Summary of “BIPED” (Burden of disease, Investigative, Prognostic, Efficacy and Diagnostic) biomarker classification for osteoarthritis (OA). Adapted from Bauer, et al. Osteoarthritis Cart 2006;14:723–7; with permission.
| Burden of Disease | Investigative | Prognosis | Efficacy of Intervention | Diagnostic | |
|---|---|---|---|---|---|
| Definition | Biomarker associated with extent or severity of OA | Biomarker not yet meeting criteria for another category | Predicts onset or progression | Indicative or predictive of treatment efficacy | Differentiates diseased from non-diseased |
| Subjects | Must have OA | NA | With and/or without OA | With OA | With and/or without OA |
| Design | Cross-sectional, case-control | NA | Longitudinal | Controlled trial | Cross-sectional or case-control |
| Outcomes | Extent or severity of OA | NA | New or worsening OA | Ameliorated OA | OA vs no OA |
| Analysis | Correlation of biomarker with burden; percent of variance explained | NA | Sensitivity, specificity to predict poor or good prognosis; if continuous; consider variance explained | Risk or OR with 95% CI among successfully vs unsuccessfully treated | Sensitivity, specificity, LR AUC from ROC curve |
| Criteria | Significant association between marker and extent or severity of OA | NA | Significant association between marker and onset or progression of OA | Significant association between marker and treatment effect | Significant association between marker and OA diagnosis |
LR: Likelihood ratio; AUC: area under the curve; ROC: receiver-operating characteristic curve; NA: not applicable.