Baseline Characteristics of Participants in the ASPREE (ASPirin in Reducing Events in the Elderly) Study

Abstract

Background: There are no primary prevention trials of aspirin with relevant geriatric outcomes in elderly people. ASPirin in Reducing Events in the Elderly (ASPREE) is a placebo-controlled trial of low-dose aspirin that will determine whether 5 years of daily 100-mg enteric-coated aspirin extends disability-free and dementia-free life in a healthy elderly population and whether these benefits outweigh the risks.

Methods: Set in primary care, this randomized double-blind placebo-controlled trial has a composite primary endpoint of death, incident dementia or persistent physical disability. Participants aged 70+ years (non-minorities) or 65+ years (U.S. minorities) were free of cardiovascular disease, dementia, or physical disability and without a contraindication to, or indication for, aspirin. Baseline data include physical and lifestyle, personal and family medical history, hemoglobin, fasting glucose, creatinine, lipid panel, urinary albumin:creatinine ratio, cognition (3MS, HVLT-R, COWAT, SDMT), mood (CES-D-10), physical function (gait speed, grip strength), Katz activities of daily living and quality of life (SF-12).

Results: Recruitment ended in December 2014 with 16,703 Australian and 2,411 U.S. participants, a median age of 74 (range 65-98) years and 56% women. Approximately 55% of the U.S. cohort were from minority groups; 9% of the total cohort. Proportions with hypertension, overweight, and chronic kidney disease were similar to age-matched populations from both countries although lower percentages had diabetes, dyslipidemia, and osteoarthritis.

Discussion: Findings from ASPREE will be generalizable to a healthier older population in both countries and will assess whether the broad benefits of daily low-dose aspirin in prolonging independent life outweigh the risks.

Keywords: Clinical trial; Dementia; Disability; Primary prevention.

Figure 1.

CONSORT flowchart of ASPREE participant numbers from phone screening to randomization in both countries. Visit 1 (V1) = the first face-to-face study visit for consent, checking of eligibility criteria (blood pressure, cardiovascular disease, and other clinical history, contraindication to aspirin, 3MS, Katz ADLs) and allocation of 40 days of trial medication for compliance test; Visit 2 (V2) = second face-to-face study visit with checking of eligibility criteria (hemoglobin, drug compliance >80%, general practitioner sign-off) and randomization.

Figure 2.

(A) Map of Australia with rectangle of enlarged southeastern area showing the major ASPREE recruitment sites. Cities are depicted as black circles (and names) and include Melbourne VIC (6,422), Adelaide SA (1,253), Canberra ACT (1,007), and Hobart TAS (886), with recruitment numbers in parenthesis. Regional sites are depicted as numbered circles and include (with recruitment numbers in parenthesis): 1. Albury/Wodonga VIC/NSW (740); 2. Ballarat VIC (710); 3. Bendigo VIC (880); 4. Burnie TAS (664); 5. Geelong VIC (721); 6. Launceston TAS (554); 7. Mildura VIC (174); 8. Mount Gambier SA (196); 9. Sapphire Coast NSW (120); 10. Traralgon VIC (1,168); 11. Warrnambool VIC (681); 12. Wollongong NSW (527). (B) Recruitment sites in the United States are depicted as numbered circles and include 1. Birmingham AL; 2. Palo Alto CA; 3. Washington DC; 4. Gainesville FL; 5. Atlanta GA; 6. Augusta GA; 7. Chicago IL; 8. Iowa City IA; 9. Kansas City, KS; 10. Baton Rouge LA (two sites); 11. Monroe LA; 12. New Orleans LA (two sites); 13. Shreveport LA; 14. Ann Arbor MI; 15. Detroit MI (three sites); 16. Minneapolis MN; 17. St. Paul MN; 18. Greenville NC; 19. Winston-Salem NC; 20. Mineola NY; 21. Philadelphia PA; 22. Pittsburgh PA; 23. Pawtucket RI; 24. Memphis TN; 25. Dallas TX; 26. Galveston TX; 27. Harlingen TX; 28. San Antonio TX.