Since its creation in the late 1990s, the Québec index of material and social deprivation has been widely utilized in the field of public health for purposes that range from health monitoring and policy development to evaluation of services and resource allocation. More recently, a Canadian version of the index has been produced and used at that level.
There are provincial, regional, and local versions of the Québec index. Four revisions have been made over the years, in conjunction with the 1991, 1996, 2001, and 2006 censuses. While some publications have examined the index's construction for a specific census year, none of them have tracked its methodological components throughout the period from 1991 to 2006. Therefore we cannot easily follow up on modifications that pertain to basic area units, the indicators that comprise the index, or how they are combined.
The intent of this paper is to remedy that deficiency and to respond to index users' requests in this regard. We will not explore all index construction components in minute detail—some publications have already done so. Instead, we will cover only components that have been modified, talking about their status at four points which coincide with index revisions. In the order in which we will cover them, they are basic area units, the socio-economic indicators that comprise the index, the way these indicators are combined, and the socio-economic profile associated with the index. Our discussion will be based on the Québec version of the index, although some geographic variations will be noted.