Research Article

Efficacious End User Measures—Part 1: Relative Class Size and End User Problem Domains

Table 6

Rheumatoid arthritis is a disease where both nontreatment and unnecessary treatment have negative consequences. Thus, knowing the overall predictive accuracy rate is useful information for a practitioner. These tables show the summary likelihood ratios originally reported and the corresponding normalized predictive accuracy odds ratios. Although the anti-CCP test is significantly better, its overall accuracy is not as great, nor is the negative predictive value as poor as one might believe, based simply on the likelihood ratio. (the parenthesized range in this and subsequent tables is the 95% confidence interval).
(a)

Test Normalized odds ratio measures
+

Anti-CCP 12.46 (9.72–15.98) 0.36 (0.031–0.042)
RF 4.86 (3.95–5.97) 0.38 (0.33–0.44)

(b)

Test Normalized odds ratio measures
PPV NPV EPA

Anti-CCP 13.4 (13.0–17.0) 2.88 (2.71–3.0) 8.14 (7.86–10.0)
RF 4.6 (4.25–5.0) 2.74 (2.63–2.87) 3.67 (3.44–3.93)