Wrinkles and Smoking

Excerpt

To the editor: Dr. Daniell is to be complimented on his imaginative and methodical study of smokers' wrinkles [Ann Intern Med 75:873-880, 1971], but I am compelled to point out a logical flaw in his closing sentence. He there implies that the association between smoking and wrinkling might serve as ammunition in counseling patients on the "personal risks of cigarette smoking."

Despite his reservations on causality in the penultimate paragraph, Dr. Daniell has fallen into the cum hoc, propter hoc line of reasoning that is all too common in epidemiologic studies. He implies not only causality but also that avoidance