Clinical courses and outcomes of hospitalized adult patients with seasonal influenza in Korea, 2011-2012: Hospital-based Influenza Morbidity & Mortality (HIMM) surveillance.
Influenza is an acute respiratory illness, which can be accompanied by complications such as pneumonia. This study was conducted to survey the clinical courses and outcomes of hospitalized adult patients with laboratory-confirmed seasonal influenza. A prospective case-control study was performed in adult influenza patients who were admitted to hospitals participating in the Hospital-based Influenza Morbidity and Mortality (HIMM) surveillance system in Korea from October 2011 to May 2012. Cases with complicated influenza were compared to those without complications. A total of 123 (5.6%) patients among 2184 laboratory-confirmed adult influenza patients were hospitalized during the 2011-2012 influenza epidemic season. Forty (32.5%) experienced 50 complication episodes. Age older than 60 years (P < 0.01), male sex (P = 0.04), diabetes (P < 0.01), chronic cardiovascular disease (P < 0.01) and neuromuscular disease (P = 0.02) were significantly related to development of complications in univariate analysis. Multivariate logistic regression analysis revealed that diabetes (odds ratio [OR] 3.63, 95% confidence interval [CI] 1.15-11.51, P = 0.02) was an independent risk factor for complicated seasonal influenza. C-reactive protein (CRP) was discriminative between complicated and uncomplicated influenza (cutoff value 13 mg/L, sensitivity 70%, specificity 74%). Complicated patients received antibiotics more frequently (P < 0.01) with longer hospital stays (P = 0.01). In conclusion, diabetic patients are at great risk for complicated influenza, and CRP would be useful to predicting complication. Therefore, early interventions such as antiviral therapy should be considered for high risk patients with diabetes, especially those with increased serum CRP level.
Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea.
Kyung-Wook
KW
Hong
Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea.
Hee Jin
HJ
Cheong
Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Republic of Korea.
Won Suk
WS
Choi
Department of Internal Medicine, Hallym University Kangnam Sacred Heart Hospital, Seoul, Republic of Korea.
Jacob
J
Lee
Department of Internal Medicine, The Catholic University of Korea, School of Medicine, St. Vincent's Hospital, Suwon, Republic of Korea.
Seong-Heon
SH
Wie
Department of Internal Medicine, Inha University College of Medicine, Incheon, Republic of Korea.
Ji Hyeon
JH
Baek
Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
Hyo Youl
HY
Kim
Department of Internal Medicine, Chungbuk National University, Cheongju, Republic of Korea.
Hye Won
HW
Jeong
Department of Internal Medicine, Korea University Guro Hospital, Seoul, Republic of Korea; Transgovernmental Enterprise for Pandemic Influenza in Korea, Seoul, Republic of Korea. Electronic address: wjkim@korea.ac.kr.
Woo Joo
WJ
Kim
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006761:Hospitals; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000188:drug therapy / Q000378:metabolism / Q000401:mortality* / Q000821:virology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012621:Seasons
D002097:C-Reactive Protein
Complications; Hospitalized; Influenza; Risk factors