Author Affiliations: Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife (Drs Gross, Jones, and Inouye), Department of Medicine (Drs Gross, Jones, and Inouye), Beth Israel Deaconess Medical Center, and Department of Neurology, Massachusetts General Hospital (Dr Inouye), Harvard Medical School, Boston.
The letter by Regal offers an interesting comparison to our study. We applaud the author's motivation. Although the study by Regal raises interesting findings, the prevalence estimate for delirium at admission to the Wyong Hospital Memory Clinic is not directly comparable to our study's reported number of new cases during hospitalization for 3 important reasons: differences in time frame of ascertainment, patient populations, and method of delirium ascertainment. Most importantly, with respect to time frame of delirium, the 10.4% figure reported by Regal is an estimate of delirium prevalence at hospital admission. Our 56.3% is a proportion of new delirium cases during hospitalization.
Gross AL, Jones RN, Inouye SK. The Meaning of Delirium—Reply. JAMA Intern Med. 2013;173(7):597-599. doi:10.1001/jamainternmed.2013.3788