Description of case-patients with available risk factor data identified during active case-finding in 2009 and during three consecutive health utilization surveys in 2010, three cities in Argentina.

2009 H1N1 denotes influenza A (H1N1)pdm09, SARI denotes severe acute respiratory illness, and ILI denotes influenza-like illness.
aamong cases with available age, pregnancy, obesity, chronic obstructive pulmonary disease, or asthma status data.
bThe age of case-patients is significantly associated with decedent, SARI, or ILI case-status in linear regression (p≤0.001).
cThe sex of case-patients is significantly associated with decedent, SARI, or ILI case-status in Fisher Exact testing (p = 0.01).
dThe characteristic is significantly associated with decedent, SARI, or ILI case-status in Fisher Exact testing (p<0.001).