Shuo Feng1, Benjamin J Cowling2, Sheena G Sullivan3. 1. WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China. 2. WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China. Electronic address: bcowling@hku.hk. 3. WHO Collaborating Centre for Reference and Research on Influenza, Melbourne, Australia; Fielding School of Public Health, University of California, Los Angeles, USA.
Abstract
BACKGROUND: Observational studies of influenza vaccine effectiveness (VE) are increasingly using the test-negative design. Studies are typically based in outpatient or inpatient settings, but these two approaches are rarely compared directly. The aim of our study was to assess whether influenza VE estimates differ between inpatient and outpatient settings. METHODS: We searched the literature from Medline, PubMed and Web of Science using a combination of keywords to identify published studies of influenza VE using the test-negative design. Studies assessing any type of influenza vaccine among any population in any setting were considered, while interim studies or re-analyses were excluded. Retrieved articles were reviewed, screened and categorized based on study setting, location and influenza season. We searched for parallel studies in inpatient and outpatient settings that were done in the same influenza season, in the same location, and in the same or similar age groups. For each of the pairs identified, we estimated the difference in VE estimates between settings, and we tested whether the average difference was significant using a paired t-test. RESULTS: In total 25 pairs of estimates were identified that permitted comparisons between VE estimates in inpatient and outpatient study settings. Within pairs, the prevalence of influenza was generally higher among patients enrolled in the outpatient studies, while influenza vaccination coverage among the test-negative control groups was generally higher in the inpatient studies. There was no heterogeneity in the paired differences in VE, and the pooled difference in VE between inpatient and outpatient studies was -2% (95% confidence interval: -12%, 10%). CONCLUSIONS: We found no differences in VE estimates between inpatient and outpatient settings by studies using the test-negative design. Further research involving direct comparisons of VE estimates from the two settings in the same populations and years would be valuable.
BACKGROUND: Observational studies of influenza vaccine effectiveness (VE) are increasingly using the test-negative design. Studies are typically based in outpatient or inpatient settings, but these two approaches are rarely compared directly. The aim of our study was to assess whether influenza VE estimates differ between inpatient and outpatient settings. METHODS: We searched the literature from Medline, PubMed and Web of Science using a combination of keywords to identify published studies of influenza VE using the test-negative design. Studies assessing any type of influenza vaccine among any population in any setting were considered, while interim studies or re-analyses were excluded. Retrieved articles were reviewed, screened and categorized based on study setting, location and influenza season. We searched for parallel studies in inpatient and outpatient settings that were done in the same influenza season, in the same location, and in the same or similar age groups. For each of the pairs identified, we estimated the difference in VE estimates between settings, and we tested whether the average difference was significant using a paired t-test. RESULTS: In total 25 pairs of estimates were identified that permitted comparisons between VE estimates in inpatient and outpatient study settings. Within pairs, the prevalence of influenza was generally higher among patients enrolled in the outpatient studies, while influenza vaccination coverage among the test-negative control groups was generally higher in the inpatient studies. There was no heterogeneity in the paired differences in VE, and the pooled difference in VE between inpatient and outpatient studies was -2% (95% confidence interval: -12%, 10%). CONCLUSIONS: We found no differences in VE estimates between inpatient and outpatient settings by studies using the test-negative design. Further research involving direct comparisons of VE estimates from the two settings in the same populations and years would be valuable.
Authors: Danuta M Skowronski; Naveed Z Janjua; Gaston De Serres; Anne-Luise Winter; James A Dickinson; Jennifer L Gardy; Jonathan Gubbay; Kevin Fonseca; Hugues Charest; Natasha S Crowcroft; Monique Douville Fradet; Nathalie Bastien; Yan Li; Mel Krajden; Suzana Sabaiduc; Martin Petric Journal: Clin Infect Dis Date: 2012-04-26 Impact factor: 9.079
Authors: Allen C Cheng; Tom Kotsimbos; Heath A Kelly; Louis B Irving; Simon D Bowler; Simon G A Brown; Mark Holmes; Christine R Jenkins; Philip Thompson; Graham Simpson; Richard Wood-Baker; Sanjaya N Senanayake; Stephen J Brady; David L Paterson; Peter A Wark; John W Upham; Tony M Korman; Dominic E Dwyer; Grant W Waterer; Paul M Kelly Journal: Vaccine Date: 2011-07-31 Impact factor: 3.641
Authors: Nevil Pierse; Heath Kelly; Mark G Thompson; Ange Bissielo; Sarah Radke; Q Sue Huang; Michael G Baker; Nikki Turner Journal: Vaccine Date: 2015-12-10 Impact factor: 3.641
Authors: Fabrice Carrat; Elisabeta Vergu; Neil M Ferguson; Magali Lemaitre; Simon Cauchemez; Steve Leach; Alain-Jacques Valleron Journal: Am J Epidemiol Date: 2008-01-29 Impact factor: 4.897
Authors: Jill M Ferdinands; Manjusha Gaglani; Emily T Martin; Don Middleton; Arnold S Monto; Kempapura Murthy; Fernanda P Silveira; H Keipp Talbot; Richard Zimmerman; Elif Alyanak; Courtney Strickland; Sarah Spencer; Alicia M Fry Journal: J Infect Dis Date: 2019-09-13 Impact factor: 5.226
Authors: Mei Shang; Jessie R Chung; Michael L Jackson; Lisa A Jackson; Arnold S Monto; Emily T Martin; Edward A Belongia; Huong Q McLean; Manjusha Gaglani; Kempapura Murthy; Richard K Zimmerman; Mary Patricia Nowalk; Alicia M Fry; Brendan Flannery Journal: Vaccine Date: 2018-11-09 Impact factor: 3.641
Authors: Sarah A Buchan; Stephanie Booth; Allison N Scott; Kimberley A Simmonds; Lawrence W Svenson; Steven J Drews; Margaret L Russell; Natasha S Crowcroft; Mark Loeb; Bryna F Warshawsky; Jeffrey C Kwong Journal: JAMA Pediatr Date: 2018-09-04 Impact factor: 16.193
Authors: Marc Rondy; Nathalie El Omeiri; Mark G Thompson; Alain Levêque; Alain Moren; Sheena G Sullivan Journal: J Infect Date: 2017-09-18 Impact factor: 6.072
Authors: Katherine Adams; Mark W Tenforde; Shreya Chodisetty; Benjamin Lee; Eric J Chow; Wesley H Self; Manish M Patel Journal: Hum Vaccin Immunother Date: 2021-11-10 Impact factor: 3.452
Authors: Mark W Tenforde; Jessie Chung; Emily R Smith; H Keipp Talbot; Christopher H Trabue; Richard K Zimmerman; Fernanda P Silveira; Manjusha Gaglani; Kempapura Murthy; Arnold S Monto; Emily T Martin; Huong Q McLean; Edward A Belongia; Lisa A Jackson; Michael L Jackson; Jill M Ferdinands; Brendan Flannery; Manish M Patel Journal: Clin Infect Dis Date: 2021-08-02 Impact factor: 20.999