Effect of self-care book.

ABSTRACT To the Editor.— The study by Moore et al (1980;243:2317) is the first randomized, controlled study of any selfcare approach. This study found that our book, Take Care of Yourself, was read by an unexpectedly large portion of involuntary recipients (84% read some portion of the book); readers were more confident about their approach to health problems; and there were major decreases in total visits (6% and 9%) and visits for upper respiratory tract infections (17% and 11%) associated with the book.The study also has lessons for those who, like ourselves, are involved in research in this area. As a mass media intervention, a reference book is characterized by low cost per recipient and relatively low percentages of behavior change. For these reasons it is widely accepted that cost-effectiveness or cost benefit is the appropriate basis for evaluation. Moore et al state that the power of their test is