I took a test and the result was 73, i know that the cut off is 50 but i want to know if 73 indicates heavy usage...
You were given a quantitative value, therefore the sample had undergone a confirmation GC/MS with a cutoff level of 15 ng and not 50. The 50 ng was the cutoff limit for the initial Immunoassay screen. Immunoassays are only a "pass/fail" endeavor and have no ability to yield a quantitative value.