Influenza Burden Assessment in the United States, July1997 - up to April 2009

Study Overview
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Brief Summary
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The study will assess the burden of severe influenza outcomes by age, risk status, and influenza subtype, in order to create a profile of the burden of influenza-related morbidity and mortality in United States from July 1997 to April 2009.

Detailed Description
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This epidemiological study is a modelling of time series retrospectively extracted from multiple databases. Data will be extracted from existing electronic healthcare databases.

Official Title
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Burden of Influenza in the United States, July 1997 up to April 2009

Conditions
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Influenza

Intervention / Treatment
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* Other: Data collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Recorded in the US NIS hospitalization data or the US National Vital Statistics System (NVSS) mortality data with a pre-specified diagnostic code. Exclusion Criteria: Missing data in the following fields: age, primary discharge diagnosis, admission month (NIS) /month of death (NVSS), and status at discharge (alive / dead).
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Influenza Group<br> | Other: Data collection<br>* The study will use multiple primary data sources: the Nationwide Inpatient Sample (for hospitalisations) and the US National Vital Statistics System (for mortality), and weekly virology data from the Centers for Disease Control and Prevention (CDC) influenza surveillance program supplemented with literature data. Weekly time series of the rates of various severe influenza-related health outcomes will be constructed. Statistical models, guided by weekly numbers of cases of laboratory-confirmed influenza and respiratory syncytial virus (RSV) contained in the CDC virology data, will be constructed to estimate the portions of the various outcomes that can be attributed to influenza. Next, the seasonal impact of influenza by age, risk status, and influenza subtype will be assessed. Finally, the potential burden that a quadrivalent vaccine could have prevented over the 12 year study period will be predicted.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Occurrences of potentially influenza-attributable hospitalization or death by age, risk status, region and season. |  | From July 1997 to April 2009 (i.e., up to almost 12 years) | 
| Amount of circulating influenza A and B, and RSV strains determined for each season. |  | From July 1997 to April 2009 (i.e., up to almost 12 years) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Influenza vaccine content and effectiveness by season. |  | From July 1997 to April 2009 (i.e., up to almost 12 years) | 
| Influenza vaccine coverage by season. |  | From July 1997 to April 2009 (i.e., up to almost 12 years) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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United States, Burden of Disease, Influenza