title: Winter respiratory viruses and health care use: a population-based study in the northwest United States.
abstract: To quantify health care use among adults during influenza and respiratory syncytial virus (RSV) seasons, we identified a cohort of veterans aged >or=18 years who used Department of Veterans Affairs (VA) facilities in Oregon and Washington states as their source of health care. During 1998-2000, veterans accrued 237,159 person-years of follow-up. Using VA data sources, we measured acute cardiopulmonary hospitalizations and primary care and urgent care visits. Differences between rates of study events when influenza and/or RSV were circulating and event rates when neither virus was circulating were used to calculate winter virus-attributable morbidity. Inpatient and outpatient event rates were consistently higher during winter virus season, compared with non-winter virus season. Annual rates of cardiopulmonary hospitalizations attributable to influenza or RSV infection ranged from 0.8 (95% confidence interval [CI], 0.1-1.5) per 1000 low-risk individuals aged 18-49 years, to 10.6 (95% CI, 7.5-13.6) per 1000 high-risk individuals aged >or=65 years. Each year, circulation of influenza and RSV coincide with predictable increases in medical care use.
authors.affiliation: Department of Medicine, University of Washington School of Medicine, Seattle, USA. kneuzil@u.washington.edu
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Neuzil
authors.forename: Charles
authors.initials: C
authors.lastname: Maynard
authors.forename: Marie R
authors.initials: MR
authors.lastname: Griffin
authors.forename: Patrick
authors.initials: P
authors.lastname: Heagerty
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000553:Ambulatory Care; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization; D006787:Hospitals, Veterans; D006801:Humans; D009981:Influenza B virus; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009922:Oregon; D018357:Respiratory Syncytial Virus Infections / Q000503:physiopathology; D012136:Respiratory Syncytial Viruses; D012189:Retrospective Studies; D012621:Seasons; D014481:United States; D014861:Washington
chemical_list: D007252:Influenza Vaccines