Table 2

Validation of the use of questionnaire-based surveys for identification of psoriasis

Sensitivity (%)95% CISpecificity (%)95% CILR+95% CILR-95% CI
Patient-reported psoriasis (regardless of whether or not this was diagnosed by a physician)84.483.2 to 85.588.287.1 to 89.27.146.54 to 7.800.180.16 to 0.19
Patient-reported physician diagnosed psoriasis83.382.2 to 84.591.890.8 to 92.610.119.08 to 11.260.180.17 to 0.20
Patient-reported dermatologist diagnosed psoriasis78.877.6 to 80.1093.692.8 to 94.412.3110.90 to 13.910.230.21 to 0.24
  • True positive cases were drawn from Sample B. True negative cases were drawn from Sample C.

  • Sensitivity = true positive / (true positive + false negative).

  • Specificity = true negative / (false positive + true negative).

  • LR+ = sensitivity / (1 – specificity).

  • LR- = (1 – sensitivity) / specificity.

  • LR+, positive likelihood ratio; LR-, negative likelihood ratio.