Volume 13, Number 2—February 2007
Research
Code-based Syndromic Surveillance for Influenzalike Illness by International Classification of Diseases, Ninth Revision
Table 5
Unmatched outpatient visit data and final influenzalike illness (ILI) syndromic groupings*
ICD-9 code | Unmatched data† | ILI group | |||||
---|---|---|---|---|---|---|---|
Total volume of code use (2001–04) | Average daily count | Correlation with positive specimens | p value | Signal -to-noise ratio | Original | New (final) | |
079.99 | 1,115,143 | 718 | 0.7746 | <0.0001 | 2.84 | Yes | Large |
780.6 | 470,770 | 303 | 0.7545 | <0.0001 | 2.55 | Yes | Large |
466.0 | 632,256 | 407 | 0.6693 | <0.0001 | 2.17 | Yes | Large |
486 | 322,397 | 208 | 0.7180 | <0.0001 | 2.09 | Yes | Large |
465.9 | 3,989,688 | 2,569 | 0.6758 | <0.0001 | 1.91 | Yes | Large |
461.9 | 741,085 | 477 | 0.6017 | <0.0001 | 1.81 | No | Large |
382.9 | 1,185,809 | 764 | 0.6286 | <0.0001 | 1.76 | No | Large |
460 | 361,139 | 233 | 0.5552 | <0.0001 | 1.55 | Yes | Large |
490 | 297,918 | 192 | 0.6337 | <0.0001 | 1.50 | Yes | Large |
786.2 | 545,510 | 351 | 0.5573 | <0.0001 | 1.24 | Yes | Large |
487.1 | 62,340 | 40 | 0.8696 | <0.0001 | 5.59 | Yes | Small |
487.8 | 8,973 | 6 | 0.7926 | <0.0001 | 4.74 | Yes | Small |
487.0 | 5,093 | 3 | 0.6205 | <0.0001 | 3.11 | Yes | Small |
465.8 | 72,042 | 46 | 0.6384 | <0.0001 | 1.86 | Yes | Small |
466.11 | 18,377 | 12 | 0.4800 | <0.0001 | 1.83 | Yes | – |
466.19 | 68,127 | 44 | 0.5257 | <0.0001 | 1.65 | Yes | – |
480.2 | 451 | 0 | 0.3316 | <0.0001 | 1.64 | Yes | – |
462 | 1,436,325 | 925 | 0.5468 | <0.0001 | 1.61 | Yes | – |
480.1 | 1,790 | 1 | 0.4083 | <0.0001 | 1.58 | Yes | – |
382.00 | 277,270 | 179 | 0.4868 | <0.0001 | 1.58 | No | – |
480.9 | 10,852 | 7 | 0.4562 | <0.0001 | 1.44 | Yes | – |
478.9 | 7,434 | 5 | 0.4296 | <0.0001 | 1.23 | Yes | – |
461.8 | 123,913 | 80 | 0.3083 | <0.0001 | 1.14 | No | – |
465.0 | 33,760 | 22 | 0.4804 | <0.0001 | 1.11 | Yes | – |
484.8 | 4,312 | 3 | 0.3202 | <0.0001 | 1.11 | Yes | – |
480.8 | 11,708 | 8 | 0.3501 | <0.0001 | 1.07 | Yes | – |
079.89 | 17,729 | 11 | 0.3355 | <0.0001 | 1.05 | Yes | – |
485 | 7,954 | 5 | 0.4180 | <0.0001 | 0.99 | Yes | – |
464.20 | 3,539 | 2 | 0.3852 | <0.0001 | 0.88 | Yes | – |
463 | 168,499 | 108 | 0.3176 | <0.0001 | 0.08 | No | – |
784.1 | 59,516 | 38 | 0.2994 | <0.0001 | 0.59 | Yes | – |
464.10 | 1,736 | 1 | 0.2560 | 0.0002 | 0.56 | Yes | – |
480.0 | 287 | 0 | 0.0889 | 0.2082 | 0.24 | Yes | – |
464.00 | 22,470 | 14 | 0.1133 | 0.1085 | 0.14 | Yes | – |
*NOS, not otherwise specified; NEC, not elsewhere classified (as listed in the International Classification of Diseases, 9th Revision).
‡ Department of Defense–wide outpatient visit data, October 2000–December 2004.
1Current affiliation: Tacoma–Pierce County Health Department, Tacoma, Washington, USA
2Current affiliation: US Census Bureau, Suitland, Maryland, USA
3Current affiliation: Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA