To assess the risk of aspiration pneumonia among individuals with Parkinson’s disease (PD) compared to controls.

Aspiration pneumonia is a leading cause of morbidity and mortality in PD, accounting for up to 70% of PD-related deaths. The risk is driven by oropharyngeal dysphagia, impaired cough reflex, and reduced airway protection. Despite its clinical impact, the magnitude of risk across observational studies remains uncertain, warranting meta-analytic synthesis.

PubMed and Google Scholar were searched for studies comparing aspiration pneumonia risk in PD versus non-PD populations. Five observational studies (two cohort, three case-control) met inclusion criteria. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated using a random-effects model (DerSimonian-Laird). Heterogeneity was assessed with Cochran’s Q, I², and τ². Publication bias was evaluated using trim-and-fill and fail-safe N methods.

The random-effects pooled RR was 1.57 (95% CI: 0.91–2.23; p < 0.001), indicating a higher risk of aspiration pneumonia in PD, though the prediction interval was wide (−1.01 to 4.15). Fixed-effect analysis yielded RR = 1.34 (95% CI: 1.34–1.35). Heterogeneity was significant (Q = 377.8, p < 0.001; τ² = 0.55), but I² was low (1%). Subgroup analysis showed a stronger association in cohort studies (RR = 2.13) than in case-control studies (RR = 1.21). No evidence of publication bias was detected (trim-and-fill: 0 missing studies). Fail-safe N was high (Rosenthal = 763; Rosenberg = 1152), suggesting robust findings.

PD is associated with a significantly increased risk of aspiration pneumonia, particularly in cohort studies, highlighting a critical and preventable complication. These findings emphasize the importance of early dysphagia screening, proactive airway protection strategies, and multidisciplinary interventions to reduce aspiration-related morbidity and mortality in PD. Future large-scale prospective studies are needed to refine risk estimates and guide evidence-based preventive care.