Public health and the 1991 census

National censuses provide authoritative data on populations and housing. These results inform public understanding and the governance of society, particularly in respect of strategic planning and the allocation of resources. Assessment of health needs, the purchase and provision of services, equality of access, and evaluation of health outcomes - concerns of providers and purchasers - are are also contingent on such information.

The 1991 census broke new ground in two respects, both with major dividends for public health research. It asked respondents whether they had a limiting long term illness or handicap and it asked them to identify their ethnic group.

This last census covered 97.8% of Britain's population - a lower proportion than in previous censuses.1,2 Comparisons with population estimates based on the 1981 census show that the latest census “missed” some 1.2 million people, half of them young adults but also sizeable numbers of young children and very elderly people. The post-census validation survey located only about a fifth of this shortfall. Census undercoverage in 1991 was not random: it was higher in inner London and other metropolitan areas and among men in their 20s (9% overall and almost 20% in inner London).1,2 Particular types of households - those in converted or shared accommodation and those in inner London - were also undercounted.1 These patterns of non- response resemble those of previous censuses and of national social surveys such as the general household …