The ASPREE project continues to explore new ways to improve health and quality of life for older adults.
Its success has depended heavily on Australian general practitioners and addresses issues and conditions commonly seen in their older patients.


  1. a randomised, double-blind placebo controlled primary prevention trial of low-dose aspirin (ASPREE clinical trial) completed in mid-2017
  2. an ongoing follow-up observational study of ASPREE participants (ASPREE-XT)



ASPREE (ASPirin in Reducing Events in the Elderly) involved 19,114 community dwelling older adults:

  • 16,703 participants, all aged 70+, across south-eastern parts of Australia and
  • 2,411 participants aged 70+ (ethnic minorities aged 65+) recruited from clinics across the USA

Major points:

  • All participants were free of overt cardiovascular disease, dementia and were otherwise healthy at enrolment.
  • The primary objective was to determine whether 100mg aspirin prolonged life free of dementia and persistent physical disability in the healthy elderly.
  • The trial also examined whether low-dose aspirin affected CVD, cognitive decline, depression, cancer, physical disability and major bleeding episodes.
  • The median intervention period was 4.7 years.


The principal results of ASPREE were published in the New England Journal of Medicine in 2018. These provided the first high quality findings on the value of low-dose aspirin for primary prevention in healthy older patients, mostly aged 70+.

  • Aspirin did not prolong healthy life span free of disability and persistent physical disability (McNeil et al. 2018).
  • Mortality was slightly higher in the aspirin group than in the placebo group (5.9% aspirin: 5.7% placebo), attributed primarily to cancer-related deaths (McNeil et al. 2018).
  • Aspirin did not significantly reduce the risk of heart disease or stroke.
  • Aspirin significantly increased the risk of bleeding, primarily intracranial and in the GIT  (McNeil et al. 2018).

Media announcement of the trial’s results can be viewed here.

A series of additional reports have been published describing the impact of low- dose aspirin on other conditions including depression, cognitive decline and sepsis. These can be accessed here.

Prominent US guidelines incorporated ASPREE findings, recommending against routine use of aspirin for primary prevention in healthy adults aged 70 and older.


ASPREE-XT (eXTension) FOLLOW-UP STUDY (2017 – 2024)

Most participants of the ASPREE trial are continuing to be followed in person or through their medical records.  This is referred to as the ASPREE-XT phase of the study.

  • The primary objective is to determine whether there are delayed (legacy) effects of daily 100mg aspirin treatment, particularly on the incidence and mortality from bowel cancer.
  • An additional objective is to study the impact of various lifestyle, environmental and genomic factors on the physical and cognitive health of older adults.
  • Involves annual collection of clinical, neurocognitive and physical function measures, mood, quality of life, physical ability, demographic and lifestyle details, pathology (FBE, HbA1c, creatinine, ACR)
  • Details of relevant clinical events are sourced from medical records.
  • Participant health outcomes are adjudicated on evidence provided by medical records.


The ASPREE project is public-funded by the National Institute on Aging and the National Cancer Institute (NIA and NCI; both part of the US National Institutes of Health) the National Health and Medical Research Council of Australia, Victorian Cancer Agency and Monash University.

Key features

ASPREE Features

  • Largest USA/Australian collaborative randomised clinical trial yet reported
  • Involved collaboration with more than 2000 Australian GPs
  • Multiple university, institute and teaching hospital partners in Australia and the USA
  • 100% public funded research
  • Contributed to revised primary prevention aspirin guidelines

ASPREE Sub-studies

ASPREE embedded a large number of additional sub-studies exploring whether low-dose aspirin affected various aspects of health including: hearing loss, age-related macular degeneration, falls and fractures, cancer, sepsis, microbiome and more.

Nine out of every ten Australian participants enrolled in at least one sub-study during the ASPREE trial.

Frequently asked questions

Q: What does the ASPREE project involve?


A:  ASPREE-XT is conducted similarly to the ASPREE clinical trial, but participants are no longer taking study tablets (100mg aspirin or a matched placebo).

Your role in ASPREE-XT

  • Oversee your patients’ routine health care, including pathology. Patients do not take study tablets in ASPREE-XT.
  • Receive a summary of your patient’s clinical and performance measures, e.g. cognitive changes, BP, weight, CESD-10 etc, detected at ASPREE-XT study visits.
  • As a co-investigator to ASPREE-XT, you are acknowledged for your contribution to significant public health research.
  • You will be sent updates on the progress of ASPREE-XT and ASPREE publications (approx. 6 monthly).

 Your patient’s role in ASPREE-XT

  • Most ASPREE participants expressed a desire to continue in the follow-up ASPREE-XT study.
  • Your ASPREE-XT patients have given consent to access their medical records, +/- receive 6 monthly phone calls, and where appropriate, attend face-to-face annual study visits with our research staff.
  • Your patient undertakes clinical, neurocognitive and physical function measurements, pathology, and completes questionnaires for mood, quality of life, physical ability and provides personal health, demographic and lifestyle details.
  • Medical records provide critical data for ASPREE-XT researchers to accurately adjudicate patient health outcomes for inclusion in the analysis.

