OBJECTIVES: The objectives of this study were to test for differences in prescription monitoring program (PMP) use between two states, Connecticut (CT) and Rhode Island (RI), with a different PMP accessibility; to explore use of PMP reports in clinical practice; and to examine associations between PMP use and clinician\u27s responses to suspected diversion or doctor shopping (i.e., multiple prescriptions from multiple providers). DESIGN, SETTING, SUBJECTS: From March to August 2011, anonymous surveys were emailed to providers licensed to prescribe Schedule II medications in CT (N = 16,924) and RI (N = 5,567). OUTCOME MEASURES: PMP use, use of patient reports in clinical practice, responses to suspected doctor shopping, or diversion. RESULTS: Responses from 1,385 prescribers were received: 998 in CT and 375 in RI. PMP use was greater in CT, where an electronic PMP is available (43.9% vs 16.3%, chi(2) = 85.2, P \u3c 0.0001). PMP patient reports were used to screen for drug abuse (36.2% CT vs 10.0% RI, chi(2) = 60.9, P \u3c 0.0001) and detect doctor shopping (43.9% CT vs 18.5% RI, chi(2) = 68.3, P \u3c 0.0001). Adjusting for potential confounders, responses by PMP users to suspicious medication use behavior were more likely to entail clinical response (i.e., refer to another provider odds ratio, OR, 1.75 [95% confidence interval, CI, 1.10, 2.80]; screen for drug abuse OR 1.93 [1.39, 2.68]; revisit pain/treatment agreement OR 1.97 [1.45, 2.67]; conduct urine screen OR 1.82 [1.29, 2.57]; refer to substance abuse treatment OR 1.30 [0.96, 1.75]) rather than legal intervention (OR 0.45 [0.21, 0.94]) or inaction (OR 0.09 [0.01, 0.70]). CONCLUSIONS: Prescribers\u27 use of an electronic PMP may influence medical practice, especially opioid abuse detection, and is associated with clinical responses to suspected doctor shopping or diversion