We read with interest the paper by Keenan and colleagues.1

We recently studied the 2005/2006 Hospital Episode Statistics (HES) data for cataract and have reached similar conclusions. We agree with the authors’ observations that as NHS cataract surgery rates (CSRs) in England have increased significantly in recent years, several questions are now raised. What is the appropriate CSR in a developed market economy? Is the observed geographical variation in CSR in England a marker of increased incidence and requirement for surgery in some “high activity” regions or a marker for overprovision? Conversely, in relation to lower activity regions, are there data set issues from the use of an administrative database such as the HES, or are there genuine clinical differences or variations in the organisational provision of cataract care? Private CSR rates are …