Table 2.
Cerebrospinal fluid parameters as discriminators between cerebral malaria and presumed viral encephalitis
| Cut-off | Sensitivity1 (%) | Specificity2 (%) | Negative predictive Value3 (%) | Positive predictive Value4 (%) |
| (95% CI) | (95% CI) | (95% CI) | (95% CI) | |
| CSF white cell count <4 cells/microl | 100 (76–100) | 57 (32–78) | 100 (67–100) | 66 (43–83) |
| CSF protein <0.43 g/l | 92 (64–98) | 78 (52–92) | 91 (64–98) | 78 (52–92) |
| CSF glucose <3.4 mmol/l | 100 (78–100) | 100 (75–100) | 100 (75–100) | 100 (78–100) |
| Ratio CSF/serum ADA <0.385 | 91 (64–98) | 100 (78–100) | 93 (70–100) | 100 (74–100) |
| CSF LDH < 22.5 IU/ml | 75 (46–91) | 71 (44–88) | 76 (49–92) | 69 (42–87) |
1Sensitivity is the true positive rate in percent. It is calculated as the ratio of the number of true positive over the sum of true positive and false negative patients. True positive meant in the context of this study the presence of cerebral malaria in a group of patients with presumed viral encephalitis or cerebral malaria below a certain value of a parameter, the "cut-off". 2Specificity is the true negative rate in percent. It is calculated as the ratio of the number of true negative over the sum of false positive and true negative patients. True negative meant the patient has presumed viral encephalitis if the parameter is above the "cut-off" chosen. 3The negative predictive value is the ratio of the number of true negative over the sum of false negative and true negative patients. Positive predictive value is the post-test probability of a positive test and negative predictive value the post-test probability of a negative test. 4The positive predictive value is calculated as the ratio of the number of true positive over the sum of true positive and false positive patients.