Statistical analysis of dental caries: different methods for different outcomes.

subject reports to smoke ! 10 cigarettes and has started the habit ! 3 years, and heavy smoker when he/she smokes 1 10 cigarettes a day and he/she is smoking for 1 3 years’. The italics have been added for emphasis to highlight that one of the ‘and’ should have been written as ‘or’ so that any smoker in the sample may be categorized as a light or heavy smoker. Clearly, the Campus et al. smoker classification scheme is non-exhaustive, and does not comport with established methods. How, for example, did Campus et al. classify smokers using 1 10 cigarettes a day, smoking for ! 3 years, or smokers using ! 10 cigarettes a day for