Dr Y. K. Siu in his letter headlined, 'Two groups approach medicine in different way' (South China Morning Post, November 11), asserted that traditional healers practise medicine that has not been validated by modern scientific methods. This seems to be in support of Dr David C. Anderson's letter headlined, 'Traditional medicine must join modern world', (Post, October 27), which advocated a similar view. I have been watching expectantly for a response to these deeply flawed letters and have seen none, not even from the Natural Health Association, which has left a very biased impression. I think it would be helpful if the good doctors would answer some of the many questions that arise from their letters. For example: Would they regard an analysis of the use of a herb over a thousand years revealing the exact effects and side effects on all constitutions of patients as not scientific? In comparing the danger of Traditional Chinese Medicine (TCM) herbs with the safety of modern drugs, how do they explain how thalidomide was given general release for pregnant women and can they quote any comparable crisis involving TCM herbs? Are they aware of the 1998 report that revealed adverse reactions to prescription drugs (safe?) are killing about 106,000 Americans each year, making prescription drugs the fourth leading killer in the US after heart disease, cancer and stroke? How do they expect acupuncture, which is now generally regarded as multi-factorial, to be tested scientifically by modern medical uni-factorial reductionist science? Are they aware that acupuncture is now readily available on the UK National Health Service? Do they regard preventive medicine and the promotion of health as scientifically based? As surveys have shown, 60 per cent of patients in Hong Kong prefer TCM to conventional medicine in the first instance. Does this not convince the good doctors that the integration of traditional and conventional medicine is inevitable? KEN BRIDGEWATER New Territories