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Comparison of active versus passive surveillance adverse event reporting in a paediatric ambulatory chiropractic care setting: a cluster randomised controlled trial
  1. Katherine A Pohlman1,
  2. Linda Carroll2,
  3. Ross T Tsuyuki3,
  4. Lisa Hartling4,
  5. Sunita Vohra5
  1. 1Research Center, Parker University, Dallas, Texas, USA
  2. 2School of Public Health, University of Alberta, Edmonton, Alberta, Canada
  3. 3Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
  4. 4Department of Paediatrics, University of Alberta, Edmonton, Alberta, Canada
  5. 5Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
  1. Correspondence to Dr Sunita Vohra; svohra{at}


Objectives This pragmatic, cluster, stratified randomised controlled trial (RCT) compared the quantity and quality of adverse event (AE) reports after chiropractic manual therapy in children less than 14 years of age, using active versus passive surveillance reporting systems.

Method Data were collected between November 2014 and July 2017 from 60 consecutive paediatric patient visits to participating chiropractors. Those allocated to active surveillance collected AE information with three paper-based questionnaires (two from patients, one from chiropractors) to identify any new or worsening symptoms after treatment. Passive surveillance involved AE information reported by chiropractors on a web-based system. To assess quality of reporting, AE reports greater than mild were reviewed by content experts. The primary outcome was the cumulative incidence of AE reports in active versus passive surveillance.

Results Ninety-six chiropractors agreed to participate and enrolled in the study: 34 chiropractors in active surveillance with 1894 patient visits from 1179 unique patients and 35 chiropractors in passive surveillance with 1992 patient visits from 1363 unique patients. In the active arm, AEs were reported in 8.8% (n=140, 95% CI 6.72% to 11.18%) of patients/caregivers, compared with 0.1% (n=2, 95% CI 0.02% to 0.53%) in the passive arm (p<0.001). The quality of AE reports was not evaluated because the five AE reports reviewed by the content experts were determined to be of mild severity.

Conclusion We found that active surveillance resulted in significantly more AE reports than passive surveillance. Further prospective active surveillance research studies should be conducted with children receiving chiropractic manual therapy to understand mechanisms and risk factors for moderate and severe AEs, and to further explore how and when to solicit patient safety information.

  • Patient safety
  • Adverse events
  • epidemiology and detection
  • Randomised controlled trial

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  • Contributors KAP, SV, and LC were responsible for study conception and interpretation of data. Trial design was the responsibility of all authors (KAP, SV, LC, RTT, LH). KAP was responsible for conducting the trial and writing the manuscript with critical review and contributions by all other authors (SV, LC, RT, and LH). All authors read and approved the final manuscript and agree to be accountable for all aspects of the work.

  • Funding This study has been supported by the Women’s and Children’s Health Research Institute, University of Alberta (RES0013182) and the Canadian Institutes of Health Research (TGSTAIR 112758). LJC and SV received salary support as an Alberta Innovates-Health Solutions: Health Senior Scholar and Health Scholar, respectively.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Patient consent for publication Not required.

  • Ethics approval The University of Alberta Health Research Ethics Board reviewed and approved this study (Pro00027903).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available on reasonable request. Data that are available on request include individual responses and a data dictionary. Identification of different participating chiropractors will not be available per participant’s informed consent. Data requests can be made to corresponding author. Reuse of data is not permitted without authorisation from the entire authorship team.