Table 1.

Results of the negative binomial regression model for treatment initiations per 100,000 population

Variable	Adjusted treatment initiation rate ratio	Lower bound	Upper bound	P-value
Constant	100.153	68.292	146.879	<0.001***
IRSD (vs quintile 1, the most disadvantaged)
Quintile 1	Ref	—	—	—
Quintile 2	1.279	0.885	1.848	0.191
Quintile 3	1.777	1.187	2.658	0.005**
Quintile 4	1.385	0.955	2.009	0.086
Quintile 5	1.546	1.064	2.245	0.022*
Remoteness Area classification (vs major city)
Major city	Ref	—	—	—
Inner regional	0.706	0.470	1.061	0.094
Outer regional	0.585	0.350	0.978	0.041*
Remote	0.402	0.172	0.938	0.035*
Very remote	1.619	0.527	4.974	0.400
Proportion of population of ATSI descent	1.001	0.999	1.003	0.271
Proportion of population born overseas	0.997	0.995	0.999	<0.001***
Number of NSP sites in SA3	0.999	0.969	1.030	0.969
Number of GP clinics in SA3	1.001	0.995	1.007	0.805
Number of drug and alcohol services in SA3	1.007	0.984	1.030	0.557
Number of hospitals in SA3	1.018	0.991	1.046	0.195
Number of specialists in SA3	1.007	1.004	1.010	<0.001***
Prison (vs no)	0.805	0.563	1.151	0.234

IRSD: Index of Relative Socio-economic Disadvantage