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. Author manuscript; available in PMC: 2013 Jun 1.
Published in final edited form as: Pharmacoepidemiol Drug Saf. 2012 Apr 24;21(6):666–669. doi: 10.1002/pds.3243

Table 1.

Diagnostic Test Characteristics of TB case-ascertainment strategies using ICD9-CM data and two different sets of pharmacy criteria. A) ICD9-CM coded patient-provider encounters (010–018, V12.01, V01.1, and 647.3) and pharmacy data (two anti-tuberculosis medications (isoniazid, rifampin, pyrazinamide, ethambutol, rifabutin, amikacin and fluoroquinolones) filled on the same day). B) ICD9-CM coded patient-provider encounters and pharmacy data (isoniazid and rifampin filled on the same day, or any prescription for rifamate (isoniazid/rifampin combination) or pyrazinamide)

TABLE 1A. Diagnostic Test Characteristics of strategies based on ICD-9CMa and pharmacyb data for diagnosis of TB
TB Definition N TB cases Sensitivity % (95% CI) Specificity % (95% CI) PPV % (95% CI) NPV % (95% CI)

ICD9-CM 449 60 (26.2–87.8) 97.6 (97.3–97.8) 1.3 (0.5–2.9) 99.9 (99.9–100)
Pharmacy 49 20 (2.5–55.6) 99.7 (99.7–99.8) 4.1 (0.5–14.3) 99.9 (99.9–100)
Both 8 20 (2.5–55.6) 99.9 (99.9–100) 25 (3.2–65.1) 99.9 (99.9–100)

TABLE 1B. Diagnostic Test Characteristics of strategies based on ICD9-CMa and pharmacyc data for diagnosis of TB
TB Definition N TB cases Sensitivity % (95% CI) Specificity % (95% CI) PPV % (95% CI) NPV % (95% CI)

ICD9-CM 449 60 (26.2–87.8) 97.6 (97.3–97.8) 1.3 (0.5–2.9) 99.9 (99.9–100)
Pharmacy 12 20 (2.5–55.6) 99.9 (99.9–100) 16.7 (2.1–48.4) 100 (99.9–100)
Both 6 20 (2.5–55.6) 100 (99.9–100) 33.3 (4.3–77.7) 100 (99.9–100)