Changes in knowledge of stroke risk factors and warning signs among Michigan adults

Increasing the public's awareness of stroke is a public health priority. Our objective was to assess changes in the public's knowledge of stroke risk factors and warning signs in Michigan during a 5-year period characterized by a sustained statewide public education effort.

Questions regarding knowledge of stroke risk factors and warning signs were included in the 1999 and 2004 Michigan Behavioral Risk Factor Surveys - random-digit-dialed statewide surveys of adults. Respondents were asked to report up to 3 risk factors and warning signs for stroke.

Between 1999 and 2004, the proportion of respondents who reported 3 correct stroke warning signs increased substantially from 14.3 to 27.6% (p < 0.001), whereas the proportion reporting 3 correct risk factors remained almost unchanged (27.9 vs. 29.1%). The reporting of 2 warning signs in particular increased substantially over the 5-year period; 'any weakness or numbness' increased from 45.7 to 65.6%, while 'confusion, trouble speaking or understanding' increased from 29.9 to 46.5%. Knowledge of stroke warning signs increased across nearly all demographic subgroups, but remained poor for several high-risk groups including the elderly, minorities and those with less education.

Knowledge of warning signs increased during this period while there was little change in knowledge of risk factors. The results suggest that these changes occurred in response to the public education campaign which focused primarily on warning signs. The findings further emphasize the need to target those subgroups who are at highest risk of stroke and where knowledge remains poorest.