That said, I usually try to spend part of the visit alone with a child starting at age 12 or 13. Initially, this may just be 5 minutes. Gradually, as the adolescent matures, the time alone with the adolescent gets to be a greater portion of the visit, and the time with the parent is shorter. In most visits I start out with parent and child together and get all the information about the child's health and any particular concerns either may have. Then I may ask the parent to excuse herself and I'll talk with the child and do the exam; but this may vary. Some 12-year-olds want their parents to leave, while others desperately want them to stay for the exam. If the latter is the case, I will do the exam with the parents present, and then talk with the child alone for a few minutes afterwards. By age 14 or 15, most kids want some independence and privacy, and will ask their parents to step out.
The purpose of my talking to the child alone is not to try to conceal information from the parents, but rather to have the child start to learn how to manage his own health. This means letting them know that they can ask questions that they might be embarrassed to ask their parents -- particularly in regard to puberty, body changes, and sex. And also to make sure they are not beginning to engage in any risky behaviors that could be harmful to them. Not many 12-year-olds are engaged in smoking, alcohol, drugs, and sex, but many 15- and 16-year-olds are, and it is important that they feel they can tell me the truth about those experiences.