[aafp.org] https://www.aafp.org/afp/1999/0201/p575.html This study [aafp.org] [aafp.org] [aafp.org] [aafp.org] [aafp.org] [aafp.org] [aafp.org] https://www.aafp.org/afp/1999/0201/p575.html [aafp.org] [aafp.org] [aafp.org] [aafp.org] [aafp.org] [aafp.org] American Family Physician https://www.aafp.org/afp/1999/0201/p575.html [aafp.org] [aafp.org]