[Application of the trend-surface analysis for studying the geographical distribution of lung cancer mortality].
OBJECTIVE
To apply trend-surface analysis on lung cancer mortality in China.


METHODS
To overview the theory and approach of trend-surface analysis and to fit the first to fifth order regression equations, where dependent variables were latitude and longitude, and the independent one was the standardized mortality ratio (SMR) of lung cancer for various provinces. Data was from the second mortality survey in the whole country, then proper regression equation was chosen.


RESULTS
Fifth-order regression equation was established for mortality of lung cancer in males with its fit goodness as 76.06%. The third-order regression equation was established for mortality of lung cancer in females with its fit goodness as 89.77%. There were positive residuals in Shanghai, Hubei and Tianjin, while the negative residuals were in Zhejiang, Anhui, Henan, Beijing and Guangxi for males. There were positive residuals in Tianjin, Hubei and Guangdong, while negative residuals appeared in Zhejiang, Shanxi, Guizhou, Hainan, Henan, Jilin and Neimenggu for females.


CONCLUSIONS
The geographic distribution trend of lung cancer mortality between males and females appeared to be different. The mortality of lung cancer among males was high in the northeast provinces while the mortality of lung cancer for females was high in the southeast areas. In those areas where the residual values were anomalous, further studies need to be carried out.
Wang
Xiao-yan
XY
Institute of Epidemiology and Health Statistics, School of Public Health, Zhejiang University, Hangzhou 310058, China.
Shen
Yi
Y
Chen
Kun
K
Miao
Fan
F
D002681:China / Q000453:epidemiology; D005260:Female; D005843:Geography; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000401:mortality*; D008297:Male; D012044:Regression Analysis