Leite Andreia, Thomas Sara L, Andrews Nick J
Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK.
Statistics, Modelling and Economics Department, Public Health England, London, UK.
Pharmacoepidemiol Drug Saf. 2018 Jan;27(1):25-29. doi: 10.1002/pds.4356. Epub 2017 Nov 28.
Near real-time vaccine safety surveillance (NRTVSS) using electronic health records has been used to detect timely vaccine safety signals. Trial implementation of NRTVSS using the Clinical Practice Research Datalink (CPRD) has shown that there is limited power to detect safety signals for rare events. Delays in recording outcomes and receiving data influence the power and timeliness to identify a signal. Our work aimed to compare how different sources of delays influence power and expected time to signal to implement NRTVSS using CPRD.
We studied seasonal influenza vaccine/Guillain-Barré syndrome and performed power and expected time to signal calculations for the 2013-2014/2014-2015 seasons. We used the Poisson-based maximised sequential probability ratio test, which compares observed-to-expected events. For each study season, we obtained an average Guillain-Barré syndrome/seizures age-sex-adjusted rate from the 5 previous seasons and then used this rate to calculate the expected number of events, assuming a 42-day risk-window. Calculations were performed for detecting rate ratios of 1.5 to 10. We compared power and timeliness considering combinations of the presence/absence of delays in recording outcomes and in receiving data. The R-package Sequential was used.
In general, there was ≥80% power to detect increases in risk of ≥4 at the end of the season. Assuming absence of delays slightly improved power (a maximum increase of 4%) but did not noticeably reduce time to detect a signal.
Removing delays in data availability is insufficient to significantly improve the performance of a NRTVSS system using CPRD. Expansion of CPRD data is required. KEY POINTS The Clinical Practice Research Datalink (CPRD) can be used to implement near real-time vaccine safety surveillance, but there is limited power to detect signals for rare outcomes. Delays in recording outcomes and in receiving data might limit power and timeliness of a system. We assessed the influence of these sources of delays to inform data providers of the steps required to improve a system using CPRD data. Removing delays in recording outcomes and receiving data is unlikely to significantly improve the performance of a system using CPRD data. Expansion of the data available is needed.
利用电子健康记录进行的近实时疫苗安全性监测（NRTVSS）已被用于及时检测疫苗安全信号。使用临床实践研究数据链（CPRD）对NRTVSS进行的试验实施表明，检测罕见事件安全信号的能力有限。结果记录和数据接收的延迟会影响识别信号的能力和及时性。我们的工作旨在比较不同来源的延迟如何影响使用CPRD实施NRTVSS的能力和信号出现的预期时间。
我们研究了季节性流感疫苗/格林-巴利综合征，并对2013 - 2014/2014 - 2015季节进行了能力和信号出现预期时间的计算。我们使用基于泊松分布的最大化序贯概率比检验，该检验比较观察到的事件与预期事件。对于每个研究季节，我们从前五个季节获得年龄和性别调整后的格林-巴利综合征/癫痫平均发病率，然后使用该发病率计算预期事件数，假设风险窗口为42天。计算检测率比为1.5至10时的情况。我们考虑了结果记录和数据接收中有无延迟的组合来比较能力和及时性。使用了R包Sequential。
总体而言，在季节结束时检测风险增加≥4倍时有≥80%的能力。假设无延迟会略微提高能力（最大提高4%），但不会显著缩短检测信号的时间。
消除数据可用性方面的延迟不足以显著提高使用CPRD的NRTVSS系统的性能。需要扩展CPRD数据。要点临床实践研究数据链（CPRD）可用于实施近实时疫苗安全性监测，但检测罕见结果信号的能力有限。结果记录和数据接收的延迟可能会限制系统的能力和及时性。我们评估了这些延迟来源的影响，以告知数据提供者使用CPRD数据改进系统所需的步骤。消除结果记录和数据接收中的延迟不太可能显著提高使用CPRD数据的系统的性能。需要扩展可用数据。
