O21 PLATELET COUNT-TO-PLATELET DISTRIBUTION WIDTH RATIO AND OTHER PLATELET INDICES AS COST-EFFECTIVE MARKERS OF PREECLAMPSIA: A CASE CONTROL STUDY

Background and objective: Platelet indices, like platelet count (PC), plateletcrit, mean platelet volume (MPV) and platelet distribution width (PDW), and their ratios have shown to be cost-effective and better predictors of preeclampsia (PE). However, PC/PDW ratio was not studied. Thus, this study aimed to compare platelet indices and their ratios between pregnant women with and without PE. Methods: An analytical, comparative, case-control study. Two groups were compared; pregnant women with PE (case, n=24) and without PE (control, n=72). The differences between cases and controls were compared using Student's t-test and Mann–Whitney U-test for continuous variables and chi-square tests and Fisher's exact test for categorical. Multivariable linear regression analysis for hematological parameters was performed to assess the effect of gestational age. Logistic regression was performed to calculate the odds ratio. Receiver operating characteristic curve was used to determine sensitivity, specificity and cutoff values. P < 0.05 was considered significant. Results: There was significant reduction in values of PC (p=0.004), plateletcrit (p=0.012), PC/MPV ratio (p=0.002), and PC/PDW (p= <0.001) among the pregnant women with PE compared to the control study group, while a significant increase was noticed in the values of PDW (p= <0.001) and MPV (p=0.021). PC/PDW had the highest area under the curve (AUC) of 0.767, followed by PDW (AUC=0.752). At the cutoff value of 15.1 (p<0.001) for PC/PDW, sensitivity was 70.8%, and specificity was 81.9%. The odds of diagnosing true positive cases of PE was 11.02 (95% CI =3.79-31.99, p=<0.001) times higher compared to values below it at this cutoff point. Conclusions: Present study suggests that platelet indices are economical tests that can act as indicators of risk of PE. Among all the parameters, PC/PDW has the highest sensitivity and specificity in the detection of PE at the cutoff of 15.1 and has emerged as a better predictor of PE.