A direct approach to control short term population dynamics in time series studies.
BACKGROUND
Short term population dynamics is an important issue in several epidemiological studies. Usually, calendar time or dummy variables are used to control indirectly for this confounding. This study tested a direct method.


METHODS
The study compared as proxy variables of population dynamics the summer 2003 data of cooking gas consumptions, solid urban waste production, and television access for the municipality of Bologna (Italy).


RESULTS
Solid urban waste production and television access data showed similar trends. Considerably different were the >65 year olds estimates with respect to total population based on television access.


CONCLUSIONS
Television access data are probably the best indicator in the estimates of population dynamics in large or densely populated areas, especially because of the possibility of stratifications with respect to age.
Zauli Sajani
Stefano
S
Environmental Epidemiology Unit, ARPA Emilia Romagna, Viale Fontanelli 23, 41100 Modena, Italy. szauli@epam.arpa.emr.it
Scotto
Fabiana
F
Lauriola
Paolo
P
D000368:Aged; D003627:Data Interpretation, Statistical; D005579:Fossil Fuels / Q000706:statistics & numerical data; D006801:Humans; D007558:Italy; D008137:Longitudinal Studies; D011157:Population Dynamics; D013690:Television / Q000706:statistics & numerical data; D014866:Waste Products / Q000706:statistics & numerical data
D005579:Fossil Fuels; D014866:Waste Products