Effect of typhoons on the Korean national emergency medical service system

Article information

Clin Exp Emerg Med. 2018;5(4):272-277

Publication date (electronic) : 2018 December 31

doi : https://doi.org/10.15441/ceem.17.255

Soo Hyun Park¹, Won Chul Cha^,1, Giwoon Kim², Tae Rim Lee¹, Sung Yeon Hwang¹, Tae Gun Shin¹, Min Seob Sim¹, Ik Joon Jo¹

¹Department of Emergency Medicine, Samsung Medical Center, Seoul, Korea

²Department of Emergency Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea

Correspondence to: Won Chul Cha Department of Emergency Medicine, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Korea E-mail: docchaster@gmail.com

Received 2017 July 14; Revised 2017 September 22; Accepted 2017 October 12.

Abstract

INTRODUCTION

Typhoons occur frequently in East Asia and the Pacific region. Several studies have reported that the typhoon intensity may increase with global warming [1]. The number of severe typhoons has increased in recent decades [2]. Typhoons affect tropical and subtropical zones and are often accompanied by high tides and heavy rain [3]. In Korea, typhoon warnings (Kyungbo) are issued when heavy widespread damage is expected due to the weather.

The effect of typhoons on emergency medicine has been evaluated previously. Most previous research has assessed the impact of typhoons on the emergency room services, focusing on the number or patient characteristics [2,4]. However, the most critical adverse effect of disasters is not only the increased medical demand but also the compromise of the healthcare system itself. The emergency medical service (EMS) is the key factor of the emergency healthcare delivery system; thus, it is important to determine the effect of natural disasters on the EMS in order to evaluate its effect on the healthcare system.

The EMS response interval is considered one of the most important emergency medical quality measures. Transportation time is one of the most important factors in emergency medical care. Ways to reduce EMS performance time have been studied in order to identify efficient solutions [5]. The purpose of the present study was to evaluate the influence of typhoons on the EMS, including the patients and EMS performance.

METHODS

Meteorological data

Meteorological data regarding typhoons were provided by the Korean Meteorological Administration (KMA). The KMA is a governmental organization under the Ministry of Environment. Its role is the observation and forecast of natural disasters and the issue of warnings regarding hazardous weather conditions. There are 97 weather stations including 10 radar installations, four upper-air observation stations, and Automatic Weather Stations in Korea [8]. Data were gathered from each weather station in specific regions.

The criteria used by the KMA typhoon warning system are shown in Table 1. The international classification of typhoons is described in Table 2. Any of the following are expected during a typhoon: strong wind or waves (with criteria for wind speeds for flat land and mountainous areas), total precipitation greater than 200 mm, and storm surge expected to reach warning levels. We analyzed the intensity and pathway of typhoons, respectively, based on the KMA criteria (Table 3). Warnings were categorized into si, do units (Fig. 1).

Table 1.

Typhoon warning system of the Korea Meteorological Administration

Table 2.

Classifications of typhoon intensity

Table 3.

Characteristics of the selected typhoons

Fig. 1.

The number of typhoon alerts. This figure shows the number of alerts activated by the Korea Meteorological Administration.

RESULTS

A total of 11 typhoons affected Korea during the study period. There were three typhoons in 2010, three in 2011, and five in 2012 (Fig. 1). Five (45%) typhoons made landfall and passed through, while the others passed near the coast. We used ‘Kyungbo,’ which is the highest alert level in the Korea Meteorological Agency typhoon warning system.

We counted the number of alerts activated by the KMA by region (Fig. 2). Some areas had many alerts, including Jeollanamdo (eight), Jeju Island, and Jeollabukdo (seven). The southern part of Korea was disproportionately affected by typhoons.

Fig. 2.

Typhoons pathways. A total of 11 typhoons affected Korea during the study period. There were three typhoons in 2010, three in 2011, and five in 2012. Five made landfall and passed through the country; the others passed along the coast.

