• Title/Summary/Keyword: Observational methods

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A Study on the Calculation of Evapotranspiration Crop Coefficient in the Cheongmi-cheon Paddy Field (청미천 논지에서의 증발산량 작물계수 산정에 관한 연구)

  • Kim, Kiyoung;Lee, Yongjun;Jung, Sungwon;Lee, Yeongil
    • Korean Journal of Remote Sensing
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    • v.35 no.6_1
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    • pp.883-893
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    • 2019
  • In this study, crop coefficients were calculated in two different methods and the results were evaluated. In the first method, appropriateness of GLDAS-based evapotranspiration was evaluated by comparing it with observed data of Cheongmi-cheon (CMC) Flux tower. Then, crop coefficient was calculated by dividing actual evapotranspiration with potential evapotranspiration that derived from GLDAS. In the second method, crop coefficient was determined by using MLR (Multiple Linear Regression) analysis with vegetation index (NDVI, EVI, LAI and SAVI) derived from MODIS and in-situ soil moisture data observed in CMC, In comparison of two crop coefficients over the entire period, for each crop coefficient GLDAS Kc and SM&VI Kc, shows the mean value of 0.412 and 0.378, the bias of 0.031 and -0.004, the RMSE of 0.092 and 0.069, and the Index of Agree (IOA) of 0.944 and 0.958. Overall, both methods showed similar patterns with observed evapotranspiration, but the SM&VI-based method showed better results. One step further, the statistical evaluation of GLDAS Kc and SM&VI Kc in specific period was performed according to the growth phase of the crop. The result shows that GLDAS Kc was better in the early and mid-phase of the crop growth, and SM&VI Kc was better in the latter phase. This result seems to be because of reduced accuracy of MODIS sensors due to yellow dust in spring and rain clouds in summer. If the observational accuracy of the MODIS sensor is improved in subsequent study, the accuracy of the SM&VI-based method will also be improved and this method will be applicable in determining the crop coefficient of unmeasured basin or predicting the crop coefficient of a certain area.

Long-term Efficacy of S-1 Monotherapy or Capecitabine Plus Oxaliplatin as Adjuvant Chemotherapy for Patients with Stage II or III Gastric Cancer after Curative Gastrectomy: a Propensity Score-Matched Multicenter Cohort Study

  • Lee, Chang Min;Yoo, Moon-Won;Son, Young-Gil;Oh, Sung Jin;Kim, Jong-Han;Kim, Hyoung-Il;Park, Joong-Min;Hur, Hoon;Jee, Ye Seob;Hwang, Sun-Hwi;Jin, Sung-Ho;Lee, Sang Eok;Park, Ji-Ho;Seo, Kyung Won;Park, Sungsoo;Kim, Chang Hyun;Jeong, In Ho;Lee, Han Hong;Choi, Sung Il;Lee, Sang-Il;Kim, Chan Young;Kim, In-Hwan;Son, Myoung-Won;Pak, Kyung Ho;Kim, Sungsoo;Lee, Moon-Soo;Min, Jae-Seok
    • Journal of Gastric Cancer
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    • v.20 no.2
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    • pp.152-164
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    • 2020
  • Purpose: To compare long-term disease-free survival (DFS) between patients receiving tegafur/gimeracil/oteracil (S-1) or capecitabine plus oxaliplatin (CAPOX) adjuvant chemotherapy (AC) for gastric cancer (GC). Materials and Methods: This retrospective multicenter observational study enrolled 983 patients who underwent curative gastrectomy with consecutive AC with S-1 or CAPOX for stage II or III GC at 27 hospitals in Korea between February 2012 and December 2013. We conducted propensity score matching to reduce selection bias. Long-term oncologic outcomes, including DFS rate over 5 years (over-5yr DFS), were analyzed postoperatively. Results: The median and longest follow-up period were 59.0 and 87.6 months, respectively. DFS rate did not differ between patients who received S-1 and CAPOX for pathologic stage II (P=0.677) and stage III (P=0.899) GC. Moreover, hazard ratio (HR) for recurrence did not differ significantly between S-1 and CAPOX (reference) in stage II (HR, 1.846; 95% confidence interval [CI], 0.693-4.919; P=0.220) and stage III (HR, 0.942; 95% CI, 0.664-1.337; P=0.738) GC. After adjustment for significance in multivariate analysis, pT (4 vs. 1) (HR, 11.667; 95% CI, 1.595-85.351; P=0.016), pN stage (0 vs. 3) (HR, 2.788; 95% CI, 1.502-5.174; P=0.001), and completion of planned chemotherapy (HR, 2.213; 95% CI, 1.618-3.028; P<0.001) were determined as independent prognostic factors for DFS. Conclusions: S-1 and CAPOX AC regimens did not show significant difference in over-5yr DFS after curative gastrectomy in patients with stage II or III GC. The pT, pN stage, and completion of planned chemotherapy were prognostic factors for GC recurrence.

