, , ȯ    ߱Ǵ    ſ ұϰ   Ȥ  ϰ ִ    ִ.  Ƹ  ƴϰ.   .    ݿ ؾ  ϳ   Ѵ. ٷ  ̴. 踦  ʰ  Ѵٸ  Ƴ, Ȥ  տ   ڷ ƾ  . 
 2007 9 ̿(The American Journal of Epidemiology) ǥ  ϸ 踦 ǿ      ߱   41%  ٰ Ѵ.   踦 ǿ ǿ    µ Ϸ翡 10 踦 ǿ  27% ߱ ɸ  , 11~20 踦 ǿ  45%,   ̻ ǿ  65% ߱   ٰ Ѵ.
̿Ρ Ǹ  ٸ  ϸ 40    50    ߱  2 ϴ  ɿ  ǿ ġ     ̴. 
߱  ⸦ ϰ ִ    Ǿ ϴ     Ű ̱   ߱ ǿ ִ  翬  . 
,  ߱ Ű  ƴϴ.  ̿ܿ   索, ȯ, ȯ  ߱ Ű  Ǵ  ̳ ݿ õϴ  , ߱ Ű Ѱ  ŵǴ ̴. 
Ƴ,  տ   ٽ ¾    ˾ Ծٸ    ݿ õϰ     Ѵٸ  ̻     ߱    ̴.