Member of household = significantly bigger. I believe your numbers suggest a household size of 1 person. I also would suggest that most likely old people live

Member of household = significantly bigger. I believe your numbers suggest a household size of 1 person. I also would suggest that most likely old people live with their families, and skew towards "which member" of the household went to the doctor. Well, with such a low mean age it could also be very young people skewing the number, im fully speculating.