Clinical Characteristics of Chronic Cough in Korea

  • An, Tai Joon;Kim, Jin Woo;Choi, Eun Young;Jang, Seung Hun;Lee, Hwa Young;Kang, Hye Seon;Koo, Hyeon-Kyoung;Lee, Jong Min;Kim, Sung-Kyung;Shin, Jong-Wook;Park, So Young;Rhee, Chin Kook;Moon, Ji-Yong;Kim, Yee Hyung;Lee, Hyun;Kim, Yong Hyun;Kim, Je Hyeong;Lee, Sang Haak;Kim, Deog Kyeom;Yoo, Kwang Ha;Kim, Dong-Gyu;Jung, Ki-Suck;Kim, Hui Jung;Yoon, Hyoung Kyu;Cough Study Group of the Korean Academy of Tuberculosis and Respiratory Diseases
    • Tuberculosis and Respiratory Diseases
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    • v.83 no.1
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    • pp.31-41
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    • 2020
  • Background: Chronic cough is defined as a cough lasting more than 8 weeks and socio-economic burden of chronic cough is enormous. The characteristics of chronic cough in Korea are not well understood. The Korean Academy of Tuberculosis and Respiratory Diseases (KATRD) published guidelines on cough management in 2014. The current study evaluated the clinical characteristics of chronic cough in Korea and the efficacy of the KATRD guidelines. Methods: This was a multi-center, retrospective observational study conducted in Korea. The participants were over 18 years of age. They had coughs lasting more than 8 weeks. Subjects with current pulmonary diseases, smokers, exsmokers with more than 10 pack-years or who quit within the past 1 year, pregnant women, and users of cough-inducing medications were excluded. Evaluation and management of cough followed the KATRD cough-management guidelines. Results: Participants with chronic cough in Korea showed age in the late forties and cough duration of more than 1 year. Upper airway cough syndrome was the most common cause of cough, followed by cough-variant asthma (CVA). Gastro-esophageal reflux diseases and eosinophilic bronchitis were less frequently observed. Following the KATRD cough-management guidelines, 91.2% of the subjects improved after 4 weeks of treatment. Responders were younger, had a longer duration of cough, and an initial impression of CVA. In univariate and multivariate analyses, an initial impression of CVA was the only factor related to better treatment response. Conclusion: The causes of chronic cough in Korea differed from those reported in other countries. The current Korean guidelines proved efficient for treating Korean patients with chronic cough.

Vitamin D and Risk of Respiratory Tract Infections in Children: A Systematic Review and Meta-analysis of Randomized Controlled Trials (비타민 D와 소아 호흡기 감염의 위험성: 무작위 대조 연구에 대한 체계적 문헌고찰 및 메타분석)

  • Ahn, Jong Gyun;Lee, Dokyung;Kim, Kyung-Hyo
    • Pediatric Infection and Vaccine
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    • v.23 no.2
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    • pp.109-116
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    • 2016
  • Purpose: Recent observational studies have found that vitamin D deficiency is associated with respiratory tract infections. However, randomized controlled trials (RCTs) regarding the efficacy of vitamin D in childhood respiratory tract infection (RTI) have yield inconsistent results. We performed a systematic review and meta-analysis to evaluate the association between vitamin D supplementation and the risk of RTI. Methods: A comprehensive search was conducted using MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trial. Randomized controlled trials of vitamin D supplementation for prevention of RTI in children were included for the analysis. Cochrane Collaboration's tool for assessing the risk of bias was used to assess the quality of the studies. Pooled risk ratios with 95% confidence intervals (CIs) were meta-analyzed using Review Manager 5.3. Results: A total of seven RCTs were included in the meta-analysis. According to a random-effects model, the risk ratio for vitamin D supplementation was 0.82 (95% CI: 0.69-0.98) and $I^2=62%$ for heterogeneity. On subgroup analysis, heterogeneity decreased in the subgroup with follow-up less than 1 year, participants ${\geq}5years$ of age, patients subgroup, and subgroup with dosing daily. Funnel plot showed that there might be publication bias in the field. Conclusions: The present meta-analysis supports a beneficial effect of vitamin D supplementation for the prevention of RTI in children. However, the result should be interpreted with caution due to limitations including a small number of available RCTs, heterogeneity among the studies, and potential publication bias.

