Objectives/hypothesis The natural clinical progression of aspiration to eventual pulmonary compromise is not well understood. We hypothesized that dietary modification recommendations, penetration-aspiration scale (PAS) score, and dysphagia etiology would be associated with changes in time to first pulmonary event and overall survival for patients with documented aspiration on radiologic testing. This study identified a cohort of patients with detectable unsensed penetration or aspiration on videofluoroscopic swallowing study (VFSS) and followed this cohort over time for development of pulmonary events and death. We then evaluated the association of aspiration severity and dietary modification recommendations on incidence of these endpoints. Study Type/Design Retrospective chart review. Methods A total of 2616 VFSS exam reports were reviewed from our institution performed between January 1, 2009 and December 31, 2010. Aspiration or unsensed penetration (PAS of 5 or greater) was detected in 564 (21.5%) of these patients, who were then included in the study cohort. Medical records were reviewed retrospectively for development of pulmonary events (pneumonia, pneumonitis, or other life-threatening pulmonary illness) and all-cause mortality for up to 54 months after initial VFSS. Univariate Kaplan-Meier analysis and multivariate Cox regression were performed for time to first pulmonary event and survival predicted by recommended diet, PAS score, and dysphagia etiology. Results Dysphagia etiology was highly associated with increased development of pulmonary events for some patients, especially those with generalized nonspecific dysphagia due to deconditioning or frailty (hazard ratio [HR] versus stroke 2.95, 95% CI: 1.53–5.69, p=0.001) and esophageal dysphagia (HR 2.66, 95% CI: 1.17–6.02, p=0.019). Dysphagia etiology was also associated with increased mortality for patients with generalized nonspecific dysphagia due to deconditioning or frailty (HR 3.32, 95% CI: 2.0–5.52, p<0.001), post-surgical patients (HR 1.73, 95% CI: 1.05–2.86, p=0.032) and chronic neurologic disease (HR 1.87, 95% CI: 1.12–3.13, p=0.017). Dietary modification recommendations at the time of VFSS (prohibition of oral intake or modification of food consistency) had no significant impact on time to first pulmonary event (p=0.37) or survival (p=0.17), while PAS score was associated with decreased time to first pulmonary event on univariate but not multivariate analysis (hazard ratio for 1-point increase 1.6, 95% CI: 0.99–1.36, p=0.067). Kaplan-Meier estimate of overall 3-year mortality for this patient cohort was 39%. Conclusions Etiology of dysphagia is associated with a higher mortality rate and development of pulmonary events in patients with unsensed penetration or aspiration on VFSS, especially for those patients with generalized deconditioning and frailty or esophageal dysphagia. Severity of aspiration as defined by PAS was not associated with altered overall survival. Recommendations for dietary modification to an NPO status or modifie...