Appeli Saidi, Omala Saint Kizito, Izudi Jonathan
Department of Agribusiness and Extension, Faculty of Agriculture and Animal Sciences, Busitema University, Soroti, Uganda.
Department of Statistical Methods and Actuarial Sciences, School of Statistics and Planning, Makerere University, Kampala, Uganda.
PLOS Glob Public Health. 2024 Sep 12;4(9):e0003707. doi: 10.1371/journal.pgph.0003707. eCollection 2024.
Blood pressure (BP) is a repeated measurement data as multiple measurements of both systolic blood pressure (SBP) and diastolic blood pressure (DBP) are simultaneously obtained on a patient to determine a raised blood pressure (hypertension). In examining factors associated with hypertension, BP is measured either as a binary outcome leading to information loss and reduced statistical efficiency or as a continuous outcome based on the average of one of the measurements or a combination of the two but independently thus ignoring possible correlation. We simultaneously modeled the risk factors for increased SBP and DBP among adults in Uganda and tested the difference in the effect of certain determinants on SBP versus DBP. We analyzed the 2014 nationwide non-communicable disease risk factor baseline survey data of Ugandans aged 18-69 years. We considered SBP and DBP as two continuous outcomes and conducted multivariate linear regression to jointly model SBP and DBP accounting for their distribution as bivariate normal. Of 3,646 participants, 950 (26.1%) had hypertension based on SBP (BP ≥ 140 mmHg) and DBP (BP ≥ 90 mmHg), 631 (17.3%) based on SBP alone, and 780 (21.4%) based on DBP alone. The study found that an increase in age (ranging from 18-69 years), obesity, income, being centrally obese, and hypercholesterolemia were significantly associated with higher SBP levels. Living in eastern, northern, and western Uganda regions was significantly associated with lower SBP, whereas increasing age, obesity, and hypercholesterolemia were significantly associated with higher DBP. Adults who rarely added salt to their meals were on average associated with higher DBP levels than those who never added salt to their meals. We found a strong residual correlation between SBP and DBP (r = 0.7307) even after accounting for covariates at the marginal level. This study presents a statistical technique for joint modeling of blood pressure, enabling the estimation of correlation between two outcomes and controlling family-wise error rate by testing the effect of a risk factor across both outcomes simultaneously.
血压（BP）是一种重复测量数据，因为要对患者同时进行多次收缩压（SBP）和舒张压（DBP）测量，以确定血压升高（高血压）。在研究与高血压相关的因素时，血压要么被视为导致信息丢失和统计效率降低的二元结果，要么被视为基于其中一次测量的平均值或两者组合的连续结果，但独立处理，从而忽略了可能的相关性。我们同时对乌干达成年人中收缩压和舒张压升高的风险因素进行建模，并测试某些决定因素对收缩压和舒张压影响的差异。我们分析了2014年全国18至69岁乌干达人的非传染性疾病风险因素基线调查数据。我们将收缩压和舒张压视为两个连续结果，并进行多变量线性回归，以联合对收缩压和舒张压进行建模，同时考虑它们的二元正态分布。在3646名参与者中，950人（26.1%）基于收缩压（血压≥140 mmHg）和舒张压（血压≥90 mmHg）患有高血压，631人（17.3%）仅基于收缩压，780人（21.4%）仅基于舒张压。研究发现，年龄增加（18至69岁）、肥胖、收入、中心性肥胖和高胆固醇血症与较高的收缩压水平显著相关。生活在乌干达东部、北部和西部地区与较低的收缩压显著相关，而年龄增加、肥胖和高胆固醇血症与较高的舒张压显著相关。很少在饭菜中加盐的成年人平均比从不往饭菜中加盐的成年人舒张压水平更高。即使在边际水平上考虑了协变量之后，我们仍发现收缩压和舒张压之间存在很强的残余相关性（r = 0.7307）。本研究提出了一种用于血压联合建模的统计技术，能够估计两个结果之间的相关性，并通过同时测试风险因素对两个结果的影响来控制家族性错误率。
