the prevalence of dysphagia in parkinson's disease: a systematic review and meta-analysis

Background: there is still disagreement about the prevalence and incidence of dysphagia in parkinson's disease (pd). since the prevalence of dysphagia has been reported very differently in the related literature, it is imperative to estimate pooled prevalence in pd patients. thus, we conducted a systematic review and meta-analysis to estimate the pooled prevalence of dysphagia in pd overall and separately for each assessment method (subjective and objective). methods: these databases were searched: scopuspubmed web of science ,and google scholar, january 1990 to october 2021. a random-effects model was used to pool the prevalence rates reported in the included studies by the comprehensive meta-analysis (cma( software .all designs of the studies were included. results :thirty-nine articles entered the current meta-analysis. the global estimation of the overall prevalence of dysphagia in pd patients was 50.4% )95%ci:42.2-58.6) in all the 39 studies, which proved statistically heterogeneous (p<0.001). moreover, the pooled prevalence by the subjective (30 studies) and objective (19 studies) methods of assessment were estimated to be 39.5 and 68.8%, respectively. there was also a significant relationship between the prevalence of dysphagia and age of parkinson's patients )r=0.44, p=0.011) and also between the prevalence of dysphagia and the duration of pd (r=0.55, p=0.006). conclusion: based on the results, one in two patients with pd has dysphagia. this is proven that dysphagia is common in pd. the prevalence of objective dysphagia and subjective dysphasia were very different. it suggests that all parkinson's patients should be evaluated for swallowing disorders regularly with objective tools.