APPENDIX B

Co-morbidities for Influenza

Historical Factors/Co-morbid Conditions: claims evidence within the year before the start date of the initial influenza episode (except for HIV, which is at any time during the study period (10/1/96 – 9/30/97 + 21 days)):

  • Immunosuppressive Drugs – any prescription claim within the year prior to the start date of the initial influenza episode for any of the following drugs:
  • Aldesleukin
  • Azathioprine
  • Cyclophosphamide
  • Cyclosporine
  • Leflunomide
  • Methotrexate
  • Muromonab-CD3
  • Mycophenolate Mofetil
  • Tacrolimus Anhydrous
  • Chronic Corticosteroid Use (oral) – evidence of a total of 60 days or more dispensed prescription claim within the year prior to the start date of the initial influenza episode for any of the following drugs:
  • Betamethasone
  • Cortisone Acetate
  • Dexamethasone
  • Fludrocortisone Acetate
  • Hydrocortisone
  • Hydrocortisone Cypionate
  • Methylprednisolone
  • Prednisolone
  • Prednisolone Sod Phosphate
  • Prednisone
  • Triamcinolone
  • Triamcinolone Diacetate
  • HIV Infection – any one of the following found from 1 year before the initial influenza diagnosis through the end of the study period (10/1/96 – 9/30/97+21 days).
  • ICD-9 code 042 associated with a physician encounter (outpatient or inpatient), OR
  • ICD-9 code 136.3 pneumocystsis associated with a physician encounter (OP or IP), OR

Dispensings for HIV drugs, including ntiretroviral Agents, AHFS category 8:18:08. identified in the NEI database: abacavir sulfate, amprenavir/vitamin E, delavirdine mesylate, didan/calcium carb/magnesium, didanosine, didanosine/sodium citrate, efavirenz, indinavir sulfate, lamivudine, nelfinavir mesylate, nevirapine, ritonavir, saquinavir, saquinavir mesylate, stavudine, zalcitabine, zidovudine, zidovudine/lamivudine, plus foscarnet.

  • Malignancy – ICD-9 codes 140 through 208 except for 173; there must be evidence of two outpatient physician encounters or one hospitalization within the one year before the initial influenza diagnosis.
  • Chronic Heart Disease – There must be evidence of 2 outpatient physician encounters or one hospitalization within the one year prior to the initial influenza diagnosis for any of the following ICD-9 codes:

393 through 398, 416, 428, 402, 424, 429, 404, 425, 093, 410, 745, 746, 411, 413. 414

OR prescription for digoxin use.

  • Chronic Lung Disease - must have 2 outpatient physician encounters or one hospitalization within the one year prior to the initial influenza diagnosis for any of the following ICD-9 codes

277500 through 506

491 though 496515 through 517

519.9

OR prescriptions for respiratory drugs listed in Appendix E –

(includes non-chronic (<60 days) corticosteroid use in prior year or any use of the respiratory drugs in the attachment in the prior year)

  • Chronic Renal Disease – There must evidence of one of the following within one year prior to the initial influenza diagnosis:
  • 2 outpatient physician encounters with ICD-9 diagnosis codes of
  • 581 (nephrotic syndrome),
  • 582 (chronic glomerulonephritis),
  • 583 (nephritis and nephropathy not specified as acute or chronic),
  • 584,
  • 585,
  • 586,
  • 587 (renal sclerosis);
  • 1 hospitalization with ICD-9 diagnosis code
  • 581 (nephrotic syndrome),
  • 582 (chronic glomerulonephritis),
  • 583 (nephritis and nephropathy not specified as acute or chronic),
  • 585,
  • 586,
  • 587 (renal sclerosis);

-evidence of dialysis by ICD-9 procedure code 39.95 or CPT codes 90918 through 90937

  • Diabetes – There must be evidence of one of the following within one year prior to the initial influenza diagnosis:
  • 2 outpatient physician encounters with ICD-9 diagnosis code 250
  • 1 hospitalization with ICD-9 diagnosis code 250
  • 1 procedure related to diabetes (HCPCS Codes)
  • A4230E0607G0108 (1999 code no mapback)
  • A4231E0609G0109 (1999 code no mapback)
  • A4232E0784J1820
  • 1 prescription for an anti-diabetic agent

AHFS category 68:20 Antidiabetic Agents