In prespecified models stratified by stroke subtypes , there was a graded association of FGF23 with risk of cardioembolic stroke in fully adjusted models ( quartile 1 , reference ; quartile 2 hazard ratio , 1.48 ; 95 % confidence interval , 0.63-3 .47 ; quartile 3 hazard ratio , 1.99 ; 95 % confidence interval , 0.89-4 .44 ; quartile 4 hazard ratio , 2.52 ; 95 % confidence interval , 1.08-5 .91 ) .