Table 1.
Baseline characteristics of the selected studies and participants.
| Study/year | Location | Population | Diabetes patients (n) |
Age groups |
Men (%) | Aspirin dose | Medication compliance (%) |
Follow-up (years) |
CRoBb |
|---|---|---|---|---|---|---|---|---|---|
| PHS 198911 | USA | Healthy men | 533 | 40–84 | 100 | 325 mg every other day | – | 5.0 | ***** |
| ETDRS 19928 | USA | Diabetes patients | 3711 | 18–70 | 56.5 | 650 mg daily | 91.8 | 5.0 | ***** |
| HOT 19981,2 | Europe, America, Asia | Patients with hypertension | 1501 | 50–80 | 53.0 | 75 mg daily | – | 3.8 | ***** |
| PPP 20031,3 | Italy | >50 Years with known cardiovascular risk factors | 1031 | 64.3a | 48.2 | 100 mg daily | 71.8 | 3.7 | ***** |
| WHS 20051,4 | USA | Healthy women | 1027 | ≥45 | 0.0 | 100 mg on alternate days | – | 10.1 | ****** |
| POPADAD 20089 | UK | Participants >40 years with diabetes | 1276 | ≥40 | 44.1 | 100 mg daily | 50.0 | 6.7 | ****** |
| JPAD 201710 | Japan | Diabetes patients | 2160 | 65a | 55.0 | 81 or 100 mg daily | 90.0 | 10.3 | ****** |
| JPPP 20141,5 | Japan | Patients >60 years with multiple risk factors | 4903 | 60–85 | 42.3 | 100 mg daily | 76.0 | 5.0 | ***** |
| ASCEND 20183 | UK | Participants >40 years with diabetes | 15480 | >40 | 62.5 | 100 mg daily | 70.0 | 7.4 | ****** |
| ASPREE 20181,6 | Australia, USA | Healthy elderly >65 years | 2057 | ≥65 | 43.6 | 100 mg daily | 72.9 | 4.7 | ****** |
Average age.
CRoB consists of seven domains: randomization (selection bias); allocation concealment (selection bias); blinding of patients and personnel (performance bias); blinding of outcome assessment (detection bias); incomplete data reporting (attrition bias); selective reporting (reporting bias) and other biases. Each domain carries one star and five or more stars qualify for a good quality study.
ASPREE: Aspirin in Reducing Events in the Elderly Trial; ASCEND: A Study of Cardiovascular Events in Diabetes Trial; BMD: British Male Doctors study; CRoB: Cochrane Risk of Bias Scale; ETDRS: Early Treatment Diabetic Retinopathy Study; HOT: Hypertension Optimal Treatment trial; JPAD: Japanese Primary Prevention of Atherosclerosis with Aspirin for Diabetes; JPPP: Japanese Primary Prevention Project; PHS: Physicians’ Health Study; POPADAD: Prevention Of Progression of Arterial Disease And Diabetes; PPP: Primary Prevention Project; WHS: Women’s Health Study.