Each year on the GHS there are a small proportion of responding households where one or more members do not complete the individual questionnaire. For these households there is a complete set of data at household level and a full individual interview for at least one adult in the household. Prior to 2001, these households were excluded from the analysis which resulted in the loss of some data each year. From 2001, these households are included in the analysis. This serves to increase both the household sample size and the individual sample size. The effect on the non-response weighting, which was calculated based on a responding sample which excluded these households, was judged to be negligible since the numbers involved are small (around 240 households).

It should be noted that the response rate quoted for 2001/2 excluded these households to provide direct comparison with previous years. See Appendix B for full details.