In NESARC, the AUDADIS-IV was used to measure marijuana use (also defined as any use) and marijuana use disorders. Symptom items (n = 22) that assessed DSM-IV marijuana use disorders in NESARC and NESARC-III were virtually identical. However, 4 items were slightly reworded, and 1 abuse item appeared in NESARC but not NESARC-III, while a different abuse item appeared in NESARC-III but not NESARC. Comparisons between DSM-IV past-year marijuana use disorder diagnoses with and without the additional questions in each survey yielded virtually identical prevalence (NESARC: 1.45% vs 1.45%; NESARC-III: 2.91% vs 2.91%), with corresponding near-perfect concordance (κ = 0.997 and 0.999, respectively), suggesting that these trivial differences in operation-alization could not account for more substantial differences in prevalence between the surveys.
