Review PBS lipid therapy criteria: experts

LEADING Australian medical experts have reignited the debate over PBS criteria for prescribing lipid-lowering medications, claiming most high-risk patients are missing out on vital treatment.

Representatives from the Baker IDI Heart and Diabetes Institute, Kidney Health Australia, the National Heart Foundation, the National Stroke Research Institute, and other bodies are calling for absolute CVD risk – based upon multiple independent risk factors – to be used as the key criteria for access to subsidised lipid-lowering drugs.

They say the current PBS criteria, based largely on cholesterol levels, mean that more than 80% of high-risk patients are not receiving treatment. And 27% of those who are currently eligible for lipid-lowering medications, but do not have CVD or diabetes, have a high absolute risk, meaning many may be receiving the treatment unnecessarily.

“In those who do not have known cardiovascular disease or diabetes, an approach which is based upon an estimation of absolute risk would be superior,” according to study co-author Professor Andrew Tonkin, who is head of the Cardiovascular Research Unit at Monash University.

While acknowledging that existing PBS criteria did accurately identify high-risk individuals with CVD and diabetes, Professor Tonkin argued the system was failing many so-called ‘healthy’ individuals who were also ‘high-risk’ under the absolute risk model.

He expressed frustration that the PBS criteria had not changed despite the absolute CVD risk model first being put forward in the early 1990s.

A 2005 position statement from the Heart Foundation and the Cardiac Society of Australia and New Zealand advocated the absolute risk model, but this had “yet to be adopted in guidelines governing eligibility for subsidy of lipid-lowering drugs”, Professor Tonkin said.

Emeritus Professor Lloyd Sansom, chair of the Pharmaceutical Benefits Advisory Committee, said his organisation had reconsidered eligibility criteria in 2004 and that it “believes the current eligibility guidelines reflect an absolute risk approach”.

The PBS criteria incorporated other risk factors not inherent in the absolute risk model, including microalbuminuria, but had omitted smoking and ECG criteria, he said.

Professor Sansom questioned the authors’ use of 1999/2000 AusDiab study data to quantify the ‘treatment gap’.

“[This] assumes that the decision context of prescribers has not changed since 2000 as a result of the changing guidelines.”

Professor Tonkin agreed this was a limitation, but argued: “It’s the best available data that we have.”

MJA 2008; 189:319-22.