A Study on Significance Testing of Driver's Visual Behavior due to the VMS Message Display Forms on the Road (도로상 VMS 표출방식별 운전자 유의성 검증에 관한 연구)

  • Kum, Ki-Jung;Son, Young-Tae;Bae, Deok-Mo;Son, Seung-Neo
    • International Journal of Highway Engineering
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    • v.7 no.4 s.26
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    • pp.151-162
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    • 2005
  • Variable Message Sign (VMS), which provides drivers with direct information about state of traffic congestion and for prevent an accident, is the most effective method among the methods of providing information in Advanced Transportation Management System. Currently establishment and the VMS which is operated foundation lets in Guidelines on the use of Variable message sign (a book of the VMS) of 1999 November the Ministry Construction & Transportation, these contents mean main viewpoint on physical part such as message special quality variable (font, character size and line space, word interval) and position mainly among standard about establishment in general. But, it is true that using without effect verification on the character of VMS display and that using mode of stationary-centered. In this paper, it executed significance test to effort verification on the character of VMS display for more practical and effective information transmission based on the driver viewpoint For the researches; develop 3D-Simulation, select characteristics of driver's visual cognition behavior (the conspicuity, the legibility and the comprehensibility), evaluation each issue (day or night, 80km/h or 100km/h). Especially, that used the Eye Marker Recorder to measure of reading-time (legibility) thus, confirmed objectivity and reduce an observational error. The results showed that the conspicuity is Flashing> Stationary>Scroll. The legibility is not deference that Flashing between stationary form. Also the comprehensibility result showed that Flashing> Stationary>Stroll form.

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A Study on the Environment for Lowbirth Weight Infants in Neonatal Intensive Care Unit in the United States (신생아집중간호단위 환경과 저체중출생아의 반응에 대한 연구)

  • Han Kyung Ja
    • Child Health Nursing Research
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    • v.4 no.2
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    • pp.159-176
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    • 1998
  • In effort to conduct comparative study on the caregiving environment of Neonatal Intensive Care Unit(NICU) in both U. S and Korea, this study was been conducted first in the U.S. Purpose : The purpose of this study is to identify the physical environment and direct caregiving practices to lowbirth weight infants in NICU in the US. It also aims to examine the NICU outcome status and behavioral reponses of lowbirth weight infants. Methods : A study design using descriptive and inferential statistics was been conducted through an observational, field method. A sample of 15 preform infants admitted to NICU were recruited for the study. The subjects were those with birth weight between 1,000 gm to 1,500 gm, born at the gestation period of 27 to 33 weeks, and without any chromosomal or other genetic anomalies, major congenital infections, or maternal illness. Thirty minutes observation(three times of ten minutes of continuous observation)of the infant's behavior and physiological status, and an four-hour observation of the physical environment and direct care giving procedures were been conducted on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. The data to be collected were in four areas : the demograghic characteristics of the infants, the physical environment and care giving procedures, the frequency of the infant's designated behavior and physiological response, and NICU outcome variables. A descriptive analysis and Kruskal-Wallis, Pearson r were been applied according to variable characteristics. Results : 1. Mother's mean age was 29.47. The sample consisted of 6 males and 9 females. Mean gestational ages were 29.17 weeks. Mean birth weight was 1236.33g. Mean Apgar scores at one minute were 6.6, and 7.8 at five minutes. 2. The location for the incubator was in the distance from the light, X-ray screens and nursing station, in proximity to side-lamp, telephone and faucet on the third day after birth. The location for the incubator was in the distance from the light and radio on the tenth day and in proximity to nursing station on the day of dischage from the NICU or at 34weeks postconception. 3. Nesting was the most applying aids to the infants. And foot roll, shielding and plastic frame were frequently using by nurses for facilitating well modulated restful posture. 4. There were statistically significant changes in the patterns of physical environment included locating the infant's incubator and bedding, specific aids to self regulation on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. 5. Statistically significant changes were not appeared in the patterns of direct caregiving procedure to the infants included stress inducing or reducing manipulations on the 3rd and 10th day after birth, and on the day of discharge from the NICU or at 34weeks postconception. 6. The stress response of the infants in NICU were significantly reduced as the infants grow older. 7. There were not statistically significant correlation between the physical envronment and the stress responses of the infants in NICU. 8. There were statistically significant correlation between the direct caregiving procedure to the infants and the stress response of the infants in NICU in the second and third observation on the day three. 9. Average weight gain per day from birth to discharge was 38.73g, number of days in the hospital was 42.60, number of days before bottle feeding was 3.6. Postconception age starting bottle feed ing was 31/sup +5/ weeks. Number of days on mechanical ventilator was average 7.64, 11.42 was an average number of days of oxygen need. Conclusion : It, thus, appears that to minimize the sensorymotor stimulation for the low birthweight preterm infant in NICU, manipulation of care giving practices to the babies whatever the stress inducing or reducing procedures, have to be limited in the immediate early stage after birth. And it needed to be reexamine to identify the appropriate and specific physical environment and the patterns of direct caregiving to the low birthweight preform infant as the infants grow older in NICU.

