Addition of objective data to identify risk for medication misuse and abuse: the inconsistency score.

OBJECTIVE

To identify and quantify the rate of aberrant drug-taking behaviors using objective data.

DESIGN

Institutional Review Board-approved anonymous, voluntary, quality improvement project.

SETTING

University-based, multidisciplinary pain management center.

SUBJECTS

Consecutive initial visit patients.

METHODS

Patients were interviewed, asked to provide a urine sample, and filled out a brief questionnaire about recent prescription, over-the-counter, and illicit drug use. Discrepancies between patient report (PQ), the Virginia State prescription monitoring program (PMP), referring physician records (MRs), and the point-of-care urine drug screen (POC UDS) results were scored from 0 (none) to a maximum of 2 points (2+ discrepancies) for each potential comparator between data sets. Maximum potential inconsistency score (IS) was 16 points.

RESULTS

Two hundred nine patients were interviewed to yield 118 specimens. Mean age of participants was 48.2 years (22-83 year); 65.3% were female. IS scores ranged from 1 to 11, and 52.5% of the patients had an IS ≥ 3. Higher IS scores correlated with higher numbers of pharmacies, prescribing physicians, prescriptions on the PMP, and presence of illicit substances in the urine. Addition of either POC UDS or PMP to PQ and MR increased identification of inconsistencies by >400%, and PMP plus UDS by >900%.

CONCLUSIONS

Patient report and the medical record are inadequate to screen for aberrant drug-related behaviors. Addition of PMP and POC UDS contribute significantly to identification of inconsistencies through higher IS scores and differentiate patients at higher risk of medication misuse, abuse, or diversion. Comparison of multiple sources of objective information provides better insight into inconsistencies of report and behavior, and may assist in more appropriate and safer prescribing decisions.