[Intercensal reconstruction of population and descriptive epidemiological measures in Italy: what is the impact on the cancer incidence rates?].
OBJECTIVE
to test the effect on cancer incidence rates when using precensal computation (computed population) or intercensal reconstruction of population (reconstructed population).


METHODS
comparison between computed and reconstructed population by area and period in 2002-2011; evaluation of the effect on cancer rates using Italian cancer registries data. Setting e participants: population data from the Italian National Institute for Statistics, cancer data from Italian cancer registries; specific analysis involves data from Parma (Emilia-Romagna Region, Northern Italy) and Taranto (Apulia Region, Southern Italy) cancer registries.


METHODS
ratio between computed and reconstructed population by area, gender, age, and period; ratio between corresponding age-standardized incidence rates.


RESULTS
Italian population estimates by precensal computation for years 2002-2011 was generally higher than that obtained by intercensal reconstruction especially in 2011, when this has been found in more than 86% of Italian Municipalities. In the same year a smaller proportion of Municipalities (11%) showed an inverse population ratio. Among the most populated Municipalities, the City of Milan showed the higher precensal to intercensal population ratio (1.076), while the City of Taranto showed the lower precensal to intercensal population ratio (0.956). The ratios between age standardized rates obtained with precensal population to those obtained with intercensal population show similar differences; in particular, for all cancer in males and females they were, respectively, 0.985 and 0.982 in the Province of Parma, 0.974 and 0.968 in the City of Parma, 1.023 and 1.013 in the Province of Taranto, and 1.08 and 1.051 in the City of Taranto.


CONCLUSIONS
using precensal population as denominator for the year 2002- 2011 produces a remarkable distortion of both temporal trend and geographical comparisons. It is, therefore, necessary that researchers take into account this possible distortion when reporting descriptive measures in the years between the last two censuses in Italy.
Unità operativa complessa di statistica ed epidemiologia, Istituto di ricovero e cura a carattere scientifico Ospedale oncologico Giovanni Paolo II, Bari. ivrashid@gmail.com.
Ivan
I
Rashid
Registro tumori Piemonte, Provincia di Biella, Centro di riferimento per l'epidemiologia e la prevenzione oncologica in Piemonte, Azienda sanitaria locale di Biella.
Adriano
A
Giacomin
Registro tumori di Parma, Unità operativa complessa di oncologia medica, Azienda ospedaliero-universitaria, Parma.
Maria
M
Michiara
Registro tumori di Taranto, Unità operativa complessa di statistica ed epidemiologia, Azienda sanitaria locale Taranto.
Sante
S
Minerba
Registro tumori di Parma, Unità operativa complessa di oncologia medica, Azienda ospedaliero-universitaria, Parma.
Paolo
P
Sgargi
Registro tumori di Taranto, Unità operativa complessa di statistica ed epidemiologia, Azienda sanitaria locale Taranto.
Antonia
A
Mincuzzi
Direzione centrale delle statistiche sociodemografiche e ambientali, Istituto nazionale di statistica, Roma.
Angela
A
Silvestrini
D019352:Censuses; D005260:Female; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D009369:Neoplasms / Q000453:epidemiology* / Q000401:mortality; D012042:Registries; D012189:Retrospective Studies