a) Adjusted association between antipsychotic exposure and aspiration pneumonia, by age category. We used a multivariable GEE to adjust for all variables listed in Table 1 except insomnia, plus the Healthcare Cost and Utilization Project comorbidities with the exception of peptic ulcer disease without bleeding, acquired immune deficiency syndrome (AIDS), solid tumor without metastasis, and drug abuse.
b) Adjusted absolute incidence of aspiration pneumonia attributable to antipsychotic exposure (attributable risk), calculated as the difference between the adjusted incidence of aspiration pneumonia among exposed and unexposed, derived using Bayes theorem. Number-needed-to-harm calculated by taking the inverse of the attributable risk. Antipsychotic exposure and aspiration pneumonia incidence both increased with age (5.2%, 7.3%, and 12.5% exposed and 0.2%, 0.6%, and 0.7% aspiration pneumonia incidence for age <65, 65–74, and ≥75, respectively).