Table 1.
CPPD Combined Expert Committee rating of influence on the likelihood of CPPD (−3 to +3) for candidate clinical and laboratory items
| Candidate criteria | Modal rating score | Standard deviation |
|---|---|---|
| Age at symptom onset | ||
| 91 years or older | 3 | 0.81 |
| 81–90 | 3 | 0.84 |
| 71–80 | 2 | 0.82 |
| 61–70 | 1 | 0.82 |
| 51–60 | 0 | 1.03 |
| 50 years or younger | −2 | 1.11 |
| Acute inflammatory arthritis of the following joint | ||
| Crowned dens syndrome | 3 | 0.84 |
| Knee | 2 | 0.90 |
| Wrist | 2 | 0.77 |
| Diffuse inflammatory hand swelling involving periarticular structures | 1 | 1.24 |
| Ankle | 0 | 1.21 |
| Spine | 0 | 1.50 |
| Mid-foot | −1 | 1.06 |
| 1st MTP joint | −2 | 1.21 |
| Recurrence and pattern of joint involvement | ||
| One self-limiting episode of acute inflammatory arthritis that resolved without treatment | 2 | 0.83 |
| Recurrent attacks of acute inflammatory arthritis in a characteristic joint (e.g. wrist, knee) | 2 | 0.77 |
| Additive attacks of inflammatory polyarthritis (i.e. the episode starts in one joint, then another joint becomes involved, then another, etc.) | 1 | 1.32 |
| Asymmetric attacks of inflammatory polyarthritis | 1 | 1.12 |
| Inflammatory oligoarthritis with asymmetric joint involvement | 1 | 0.98 |
| Persistent inflammatory polyarthritis with intermittent flares | 1 | 1.12 |
| Recurrent attacks of acute inflammatory arthritis in joints other than those that are typically involved by CPPD | 0 | 1.21 |
| Persistent inflammatory polyarthritis without flares | −2 | 1.32 |
| Onset and treatment response | ||
| Rapid onset acute inflammatory arthritis (time to maximal pain <24 hours)* | 1 | 1.01 |
| Acute inflammatory arthritis that developed in the context of acute illness, surgery, or joint trauma | 1 | 0.97 |
| Inflammatory oligoarthritis with good response to colchicine | 1 | 1.23 |
| Inflammatory oligoarthritis with good response to colchicine | 1 | 1.14 |
| Inflammatory polyarthritis with good response to colchicine | 1 | 1.15 |
| Acute inflammatory arthritis that developed in the context of recent bisphosphonate use | 1 | 1.06 |
| Physical findings | ||
| Erythema of the involved joint(s) during acute inflammatory arthritis | 1 | 0.70 |
| Hemarthrosis without other explanation (e.g. without joint injury, anticoagulation or pigmented villonodular synovitis) | 1 | 1.23 |
| Palpable subcutaneous tophus | −3 | 1.00 |
| Psoriasis | −2 | 1.16 |
| Co-morbidities and family history | ||
| History of familial CPPD | 3 | 0.81 |
| Gitelman disease | 3 | 0.86 |
| Hereditary hemochromatosis | 3 | 0.87 |
| Wilson disease | 2 | 1.24 |
| Ochronosis | 2 | 1.33 |
| History of meniscectomy or arthroscopy | 0 | 1.26 |
| Acromegaly | 0 | 1.10 |
| Short bowel disease | 0 | 1.76 |
| Osteoarthritis location and features | ||
| Wrist | 2 | 0.90 |
| 2nd and 3rd MCPJs | 2 | 1.08 |
| 2nd or 3rd MCPJs*+ | 1 | 0.84 |
| Scapho-trapezium joint* | 1 | 0.69 |
| Scapho-trapezium joint without OA of the trapezio-metacarpal joint | 1 | 0.82 |
| Scapho-lunate advanced collapse (SLAC) wrist* | 1 | 0.83 |
| Elbow | 1 | 1.00 |
| Patello-femoral joint without OA of the tibio-femoral joint | 1 | 1.09 |
| Ankle, without history of trauma | 1 | 1.01 |
| More than one of the following: ankle, wrist, shoulder, elbow | 1 | 0.97 |
| OA at one or more joint with signs of joint inflammation on examination | 1 | 0.90 |
| Scapho-trapezium joint without OA of the 1st MCP joint | 0 | 1.14 |
| Lateral tibiofemoral joint | 0 | 0.78 |
| Patello-femoral and tibio-femoral joints | 0 | 0.89 |
| Shoulder | 0 | 1.20 |
| Scapho-trapezium joint without OA of the 1st MCP joint | 0 | 0.95 |
| Scapho-trapezium and trapezio-metacarpal joints | 0 | 1.00 |
| Trapezio-metacarpal joint | 0 | 0.61 |
| Synovial fluid findings | ||
| At least one joint aspirate demonstrating CPP crystals | 3 | 0.26 |
| CPP crystals absent 1 occasion* | −1 | 0.63 |
| CPP crystals absent on 2 or more occasions | −2 | 0.85 |
| Monosodium urate crystals present, no CPPD crystals, and no micro-organisms | −3 | 0.83 |
| Micro-organisms on culture, no monosodium urate crystals, no CPPD crystals | −3 | 0.99 |
| Laboratory findings | ||
| Hypomagnesemia | 3 | 0.83 |
| Hyperparathyroidism | 3 | 0.78 |
| Hypercalcemia | 2 | 0.92 |
| Low-titer positive RF (1–3 times upper limit of normal) | 0 | 0.68 |
| High-titer positive RF (>3 times upper limit of normal) | −2 | 0.96 |
| Low-titer positive ACPA (1–3 times upper limit of normal)* | 0 | 0.98 |
| High-titer positive ACPA (>3 times upper limit of normal) | −3 | 0.97 |
*
Retained despite mode rating score −1, 0, or +1 per Steering Committee discussion
+
OA of 2nd MCP joint and OA of 3rd MCP joint were split into two discrete items