LAUSR

Dear Editor, My colleagues and I have read the review and metaanalysis of TCRT by Tse et al. (2017) with substantial interest. Indeed, our team was the first to note the predictive value of increased spatial QRST angle (Zabel et al., 2000) and in this seminal clinical study, we used the TCRT technology that we previously developed (Acar, Yi, Hnatkova, & Malik, 1999). The conclusions reached by Tse et al. in their metaanalysis agree well with our experience including the recent comparison of different methods of QRST angle measurements (Hnatkova et al., 2017). Nevertheless, and with substantial regret, we need to point out problems in the metaanalysis by Tse et al. The presented metaanalysis was based on 13 studies which included three older publications by our team (Batchvarov et al., 2003; Hnatkova et al., 2001; Malik, Hnatkova, & Batchvarov, 2004). If Tse et al. have read our articles, they would have realized that while these three publications dealt with different uniand multivariable aspects of risk prediction, they shared the source data of the PostInfarction Survey of St. George’s Hospital in London. Their patient populations therefore either fully or partially overlapped and should not have been used as independent data sources. We also note that Tse et al. have omitted the publication by Okin et al. (2005). This study also investigated allcause and cardiovascular mortality and reported significant TCRT differences between lowand highrisk subgroups. It researched a population of 1,729 individuals and thus was, aside from the study by Porthan et al. (2009), larger than the studies included in the metaanalysis. The members of the International Health Informatics Study (IHIS) Network have very recently published significant number of metaanalyses on a fairly broad variety of topics. Nevertheless, we believe that they will agree that careful, detailed, and truly comprehensive review of studies that they summarize is essential. Without such an approach to the previously published material, the old saying comes to mind that metaanalysis is to analysis as metaphysics to physics.