TABLE 2—
Parameter Estimates From Conditional Least Squares Autoregressive Integrated Moving Average Model of Monthly Adult Smoking Prevalence: Australia, June 1995 to December 2006
| Model 1 | Model 2 | Model 3 | Model 4 | |||||
| b (SE) | P | b (SE) | P | b (SE) | P | b (SE) | P | |
| Tobacco control GRPs (2 months’ laga) | −0.00060 (0.00036) | .103 | −0.00064 (0.00040) | .080 | −0.00065 (0.00036) | .074 | −0.00077b (0.00034) | .025 |
| Cigarette costliness (immediate effect) | −5.227 (3.691) | .159 | −5.813 (3.800) | .129 | −8.425 (2.917) | .005 | −8.802c (2.891) | .003 |
| NRT GRPs (2 months’ lag) | −0.00030 (0.00042) | .476 | −0.00043 (0.00040) | .290 | −0.00043 (0.00040) | .283 | ||
| Smoke-free restaurant laws (immediate effect) | −0.0104 (0.0098) | .293 | −0.0104 (0.0103) | .317 | ||||
| NRT sales (immediate effect) | −0.00011 (0.00009) | .232 | ||||||
| Moving average, 1-month lag (θ1d) | 0.905 (0.040) | <.001 | 0.890 (0.041) | <.001 | 0.878 (0.043) | <.001 | 0.879 (0.043) | <.001 |
| Residual auto-correlation at 6-month lag e | 2.65 | .753 | 2.51 | .774 | 2.76 | .736 | 2.23 | .816 |
| Residual auto-correlation at 12-month lag e | 4.65 | .947 | 4.33 | .959 | 4.64 | .948 | 3.80 | .975 |
| Residual auto-correlation at 18-month lag e | 15.32 | .572 | 13.16 | .725 | 14.74 | .614 | 15.00 | .595 |
| Residual auto-correlation at 24-month lag e | 25.65 | .318 | 23.17 | .451 | 24.56 | .373 | 24.39 | .382 |
Note. GRPs = gross television audience rating points for the population 18 years and older representing average potential exposure to ads; NRT = nicotine replacement therapy.
aTransfer function.
bAn increase of 1 GRP per month is associated with a decline in prevalence of 0.00077 percentage points; to estimate a reduction in smoking prevalence of 0.30 percentage points, we divided the desired prevalence percentage point change required (−0.30) by the unstandardized parameter estimate for tobacco control GRPs (−0.00077), giving 390 GRPs.
cAn increase of 1% in cigarette costliness is associated with a decline in prevalence of 8.802 percentage points; to estimate a reduction in smoking prevalence of 0.30 percentage points, we divided the desired prevalence percentage point change required (−0.30) by the coefficient for cigarette costliness (−8.802), giving a 0.03-percentage-point increase in cigarette costliness.
dThis parameter estimate accounts for the effects of time.
eThese are diagnostic parameter estimates that must be nonsignificant for the model to be acceptable.