1 Overview

Initially developed to look at MCV vs. MPV correlation I expect this to be useful as a template for other examples. This file is relatively simple, but has some infrastructure remaining from RangesMortality file used as starting point.

## Loading saved NHANES III data from NHANES3_20160629.rda

Get NHANES III variable names, blank values, etc. from heq_nhanes_fields_key spreadsheet.

2 MCV vs. MPV Correlation

Note need to turn Blank observations (here 88888) into NA. MCV is mvpsi. MPV is pvpsi.

2.1 Individual Variable Statistics

x$mvpsi[x$mvpsi == 88888] = NA
hist(x$mvpsi)

hist(x$mvpsi, breaks=seq(floor(min(x$mvpsi, na.rm=TRUE)), ceiling(max(x$mvpsi, na.rm=TRUE)), 1))

summary(x$mvpsi)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.    NA's 
##   51.20   86.60   89.80   89.44   92.80  118.50     370
x$pvpsi[x$pvpsi == 88888] = NA
hist(x$pvpsi)

hist(x$pvpsi, breaks=seq(floor(min(x$pvpsi, na.rm=TRUE)), ceiling(max(x$pvpsi, na.rm=TRUE)), 0.2))

summary(x$pvpsi)
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max.    NA's 
##   3.900   7.850   8.400   8.509   9.100  14.950     370

2.2 Bivariate Relationship

cor(x$mvpsi, x$pvpsi, use="pairwise.complete.obs")
## [1] -0.0815378
scatterplot(x$mvpsi, x$pvpsi)

2.3 Paper Comparing Platelet and RBC Measures

Plateletcrit, mean platelet volume, platelet distribution width: its expected values and correlation with parallel red blood cell parameters (Wiwanitkit 2004)

Abstract: The quantitation of platelets in peripheral blood is a well-recognized tool. Recently, new indices related to erythrocytes and platelet counts have been provided by hematologic analyzers. Concerning the platelet parameter, the three important parameters are plateletcrit (PCT), mean platelet volume (MPV), platelet distribution width (PDW). The purpose of the study is to investigate these three parameters to define their expected values and the correlation with the parallel red blood cell parameters, hematocrit (HCT), mean corpuscular volumer (MCV), and red blood cell distribution width (RDW). Blood samples form 215 volunteers were analyzed for platelet parameters using Technicon H*3. The average (mean +/- SD) values obtained with expected ranges were PCT 0.24 +/- 0.05% (range, 0.23-0.24%), MPV 12.79 +/- 5.91 fL (range, 12.39-13.19 fL), and PDW 46.79 +/- 2.70% (range, 46.61-46.97%). Concerning the correlation between PCT, MPV, and RDW and their parallel red blood cell parameters, there was no significant correlation between PCT and HCT, and between MPV and MCV. However, there was a significant correlation between PDW and RDW. It seems that the anisocytosis of red blood cells and platelets might co-occur. However, these data are basic observations; further in-depth evaluation of the platelet parameters is recommended.

Note that their mean values for MPV and MCV were significantly different from those in NHANES III!

Table 2 gives a correlation coefficient between MPV and MCV of 0.08. So similar magnitude as that observed above, but opposite sign.

2.4 Conclusion

It appears that MCV and MPV blood test values are essentially uncorrelated between subjects. It is possible there is a correlation between readings for the same subject, but this seems unlikely.

File originally created: Monday, March 16, 2020
File knitted: Tue Mar 17 09:47:01 2020

3 Bibliography

Completed run at 2020-03-17 09:47:01

Wiwanitkit, Viroj. 2004. “Plateletcrit, Mean Platelet Volume, Platelet Distribution Width: Its Expected Values and Correlation with Parallel Red Blood Cell Parameters.” Clinical and Applied Thrombosis/Hemostasis 10 (2): 175–78. https://doi.org/10.1177/107602960401000208.