Table 4.

Predictors of ambulance usage

Variables assessed	Univariate analysis			Multivariate analysis
	OR	95% CI	Significant	OR	95% CI	Significant
Age group1 (years)
40-59	1.675	1.417-1.982	<0.001	0.832	0.677-1.022	0.079
>60	2.074	1.756-2.450	<0.001	0.867	0.703-1.069	0.182
Gender2
Male	1.236	1.070-1.429	0.004	1.109	0.935-1.314	0.235
Triage category3
Red	11.625	9.005-15.009	<0.001	5.223	3.887-7.019	<0.001
Yellow	3.703	2.864-4.788	<0.001	2.06	1.553-2.732	<0.001
Arrival time4
8 PM to 8 AM	1.561	1.358-1.795	<0.001	1.157	0.979-1.369	0.088
Distance from hospital5 (km)
20-50	3.287	2.697-4.006	<0.001	1.339	1.057-1.696	0.015
50-100	3.064	2.381-3.941	<0.001	1.166	0.859-1.584	0.325
>100	2.640	2.232-3.123	<0.001	1.268	1.034-1.555	0.023
Referral pattern6
Public healthcare facility	16.137	12.167-21.041	<0.001	10.666	7.901-14.398	<0.001
Private healthcare	7.528	6.326-8.959	<0.001	4.497	3.708-5.455	<0.001

Reference Variables: 1: 18-39 years, 2: Female, 3: Green category, 4: 8 AM to 8 PM, 5: <20 km; 6: Not referred cases. Variables included for multivariate analysis: Age, gender, triage category, time of arrival, the distance of residence, referring hospital. OR: Odds ratio, CI: Confidence interval