Up-to-date denominators: evaluation of taxation family file for public health planning.
Public Health agencies need up-to-date population data, and Statistics Canada's Taxation Family File (T1FF) database, developed annually from T1 personal income tax forms, may meet this need. We compared 1989 T1FF data for Ottawa-Carleton with census data. The overall population estimate for the region was 98% of the census figure. Equivalent figures were 94% for central cities, 98% for suburbs and 122% for rural areas. The T1FF underestimated the population of children (89%) and seniors (93%). Population estimates for smaller neighbourhoods were poorer, some being wrong by a factor of more than two. The errors are probably due to postal code conversion. The T1FF provides fairly accurate estimates of the population of larger areas, and can be much more current than census data. It is less accurate for smaller areas, offers a limited range of variables, does not specify gender for children, and is fairly expensive. Health units with a major commitment to needs-based planning should consider using the T1FF for denominator data, despite its limitations.
Spasoff
R A
RA
Dept of Epidemiology and Community Medicine, University of Ottawa, ON.
Gilkes
D T
DT
D002170:Canada; D003625:Data Collection / Q000191:economics / Q000379:methods*; D016208:Databases, Factual; D003710:Demography; D005843:Geography; D006285:Health Planning / Q000706:statistics & numerical data*; D006801:Humans; D007183:Income Tax; D011156:Population Density