Monday, June 27, 2016 Study: Primary Prevention Key to Decreasing Disparity in Black-White Stroke Mortality Rate Reducing the stark disparity in stroke mortality between black and white Americans requires a focus on risk prevention in primary care and public health, say authors of a new study. But, they add, those efforts need to "go further upstream" by examining the reasons for the higher prevalence of stroke risk factors among black Americans, including consideration of what authors call "nontraditional risk factors." While overall stroke mortality and risk factors such as hypertension have declined over the years for both groups, black Americans at age 45 are more than 3 times as likely as their white peers to die of the disease. Although this difference has existed for decades, it wasn’t clear, based on evidence, where and how to target interventions accordingly. The big question, according to authors, has to do with whether black Americans are having more strokes than white Americans, or whether strokes are more often fatal for black Americans. The answer could help health care providers, including physical therapists, understand the best way to approach this public health issue. Enter the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a longitudinal cohort study of 30,239 black and white individuals aged 45 years and older. Between 2003 and 2007, 12,212 black and 17,470 white participants were assessed for risk factors via phone interview and in-home visits. Researchers followed up with the participants every 6 months for risk surveillance, and also documented any health risks or events from medical record data. Results were published in the journal Stroke (abstract only available for free). Among participants, aged 45–54, the black-to-white ratio of stroke mortality—the percentage of people who die from stroke among that population—is approximately 3:1, but by age 75 the rate is roughly equal. The ratio of stroke incidence showed a similar pattern. However, researchers found that the "fatality" of stroke—that is, the percentage of people who die from stroke among the population of people who experience a stroke—is not significantly different between blacks and whites. In other words, a black American who has a stroke isn't more likely to die from the stroke than a white American, but black Americans are more likely than whites to experience a stroke in the first place—at least until late in life when rates even out. According to the researchers, the findings mean that primary prevention, not secondary prevention, should be the main focus in efforts to reduce the disparity. Stroke risk factors such as diabetes, they say, account for 40% of this disparity in stroke incidence, and the remaining 60% could be related to: "awareness, treatment, and control of risk factors," such as hypertension, which may have a "more potent effect" in black individuals; nontraditional risk factors, such as depressive symptoms or higher rate of environmental exposures; or measurement error and confounding. Authors also acknowledge that there are "substantial black-white differences in care after stroke" but note that in this study, at least, there was no difference in case fatality after stroke. Researchers hope this study will lead to better-targeted research and patient care in the future. They write, "We are at the early phase of processes to understand these alternative pathways that potentially contribute to the black-white disparity in stroke incidence, and we need to redouble our efforts to the investigation of these pathways." How do health disparities affect physical therapist practice, and what are some of the driving forces behind them? Check out APTA's health disparities webpage for more insight. Research-related stories featured in PT in Motion News are intended to highlight a topic of interest only and do not constitute an endorsement by APTA. For synthesized research and evidence-based practice information, visit the association's PTNow website.