<p><i>Background:</i> In 1938, J. Alison Glover published a study on incidence of tonsillecto-mies in school children, demonstrating variation in treatment rates across school districts. Consequently, it rates raised questions as to what determines when to treat a patient. After Wennberg and Gittelsohns’ paper ‘Small Area Variations in Health Care Delivery’ was pub-lished in 1973, it became clear ...