Volume 13, Number 2—February 2007
Code-based Syndromic Surveillance for Influenzalike Illness by International Classification of Diseases, Ninth Revision
|Match day||No. specimens†|
|Did not match (removed from study)||1,153|
|Clinic day – 2 = specimen day||47|
|Clinic day – 1 = specimen day||125|
|Exact day match||5,267|
|Clinic day + 1 = specimen day||680|
|Clinic day + 2 = specimen day||117|
*ICD-9, International Classification of Diseases, Ninth Revision.
†No. specimens obtained by day of matching visit.