Zahn et al reported a Tuberculosis Risk Score based on a patient's laboratory values. The score appears to predict outcome following antituberculous therapy. The authors are from Nanjing Medical University in China.
Patient selection: tuberculosis, prior to antituberculous therapy
Parameters:
(1) platelet count in 10^9/L
(2) packed cell volume (PCV, hematocrit) as a decimal fraction
(3) absolute lymphocyte count in 10^9/L
(4) percent monocytes
(5) absolute neutrophil count in 10^9/L
(6) percent neutrophils
(6) serum total bilirubin in µmol/L
(7) serum ALT in U/L
(8) serum uric acid in µmol/L
(9) serum cystatin C in mg/L
|
Parameter
|
Points
|
|
platelet count
|
0.8236 * (count)
|
|
packed cell volume
|
-0.6823 * (PCV)
|
|
absolute lymphocyte count
|
-0.4442 * (count)
|
|
percent monocytes
|
-0.272 * (percent)
|
|
absolute neutrophil count
|
0.0222 * (count)
|
|
percent neutrophils
|
0.0027 * (percent)
|
|
serum total bilirubin
|
-0.5511* (bilirubin)
|
|
serum ALT
|
-0.6839 * (ALT)
|
|
serum uric acid
|
0.6198 * (uric acid)
|
|
serum cystatin C
|
0.6040 * (cystatin)
|
Interpretation:
• The risk score varies with the inputs.
• The range reported by Zhan et al was 0 to 2.8. The values from the above is about 200 times greater. This primarily based on points assigned for the platelet count and uric acid.
• If log transforms were performed on platelet count, bilirubin, ALT and uric acid then values close to this shown by Zhan are seen.
• The hazard ratio for the score was 4.98.
