Background of study participants.

*Frequencies between intervention and control groups were compared by 1)chi-square test, 2)wilcoxon rank-sum test, and 3)fisher's exact test.†The knowledge, attitude and practice survey on before the educational intervention.‡The knowledge, attitude and practice survey on after the educational intervention.§Economic level was qualified based on the possessions of assets such as a television, radio, telephone, water machine, refrigerator, buffalo, bicycle, motorbike, car and air conditioner, and was divided into quintiles of family income.