Prevalence of hyposalivation in older people: A systematic review and meta-analysis

The proportion of elders is increasing worldwide, and hyposalivation has been associated with the ageing process. Therefore, there has been growing interest in the frequency of hyposalivation in older people since it can cause transient or permanent problems that could affect oral health.

To determine the prevalence of hyposalivation in older people (aged ≥ 60 years).

The review was registered at Prospero - International Prospective Register of Systematic Reviews under number CRD42018106322. The search was performed in six electronic databases (Embase, LILACS, Medline, PubMed, Web of Science and Abstracts in Social Gerodontology) and grey literature (Google Scholar) for articles published up to February 2019. The methodology of selected studies was evaluated using the Meta-Analysis of Statistics Assessment and Review (MAStARI) risk of bias checklist. Meta-analyses were performed using Medcalc and Stata 15.

Thirteen studies totalising 3,885 individuals (≥60 years) were included in this systematic review. The meta-analysis showed an overall hyposalivation prevalence of 33.37% (95% confidence interval [CI] 23.90 - 43.57, P < .0001, n = 3,447). The prevalence of hyposalivation for unstimulated and stimulated methods was 33.39% (95% CI 21.08 - 46.96, P < .0001, n = 2,425 individuals) and 30.47% (95% CI 22.53-39.04, P < .0001, n = 1,495 individuals), respectively. Most of the studies were evaluated as low risk of bias. Some study limitations were related to the observational studies potential risk of bias, and different criteria to measure saliva flow rate.

This study suggests that the overall prevalence of hyposalivation in older people is 33.37%. When considering stimulated methods, the prevalence of hyposalivation was slightly lower (30.47%).