Issue 12 / 8 April 2013

THE re-education of primary care providers and patients about the risks and benefits of taking aspirin for primary and secondary prevention of cardiovascular disease is happening, but slowly, according to the head of the national organisation advising on quality use of medicines.

Dr Janette Randall, chair of the board of NPS MedicineWise and a practising GP, said there was still a gap in the application of clear evidence in favour of using acetylsalicylic acid (ASA) in secondary prevention. “The data here in Australia is not very comprehensive, and that’s the biggest problem”, she told MJA InSight.

Dr Randall said research published earlier this year in Canadian Family Physician rang true in an Australian setting, although data were hard find. (1)

The Canadian research found that, of patients taking ASA for primary prevention of heart disease, 62.8% did so on the advice of their GP. This was despite the fact that “the literature does not show a net clinical benefit to using ASA for primary cardiovascular prevention”.

Among patients who decided to take ASA on their own initiation, only 3.5% were doing it for secondary prevention, the authors wrote.

In a recent interview with, the lead author, Dr Michael Kolber, said “we’re actually missing the boat”. (2)

“It is likely that many patients of relatively low cardiovascular risk are taking ASA for primary cardiovascular prevention, while many of those who might benefit from ASA for secondary prevention are not taking it”, Dr Kolber said.

Dr Randall agreed, telling MJA InSight: “The big message for me is in the numbers who are not taking ASA for secondary prevention.

“Our gut instinct is that there are people who would benefit from taking aspirin but it is hard to target them because we don’t know who they are and why they are not taking it. Are they on other anticoagulants? Do they have adverse responses to aspirin? We just don’t know.”

Dr Randall said many people who took ASA had been doing so for a while, based on advice from their GP several years ago.

“That was probably quite reasonable [advice] to start with”, she said. “It highlights the need to review patients’ medications and history very regularly.

“De-prescribing a medication — stopping the patient taking it — is just as appropriate as it is to start them on one. It’s something that we’re not very good at yet.”

Dr Randall said GPs often lacked confidence to question treatment prescribed by a specialist if they felt it didn’t gel with the latest evidence.

“How do we empower GPs to go to the data and the evidence in order to provide an alternative for their patients? There’s a reluctance to challenge specialists and that’s a cultural thing”, she said.

NPS MedicineWise has used federal government funding to set up MedicineInsight, a data collection project accessing the prescribing data from 500 Australian practices. (3)

“Post-market surveillance data is very lacking in this country”, Dr Randall told MJA InSight.

“We’re 12 months into this project and we’re hopeful the data will help us to be more sophisticated with the way we target treatment.”

– Cate Swannell

1. Can Fam Physician 2013; 59: 55-61
2. 2013; Online 28 March
3. NPS MedicineWise: MedicineInSight

Posted 8 April 2013

3 thoughts on “Data on aspirin lacking

  1. Brian Parker says:

    The taking of aspirin has become a vexed affair. Patients must be pulling their hair out because of the divergent advice floating around. I am quite certain that aspirin is a very useful medication to take over the age of 55 if there is a family history of CVD. Aspirin thins the blood as you know and allows anastomotic little arteries to grow around the blocked site. I know this from personal experience, having had 2 stents put in 12 years ago. I am now 79…I put myself on aspirin at age 60 and this move saved my life. I also have a very strong family history of carcinoma of the colon and, as you will know, the effect of aspirin is to reduce the incidence of this disease.Your article, in paragraph 3, states “although data were hard to find”. Data must be succinct and definite.

  2. JEROME GELB says:

    If ASA is useful in secondary prevention of CVS events and those who might benefit from taking it are not, would it not be a good idea to commence a campaign directed at this group suggesting that they make an appointment with their GP to discuss this important preventative measure?

    I could imagine Public Service Announcements on TV and radio, press ads, letters to discharged patients & notification of GP’s. Of course, GP education could be a component of such a campaign.

  3. Martin Knapp FRACP says:

    The problem for GPs and specialists is even greater in the older age groups as there is so little data in the over 70s. This question is being addressed by the ASPREE study (visit Many like myself, well over 70, have been recruited into this international multi-centre trial comparing daily aspirin or placebo when over 70. There is still active recruitment in Australia and in some other countries into this study. This provides a rational route to follow for the over 70 person; as no-one knows IF your patient (or you) should take Aspirin, so sign them up as a subject in this trial. There are the extra benefits that any patient in any trial gets ie regular free treatment, free testing and reminders regarding check-ups etc. When aspirin has been proven to be good or bad or ineffective for the over 70s I am trusting the trial organisers will let me know whether I should continue my tablet (if aspirin), change to aspirin (if placebo) or stop the daily tablet.
    One question that this trial is not asking is what time of day I should take my tablet. The instructions are to take it in the morning (but in some situations evening asprin has been suggested as more effective than morning aspirin). Martin Knapp FRACP

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