| winter respiratory viruses and health care use: a population-based study in the northwest united states. | 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 ev ... | 2003 | 12856212 |