6.1. Four key factors influence the strength of a recommendation

• Balance between desirable and undesirable effects (not considering costs)

The larger the difference between the desirable and undesirable consequences, the more likely a strong recommendation is warranted. The smaller the net benefit and the lower the certainty for that benefit, the more likely a weak recommendation is warranted.

• Quality of the evidence

The higher the quality of evidence, the more likely is a strong recommendation.

• Values and preferences

 The greater the variability in values and preferences, or uncertainty in values and preferences, the more likely a weak recommendation is warranted.

• Costs (resource utilization)

 The higher the costs of an intervention – that is, the more resources are consumed – the less likely a strong recommendation is warranted.