Using inpatient electronic medical records to study influenza for pandemic preparedness

Abstract

Background We assessed the ability to identify key data relevant to influenza and other respiratory virus surveillance in a large‐scale US‐based hospital electronic medical record (EMR) dataset using seasonal influenza as a use case. We describe characteristics and outcomes of hospitalized influenza cases across three seasons. Methods We identified patients with an influenza diagnosis between March 2017 and March 2020 in 140 US hospitals as part of the US FDA's Sentinel System. We calculated descriptive statistics on the presence of high‐risk conditions, influenza antiviral administrations, and severity endpoints. Results Among 5.1 million hospitalizations, we identified 29,520 hospitalizations with an influenza diagnosis; 64% were treated with an influenza antiviral within 2 days of admission, and 25% were treated >2 days after admission. Patients treated >2 days after admission had more comorbidities than patients treated within 2 days of admission. Patients never treated during hospitalization had more documentation of cardiovascular and other diseases than treated patients. We observed more severe endpoints in patients never treated (death = 3%, mechanical ventilation [MV] = 9%, intensive care unit [ICU] = 26%) or patients treated >2 days after admission (death = 2%, MV = 14%, ICU = 32%) than in patients treated earlier (treated on admission: death = 1%, MV = 5%, ICU = 23%, treated within 2 days of admission: death = 1%, MV = 7%, ICU = 27%). Conclusions We identified important trends in influenza severity related to treatment timing in a large inpatient dataset, laying the groundwork for the use of this and other inpatient EMR data for influenza and other respiratory virus surveillance.

Understanding the Global Burden of Influenza in Adults Aged 18–64 years: A Systematic Literature Review from 2012 to 2022

“…Overall, the findings of this SLR suggest that adults aged 50–64 years are more likely to be hospitalized due to influenza than those aged 18–49 years, of which three studies found this difference to be statistically significant (Table 3 ) [ 22 – 26 , 28 ]. However, the seasonal variation in hospitalization rates were exemplified in Lemaitre et al, where a higher rate of influenza-associated hospitalization was reported in adults aged 20–49 years compared with adults aged 50–64 years (Fig.…”

“…The SLR identified 23 studies that reported the clinical burden, exerted by at least one of influenza-associated hospital or ICU admissions or ER or outpatient visits, while 10 studies were identified reporting influenza-related mortality in the general population aged 18–64 years. Influenza-related hospitalization was reported in eight countries where most studies were conducted in the US ( n = 5) [ 20 , 22 – 25 ], followed by Spain ( n = 3) [ 21 , 26 , 27 ], two in Japan [ 28 , 29 ], and only one in Italy [ 30 ], Germany [ 31 ], France [ 32 ], China [ 33 ], and Brazil [ 34 ], as shown in Fig. 4 .…”

“…(2022) [ 26 ] Hospitalization with severe and non-severe influenza 50–64 n = NR 486 (NR) 18–49 n = NR 303 (NR) < 0.001 US Fuller et al . (2022) [ 22 ] Adults hospitalized with influenza 50–64 n = NR n = NR (23.7) 18–49 n = NR n = NR (20.1) NR Ortiz et al . (2014) [ 23 ] Hospitalized due to influenza-related critical illness 50–64 n = NR 4,986 (NR) 18–49 n = NR 3,161 (NR) NR Yandrapalli et al .…”

“…The data identified in this SLR reflect a trend of increased influenza-associated clinical burden with increased age among those aged 18–64 years, including hospitalizations [ 22 – 26 , 28 ], ICU admissions [ 26 , 34 ], mortality [ 26 , 34 , 39 ], ER/outpatient visits [ 34 ], and use of mechanical ventilation [ 26 , 39 ]. Of note, in studies that stratified by age, the ‘older’ age range with greater associated burden was most frequently 50–64 years [ 22 , 23 , 25 , 26 , 34 , 39 ].…”

Treatment and care received by children hospitalized with COVID-19 in a large hospital network in the United States, February 2020 to September 2021

“…The US Food and Drug Administration’s (FDA) Sentinel System [ 19 , 20 ] is an active post-marketing surveillance system that uses curated, quality checked administrative claims and electronic health record (EHR) data to study medical products, and has implemented an array of public health surveillance activities to respond to the COVID-19 pandemic [ 21 ]. This includes partnering with a large US hospital system to allow for near real-time monitoring of hospitalized patients with COVID-19 [ 21 , 22 ].…”