General practice underpins the ASPREE project.  We thank practice staff and GPs supporting this important research.

Frequently asked questions

Q: What are the implications of ASPREE findings for general practice?


A:  Results from the ASPREE trial are applicable to ONLY primary prevention.
Ninety percent of the participants in ASPREE had not previously taken aspirin regularly. Therefore, strictly, the ASPREE results apply most clearly to those initiating aspirin for the first time. Advice about whether to continue low-dose aspirin in a person who has been taking it regularly for some time is uncertain.
The use of low-dose aspirin for secondary prevention (after a myocardial infarction, stroke, angina, TIA etc) is much better established and should continue.

Frequently asked questions

Q: Why are ASPREE and ASPREE-XT looking at cancer outcomes?

Meta-analyses published in The Lancet by other researchers such as Rothwell et al. provided evidence in support of low-dose aspirin preventing cancers of the colon, oesophagus, lung and stomach.


A:  ASPREE reported a slightly higher death rate amongst the aspirin-treated group than in those taking placebo.  It was mostly explained by more rapid progress of cancers that were already advanced when they were diagnosed.

This finding was based on small numbers and could have occurred by chance. Also, in many previous aspirin trials, no similar findings have been observed and there is considerable evidence suggesting the aspirin may lead to a reduction in cancer.

However, studies that have described a reduction in cancer mortality (particularly colorectal cancer mortality) have found that the effect starts to appear only 5-10 years after a period of prolonged intake of aspirin. Mostly these findings have originated from studies in younger populations.

At present the existence of a cancer-reducing effect of aspirin is controversial, especially since the findings of ASPREE were published. The continued follow-up of ASPREE participants after a median 4.7 years of intervention will determine whether the early increase in cancer mortality is followed by a later decline.

View selected cancer papers here.

Frequently asked questions

Q: What happens when your patient may have cognitive decline?


A:  At every annual study visit, our research staff track the cognitive state of study participants by administering the 3MS; an internationally accepted neuro-cognitive screening tool that uses a 100 point scale.  The 3MS is more sensitive to cognitive change than the MMSE, which uses a 30 point scale.

If a participant’s 3MS score declines to a predetermined level (set by population normative data) at any point during the study then:

  • The participant is invited to undertake further cognitive measures with specially trained ASPREE research staff.
  • ASPREE staff will notify the participant’s general practitioner of the 3MS decline and recommend further follow-up such as referral for specialist or assessment clinic review, brain imaging and dementia screening pathology.

NOTE: In Victoria, CDAMS offers a free dementia service and will welcome referrals from all GPs. Services in other states may be fee-based.


  • Findings from additional cognitive measures are provided to the participant’s general practitioner and if a specialist referral is not appropriate or possible, the general practitioner will be asked to provide a clinical opinion on a short questionnaire (DSM-IV proforma).
  • ASPREE staff seek medical documentation relevant to dementia investigations from medical practices, specialists and assessment clinics.

Findings from routine cognitive measures (i.e. 3MS) and the specialised cognitive review, dementia investigative reports and the GP completed DSM-IV proforma (if available) are then collated and form the basis for specialist adjudication on whether the participant has reached a dementia ‘endpoint’ during the ASPREE-XT study period.

ASPREE does not initiate clinical assessment or treatment of cognitive decline.  The literature highlights the value of early diagnosis of dementia, as there are now effective interventions that may improve patient quality of life. Recent research also shows a reversible cause may be present in some cases.

Frequently asked questions

Q: How does ASPREE collect participant medical records?


A: All study participants have consented for trained ASPREE staff members to review their medical records and collect documentation of clinical events from their GP practice, specialist and hospital.

Medical records provide the documentation necessary for ASPREE investigators with the relevant clinical expertise, to adjudicate whether a participant has reached a predetermined study ‘endpoint’, such as cancer or dementia. This process is critical to the project’s findings and maintenance of high quality data.

Our research staff use key terms to search medical records for evidence of clinical health events studied in the ASPREE project. For instance, key search terms used to identify stroke events include ‘stroke’, ‘CVA’, ‘cerebrovascular accident’ and ‘cerebral infarct’.

GPs are always welcome to proactively advise ASPREE of their patient’s clinical event, however, we understand that most practices are too busy. Our trained staff securely and confidentially collect this information when they review the participant’s medical record.

Frequently asked questions

Q: What happens when patients reach a study endpoint?


A: We ask all participants to continue in the study, attending scheduled study visits where ever possible.

Tracking the ongoing health of each participant after a study endpoint is pivotal. All health data from ASPREE participants collected for the duration of the project greatly contribute to the study’s quality and findings.