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The Etiologic Agents and Clinical Outcomes of Adult Community-acquired Pneumonia in Jeju (제주지역 성인 지역사회획득 폐렴의 원인균 및 임상양상)

  • Jeon, Bong-Hee;Kim, Miok;Kim, Jeong Hong;Shin, Sang Yop;Lee, Jaechun
    • Tuberculosis and Respiratory Diseases
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    • v.66 no.5
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    • pp.358-364
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    • 2009
  • Background: The appropriate empirical antimicrobial choice in the treatment of community-acquired pneumonia (CAP) should be advocated by community-based information on the etiologic pathogens, their susceptibility to antimicrobials, clinical characteristics and outcomes. Jeju is a geographically isolated and identical region in Korea. However, there is no regional reference on adult CAP available. This study investigated the etiologic agents and clinical outcomes of adult patients diagnosed with CAP in Jeju, Korea, to help guide the empirical antimicrobial choice. Methods: A prospective observational study for one year in a referral hospital in Jeju, Korea. Patients diagnosed with CAP were enrolled with their clinical characteristics. Microbiological evaluations to identify the etiologic agents in the adult patients with CAP were performed with blood culture, expectorated sputum smear and culture, antibody tests for mycoplasma, chlamydophila, and antigen tests for legionella and pneumococcus. The clinical outcomes of the initial empirical treatment were analyzed. Results: Two hundred and three patients with mean age of 64 and 79 females were enrolled. Ten microbials from 90 cases (44.3%) were isolated and multiple isolates were confirmed in 30. Among the microbial isolates, S. pneumoniae (36.3%) was the most common, followed by M. pneumoniae (23.0%), C. pneumoniae (17.0%), S. aureus (9.6%) and P. aeruginosa (5.9%). The initial treatment failure (23.8%) was related to the isolation of polymicrobial pathogens, elevated inflammatory markers, and the presence of pleural effusion. Among the 30 isolates of S. pneumoniae, 16 (53.3%) were not susceptible to penicillin, and 19 isolates (63.3%) to erythromycin and clarithromycin. However, 29 isolates (96.7%) were susceptible to levofloxacin and ceftriaxone. Conclusion: S. pneumoniae, M. pneumoniae, S. aureus, and P. aeruginosa are frequent etiologic agents of adult CAP in Jeju, Korea. The clinical characteristics and antibiotic resistance should be considered when determining the initial empirical antimicrobial choice. Respiratory quinolone or ceftriaxone is recommended as an empirical antimicrobiotic in the treatment of adult CAP in Jeju, Korea.

Occurrence Pattern of Intussusception according to the Introduction of Rotavirus Vaccine: An Observational Study at a University Hospital (로타바이러스 백신 도입에 따른 장겹침증 발생 경향: 한 대학병원 관찰 연구)

  • Nam, Hye Na;Lim, Kyung In;Tchah, Hann;Ryoo, Eell;Sun, Yong Han;Cho, Hye-Kyung
    • Pediatric Infection and Vaccine
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    • v.23 no.3
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    • pp.202-208
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    • 2016
  • Purpose: Rotavirus vaccine (RV) was introduced in Korea since 2007, and intussusception (IS) remains an important safety concern. This study investigated the trend of IS occurrence related to RV as well as the temporal relevance between vaccination and IS in children. Methods: We collected data of the patient aged ${\leq}18$ years with IS admitted to Gachon University Gil Medical Center, 2003 to 2015. For the patients that have occurred since 2008, the immunization records of RV were collected. The proportion of cases <1 year was calculated by the year and the temporal relationship between vaccination and IS occurrence was analyzed. Results: A total of 696 IS cases were noted. The cases <1 year were 30.7% (214/696). Although the incidence of all IS has increased over the 13-year period (from 74.1 in 2003 to 89.5 in 2015, linear by linear association, P=0.003), the incidence of IS <1 year has not increased (from 56.9 in 2003 to 53.3 in 2015, P=0.910), and the proportion of cases <1 year has decreased (from 35.4 in 2003 to 18.8 in 2015, P=0.000). Of 128 cases <1 year since 2008, 53.9% received RV. In the vaccinated group, 10 cases of IS occurred within 30 days, and eight cases did within 31 to 60 days. Numbers of IS after first, second, and third dose were three, 10, and five cases, respectively. Conclusions: Occurrence of IS in children <1 year of age did not increase since the introduction of RV. Further monitoring is essential for evaluation of vaccine safety.

