A validation of self-reported substance use with biochemical testing among patients presenting to the emergency department seeking treatment for backache, headache, and toothache.

PURPOSE: This study tests the validity of self-reported illicit substance use against biochemical testing among Emergency Department (ED) patients seeking treatment with narcotics for backache, headache, and toothache and to characterize patients who provide false reports. METHODS: Retrospective chart review comparing the self-reported drug use history obtained during an ED visit during a six-year period (1995-2001) with the results of a biochemical drug screen obtained the same day. RESULTS: 248 patients met screening criteria, 79 (32%) of whom tested positive for unclaimed "drugs of abuse." Patients with a history of "drug abuse" and chronic pain were significantly more likely to test positive for unclaimed drugs than were their counterparts (p=.05 and p<.0001, respectively). No significant difference was found in comparing those with and without multiple ED visits or those requesting a specific narcotic. CONCLUSION: Self-reported drug use is unreliable in this ED subpopulation. When this knowledge is critical for patient care, biochemical testing may be indicated.