Table 1

Rate ratios (with 95% CIs) from segmented regression models of monthly prevalence of smoking during pregnancy in New South Wales, 2003–2011

Overall
N#=8 00 619		<30 years
n=4 09 942		≥30 years
n=3 90 677		Primiparous
n=3 38 752		Multiparous
n=4 61 552		Disadvantaged SES
n=2 21 097		Average SES
n=2 63 514		Advantaged
SES
n=3 06 207
Time onlyTime0.9961* (0.9959 to
0.9964)		0.9966* (0.9963 to
0.9969)		0.9956* (0.9952 to
0.9960)		0.9958* (0.9952 to
0.9964)		0.9964* (0.9961 to
0.9967)		0.9980* (0.9976 to
0.9984)		0.9964* (0.9960 to
0.9968)		0.9957* (0.9952 to
0.9963)
Partially adjustedTime0.9966* (0.9952 to
0.9980)		0.9978* (0.9964 to
0.9992)		0.9955* (0.9934 to
0.9976)		0.9927* (0.9901 to
0.9954)		0.9984* (0.9969 to
1.0000)		0.9975* (0.9957 to
0.9994)		0.9972* (0.9953 to
0.9992)		0.9914* (0.9888 to
0.9941)
50% and 75% ban and graphic warnings†0.9995 (0.9970 to
1.0021)		0.9986 (0.9959 to
1.0012)		1.0008 (0.9969 to
1.0047)		1.0054* (1.0005 to
1.0103)		0.9967* (0.9939 to
0.9996)		1.0027 (0.9993 to
1.0062)		0.9985 (0.9950 to
1.0021)		1.0061* (1.0011 to
1.0113)
100% ban†1.0000 (0.9972 to
1.0028)		0.9998 (0.9969 to
1.0026)		1.0000 (0.9958 to
1.0043)		1.0013 (0.9960 to
1.0065)		0.9995 (0.9963 to
1.0026)		0.9975 (0.9937 to
1.0014)		1.0004 (0.9966 to
1.0042)		1.0002 (0.9948 to
1.0057)
Tobacco tax†0.9982 (0.9937 to
1.0028)		1.0000 (0.9952 to
1.0047)		0.9938 (0.9869 to
1.0009)		0.9761* (0.9678 to
0.9845)		1.0107* (1.0054 to
1.0159)		0.9909* (0.9844 to
0.9975)		1.0032 (0.9970 to
1.0094)		0.9905* (0.9818 to
0.9993)
Pregnancy advertising†1.0026 (0.9915 to
1.0139)		0.9994 (0.9880 to
1.0111)		1.0096 (0.9923 to
1.0274)		1.0320* (1.0107 to
1.0539)		0.9864* (0.9741 to
0.9989)		1.0177* (1.0012 to
1.0344)		0.9945 (0.9798 to
1.0094)		1.0065 (0.9849 to
1.0286)
TARPs‡§1.0028 (0.9906 to
1.0151)		1.0061 (0.9936 to
1.0188)		0.9937 (0.9754 to
1.0124)		1.0038 (0.9810 to
1.0272)		1.0020 (0.9885 to
1.0158)		1.0031 (0.9868 to
1.0197)		0.9967 (0.9801 to
1.0136)		1.0079  (0.9841 to
1.0323)
Fully adjustedTime0.9988 (0.9958 to
1.0018)		1.0005 (0.9975 to
1.0035)		0.9968 (0.9922 to
1.0014)		1.0000 (0.9946 to
1.0055)		0.9980 (0.9946 to
1.0015)		0.9998 (0.9959 to
1.0038)		1.0005 (0.9963 to
1.0046)		0.9962  (0.9904 to
1.0020)
Baby Bonus†0.9952 (0.9895 to
1.0010)		0.9941 (0.9884 to
1.0000)		0.9973 (0.9884 to
1.0062)		0.9841* (0.9738 to
0.9946)		1.0009 (0.9943 to
1.0075)		0.9950 (0.9874 to
1.0026)		0.9930 (0.9850 to
1.0011)		0.9896  (0.9784 to
1.0008)
50%and 75% ban and graphic warnings†1.0025 (0.9981 to
1.0069)		1.0022 (0.9977 to
1.0067)		1.0025 (0.9957 to
1.0093)		1.0155* (1.0073 to
1.0238)		0.9962 (0.9912 to
1.0012)		1.0059* (1.0000 to
1.0119)		1.0029 (0.9967 to
1.0090)		1.0129* (1.0041 to
1.0217)
100% ban†0.9996 (0.9968 to
1.0024)		0.9992 (0.9964 to
1.0021)		0.9998 (0.9955 to
1.0041)		0.9998 (0.9946 to
1.0049)		0.9995 (0.9963 to
1.0027)		0.9971 (0.9932 to
1.0009)		0.9997 (0.9959 to
1.0036)		0.9992  (0.9938 to
1.0047)
Tobacco tax†0.9983 (0.9938 to
1.0029)		1.0001 (0.9954 to
1.0048)		0.9939 (0.9869 to
1.0010)		0.9764* (0.9684 to
0.9844)		1.0107* (1.0054 to
1.0159)		0.9910* (0.9845 to
0.9975)		1.0033 (0.9972 to
1.0094)		0.9907* (0.9822 to
0.9993)
Pregnancy advertising†1.0027 (0.9916 to
1.0138)		0.9994 (0.9882 to
1.0109)		1.0096 (0.9923 to
1.0274)		1.0322* (1.0116 to
1.0533)		0.9864* (0.9741 to
0.9988)		1.0177* (1.0013 to
1.0343)		0.9945 (0.9800 to
1.0092)		1.0066  (0.9853 to
1.0283)
TARPs‡§1.0045 (0.9923 to
1.0168)		1.0081 (0.9957 to
1.0208)		0.9947 (0.9761 to
1.0136)		1.0092 (0.9869 to
1.0321)		1.0017 (0.9880 to
1.0157)		1.0049 (0.9885 to
1.0217)		0.9991 (0.9825 to
1.0159)		1.0116  (0.9878 to
1.0359)

  • *p<0.05.

  • #Size of strata do not sum to the size of the overall population due to missing data.

  • †Represented in the model as a trend indicator term.

  • ‡Entered as a continuous variable.

  • §Rate ratios for antismoking advertisements represent the change in trend associated with an increase of 1000 TARPs.

  • SES, socioeconomic status; TARPs, Target Audience Rating Points.