Shah Anoop Dinesh, Thornley Simon, Chung Sheng-Chia, Denaxas Spiros, Jackson Rod, Hemingway Harry
Farr Institute of Health Informatics Research, UCL Institute of Health Informatics, London, UK.
University College London Hospitals NHS Trust, London, UK.
BMJ Open. 2017 Feb 17;7(2):e013100. doi: 10.1136/bmjopen-2016-013100.
Electronic health records offer the opportunity to discover new clinical implications for established blood tests, but international comparisons have been lacking. We tested the association of total white cell count (WBC) with all-cause mortality in England and New Zealand.
Primary care practices in England (ClinicAl research using LInked Bespoke studies and Electronic health Records (CALIBER)) and New Zealand (PREDICT).
Analysis of linked electronic health record data sets: CALIBER (primary care, hospitalisation, mortality and acute coronary syndrome registry) and PREDICT (cardiovascular risk assessments in primary care, hospitalisations, mortality, dispensed medication and laboratory results).
People aged 30-75 years with no prior cardiovascular disease (CALIBER: N=686 475, 92.0% white; PREDICT: N=194 513, 53.5% European, 14.7% Pacific, 13.4% Maori), followed until death, transfer out of practice (in CALIBER) or study end.
HRs for mortality were estimated using Cox models adjusted for age, sex, smoking, diabetes, systolic blood pressure, ethnicity and total:high-density lipoprotein (HDL) cholesterol ratio.
We found 'J'-shaped associations between WBC and mortality; the second quintile was associated with lowest risk in both cohorts. High WBC within the reference range (8.65-10.05×10/L) was associated with significantly increased mortality compared to the middle quintile (6.25-7.25×10/L); adjusted HR 1.51 (95% CI 1.43 to 1.59) in CALIBER and 1.33 (95% CI 1.06 to 1.65) in PREDICT. WBC outside the reference range was associated with even greater mortality. The association was stronger over the first 6 months of follow-up, but similar across ethnic groups.
Clinically recorded WBC within the range considered 'normal' is associated with mortality in ethnically different populations from two countries, particularly within the first 6 months. Large-scale international comparisons of electronic health record cohorts might yield new insights from widely performed clinical tests.
NCT02014610.
电子健康记录为发现现有血液检测的新临床意义提供了机会，但缺乏国际间的比较。我们检测了英格兰和新西兰全白细胞计数（WBC）与全因死亡率之间的关联。
英格兰的基层医疗实践（使用链接定制研究和电子健康记录的临床研究（CALIBER））和新西兰的基层医疗实践（PREDICT）。
对链接的电子健康记录数据集进行分析：CALIBER（基层医疗、住院、死亡率和急性冠状动脉综合征登记处）和PREDICT（基层医疗中的心血管风险评估、住院、死亡率、配药和实验室结果）。
年龄在30 - 75岁之间且无心血管疾病史的人群（CALIBER：N = 686475，92.0%为白人；PREDICT：N = 194513，53.5%为欧洲人，14.7%为太平洋岛民，13.4%为毛利人），随访至死亡、转出实践（在CALIBER中）或研究结束。
使用Cox模型估计死亡率的风险比（HRs），并对年龄、性别、吸烟、糖尿病、收缩压、种族和总胆固醇与高密度脂蛋白（HDL）胆固醇比值进行调整。
我们发现WBC与死亡率之间呈“J”形关联；在两个队列中，第二个五分位数与最低风险相关。与中间五分位数（6.25 - 7.25×10⁹/L）相比，参考范围内的高WBC（8.65 - 10.05×10⁹/L）与死亡率显著增加相关；CALIBER中的调整后HR为1.51（95%可信区间1.43至1.59），PREDICT中的调整后HR为1.33（95%可信区间1.06至1.65）。参考范围外的WBC与更高的死亡率相关。这种关联在随访的前6个月更强，但在不同种族群体中相似。
在两个国家不同种族人群中，临床记录的处于“正常”范围内的WBC与死亡率相关，尤其是在最初6个月内。对电子健康记录队列进行大规模国际比较可能会从广泛开展的临床检测中获得新的见解。
NCT02014610。
