The use of verbal and written consent to review primary care medical records in a randomised controlled trial: Evaluation of a two-stage process

Conference: 
SAPC ASM 2015 - Oxford - Evidence and innovation in primary care
Talk Code: 
EP3B.6

The problem

The need to obtain patients' consent to access their medical records risks selection bias within randomised controlled trials. A novel approach for obtaining consent to access records has recently been employed within a large cluster RCT in primary care.

The approach

Patients telephoning seeking a same-day, face-to-face, consultation with a GP were recruited from 42 general practices across 4 UK regions (Devon, Bristol, Warwickshire and Norfolk). Patients were asked for their consent to a review of their medical records through a two-stage procedure: (1) firstly a request for verbal consent was sought by the consulting clinician at the end of the initial contact, (2) this verbal consent was followed by a request for written consent by the research team using a postal questionnaire sent to patients 4 weeks later. Individuals providing verbal consent could confirm their consent, could opt out via the questionnaire, or could opt in if they had previously declined. Verbal consent constituted final consent for questionnaire non-respondents. The primary study outcome was the rates of consent to medical notes review using verbal or written consent. We examined the differences in characteristics between individuals providing or declining consent, relating this to the mode of consent (verbal and/or written).

Findings

Of 20,990 patients who requested a ‘same-day' GP consultation, 16,369 (78%) gave verbal consent. Of these, 7,813 returned the questionnaire and confirmed consent, 1,820 returned the questionnaire and opted out and 6,736 did not respond (verbal consent retained). 819 (3.9% [819/20,990]) declined verbal consent, and of these 255 returned the questionnaire and opted in. Verbal consent was missing for 3,802 patients and of these, 1,475 returned the questionnaire and opted in. Overall, 16,279 (78% [16,279/20,990]) patients consented, exceeding our target sample of 11,253 records to review.Age, gender and deprivation status were available for 20,836 patients. Questionnaire respondents (response rate: 58% [12,179/20,990]) were less likely to be male, aged 16-24years, living in a deprived area and were more likely to be aged >60years. 78% (9,543/12,179) of questionnaire respondents provided written consent. Consenting patients among both the total sample and the questionnaire respondent sub-sample were more likely to be male and older (>60years), and less likely to be aged 16-24years. Patients giving only verbal consent were more likely to be male, aged 16-24years, living in deprived areas and less likely to be aged >60years.

Consequences

This novel two-stage method of obtaining consent to review medical records improved participation rates in this trial, reducing potential selection bias by improving access to hard-to-reach patient demographic groups. Based on our findings, we would encourage trialists and ethics committees to allow for verbal consent followed by opt-out written consent in studies involving patients consenting to a review of medical records in similar settings.

Credits

  • Katherine Chaplin, Institute of Health Services Research, University of Exeter Medical School, Exeter, UK
  • Emily Fletcher, Centre for Academic Primary Care, School of Social and Community Medicine, University of Bristol, Bristol, UK
  • Fiona Warren, Centre for Academic Primary Care, School of Social and Community Medicine, University of Bristol, Bristol, UK
  • Chris Salisbury, Institute of Health Services Research, University of Exeter Medical School, Exeter, UK
  • Rod Taylor, Centre for Academic Primary Care, School of Social and Community Medicine, University of Bristol, Bristol, UK
  • Suzanne Richards, Centre for Academic Primary Care, School of Social and Community Medicine, University of Bristol, Bristol, UK
  • David Richards, School of Nursing Sciences, Faculty of Medicine and Health Sciences, University of East Anglia, Norwich, UK
  • Raff Calitri, Centre for Academic Primary Care, School of Social and Community Medicine, University of Bristol, Bristol, UK
  • Anna Varley
  • John Campbell, Centre for Academic Primary Care, School of Social and Community Medicine, University of Bristol, Bristol, UK