Table 5.

Relationship between LOS and all confounding variables for admitted patients

Confounding variables	IV LOS in hour (N=558)	Other than IV LOS in hour (N=289)
Categorical confounders	Median (25th–75th centile)	Median (25th–75th centile)
Gender
Male	15.4 (10.5–23.6)*	18.9 (11.4–27.5)
Female	18.0 (11.7–25.4)	19.5 (12.7–27.9)
Triage priority
High (1–2)	16.4 (10.4–24.5)	18.4 (11.1–25.8)
Low (3–5)	17.2 (11.7–25.0)	19.5 (12.9–27.6)
Arrival
Ambulance	17.0 (10.7–25.3)	20.7 (13.5–28.4)
Walk-in	16.6 (11.4–24.5)	18.4 (12.0–26.9)
Trauma injury
Yes	12.5 (8.7–21.1)*	15.7 (8.2–27.6)
No	17.0 (11.4–24.8)	19.4 (12.6–27.6)
Abdominal pain
Yes	16.0 (10.9–23.3)*	19.4 (12.9–26.7)
No	18.0 (11.5–27.6)	19.3 (11.6–28.2)
Blood test
Yes	19.8 (11.8–28.5)	27.9 (16.4–35.8)**
No	16.4 (10.9–24.5)	18.8 (11.6–26.8)
Heart-rate monitoring
Yes	23.1 (16.2–38.6)**	30.0 (25.3–45.2)**
No	15.6 (10.7–23.1)	17.8 (11.3–25.7)
Oxygen support
Yes	20.9 (12.3–34.4)**	26.8 (15.1–45.0)**
No	15.9 (10.8–24.1)	18.7 (11.7–26.7)
Isolation
Yes	30.1 (21.8–54.3)**	35.5 (22.6–57.8)**
No	15.9 (10.8–23.8)	18.5 (11.6–26.7)
Time of day of arrival with
Low LOS	15.7 (9.7–29.1)	16.2 (10.6–24.2)
High LOS	17.0 (11.4–24.5)	19.8 (12.7–27.8)
Continuous confounders	Spearman rank-order correlation	Spearman rank-order correlation
Age	0.15**	0.22**
Crowding	0.03	0.17**
Time to patient care by physician	0.16**	0.06
Number of examinations (range 0–15)	0.34**	0.36**
Number of specialist consultations (range 0–8)	0.31**	0.37**
Number of doses (range 1–7)	−0.03	−0.15**
Baseline pain intensity score	0.003	−0.12*

IV, intravenous route of analgesia administration; LOS, length of stay.

*p<0.05; **p<0.01.