ADA and meningeal tuberculosis: In this analysis, regarding the ADA assay method, nine studies have used the older Guisti method while seven studies have used non-Guisti method that suggested that non-Guisti method had a higher diagnostic odds ratio (dOR=51) with heterogeneity I2=74.5% for specificity and I2=51.1% for sensitivity, while comparatively lower diagnostic odds ratio in Guisti method (dOR=32) with I2=60% in specificity and I2=83.4% in the sensitivity for diagnosing tuberculous meningitis using CSF-ADA (Table 3).