medians 如何理解？谢谢

Youhanna et al. compared calculated Uosm (eUosm) to values measured with an osmometer (mUosm) [2]. Samples were obtained from three population-based cohorts including >3000 normal subjects and from a study of 146 ambulatory patients with chronic kidney disease. Urine solute concentrations were measured by autoanalyzer. Highly significant linear correlations were observed between mUosm and eUosm in the three population studies (r=0.98,r=0.98, r=0.99). The best-fit linear regression lines were almost superimposed with the medians and the precision range was relatively narrow (-44 to 90, -54 to 43 and -80 to 34). Among 58 subjects in the three cohorts with glucosuria (>1.66mmol/L), mUosm was 642±32 milliosmoles (mOsm)/kg H2O; eUosm, calculated without or with the addition of urinary glucose, was 624±31 and 635±32 mOsm/L, respectively, both within 3% of mUosm. In the cohort with chronic kidney disease, eUosm was also very close to mUosm, with a similar precision range (-37 to 67).

Youhanna等人将计算出的Uosm（eUosm）与用渗透计（mUosm）测量的值进行了比较。来自三个以人群为基础的队列样本（包括>3000名正常受试者和一项对146名患有慢性肾病的卧床患者）的研究，用自动分析仪测定尿溶质浓度。在三个群体研究中，mUosm与eUosm呈极显著的线性相关（r = 0.98，r = 0.98，r = 0.99）。最佳拟合线性回归线几乎与中位线重叠，精度范围相对较窄（-44到90，54到43，80到34）。三组共58名患者（>1.66mmol/L）， mUosm为642±32 mmol（mOsm）/kg H2O；不加尿葡萄糖和加尿葡萄糖计算的eUosm分别为624±31和635±32 mOsm/L，均在mUosm的3%范围内。在慢性肾脏疾病队列中，eUosm与mUosm也非常接近，精确度范围相似（-37到67）。

 medians 如何理解？谢谢