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General practitioners’ use of absolute risk versus individual risk factors in cardiovascular disease prevention: an experimental study
  1. Jesse Jansen1,2,
  2. Carissa Bonner1,2,
  3. Shannon McKinn1,2,
  4. Les Irwig1,
  5. Paul Glasziou1,3,
  6. Jenny Doust1,3,
  7. Armando Teixeira-Pinto1,
  8. Andrew Hayen4,
  9. Robin Turner1,
  10. Kirsten McCaffery1,2
  1. 1Screening and Test Evaluation Program (STEP), School of Public Health, The University of Sydney, Sydney, New South Wales, Australia
  2. 2Centre for Medical Psychology & Evidence-based Decision-making (CeMPED), The University of Sydney, Sydney, New South Wales, Australia
  3. 3Centre for Research in Evidence Based Practice Faculty of Health Sciences and Medicine, Bond University, Robina, Queensland, Australia
  4. 4School of Public Health and Community Medicine, University of New South Wales, Sydney, New South Wales, Australia
  1. Correspondence to Dr Jesse Jansen; jesse.jansen{at}sydney.edu.au

Abstract

Objective To understand general practitioners’ (GPs) use of individual risk factors (blood pressure and cholesterol levels) versus absolute risk in cardiovascular disease (CVD) risk management decision-making.

Design Randomised experiment. Absolute risk, systolic blood pressure (SBP), cholesterol ratio (total cholesterol/high-density lipoprotein (TC/HDL)) and age were systematically varied in hypothetical cases. High absolute risk was defined as 5-year risk of a cardiovascular event >15%, high blood pressure levels varied between SBP 147 and 179 mm Hg and high cholesterol (TC/HDL ratio) between 6.5 and 7.2 mmol/L.

Setting 4 GP conferences in Australia.

Participants 144 Australian GPs.

Outcomes GPs indicated whether they would prescribe cholesterol and/or blood pressure lowering medication. Analyses involved logistic regression.

Results For patients with high blood pressure: 93% (95% CI 86% to 96%) of high absolute risk patients and 83% (95% CI 76% to 88%) of lower absolute risk patients were prescribed blood pressure medication. Conversely, 30% (95% CI 25% to 36%) of lower blood pressure patients were prescribed blood pressure medication if absolute risk was high and 4% (95% CI 3% to 5%) if lower. 69% of high cholesterol/high absolute risk patients were prescribed cholesterol medication (95% CI 61% to 77%) versus 34% of high cholesterol/lower absolute risk patients (95% CI 28% to 41%). 36% of patients with lower cholesterol (95% CI 30% to 43%) were prescribed cholesterol medication if absolute risk was high versus 10% if lower (95% CI 8% to 13%).

Conclusions GPs’ decision-making was more consistent with the management of individual risk factors than an absolute risk approach, especially when prescribing blood pressure medication. The results suggest medical treatment of lower risk patients (5-year risk of CVD event <15%) with mildly elevated blood pressure or cholesterol levels is likely to occur even when an absolute risk assessment is specifically provided. The results indicate a need for improving uptake of absolute risk guidelines and GP understanding of the rationale for using absolute risk.

  • Cardiology
  • General Medicine (see Internal Medicine)
  • Public Health

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/3.0/

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