Table 5

Performance of the decision rule (mean predicted probability and observed prevalence of laboratory animal sensitisation relative to the number of risk factors derived from a questionnaire (step 1), and results from SPTs to common allergens in step 2)

No risk factors1 Risk factor2–3 Risk factors≥4 Risk factors
Initial survey (questionnaire results):
    %2041337
    n/N93/472192/472154/47233/472
    Observed prevalence
 of sensitisation:
        %13134476
        n/N12/9325/19267/15425/33
    Predicted probability
 of sensitisation:
        %9154374
        SD1 1 1 1
Second survey (SPT results):
    Skin prick testPosNegPosNeg
        %55457921
        n/N84/15470/15426/337/33
    Observed prevalence
 of sensitisation:
        %66177771
        n/N55/8412/7020/265/7
    Mean predicted
 probability
        %62198343
        SD2121