Riddell Tania, Wells Sue, Jackson Rod, Lee Ai-Wei, Crengle Sue, Bramley Dale, Ameratunga Shanthi, Pylypchuk Romana, Broad Joanna, Marshall Roger, Kerr Andrew
Section of Epidemiology and Biostatistics, School of Population Health, University of Auckland, Auckland, New Zealand.
N Z Med J. 2010 Feb 19;123(1309):50-61.
To compare the calibration performance of the original Framingham Heart Study risk prediction score for cardiovascular disease and an adjusted version of the Framingham score used in current New Zealand cardiovascular risk management guidelines for high and low risk ethnic groups.
Since 2002 cardiovascular risk assessments have been undertaken as part of routine clinical care in many New Zealand primary care practices using PREDICT, a web-based decision support programme for assessing and managing cardiovascular risk. Individual risk profiles from PREDICT were electronically and anonymously linked to national hospital admissions and death registrations in January 2008. Calibration performance was investigated by comparing the observed 5-year cardiovascular event rates (deaths and hospitalisations) with predicted rates from the Framingham and New Zealand adjusted Framingham scores. Calibration was examined in a combined 'high risk' ethnic group (Maori, Pacific and Indian) and a European 'low risk' ethnic group. There was insufficient person-time follow-up for separate analyses in each ethnic group. The analyses were restricted to PREDICT participants aged 30-74 years with no history of previous cardiovascular disease.
Of the 59,344 participants followed for a mean of 2.11 years (125,064 person years of follow-up), 1,374 first cardiovascular events occurred. Among the 35,240 European participants, 759 cardiovascular events occurred during follow-up, giving a mean observed 5-year cumulative incidence of 4.5%. There were 582 events among the 21,026 Maori, Pacific and Indian participants, corresponding to a mean 5-year cumulative incidence rate of 7.4%. For Europeans, the original Framingham score overestimated 5-year risk by 0.7-3.2% at risk levels below 15% and by about 5% at higher risk levels. In contrast, for Maori, Pacific, and Indian patients combined, the Framingham score underestimated 5-year cardiovascular risk by 1.1-2.2% in participants who scored below 15% 5-year predicted risk (the recommended threshold for drug treatment in New Zealand), and overestimated by 2.4-4.1% the risk in those who scored above the 15% threshold. For both high risk and low risk ethnic groups, the New Zealand adjusted score systematically overestimated the observed 5-year event rate ranging from 0.6-5.3% at predicted risk levels below 15% to 5.4-9.3% at higher risk levels.
The original Framingham Heart Study risk prediction score overestimates risk for the New Zealand European population but underestimates risk for the combined high risk ethnic populations. However the adjusted Framingham score used in New Zealand clinical guidelines overcompensates for this underestimate, resulting in a score that overestimates risk among the European, Maori, Pacific and Indian ethnic populations at all predicted risk levels. When sufficient person years of follow-up are available in the PREDICT cohort, new cardiovascular risk prediction scores should be developed for each of the ethnic groups to allow for more accurate risk prediction and targeting of treatment.
比较原始的弗雷明汉心脏研究心血管疾病风险预测评分与新西兰当前心血管风险管理指南中用于高风险和低风险种族群体的弗雷明汉评分调整版的校准性能。
自2002年以来，许多新西兰初级医疗实践将心血管风险评估作为常规临床护理的一部分，使用PREDICT（一个基于网络的用于评估和管理心血管风险的决策支持程序）。2008年1月，PREDICT中的个体风险概况以电子方式且匿名地与国家医院入院记录和死亡登记相链接。通过比较观察到的5年心血管事件发生率（死亡和住院）与弗雷明汉评分及新西兰调整后的弗雷明汉评分预测的发生率来研究校准性能。在一个合并的“高风险”种族群体（毛利人、太平洋岛民和印度人）和一个欧洲“低风险”种族群体中检查校准情况。每个种族群体的随访人时不足，无法进行单独分析。分析仅限于年龄在30 - 74岁且无既往心血管疾病史的PREDICT参与者。
在59344名平均随访2.11年（125064人年随访）的参与者中，发生了1374例首次心血管事件。在35240名欧洲参与者中，随访期间发生了759例心血管事件，观察到的5年累积发病率平均为4.5%。在21026名毛利人、太平洋岛民和印度参与者中发生了582例事件，对应的5年累积发病率平均为7.4%。对于欧洲人，原始的弗雷明汉评分在风险水平低于15%时高估5年风险0.7 - 3.2%，在较高风险水平时高估约5%。相比之下，对于合并的毛利人、太平洋岛民和印度患者，弗雷明汉评分在5年预测风险低于15%（新西兰药物治疗推荐阈值）的参与者中低估5年心血管风险1.1 - 2.2%，在评分高于15%阈值的参与者中高估风险2.4 - 4.1%。对于高风险和低风险种族群体，新西兰调整后的评分在预测风险水平低于15%时系统地高估观察到的5年事件发生率0.6 - 5.3%，在较高风险水平时高估5.4 - 9.3%。
原始的弗雷明汉心脏研究风险预测评分高估了新西兰欧洲人群的风险，但低估了合并的高风险种族群体的风险。然而，新西兰临床指南中使用的调整后的弗雷明汉评分过度补偿了这种低估，导致在所有预测风险水平下，该评分高估了欧洲、毛利、太平洋岛民和印度种族群体的风险。当PREDICT队列中有足够的人年随访数据时，应为每个种族群体开发新的心血管风险预测评分，以实现更准确的风险预测和治疗目标。
