Were the measurements standardized sufficiently in published studies about mean platelet volume?

: Recently, several studies about mean platelet volume (MPV) changes in various pathological conditions were published. The aim of this study was to evaluate the accuracy of the measurement in these studies. The study was performed using the data of 181 studies containing a healthy control groups within 1181 studies about MPV indexed PubMed database since 2012. A total of 81 studies were included retrospectively. The distributions of sex, age, and platelet counts were not reported in 16, 12, and 28 studies, respectively. Type of anticoagulant was not noted in 60 studies. The technology used was not specified in 36 studies. The MPV values measured with Sysmex were significantly higher than measured with Beckman Coulter, Abbott CELL-DYN, and Siemens ADVIA. The MPV measurements varied up to 17.8% by the instruments. The measurement times between 15 min and 2 h was significantly different from the measurement times less than 15 min and more than 2 h. The MPV measurement times from venipuncture were not indicated in 86 studies (47.5%). Maximum deviations in MPV measurements by the MPV measurement times and plus the instruments used varied up to 17.8 and 27.7%, respectively. Both the MPV measurement times and instruments used were not stated in 29 studies (16.0%). Only 47 prospective studies (26.0%) enlightened about the type of anticoagulant, instruments used for MPV measurement, MPV measurement time, platelet counts, and MPV values. As a result, the measurements were not standardized sufficiently in published studies about MPV. It may be explained that the differences between the results of studies made the same pathological conditions.