Frequently asked questions

Q: What sub-studies were incorporated into the ASPREE project?


A:  Large-scale research projects take many years and cost tens of millions of dollars. Because of the cost and the logistics, such studies are infrequently undertaken. ASPREE was a rare opportunity to undertake many ancillary studies to provide important public health information.  Study participants largely found sub-studies interesting and engaging. View ASPREE sub-studies here.

ASPREE-XT Study Protocol


ASPREE-XT is a longitudinal, observational follow-up study of ASPREE participants to determine whether there are long-lasting (legacy) effects of a median 4.7 years of treatment with daily low-dose aspirin on the key outcome measures of:

1) cancer, metastases and cancer mortality

2) the composite primary ASPREE-XT outcome of dementia, disability or death

3) secondary ASPREE-XT outcomes of all-cause mortality, dementia, physical disability, cancer, mild cognitive impairment, depression and frailty, incidence of cardiovascular disease including fatal and non-fatal stroke, major haemorrhage.

  • An additional objective is to study the impact of demographic, comorbid, environmental and genomic factors on the maintenance of cognition and other aspects of health amongst older adults.
  • Study methodology is based closely on the ASPREE clinical trial.
  • Involves annual data collection of clinical, neurocognitive and physical function measures, mood, quality of life, physical ability, demographic and lifestyle details, pathology (FBE, HbA1c, creatinine, ACR) and/or clinical events via medical records.
  • ASPREE-XT is funded by the National Institute on Aging and the National Cancer Institute (NIA and NCI; part of the National Institutes of Health, USA) and the National Health and Medical Research Council of Australia.
  • The study is being conducted in the community with the help of more than 4000 Australian general practitioners.

Download the ASPREE-XT Study Protocol

ASPREE Clinical Trial Protocol


  • ASPREE (ASPirin in Reducing Events in the Elderly) was a double-blind, randomised, placebo-controlled primary prevention trial to determine whether daily active treatment of 100 mg enteric-coated aspirin extended the duration of disability-free life in healthy older adults.
  • It comprised of 19,114 community dwelling participants: 16,703 Australians aged 70+ and 2,411 USA participants aged 70+ (ethnic minorities aged 65+).
  •  All participants were free of overt cardiovascular disease, dementia and were otherwise healthy and able to perform basic activities of daily living (ADLs) independently at enrolment into ASPREE.
  • The primary objective was to determine whether 100mg aspirin prolonged life free of dementia, or life free of significant, persistent physical disability in the healthy elderly.
  • Secondary objectives related to the effects of low-dose aspirin on the key outcome areas of death, cardiovascular disease, dementia and cognitive decline, depression, cancer, physical disability and major bleeding episodes.
  • Additional measures to those included in the primary and secondary objectives were haemoglobin levels, urine albumin:creatinine ratios, cognitive and physical function and hospitalisations.
  • The study examined whether the potential benefits of low-dose aspirin outweighed the risks in this age group.
  • Participants were eligible for the trial if they did not have a current clinical indication for or contraindication (i.e. allergy or increased risk of bleeding) to aspirin, did not have dementia, significant physical disability, low haemoglobin levels, or have a condition that was likely to be fatal during the five years of the trial, and were capable of attending their usual General Practitioner’s (GP’s) clinic and providing informed consent.
  • Sample size estimate required 19,000 participants to provide 90% power of a true relative risk benefit of 0.90 for the primary endpoint (a composite of all-cause mortality, incident dementia and persistent physical disability) in an intention-to-treat analysis with an average follow-up of 5 years.
  • The trial received financial support from the National Institute on Aging and the National Cancer Institute (NIA and NCI; part of the National Institutes of Health, USA), the National Health and Medical Research Council of Australia, Monash University and the Victorian Cancer Agency.
  • Bayer Pharma (Germany) provided in-kind support through the provision of low-dose aspirin and matching placebo and had no other involvement in the trial.
  • ASPREE was conducted in community settings.

Download the ASPREE Clinical Trial Protocol

Contact the ASPREE team

We are very happy to answer your questions. Contact a member of our team.

P: 1800 728 745 (toll free from a landline)


Page updated: 1 August 2023


Aspirin and anaemia risk in older adults

Aspirin and anaemia risk in older adults

A new analysis of ASPREE trial data has found that prolonged daily aspirin use increases the risk of anaemia in some older adults. Findings from ASPREE-Anaemia, a sub-study of the ASPREE trial, may help GPs identify older patients at higher risk of anaemia and who may benefit from regular monitoring for development of the condition.

Poor gait/handgrip linked to dementia risk

Poor gait/handgrip linked to dementia risk

Walking speed and grip strength could be early indicators of dementia before the onset of noticeable symptoms, new findings from the ASPREE trial reveals. Researchers found slow walking speed combined with weak hand grip was a stronger predictor of cognitive decline and dementia in older adults than either measure alone.

About ASPREE for clinicians