抄録
As Dr. Frost pointed out in his paper, for the acute communicable diseases, such as diphtheria, scarlet fever and measles, measurement of the morbidity risk of familial contacts is a simple procedure, because the excess risk is concentrated within the fewweeks following invasion of the household. Collection of the data is simple because, for any family, the required period of observation is brief; and compilation is simple because the period to which the attack rate refers may be taken as the same for all families.
