Objective To understand and differentiate the necessary and non-necessary treatment of ambulance patients, in order to analyze reasonability of use of ambulance resources and furthermore to provide scientific basis for the rational scheduling ambulance resources.

Methods The patients using "120" ambulance in five administrative districts of Shenyang City in November 2019 were divided into two groups, namely necessary and non-necessary treatments, by the emergency doctors and nurses after ambulances arrived at the call sites. Their characteristics were analyzed.

Results Totally 10 617 patients including 5 134 males(48.3%)and 5 483 females(51.6%)called "120" to use ambulances. Among them 3 902 patients (36.8%) were assessed in the non-necessary treatment group. The highest proportion of patients in non-necessary treatment was in Shenhe District (46.7%). The proportion of male patients in non-necessary treatment group was higher than that in necessary treatment group(P < 0.01). In terms of call time, the proportion of patients in non-necessary treatment group calling "120" during 8:00 to 17:00 was the highest and calling "120" during 0:00 am to 8:00 am was the lowest. The highest proportion of patients in non-necessary treatment was among patients with age under 18 years old, while the lowest was among the patients with age between 41 to 65 years old. Among the patients who called "120" by their medical staff, only 64% were assessed as "necessary treatment" by the emergency personnel; among the patients who called "120" by themselves and/or their family members, nearly 50% was assessed as non-necessary treatment, while the least proportion of non-necessary treatment was noted among the patients who called "120" by the police or passers-by(P < 0.05). Among 3 902 cases in non-necessary treatment group, only a small part (4%) was considered to be in emergency but not life-threatening; 85% of the patients were in neither life-threatening nor urgent conditions. Among the patients who did not need emergency medical help, 55% could drive or take a taxi to the hospital for treatment. Even called by medical staff, 90% the patients in non-necessary treatment group only needed a car in which they could lie down.

Conclusions In Shenyang, a large proportion of patients receiving pre-hospital emergency treatment do not actually need ambulance. The lack of effective assessment of patients after receiving the calling affects the rationality of the use of emergency resources. The pre-hospital emergency management department should establish clear standards for the use of ambulance services, so as to ensure the safety of patients and make more rational use of emergency resources.