While AIA's intention to modify its MediShield Life integrated plans in an attempt to rein in healthcare costs is a positive sign ("AIA to set up panel of preferred doctors"; Dec 4), one should be concerned about what constitutes "overtreatment".

Decision-making in medicine is based on probability. When faced with a diagnostic dilemma, multiple tests need to be performed.

The vast majority of tests are not definitive but indicative, leading to further tests for a conclusive diagnosis. The doctor decides the point at which sufficient information is obtained and when to stop further investigations.

Conventional clinical approaches will leave a minority of patients with their condition misdiagnosed because one or two critical confirmatory tests were not performed.

This decision process is prospective. However, audits for adverse events are always made retrospectively.

Performing all available tests in order not to miss any patient's diagnosis could be construed as "overtreatment" for the majority.

But not performing them might lead to a misdiagnosis.

Doctors are encouraged to educate their patients so they can share the responsibility of making decisions for treatment ("The doctor will see you now -in a new light"; Nov 8).

However, there are patients whose screening test for cancer returns a "probably benign" classification. Often, they request a biopsy to eliminate that small possibility.

Denying them a biopsy on the grounds that it is not recommended due to minute odds of a positive test could lead to delayed diagnosis for the patient and liability for the doctor.

Yet, performing the biopsy and getting a benign diagnosis could be construed as "overtreatment", introducing "unnecessary" costs.

It is interesting to note that pharmaceutical companies, laboratories, manufacturers of medical consumables and hospital management systems are not targeted by the insurance companies in their efforts to reduce costs.

Could it be a biased perception that doctors are the root cause for increasing costs and, hence, are targeted for measures to contain costs?

What about indemnity costs, which have their origins in consumer pressures?

Mona Tan (Dr)