001
Metabolic disorder excluding diabetes	7.76	2.32–26.00	0.001		4.55		1.16–17.82		0.030
Adults
Age ≥ 75 years	0.36	0.19–0.69	0.002		0.40		0.21–0.78		0.007
Male sex	0.74	0.42–1.29	0.278		NS
First Nations statusb	1.98	0.94–4.16	0.070		NS
Respiratory disease	3.20	1.79–5.73	< 0.001		3.16		1.75–5.70		< 0.001
Predictors of prolonged length of stay
Children
Age < 6 months	1.26	1.07–1.49	0.006		1.54		1.36–1.73	< 0.001
Male sex	0.96	0.88–1.05	0.346		NS
First Nations statusb	1.17	0.97–1.40	0.096		1.21		1.04–1.42	0.016
Any underlying medical condition	1.92	1.51–2.43	< 0.001		1.40		1.27–1.54	< 0.001
Preterm birth	1.58	1.17–2.15	0.003		NS
Cardiac disease	2.31	1.86–2.88	< 0.001		1.57		1.31–1.87		< 0.001
Respiratory disease	1.49	1.22–1.82	< 0.001		NS
Neurological disease	2.42	1.88–3.11	< 0.001		1.96		1.48–2.60		< 0.001
Malignancy	2.99	2.01–4.44	< 0.001		1.94		1.44–2.59		< 0.001
Immunosuppression	2.75	2.05–3.69	< 0.001		1.49		1.08–2.07		0.016
Genetic disorder	2.08	1.54–2.79	< 0.001		NS
Metabolic disorder excluding diabetes	2.35	1.21–4.58	0.012		NS
Adults
Age ≥ 75 years	1.28	1.00–1.64	< 0.001		NS
Male sex	1.06	0.92–1.22	0.408		NS
First Nations statusb	0.66	0.51–0.86	0.002		NS
Any underlying medical condition	1.27	0.99–1.64	0.063		NS
Cardiac disease	1.19	0.99–1.43	0.062		1.15		1.00–1.31		0.038
Malignancy	1.38	0.06–1.79	0.018		1.28		1.00–1.65		0.048
Immunosuppression	1.19	1.00–1.43	0.049		NS
Diabetes mellitus	0.83	0.70– 0.99	0.034		0.83		0.72–0.96		0.011

CI: confidence interval; HCU: high dependency unit; ICU: intensive care unit; OR: odds ratio; RSV: respiratory syncytial virus.

^a In addition to age, sex and First Nations status, factors associated with p value < 0.1 in univariate models were included in the multivariable model.

^b First Nations status included all Aboriginal Australian and Torres Strait Islander people based on self-report on medical records.

Children < 18 years and adults ≤ 18 years. Reference variables include all others in the cohort.