MAPT and Alzheimer disease: Blood‐based tests for AD, quantifying the ratio of plasma phosphorylated tau 217 (p‐tau217) relative to non‐p‐tau217, expressed as percentage of p‐tau217, combined with the amyloid‐β 1‐42 and amyloid‐β 1‐40 plasma ratio (the amyloid probability score 2 [APS2]) identified AD in primary care and secondary care provided superior performance compared with the diagnostic accuracy after standard clinical evaluation (not using AD biomarkers).172