Table 3 Description of intervention strategies

Environmental cueing and priming

Strategies that expose the participant to certain cues (e.g. words, smells, or images) in order to alter behaviour subliminally. These strategies work by activating particular representations or associations in memory just before carrying out the target behaviour

8

[30, 32, 37,38,39,40,41, 50]

Defaults and pre-orders

Strategies by which the default option is chosen so as to minimize or facilitate the path to the desired behaviour, for example, making all prescriptions based on generic medication and requiring additional actions to prescribe a branded medication, or having participants opt-out instead of opt-in to a desired behaviour. We have also included in this category all user-interface design strategies for electronic systems that aim to make a given behaviour more likely such as showing recommended actions more prominently, or purposefully grouping certain sets together

12

[31, 34,35,36, 43, 46, 48, 49, 53, 56,57,58]

Suggested alternatives

Strategies that automatically detect a certain behaviour and immediately suggest an alternate course of action, typically within EHR systems. We have differentiated these from Default strategies because they intrinsically include a dialog with the user, where the user is prompted to critically analyse options and make an informed decision.

1

[42]

Active choice

A strategy that prompts the user to make an immediate decision, for example, a dialog box opens when a patient record is being accessed and asks the provider to accept or reject a vaccination order. Active choice is different from suggested alternatives in that the trigger for the choice often comes from the system and not the user.

5

[45, 50,51,52, 54]

Alerts and reminders

Prompts from the system that warn the user of an event of interest, for example, an expensive medication order or a ventilation setting outside recommended limits. Unlike active choice, alerts do not necessarily present an immediate choice to be taken in the system.

5

[31, 45, 47, 58, 59]

Accountable justification

A strategy where any choice other than the recommended choice must be justified, often with a text entry. This requires a critical analysis of why that choice was made.

1

[42]

Information transparency

Strategy by which relevant information is somehow presented to the user, for example, adding the cost of a test next to the name of the test in the ordering system. Information transparency does not require any specific action from the user and the user may or may not be aware of the information shown.

2

[33, 55]

Feedback

The communication of the frequency of the target behaviour back to the user. It may be an aggregated statistic such as average compliance in the department, or it may be personalized to the participant such as the number of antibiotics prescribed in the period of interest.

2

[43, 44]

Peer comparison

A specific form of feedback where the participant is compared with other colleagues, either anonymously or transparently.

3

[38, 42, 45]

Goal setting

Strategy often combined with feedback where the participants are prompted to set a target behaviour and they follow-up on that goal.

1

[44]

Education

Not traditionally seen as a nudging strategy, but we included it as a strategy since some of the articles complemented their intervention with an educational information session.

3

[41, 49, 50]