Basic data used in the test-negative case-control study and the case-series study.

Completeness and frequency distribution of variables describing (a) the study population of patients whose sample was sent to the National Reference Center for Influenza or to one of four state laboratories and tested for pandemic influenza virus A/(H1N1) 2009 (test-negative case-control method); and (b) characteristics of the patients reported to the public health system (used in the case-series method); Germany, 2009/10.