Statistical process control of mortality series in the Australian and New Zealand Intensive Care Society (ANZICS) adult patient database: implications of the data generating process

Table 1 Parameters for GARCH (estimated from raw mortality series; de-trended linear model residuals) and ARMA (estimated from the expected mortality series; de-trended linear model residuals) models

Model	Coefficient	P	UL_95% CI	LL_95% CI
*Raw mortality*
ARMA
Autoregressive parameters
L24	0.174	0.016	0.033	0.316
Moving average parameters
L1	−0.148	0.021	−0.274	−0.022
L15	0.265	0.000	0.128	0.402
L17	−0.203	0.003	−0.340	−0.067
ARCH
L1	0.014	0.464	−0.024	0.052
GARCH
L1	0.996	0.000	0.931	1.061
*Expected mortality*
ARMA
Autoregressive parameters
L1	0.145	0.045	0.003	0.288
ARMA12
Autoregressive parameters
L1	0.132	0.075	−0.031	0.277

ISSN: 1471-2288