Design Characteristics of Included Studies (All Were Cohort and Independent, with Blinding Not Explicitly Stated)
| Study | Setting | Influenza | n | Population | Reference Standard | Inclusion Criteria |
|---|---|---|---|---|---|---|
| Nicholson et al 199710 | Community | A or B | 291 | Mean age, 73 years; 51.8% female | 4× rise in titer for Influenza A | Respiratory infection (over age 60) |
| Carrat et al, 199712 | Primary care office and home visit | A or B | 130 | Mean age, 33.2 years; 59% female | Fluorescent monoclonal antibodies | Suspected influenza (influenza-like illness, upper or lower respiratory tract infection, and/or fever >38 without other evidence of infection within 36 hours of onset) |
| Carrat et al, 19999 | Primary care office and home visits | A | 600 | Mean age, 38 years; 58% female | DIF and ELISA; 25% culture + PCR | Suspected influenza (all patients over age 1 with ≥1 of the following: influenza-like illness, upper or lower respiratory tract infectious syndrome, and/or temp >38°C without any infectious signs or symptoms.) |
| Monto et al, 199611 | Primary care office | A or B | 897 | NA | Viral culture or positive serology | Suspected influenza (influenza-like illness with fever and cough or sore throat presenting between November and April) |
| Lina et al, 199613 | Primary care office | A or B | 340 | NA (broad age range) | Culture or ELISA | Suspected influenza; data not available for patients without positive viral nasal swab. |
| Long et al, 199714 | Primary care office | A or B | 788 | Mean age, 76 in adults, 5 in children | Tissue culture, with ELISA to type the virus | Adults over age 65 and children with respiratory or febrile illness in community medical and pediatric practices. |
| Monto et al, 20008 | Outpatient | A or B | 3744 | Mean age, 34.7 years; 52% female. | Positive culture or ≥4× increase in influenza antibody titer in convalescent vs acute samples | Suspected influenza [fever (≥37.8°C; ≥37.2°C for patients ≥65 years in one study) or feverishness (subjective fever or chills) and 2 of the following: headache, myalgia, cough, or sore throat]. |
DIF, direct immunofluorescence; ELISA, enzyme-linked immunosorbent assay; NA, not available