Subgroup analysis based on study design cohort: P 0.14 case control: P 0.14 , sex RR 1.25 95 CI: 0.97 1.60 , P 0.08 , histamine 2 receptor antagonist blockers P 0.93 , and Alzheimer's disease RR 1.00 95 CI: 0.91 1.09 , P 0.93 revealed no significant association between PPI use and dementia risk. CONCLUSION: We found no significant association between PPI use and the risk of dementia or Alzheimer's disease....