"It's just a misunderstanding that medicines on the essential-drug list are substandard," said Dr Supol Limwattananont, a lecturer at Khon Kaen University's Faculty of Pharmaceutical Sciences, while announcing his findings yesterday.

His study, titled "The Tendency of Hospitals in Using Medicines from the Essential Drug List", was funded by the Thailand Research Fund.

The national drug list is compiled by the Drug Commission and prescribes the medicines that all hospitals must stock because they are considered essential. The list is updated regularly.

Supol backed medicines on the essential-drug list, saying: "Medically, economically and academically speaking, the essential-drug list is effective and efficient. There are both cheap and expensive medicines on the list."

Supol said that some heart-disease medications not on the essential-drug list were clearly not as cost-effective as the ones on the list.

He called for an effort to create better understanding among employees covered by the Social Security Fund (SSF) because they currently felt they were being short-changed by the scheme's use of medicines from the essential drug list.

The SSF requires that its members be treated mainly with medicines from the essential drug list, while the Civil Servants Medical Benefits Scheme provides a wider range of medicines - some of which are more expensive.

The government's universal healthcare scheme also uses medicines mainly from the essential-drug list.