Differences and Similarities in Explanatory Models of Hypertension in the United States of America, Tanzania and Jamaica

Background: Misperceptions detract from effective disease management in a number of conditions but the nature of underlying illness beliefs and their relative consistency in patients with chronic hypertension (cHTN) who present to the Emergency Department (ED) with poor blood pressure control is not known. Objectives: 1) To explore disease knowledge in ED patients with cHTN using explanatory modelling; and 2) to compare gaps in cHTN knowledge across racially similar but geographically divergent ED patients. Methods: Emergency department patients of African origin with cHTN were recruited from three sites: Detroit Receiving Hospital (DRH - Detroit, MI, USA), the Tanzanian Training Center for International Health (TTCIH - Ifakara, TZ) and the University Hospital of the West Indies (UHWI - Kingston, JA). Demographic and baseline data were collected along with open-ended responses to a series of questions related to cHTN. Qualitative responses were coded into predefined, disease-relevant quantitative domains by two separate, blinded reviewers and multilevel comparisons were performed using Kruskal-Wallis or analysis of variance (ANOVA) tests, where appropriate. Results: One hundred and ninety-seven patients were enrolled; mean age (50.5 years vs 51.6 years vs 50.8 years; p = 0.86) and gender distribution (% male: 49.5 vs 44 vs 40; p = 0.53) were similar across sites but patients at DRH (vs TTCIH vs UHWI) were more hypertensive at presentation (mean systolic BP in mmHg: 166.8 vs 153 vs 152.7; p = 0.003), had a longer mean duration of cHTN (12.1 years vs 4.6 years vs 9.1; p < 0.0001), and were less likely to be on antihypertensive therapy (84.5% vs 92% vs 100%, p = 0.001). Explanatory models revealed limited recognition of cHTN as a "disease" (19.6% vs 28% vs 16%; p = 0.31) and consistency in the belief that cHTN was curable (44.3% vs 36% vs 42%; p = 0.62). Stress (48.4% vs 60% vs 50%; p = 0.31) and, especially at DRH, diet (62.2% vs 22% vs 36%; p < 0.0001) were identified most frequently as causes of cHTN and an association with symptoms was common (83.5% vs 98% vs 78%; p = 0.15). Clear differences existed for perceived benefits of treatment and consequences of poor control by site, but in general, both were under-appreciated. Conclusions: Misperceptions related to cHTN are common in ED patients. While specific areas of disconnect exist by geographic region, failure to recognize cHTN as a dire and fixed disease state is consistent, suggesting that a uniform educational intervention may be of benefit in this setting.