Table 4

Attributed variation within multilevel models of practices nested within CCGs within Acute Hospital Trusts

Outcome variable	Covariates	Total R²	Intraclass correlation coefficient				AIC
Outcome variable	Covariates	Total R²	Total	CCG	Acute	% Acute	AIC
Multilevel linear regression
Standardised 2WWRR	None	0.212	0.209	0.081	0.131	63	31 993
Multilevel Poisson regression (primary analysis)
Detection rate	None	0.405	0.391	0.135	0.256	66	24 780
Detection rate	a	0.460	0.346	0.111	0.235	68	24 181
Detection rate	a+b	0.474	0.335	0.104	0.231	69	24 082
Multilevel Poisson regression (secondary analysis)
Detection rate	c	0.479	0.380	0.119	0.261	69	24 414
Detection rate	c+d	0.473	0.369	0.115	0.253	69	24 327
Detection rate	c+d+e+f	0.458	0.337	0.095	0.243	72	24 177

Covariates: a=standardised 2WWRR; b=(standardised 2WWRR) 2; c=specificity; d=(specificity) 2 ;e=proportion patients aged 65+ years and index of multiple deprivation.
AIC, Aikake information criterion; CCG, Clinical Commissioning Group; ICC, intraclass correlation coefficient; 2WWRR, two week wait referral rate.