Nationwide surveillance of acute interstitial pneumonia in Korea (급성 간질성 폐렴의 전국적 현황 조사)

  • Kim, Byoung-Ju;Kim, Han-A;Song, Young-Hwa;Yu, Jinho;Kim, Seonguk;Park, Seong Jong;Kim, Kyung Won;Kim, Kyu-Earn;Kim, Dong Soo;Park, June Dong;Ahn, Kang Mo;Kim, Hyo-Bin;Jung, Hyang-Min;Kang, Chun;Hong, Soo-Jong
    • Clinical and Experimental Pediatrics
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    • v.52 no.3
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    • pp.324-329
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    • 2009
  • Purpose : Acute interstitial pneumonia (AIP) is a rare disease, but its prognosis is fatal because of lack of efficient treatment modality. Recently, it has been reported that there was epidemic AIP in Korea. This study aims to investigate the past and current status of AIP in Korea. Methods : We performed a nationwide survey and a prospective study. From August 6 to 15, 2008, a questionnaire survey was conducted to identify the prevalence, local distribution, and response to current treatments. The questionnaire was answered by pediatrician working in 23 referral centers in Korea. In addition, 5 referral centers in Seoul performed a preliminary prospective observational study by obtaining clinical data and specimens from appropriate patients. The Korea Centers for Disease Control and Prevention analyzed the samples for possible pathogens. Results : The survey showed 78 AIP cases had occurred and 36 patients had died. Lung biopsy was performed only on 20 patients. In 2008, 9 AIP cases developed. In a prospective study, 9 (M:F=5:4) patients developed AIP in spring and 7 (78%) died, with the mean rate of death occurring 46 days after diagnosis. Human corona virus 229E, cytomegalovirus, influenza A virus, influenza B virus, and parainfluenza virus were isolated from the respiratory specimens. Conclusion : This study showed nationwide prevalence of AIP in Korea. In addition, because of the high mortality rate and rapid progress, pediatricians need to be aware of the disease. Further studies and a nationwide network are required for reducing the morbidity and mortality rates related to AIP.

Acute Respiratory Infections in the Neonatal Intensive Care Unit: Isolation of Viruses and the Characteristics of Respiratory Syncytial Virus Infection (신생아집중치료실에서의 급성 호흡기 감염-바이러스의 검출 및 respiratory syncytial virus 감염의 임상적 특징)

  • Park, Sun-Hee;Cho, Hye-Jung;Shim, So-Yeon;Son, Dong-Woo;Eun, Byung-Wook;Sun, Yong-Han;Tchah, Hann;Jeon, In-Sang
    • Neonatal Medicine
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    • v.16 no.2
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    • pp.182-189
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    • 2009
  • Purpose: Recently, it is easy to find the causal virus of acute respiratory infections using multiplex RT-PCR. The aim of this study is to show the distribution of respiratory viruses and to define the characteristics of respiratory syncytial virus (RSV) infections compared to other respiratory viral infections. Methods: This was a prospective observational study conducted in the NICU. The infants with acute respiratory infections were performed multiplex RT-PCR using nasal swabs. The demographics, initial symptoms, course of illness, and laboratory and imaging findings were recorded. The infants were divided into RSV and No RSV groups. Results: Twenty-three infants (50%) were in the RSV group. Rhinovirus was the second most common virus. Coinfections with two viruses accounted for 6.5% of respiratory infections. The number of preterm infants, exposure to cigarette smoke and having siblings were not different between the two groups. Infections in the postnatal care center were more common in the RSV group than the No RSV group (60.9% vs. 21.7%, P=.007). Dyspnea (34.8% vs. 8.7%, P=.032) and pneumonia (73.9% vs. 43.5%, P=.036) were more common in the RSV group. The RSV group frequently needed oxygen (52.5% vs. 13.0%, P=.005) and received nothing by mouth (43.5% vs. 13.0%, P=.022). The incidence of right upper consolidation was higher in RSV group (56.5% vs. 8.7%, P=.001). Conclusion: This study showed that other viruses than RSV can induce respiratory infections in neonates and young infants born prematurely. RSV infections have a more severe course of illness than other respiratory viruses. We have to be careful of prevention even for healthy neonates especially in crowed situations, such as the postnatal care center.