Dovepress Control cohort (N = 6540) $11,281 ± $29,052a $5142 ± $16,619 $1388 ± $2302 $6530 ± $17,167 Engel-Nitz et al Mean ± SD index hospitalization costs 1-year follow-up costs Medical costs Pharmacy costs combined medical and pharmacy Table 3 Cost of hospitalization for stroke and first year follow-up costs (per patient per year) Stroke cohort (N = 2180) $15,888 ± $33,466* $23,725 ± $58,227* $2950 ± $3549* $26,675 ± $58,605* New stroke (N = 1808) $15,634 ± $27,536 $22,099 ± $53,690 $2937 ± $3577 $25,036 ± $54,052 Recurrent stroke (N = 372) $17,121 ± $53,693 $31,625 ± $76,138 $3014 ± $3416 $34,639 ± $76,586 Notes: All comparisons are relative to the control cohort and are computed by t-test. aMean costs reported for 168 control subjects with a hospitalization on the index date. *P , 0.001. for diabetes (95% CI: 1.1, 1.5) to 1.6 higher for CHF (95% CI: 1.2, 2.1). Increasing age was associated with a small (,1% per year of age) but statistically significant increase in cost (P , 0.001). Discussion The results of our study are consistent with those reporting significant adverse clinical and cost consequences of non- cardioembolic ischemic stroke in other patient populations. Moreover, the study supports previous research showing that patients with recurrent stroke generally fare worse and cost more than patients experiencing first ischemic stroke, which may be related to the overall severity of the stroke for recur- rent compared with first stroke. Severe strokes cost twice as much as mild strokes, despite similar diagnostic testing. In a population study of stroke costs within 30 days of an acute event, the average cost was $7200 for mild ischemic strokes and $12,400 for severe ischemic strokes (4 or 5 on the Rankin Disability Scale).15 Inpatient hospital cost for an acute stroke event accounts for 70% of first-year poststroke cost.16 The largest components of acute care cost are room charges (50%), medical management (21%), and diagnostic costs (19%).17 Comorbidities such as ischemic heart disease may also predict higher costs.18 In our managed care population, the recurrent stroke patients had poorer outcomes on all measures. Although the study designs differed, our findings were consistent with those of Samsa et al7 which pertained exclusively to a Medicare patient population. The interpretation of the results comparing recurrent and new stroke requires some caution. Our recurrent stroke subgroup represented approximately 17% of all strokes based on a 12-month pre-index evaluation. This estimate is below the national rate of 29% reported by the American Heart Association.6 The difference between the estimates likely stems from the limited pre-index evaluation. Prior strokes may have occurred in a larger population than were identified in only the 12 months evaluated. In addition, the impact of inappropriately designating some patients as new stroke patients rather than recurrent stroke patients may falsely inflate adverse outcomes and costs among new stroke patients. However, despite this risk, the differentials between new and recurrent stroke patients in clinical outcomes and costs were substantial. Table 4 cox proportional hazards analysis of time to hospitalization Table 5 cox proportional hazards analysis of time to stroke Cox proportional hazards model Cox proportional hazards model stroke Age Male Midwest Northeast West Hypertension Diabetes TiA cOPD cHF Mi Hazard ratio 2.368 1.023 0.918 1.037 0.826 0.909 1.259 1.281 1.288 1.568 1.753 1.495 SE 0.116 0.002 0.040 0.050 0.065 0.078 0.061 0.072 0.131 0.122 0.155 0.251 P value 0.000 0.000 0.050 0.453 0.015 0.268 0.000 0.000 0.013 0.000 0.000 0.017 95% CI lower 95% CI upper 2.152 1.019 0.842 0.944 0.708 0.768 1.146 1.148 1.055 1.347 1.475 1.076 2.606 1.027 1.000 1.138 0.963 1.076 1.383 1.430 1.572 1.826 2.085 2.078 stroke Age Male Midwest Northeast West Hypertension Diabetes TiA cOPD cHF Mi Hazard ratio 20.964 1.031 0.841 1.023 0.886 0.899 1.028 1.066 1.175 1.255 1.355 1.334 SE 2.826 0.004 0.084 0.112 0.151 0.177 0.111 0.125 0.205 0.205 0.258 0.420 P value 0.000 0.000 0.082 0.833 0.477 0.590 0.797 0.588 0.355 0.163 0.111 0.361 95% CI lower 16.096 1.023 0.692 0.825 0.634 0.611 0.832 0.846 0.834 0.912 0.933 0.719 95% CI upper 27.304 1.039 1.022 1.269 1.237 1.323 1.270 1.342 1.655 1.728 1.968 2.474 Abbreviations: CHF, congestive heart failure; CI, confidence interval; COPD, chronic obstructive pulmonary disease; Mi, myocardial infarction; sE, standard error; TiA, transient ischemic attack. Abbreviations: CHF, congestive heart failure; CI, confidence interval; COPD, chronic obstructive pulmonary disease; Mi, myocardial infarction; sE, standard error; TiA, transient ischemic attack. 910 submit your manuscript | www.dovepress.com Dovepress Vascular Health and Risk Management 2010:6