Table 2.

Hospital duration (mean, median, minimum, maximum) (days) by age group, gender, residential location and disease group and HR of discharge on day 2, after having stayed for one night (HR₁), and on day 6, after having stayed for five nights (HR₅), respectively, among children in Hanoi, Vietnam

Categories	Mean	Median	Maximum	HR (95% CI)†
				After one night (HR1)	After five nights (HR5)
All	5.20	4	80
Age group
<1	6.41	5	66	Ref	Ref
1–4	4.31	3	80	1.51 (1.49 to 1.52)*	1.41 (1.39 to 1.42)*
5–9	4.37	3	77	1.52 (1.49 to 1.55)*	1.40 (1.38 to 1.42)*
10–14	5.48	3	80	1.28 (1.24 to 1.32)*	1.22 (1.19 to 1.25)*
15–17	6.87	4	58	1.04 (0.93 to 1.17)	1.01 (0.93 to 1.10)
Gender
Female	5.32	4	80	Ref	Ref
Male	5.13	4	80	1.05 (1.04 to 1.06)*	1.04 (1.03 to 1.05)*
Residential location
Inner city	4.76	3	77	Ref	Ref
Outer city	5.97	4	80	0.86 (0.85 to 0.87)*	0.88 (0.87 to 0.89)*
Unidentified location	5.58	4	66	0.94 (0.91 to 0.98)**	0.91 (0.88 to 0.94)**
Top 5 disease groups with the longest hospital duration‡
Mental and behavioural disorders	12.18	12	41	Ref	Ref
Factors influencing health status and contact with health services	10.51	5	76	2.78 (1.87 to 4.12)*	2.00 (1.41 to 2.84)*
Causes related to perinatal period	10.29	7	61	2.79 (2.40 to 3.24)*	2.18 (1.94 to 2.45)*
Neoplasms	9.57	6	80	2.61 (2.24 to 3.03)*	1.99 (1.77 to 2.23)*
Endocrinal and nutritional and metabolic diseases	9.66	7	52	2.63 (2.26 to 3.06)*	2.15 (1.92 to 2.42)*
Respiratory diseases§
Pneumonia	6.42	6	30	Ref	Ref
Bronchitis	4.91	4	30	1.63 (1.58 to 1.68)*	1.47 (1.44 to 1.49)*
Asthma	4.28	4	27	1.76 (1.67 to 1.86)*	1.44 (1.39 to 1.49)*
Other respiratory diseases	4.34	3	30	3.67 (3.57 to 3.78)*	2.05 (2.02 to 2.09)*
Influenza	3.02	2	30	3.27 (3.08 to 3.46)*	1.99 (1.90 to 2.09)*
Upper respiratory disease	2.92	2	30	2.06 (1.95 to 2.19)*	1.46 (1.40 to 1.53)*

*p<0.001, **p<0.05.

†HR >1 means higher probability of earlier discharge from hospital (thus, a shorter length of stay) than in the reference group. Hospital admissions are defined as staying at the hospital for at least one night.

‡HR was estimated from Cox proportional hazard regression model with length of hospitalisation as outcome, and age group, sex, residential location, year of admission and disease groups as predictors.

§The model has adjusted for respiratory diseases instead of disease groups. Stays of deceased children were not included in these analyses.

Ref, reference group.