Impact of CancelRx on discontinuation of controlled substance prescriptions: an interrupted time series analysis

BMC Med Inform Decis Mak. 2022 Feb 25;22(1):50. doi: 10.1186/s12911-022-01779-9.


Background: Prescription opioid misuse is a serious national crisis; in 2018 the top drugs involved in prescription overdose deaths included pain medications (opioids), benzodiazepines, and stimulants. Health information technology (health IT) provides a means to address this crisis through technologies that streamline the prescribing and discontinuation process. CancelRx is a health IT function that communicates when medications, such as controlled substances, are discontinued at the clinic and therefore should not be filled at the pharmacy. Prior to CancelRx, the communication of discontinued medications was a manual process, requiring the patient or a clinic staff member to personally contact the pharmacy to inform them of the change. The objective of this study was to assess how controlled substance medication discontinuations were communicated over time, before and after the implementation of CancelRx.

Methods: Secondary data from a midwestern academic health system electronic health record and pharmacy platform were collected 12-months prior to CancelRx implementation and for 12-months post implementation. The study utilized an interrupted time series analysis (ITSA) to capture the percentage of controlled substance medications that were discontinued in the clinic's electronic health record and discontinued in the pharmacy's dispensing software. The ITSA plotted the percentage of successful discontinuation messages over time, particularly after the health system's implementation of CancelRx, a novel technology.

Results: After CancelRx implementation there was an immediate (change = 77.7 percentage point) and significant (p < 0.001) increase in the number of controlled substance medications that were successfully discontinued at the pharmacy after being discontinued in the clinic. This change was sustained in the year following CancelRx (slope = 0.03 pp, 95% CI - 0.050 to 0.110) and did not revert to pre-CancelRx levels. The health IT functionality was able to effectively complete discontinuation tasks and potentially reduce workload for clinic staff.

Conclusions: Overall, this study demonstrates the role that technology can play in promoting communication between clinics and pharmacies, especially when medications such as controlled substances are discontinued.

Keywords: Controlled substances; Health information technology; Interrupted time series; Opioid epidemic; Prescriptions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Controlled Substances
  • Humans
  • Interrupted Time Series Analysis
  • Medical Informatics*
  • Pharmacies*
  • Prescriptions


  • Controlled Substances