Many fine points are made by Patricia Day and Rudolf Klein (cover feature, pages 20-22, 23 September).

The case for regulation in the independent sector must be based - as in the NHS - on patient access to higher standards of clinical care. The attitude that private patients are less vulnerable because of their resources implies that, should things go wrong, blame should be attached to them rather than the independent sector.

Such patients have, as in any other retail sector, the right to expect protection from unfair distortions of the products.

The authors highlight a very important aspect of NHS consultants' activities in the private sector - apparently differing standards. These standards - judged by length of stay, readmissions, etc- also need to be understood. Lessons can also be learned about the quality of the medical environment when planning protection for NHS and private patients alike.

Dr Rodney Foale Clinical director of surgical and cardiovascular services St Mary's Hospital London W2