Department of Statistics and Applied Probability, University of California-Santa Barbara, Santa Barbara, California.
Global Medical Office, Fresenius Medical Care, Waltham, Massachusetts.
Kidney360. 2020 Jan 23;1(2):93-105. doi: 10.34067/KID.0000352019. eCollection 2020 Feb 27.
All life on earth has adapted to the effects of changing seasons. The general and ESKD populations exhibit seasonal rhythms in physiology and outcomes. The ESKD population also shows secular trends over calendar time that can convolute the influences of seasonal variations. We conducted an analysis that simultaneously considered both seasonality and calendar time to isolate these trends for cardiovascular, nutrition, and inflammation markers.
We used data from adult patients on hemodialysis (HD) in the United States from 2010 through 2014. An additive model accounted for variations over both calendar time and time on dialysis. Calendar time trends were decomposed into seasonal and secular trends. Bootstrap procedures and likelihood ratio methods tested if seasonal and secular variations exist.
We analyzed data from 354,176 patients on HD at 2436 clinics. Patients were 59±15 years old, 57% were men, and 61% had diabetes. Isolated average secular trends showed decreases in pre-HD systolic BP (pre-SBP) of 2.6 mm Hg (95% CI, 2.4 to 2.8) and interdialytic weight gain (IDWG) of 0.35 kg (95% CI, 0.33 to 0.36) yet increases in post-HD weight of 2.76 kg (95% CI, 2.58 to 2.97). We found independent seasonal variations of 3.3 mm Hg (95% CI, 3.1 to 3.5) for pre-SBP, 0.19 kg (95% CI, 0.17 to 0.20) for IDWG, and 0.62 kg (95% CI, 0.46 to 0.79) for post-HD weight as well as 0.12 L (95% CI, 0.11 to 0.14) for ultrafiltration volume, 0.41 ml/kg per hour (95% CI, 0.37 to 0.45) for ultrafiltration rates, and 3.30 (95% CI, 2.90 to 3.77) hospital days per patient year, which were higher in winter versus summer.
Patients on HD show marked seasonal variability of key indicators. Secular trends indicate decreasing BP and IDWG and increasing post-HD weight. These methods will be of importance for independently determining seasonal and secular trends in future assessments of population health.
地球上所有的生命都适应了季节变化的影响。一般人群和终末期肾病（ESKD）人群的生理和结局都表现出季节性节律。ESKD 人群在日历时也表现出长期趋势，这可能会使季节性变化的影响复杂化。我们进行了一项分析，同时考虑了季节性和日历时，以分离心血管、营养和炎症标志物的这些趋势。
我们使用了 2010 年至 2014 年期间美国血液透析（HD）成年患者的数据。一个加性模型解释了日历时和透析时间的变化。日历时的趋势被分解为季节性和长期趋势。自举程序和似然比方法检验了季节性和长期变化是否存在。
我们分析了 2436 家诊所的 354176 名 HD 患者的数据。患者年龄 59±15 岁，57%为男性，61%患有糖尿病。孤立的平均长期趋势显示，预透析收缩压（pre-SBP）下降 2.6mmHg（95%CI，2.4 至 2.8），透析间期体重增加（IDWG）减少 0.35kg（95%CI，0.33 至 0.36），但 post-HD 体重增加 2.76kg（95%CI，2.58 至 2.97）。我们发现独立的季节性变化为 3.3mmHg（95%CI，3.1 至 3.5）用于 pre-SBP，0.19kg（95%CI，0.17 至 0.20）用于 IDWG，0.62kg（95%CI，0.46 至 0.79）用于 post-HD 体重，0.12L（95%CI，0.11 至 0.14）用于超滤量，0.41ml/kg 每小时（95%CI，0.37 至 0.45）用于超滤率，以及每个患者每年 3.30 天（95%CI，2.90 至 3.77）住院天数，这些都高于冬季和夏季。
HD 患者的关键指标表现出明显的季节性可变性。长期趋势表明血压和 IDWG 下降，post-HD 体重增加。这些方法对于在未来的人群健康评估中独立确定季节性和长期趋势将非常重要。
