Table 2

Behavioural constructs
Domains
 Explanation
 Domain measured for behaviour




X-ray1
 Activity2
Behavioural intention3
 Whether the GP intends to engage in the behaviour.

     Generalised
✓
 ✓
     Performance
✓
 ✓
Attitude4
 Whether the GP is in favour of performing the behaviour.

     Direct
✓
 ✓
     Indirect
✓
 ✓
Subjective norm4
 How much the GP feels social pressure to engage in the behaviour.

     Direct
✓
 ✓
     Indirect
✓
 ✓
Perceived behavioural control4
 Whether the GP feels in control of the behaviour.

     Direct
✓
 ✓
     Indirect
✓
 ✓
Beliefs about capabilities
 Whether the GP is confident in performing the behaviour.
 ✓
 ✓
Beliefs about professional role
 Whether the GP feels it is their professional responsibility to perform the behaviour.
 ✓
 ✗
Knowledge
 Whether the GP has knowledge of the behaviour.
 ✓
 ✓
Memory
 Whether the GP remembers to perform the behaviour.
 ✗
 ✓
Environmental context
 Whether the GP feels the environmental context supports performance of the behaviour.
 ✗
 ✓

1 Managing patients without referral for plain x-ray.

2 Providing advice to stay active.

3 Domain measured using generalised method (e.g., by asking GPs about their strength of intention to perform the behaviour) and performance method (e.g., asking GPs about how often they intend to perform the behaviour).

4 Domain measured directly (e.g., by asking GPs about their overall attitude) and indirectly (e.g., by asking about specific behavioural beliefs).

Details of the number of items measuring each domain, for each behaviour, and measures of reliability and validity of the constructs are available in the full protocol.

McKenzie et al. Implementation Science 2008 3:11   doi:10.1186/1748-5908-3-11