Barreto et al developed an index for identifying a patient with Schistosoma mansoni infection who has significant hepatic fibrosis. The authors are from multiple institutions in Brazil.
The index is named for Professor Amaury Domingues Coutinho from Brazil.
Patient selection: Schistosoma mansoni infection
Outcome: hepatic fibrosis grades C (peripheral), D (central), E (advanced), or F (very advanced)
Parameters:
(1) platelet count in 10^9/L
(2) serum alkaline phosphatase in IU/L
(3) upper limit of normal for serum alkaline phosphatase in IU/L
serum alkaline phosphatase as multiple of upper limit of normal =
= (serum alkaline phosphatase) / (upper limit of normal)
Coutinho index =
= (alkaline phosphatase as multiple of ULN) / (platelet count as multiple of 10^9) * 100
Interpretation:
• An index >= 0.048 was predictive of periportal fibrosis grades C, D, E or F.
Performance:
• The authors claim 100% sensitivity and 100% specificity, giving an area under the ROC curve of 1.0.
The authors also reported a risk score:
Coutinho-index risk score =
= EXP(17.25 + (0.067 * (alkaline phosphatase)) - (0.133 * (platelet count as multiple of 10^9)))
where:
• The alkaline phosphatase appears to be the multiple of the upper limit of normal.
