ASPREE (ASPirin in Reducing Events in the Elderly)
In healthy older people, daily low-dose aspirin did not extend disability-free life and, unexpectedly, was linked with more cancer deaths. It changed guidelines against routine aspirin in the elderly.
19,114 participants followed for a median 4.7 years. Aspirin did not reduce disability-free survival (HR 1.01) or cardiovascular events, increased major haemorrhage (HR 1.38), and was associated with higher all-cause mortality (HR 1.14, 95% CI 1.01-1.29), driven by cancer deaths (HR 1.31, 95% CI 1.10-1.56), particularly from advanced or metastatic cancers. Extended follow-up did not show a later emergence of cancer prevention. The finding contradicts long-term follow-up of earlier aspirin trials in middle-aged adults and is unexplained; hypotheses include a different effect of aspirin on established late-life cancers. It was central to the US Preventive Services Task Force 2022 decision to withdraw the recommendation for aspirin to prevent colorectal cancer.
- Aspirin: 295 events; Placebo: 227 events.
- These are counts of events, not percentages, so compare them with the group sizes in mind.
- Put another way, the treated group had about 31 percent higher chance of the event at any given time (hazard ratio 1.31, likely range 1.1 to 1.56).
- Overall survival counts deaths from any cause, so it is the most direct measure of whether a treatment helps people live longer.
- These results apply to the people the trial enrolled: Community-dwelling adults aged 70+ (65+ for US Black and Hispanic participants) without cardiovascular disease, dementia or disability: aspirin 100 mg/day vs placebo. People in a different situation may not see the same effect.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
19,114 participants enrolled.
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Death from cancer | Aspirin | 9,525 | 295 events | 1.31 (1.1–1.56) | — | link |
| Placebo | 9,589 | 227 events |