Table 3

Comparison of effectiveness algorithm versus effectiveness gold standard for biologic users

Effectiveness gold standard*

Met effectiveness algorithm**

Yes

No

Total

PPV (95% CI)

NPV (95% CI)


Yes

42

14

56 (28%)

75% (62 to 86)

No

14

127

141 (72%)

90% (84 to 94)

Total

56 (28%)

141 (72%)

197 (100%)

Se 75%

(95% CI = 62 to 86)

Sp 90%

(95% CI = 84 to 94)


CI: confidence interval; NPV: negative predictive value; PPV: positive predictive value; Se: sensitivity; Sp: specificity. *DAS28 ≤ 3.2 or DAS28 improvement by > 1.2 units and high adherence (for example, ≥ 80%) to the biologic started on the index date. **The components of the effectiveness algorithm are shown in Table 1.

Curtis et al. Arthritis Research & Therapy 2011 13:R155   doi:10.1186/ar3471

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