The splitting of fees, where a portion of the doctor's bill is paid to third-party administrators, is likely to be another reason for the escalating cost of private healthcare (Doctors' fees: Administrators must change formula by July 1; June 24).

There are also concerns that doctors may offer patients unnecessary services to cover this additional cost.

Another form of fee splitting is when diagnostic facilities offer schemes where referring doctors collect the full charges for tests from their patients, but are then billed at a later date, minus the discounts.

Dr Ernest Wang claims there is no basis to say that doctors may over-investigate because they do not receive any referral fees from private hospitals for ordering laboratory and radiology tests (Rational approach to rein in healthcare costs is more critical; April 28).

However, such rebates have been around for years, and act as an incentive for doctors to refer more patients for tests, which is undeniably a conflict of interest in medicine. Patients can never be completely certain that they genuinely require the tests.

I agree with Dr Wang that doctors' fees alone are not responsible for the escalating cost of healthcare; fee sharing probably plays a part in causing patients to fork out more for diagnostic services.

The splitting of fees is unethical but is such an established practice in the private sector that most doctors eventually get sucked into it.

Diagnostic centres know that paying commissions to doctors ensures a steady stream of referrals. To counter the competitive advantage of the first mover of such promotional schemes, other diagnostic facilities will start to offer even more generous incentives.

As it has become an industry norm, doctors no longer need to refer patients to a particular provider, as kickbacks can be obtained from almost any of them.

For a profession where credibility rests almost completely on trust, this perception of escalating greed in private healthcare is doing irreparable damage to the doctor-patient relationship.

In order to preserve the integrity of professional judgment as well as promote public trust, doctors must not allow their decisions regarding a primary interest to be unduly influenced by any secondary concern.

Edmund Khoo Kim Hock