Platelet count/spleen diameter ratio to predict the presence of esophageal varices in patients with cirrhosis: a systematic review.

BACKGROUND: Esophageal variceal bleeding remains the leading cause of acute mortality in patients with cirrhosis. Platelet count to spleen diameter (PC/SD) ratio less than 909 is one of several parameters proposed for the noninvasive prediction of esophageal varices. The aim of this study is to systematically review the evidence on the diagnostic accuracy of the 909 ratio.
METHODS: We identified relevant studies from a MEDLINE search and performed a meta-analysis to estimate the pooled sensitivity, specificity, and positive and negative likelihood ratios (LRs) using Meta-Disc software.
RESULTS: Eight studies met the inclusion criteria and included a total of 1275 patients. Meta-analysis yielded a pooled sensitivity of 89% [95% confidence interval (CI) 87-92%; I2 statistic 92.9%] and a pooled specificity of 74% (95% CI 70-78%; I2 statistic 94.5%). The pooled positive LR was 3.5 (95% CI 1.92-6.25; I2 statistic 94.0%) and the pooled negative LR was 0.12 (95% CI 0.05-0.32; I2 statistic 90.8%). The quality of the evidence as assessed by the GRADE methodology was low.
CONCLUSION: In its present form, the test characteristics of PC/SD ratio of 909 may not be adequate to completely replace esophagogastroduodenoscopy as a noninvasive screening tool for esophageal varices, given the low grade of evidence. However, it may be potentially useful as part of a prediction rule incorporating other clinical characteristics or varying PC/SD cutoffs. When compared with other noninvasive predictor tools, the PC/SD ratio is elegant, simple, and inexpensive. With some minor modifications, it may become a helpful tool to limit the number of endoscopies in primary prophylaxis to be performed in patients with portal hypertension.