The majority of rheumatic diseases are multisystem disorders with poorly understood etiology; they tend to be heterogeneous in their presentation, course, and outcome and do not have a single clinical, laboratory, pathologic, or radiologic feature that could serve as a “gold standard” in support of diagnosis and/or classification.
Differences Between Diagnostic and Classification Criteria
| Classification Criteria | Diagnostic Criteria |
| Classification criteria are standardized definitions that are primarily intended to enable clinical studies to have uniform cohorts for research | Diagnostic criteria are a set of signs, symptoms, and tests developed for use in routine clinical care to guide the care of individual patients |
| Need to define (relatively) homogenous group that can be compared across studies and geographic regions | Need to be broad and must reflect the all possible different features and severity of a disease (heterogeneity) |
| Very high specificity is required, even if some loss in sensitivity | Both specificity and sensitivity need to be very high, approaching 100%, which is difficult to achieve |
| Single universal classification criteria can be applied to different geographical regions, race and ethnicities | Single universal diagnostic criteria cannot be used for making diagnosis due to different disease prevalence in different geographic areas, race and ethnicities |
| Classification criteria are possible for disease with and without true “gold standards” (e.g., monosodium urate crystals in gout | Diagnostic criteria are possible for disease with a true “gold standard” like MSU crystals in gout. For such diseases, the classification and diagnostic criteria can be very similar. For diseases without gold standard, development of diagnostic criteria poses significant challenges |
| Differences in resources and feasibility has limited effect on classification criteria | Differences in resources and feasibility significantly effect development of diagnostic criteria |
| Classification criteria are for research, and therefore, should have no or little impact on billing and reimbursement | Diagnostic criteria are for diagnosis, and therefore, have implications for billing and reimbursement |
| Classification criteria have no treatment implications for patients | Diagnostic criteria have treatment implications for patients |
| Health care priorities of different geographical areas do not influence classification criteria | Health care priorities of different geographic areas may influence diagnostic criteria |
| Classification of a disease can be accomplished by a set of criteria with reasonable sensitivity and specificity | Diagnosis is a complex multi-step process by a physician, which is difficult to accomplish with a single set of criteria |
References:
- Aggarwal R, Ringold S, Khanna D, et al. Distinctions between diagnostic and classification criteria?. Arthritis Care Res (Hoboken). 2015;67(7):891-897. [Medline]
- Belmonte-Serrano MA. The myth of the distinction between classification and diagnostic criteria. Reumatol Clin. 2015;11(3):188-189. [Medline]
Created Aug 03, 2020.
