Table 5. Effect of the intervention on adherence to the guideline for the clinical behaviours x-ray referral, imaging referral, advice regarding activity and bed rest, as measured by response to the vignettes (behavioural simulation outcomes).

Variable	Intervention group adherence1		Control group adherence2		Adjusted Odds Ratio3	(95% CI)	p-value
	No.	(%)	No.	(%)
X-ray adherence4	126/152	(83)	109/160	(68)	1.76*	(1.01, 3.05)	0.045
Imaging adherence4	119/152	(78)	89/160	(56)	2.36*	(1.48, 3.79)	0.000
Activity adherence5	121/152	(80)	82/160	(51)	4.49	(1.90, 10.60)	0.001
Bed rest adherence6	163/164	(99)	168/171	(98)	2.91*	(0.30, 27.83)	0.354

¹No. Practices = 31 and No. GPs = 38, except for variable “Bed rest adherence” where No. Practices = 34 and No. GPs = 41.

²No. Practices = 36 and No. GPs = 40, except for variable “Bed rest adherence” where No. Practices = 38 and No. GPs = 43.

³Adjusted odds ratios estimated from logistic models fitted using GEEs with an exchangeable correlation structure and robust variance estimation to allow for clustering within general practices. For models where the estimated within cluster correlation was negative (indicated by ^*), the model was refitted assuming an independent correlation structure.

⁴Model adjusted for the design strata (number of GPs per practice, location of practice [metropolitan or rural/remote]) and confounders specified prior to undertaking the analysis (age of GP (years), years since GP graduated, special interest in LBP, practice method of billing [bulk bill or co-payment]).

⁵Model adjusted for the same design strata and confounders as in footnote 4, with the addition of the baseline measure of GP fear-avoidance beliefs.

⁶The planned model was to have included adjustment for the same design strata and confounders as in footnote 5, however; due to limited events of non-adherence the model was fitted with no adjustment for the design strata and confounders.