Table 3.

Characteristics of studies of aspirin and Alzheimer's disease

Study	No	Pooled relative risk or odds ratio (95%CI)	P value for heterogeneity	R(I) statistic
NSAIDs
Cohort studies	6	0.84 (0.54 to 1.05)	0.04	0.58
Case-control studies	3	0.62 (0.45 to 0.82)	0.55	0.00
All studies	9	0.72 (0.56 to 0.94)	0.06	0.49
Aspirin
Cohort studies	5	0.85 (0.71 to 1.03)	0.76	0.00
Case-control studies	3	0.84 (0.61 to 1.16)	0.77	0.00
All studies	8	0.87 (0.70 to 1.07)	0.79	0.00