Between December 2002 and December 2005, a total of 517 cases with first-ever ischemic stroke were prospectively accrued to this study. Four hundred sixty-three (90%) provided self-consent, and 54 (10%) were enrolled with surrogate authorization.
Overall, 231 subjects (45%) were women, 150 (29%) were black, and 351 (68%) were white. The median time to enrollment was 4 days in both groups. Demographic and lifestyle characteristics for the 517 cases, stratified by consent status, are summarized in . These characteristics were similar between the groups except for race. Among the 150 black subjects, 129 (86%) self-consented and 21 (14%) were enrolled by surrogate; among the 351 white subjects, 322 (92%) self-consented and 29 (8%) were enrolled by surrogate. Medical history did not differ significantly between groups, aside from migraine headaches ().
Baseline Characteristics by Consent Status (N=517)*
Medical History by Consent Status (N=517)*
Stroke Symptoms and Severity
Stroke characteristics are summarized in . Reported QVSS symptoms of weakness, numbness, and visual deficits did not differ significantly between self-consented and surrogate-authorized cases. Reported communication problems occurred more frequently among the surrogate-authorized individuals (57% vs 39% of self-consented cases; P=.02). Signs of neurologic impairment detected by NIHSS occurred much more frequently among the surrogate-authorized cases: weakness (98% vs 60%; P<.001); numbness (52% vs 28%; P=.001); visual deficits (43% vs 17%; P<.001); and communication problems (78% vs 35%; P<.001).
Stroke Symptoms and Severity by Consent Status*
Stroke severity was quantified by 4 measures—NIHSS, BI, OHS, and GOS (). Scores for each of these measures were significantly worse for the surrogate-authorized than for the self-consented cases (all P<.001).
Infarct size and location also differed between the groups (). The proportion with larger infarcts (>3.0 cm) was 31% for the self-consented cases and 61% for the surrogate-authorized cases (P<.001). In both groups, the majority of strokes were supratentorial. Surrogate-authorized cases had significantly higher rates of left supratentorial infarction (63% vs 35%; P<.001).
Subtyping classifications are summarized in . Trial of Org 10172 in Acute Stroke Treatment (TOAST) subtyping did not differ significantly between self-consented and surrogate-authorized cases (P=.75). Self-consented and surrogate-authorized cases did, however, differ significantly with respect to the OHS classification (P<.001). Notably, only 7% of the self-consented cases had total anterior circulation infarcts, whereas 33% of surrogate-authorized cases had total anterior circulation infarcts.
Stroke Subtype Classifications by Consent Status
Stroke cases were contacted approximately 90 days after the initial stroke, and BI, OHS, and GOS scores were used to quantify the individuals’ functional status (). At 90 days, surrogate-authorized cases continued to do significantly worse than those who self-consented. The change in these measures from baseline to 90 days did not differ significantly between the 2 groups, with the surrogate-authorized group consistently performing worse on all measures.
90-Day Stroke Outcomes Scores by Consent Status
Analysis From Site Restricting Enrollment
During the same study period, a total of 105 cases were enrolled from the 1 site that did not allow surrogate authorization (). An additional 56 individuals were approached but declined participation. A total of 85 otherwise eligible individuals were not approached regarding enrollment because they lacked capacity. Those lacking capacity were older (P=.002). Lack of capacity was most commonly caused by aphasia or communication difficulties (39/85 [46%]). The NIHSS scores were significantly worse for those lacking capacity than for those enrolled (P<.001). Distribution of stroke subtypes as determined by the TOAST classification showed a greater proportion of cases with cardioembolic stroke and a smaller proportion having a small-vessel mechanism (P=.01). The subtype classification using the OHS method also differed, with a greater proportion of those enrolled having lacunar infarcts or partial anterior circulation infarcts, whereas those lacking capacity were more likely to have total anterior circulation infarcts (P<.001).
Comparison of Enrolled Individuals and Those Otherwise Eligible Lacking Capacity to Consent at Site 4*