Typhoons were categorized into the following four groups based on strength by the KMA (Table 2) [9]: two were level 1 (>44 m/sec), three were level 2 (33–43 m/sec), two were level 3 (25–32 m/sec), and four were level 4 (17.2–24 m/sec). Cases were selected from among 16 days. The selected typhoons differed in characteristics (Table 3).

There were 14,521 EMS responses reported in the National Emergency Management Agency data. From these, 7,807 cases and 7,434 controls were selected for analysis. After excluding transfer and missing cases, a total of 6,489 cases and 6,845 controls were selected. There were no obvious differences between the baseline characteristics of the cases and controls (Fig. 3 and Table 4). However, there were statistically significant differences in age, place, and time request. There were fewer patients aged 0 to 15 years in the case group and fewer patients were outdoors at the time of the EMS call in this group. There were fewer evening to midnight calls in the case group and more patients were unconscious (unresponsive, comatose) in this group. There were no significant differences in vital signs (blood pressure, heart rate, and oximetry) (Table 5).

Fig. 3.

Study flow diagram of patients. This figure shows the total number of emergency medical service responses and the selected numbers of cases and controls used in the analysis except for a non-transfer case and a missing case.

Table 4.

Baseline patient characteristics

Table 5.

Patient vital signs

EMS operational performance measured by the times from call to dispatch, call to the field, and call to the hospital did not differ significantly between cases and controls (Table 6). Call to hospital arrival times did not differ significantly between cases and controls (28.67, standard deviation 16.37 vs. 28.97, standard deviation 28.91; P=0.39).

Table 6.

Emergency medical service operational performance

DISCUSSION

Using nationwide typhoon and EMS data we found no statistically significant association between EMS response time and the incidence of typhoons. We also found there was no increased call volume during typhoons and the severity and clinical characteristics of patients also did not differ.

However, the case group was older than the control group. There were more patients with abnormal mental status in the case group, which may be due to a decrease in the mild to moderate group due to bad weather conditions. Despite these differences, there was no clinically consistent difference between the two groups that could be associated with typhoons.

The negative association between typhoons and call volume is contrary to previous studies, which reported decreased numbers of emergency department visits on the first day but an increased number after a typhoon [4,10-12], This may be due to the fact that the typhoons in Korea were not as strong as those in previous reports [4,13]. Korea’s well-established typhoon warning system along with its robust infrastructure and advanced irrigation system may have reduced the number of casualties during the typhoon events included in this study.

Our negative findings may be also due to the concrete road structure and drainage system. These systems prevent flooding of major roads, thus reducing ambulance travel time. Previous studies have assessed hurricanes that caused severe flooding, which compromised EMS quality [4,14].

Participation in outdoor activities is likely decreased during a typhoon. In the case group, 12.63% of EMS requests were to an outdoor location compared to 17% of controls (P<0.001). Reduced traffic jams during a typhoon could also have counteracted EMS delays. However, we did not collect data specific to traffic flow.

This study has some potential limitations. First, the definition of typhoon exposure was defined in a meteorological manner, which could differ from that used in clinical or operational settings. We did not differentiate the specific characteristics of each typhoon such as precipitation and wind speed, which directly affect trauma incidence and ambulance operation. However, we did use the typhoon category alert, which incorporates many factors indicative of typhoon strength.

Second, the effect of weather is largely influenced by roads, housing, and urbanization, which were not considered in this study. In Korea, a large proportion of the population resides in high-rise apartments in very urbanized areas. Not adjusting for these factors could have contributed to the negative results.

Third, the travel distance between ambulance stations, patients, and destination hospitals was not considered. Ambulance crews could have headed to alternate hospitals that they would not have chosen under ordinary circumstances. However, alternate ambulance teams could also have been deployed due to typhoon-associated circumstances such as flooded roads. Therefore, there was no significant effect of typhoons on the EMS system during the study period.

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Notes