Diagnostic value of water swallow test for dysphagia in patients with head and neck cancer: A systematic review and meta-analysis

The diagnostic efficacy of the water swallow test (WST) is relatively robust for patients with neurogenic dysphagia; however, its diagnostic performance in identifying dysphagia among patients with HNC varies across studies. Our study aims to assess the diagnostic value of the WST for detecting dysphagia in patients with HNC. Systematic retrieval of studies on the use of WST for screening dysphagia in patients with HNC from databases up to August 1, 2023. Quality assessment of the included studies was performed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Calculate the pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC) to evaluate the screening ability of WST for dysphagia. A total of seven articles, encompassing eight study groups, were included, involving the analysis of 691 patients. The meta-analysis results demonstrate that the WST has a combined sensitivity, specificity, positive LR, negative LR, DOR, and AUC for diagnosing dysphagia in patients with HNC of 0.82 (95% CI [0.64, 0.92]), 0.79 (95% CI [0.70, 0.86]), 4.00 (95% CI [2.51, 6.36]), 0.22 (95% CI [0.10, 0.50]), 17.94 (95% CI [5.56, 57.92]), and 0.86 (95% CI [0.83, 0.89]), respectively. Significant heterogeneity was observed among the included studies. Meta-regression analysis showed that the pooled sensitivity of tumor sites and treatment was closely related, while the pooled specificity of treatment and version was closely related. The subgroup analysis showed that the WST's pooled sensitivity for diagnosing dysphagia in patients with nasopharyngeal cancer was 0.40 (95% CI [0.26, 0.56]), with an AUC of 0.50, lower than in other HNC sites. The WST performed better in surgical patients than in those undergoing radiotherapy (RT) or chemoradiotherapy (CRT), with lower sensitivity, specificity, and AUC values of 0.49 (95% CI [0.36, 0.61]), 0.66 (95% CI [0.59, 0.72]), and 0.64, respectively, for RT or CRT patients. The modified WST version showed different specificity values of 0.82 (95% CI [0.75, 0.87]), compared to the regular version of 0.68 (95% CI [0.61, 0.74]). Additionally, Deek's test indicated the absence of publication bias in this study (p = 0.32). The WST demonstrates favorable sensitivity and specificity in detecting dysphagia among patients with HNC. However, the diagnostic value may vary depending on factors such as tumor sites, treatment, and the specific version of the WST used.