The introduction of weighting for non-response is described in Appendix D. Since government targets for smoking were set using GHS data, the effect of the weighting on the smoking figures is also covered in this chapter.

The effect of weighting on the smoking data is slight: it increases the overall prevalence of cigarette smoking in 1998 by one percentage point, from 27% to 28%. The upward revision is due solely to a change of two percentage points among men: there is no difference in the weighted and unweighted prevalence rates among women. The change among men occurs because weighting reduces the contribution to the overall figure of men aged 60 and over, among whom prevalence is relatively low. Although unweighted 2000 data are not shown in the tables, the differences between weighted and unweighted data are the same as for 1998 (see Appendix D).