Income and the incidence of oral cavity cancer: cross-national study.
OBJECTIVE
To examine the relation between income and oral cancer incidence in countries at different stages of economic development.


METHODS
Descriptive study with regression analysis of oral cancer incidence in relation to real gross domestic product (GDP) per capita from 1970 to 2000 performed for 8 different countries.


METHODS
GDP per capita was collected from the United States, Hong Kong, Singapore, Italy, Mexico, Philippines, Poland, and Romania. Correlation factor and Pearson values were compared.


RESULTS
The association between income and the oral cavity cancer rate was significant in all the countries selected. Using linear regression analysis, the results showed high r2 value. The increase of real GDP correlated negatively with the rate of male oral cavity cancer in the United States, Italy, Hong Kong, and Singapore but not in Mexico, Philippines, Poland, and Romania.


CONCLUSIONS
The association between incidence and income appears to depend on per capita GDP, being negative in countries with GDP above US$10,000 and positive in countries with GDP below US$10,000.
Department of Otorhinolaryngology, Tzu Chi General Hospital, Tzu Chi University, Hualien City, Taiwan.
David T
DT
Chen
Yu-Fu
YF
Chou
Hong-Pin
HP
Wu
Lee-Ping
LP
Hsu
I-Shian
IS
Wen
Chia-Fone
CF
Lee
Peir-Rong
PR
Chen
D003430:Cross-Sectional Studies; D019049:Developed Countries / Q000706:statistics & numerical data; D003906:Developing Countries / Q000706:statistics & numerical data; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007182:Income; D007558:Italy / Q000453:epidemiology; D016014:Linear Models; D008297:Male; D008800:Mexico / Q000453:epidemiology; D009062:Mouth Neoplasms / Q000453:epidemiology*; D010679:Philippines / Q000453:epidemiology; D011044:Poland / Q000453:epidemiology; D012383:Romania / Q000453:epidemiology; D012846:Singapore / Q000453:epidemiology; D012959:Socioeconomic Factors; D014481:United States / Q000453:epidemiology