Factors associated with undiagnosed hypertension amongst Tongan adults: a cross-sectional study

Abstract

Background Hypertension is responsible for many premature deaths worldwide. However, many individuals with hypertension remain undiagnosed. Tonga is one of the countries that has had a steep increase in hypertension among women. Thus, undiagnosed hypertension could also be increasing. The purpose of this study was to assess the prevalence and factors associated with undiagnosed hypertension among Tongan adults. Methods This cross-sectional study used data collected from 473 participants in the six villages on the main island of Tongatapu. Trained surveyors collected the data by conducting interviews and measuring blood pressure through household visits between February and March 2023. The inclusion criteria for study participants were age of 18–65 years, residence in the villages for at least six months, and not being pregnant. Fisher’s exact test and mixed-effect logistic regression were performed using the EZR application to assess the association between undiagnosed hypertension and predictor variables. Results The prevalence of undiagnosed hypertension was 22.4% (106/473). There were five variables that were significantly associated with undiagnosed hypertension in Fisher’s exact test and were included in the multivariate logistic regression. Overall, three variables remained significant. First, participants who never had their blood pressure measured had higher prevalence compared to those who had it checked recently (33.3% vs. 26.6%). Participants who were not aware of the risk of developing hypertension were significantly more likely to have undiagnosed hypertension compared to those who were aware (27.9% vs. 16.7%). The last factor was middle-aged participants (30–49 years) and older (50–65 years), who were more likely to have undiagnosed hypertension compared to those who were 18–29 years old (prevalence of undiagnosed hypertension: 30.0% and 23.7% vs.11.8%, respectively). Conclusion The prevalence of undiagnosed hypertension could be substantial among Tongan adults, indicating a need to address this issue. Undiagnosed hypertension was associated with having experience with blood pressure measurement, lack of awareness about hypertension, and age, so the Tongan government should provide people with more opportunities to have their blood pressure measured and to improve their awareness.