Table 6 Factor analysis for the entire CRS population. The variables that predicted CRS in the most similar fashion were grouped together as Factors. Factors 1 (persistent dust mite) and 3 (seasonal pollens) implicated allergic rhinitis mechanisms. Factor 2 related asthma with polyposis. Independent factors were eosinophilia, aspirin sensitivity and low immunoglobulins.
From: Pathophysiological classification of chronic rhinosinusitis
Factors | Variables | Loading factors | Explained variance | Eigenvalue |
|---|---|---|---|---|
Factor 1 | Positive dust mite skin test Positive skin tests for persistent allergens (dust mites, cat, and fungi) Clinical diagnosis of allergic rhinitis | 0.93 0.91 0.90 | 29% | 3.5 |
Factor 2 | FEV1/FVC ratio (continuous range) FEF25%–75% ≤ 70% of predicted (score = 1) Polyposis | -0.93 0.92 0.77 | 26% | 3.2 |
Factor 3 | Positive skin test results to weeds Positive skin test results to grasses | 0.91 0.79 | 15% | 1.6 |
Factor 4 | Blood eosinophils > 4% (qualitative) | 0.92 | 12% | 0.9 |
Factor 5 | Aspirin sensitivity | 0.90 | 10% | 0.8 |
Factor 6 | Any immunoglobulin < lower limits of normal | 0.70 | 8% | 0.6 |