Diagnostic accuracy of cannabinoid testing by liquid chromatography-tandem mass spectrometry in human hair

To determine the diagnostic accuracy of Cannabinoids testing by LC-MS/MS in human hair and compare it with urine in civil heavy vehicle drivers.

Current study was a diagnostic accuracy study done in "Armed Forces Institute of Pathology Rawalpindi, Pakistan" from February to November 2017. Urine and hair samples were collected by non-probability convenient sampling technique from 151 heavy vehicle drivers from Punjab. Hair and urine samples were collected from each subject. Separation of compounds was performed on Agilent Poroshell and analyzed using 6460 Triple Quadrapole LC-MS along-with software Mass hunter ©.

Study population (151 civil heavy vehicle drivers) was divided into three main divisions There were 69 (46%) truck drivers,43 (28.5%) twenty-wheeler drivers and 39 (26%) bus drivers. Mean age of study participants was 36±10.82 years. Paired t-test was applied to check mean difference between the two tests' concentration (i.e urine and hair analysis for cannabis) which showed significant difference at p<0.001. Among the different factors of diagnostic accuracy in hair and urine specimens were: Sensitivity (96% and 62%), Specificity (93% and 95%) Positive Predictive Value (88% and 87%), Negative Predictive Value (97% and 82%) respectively. Overall diagnostic accuracy of Cannabinoids detection in hair was 94% while in urine it was 83%. ROC curve showed area under curve of 0.79 and 0.96 for urine and hair samples respectively.

Current study signified hair as a substitute matrix owing to its non-invasive specimen collection, better diagnostic yield and wider detection period compared to urine.