Objectives:

1. To examine whether patients with delirium have higher prevalence of cytochrome-P450 abnormalities compared to patients without delirium.
2. To examine whether the severity of delirium is related to a specific cytochrome P450 genotype.
3. To examine the persistence of delirium at 6-8 weeks stratified by presence of cytochrome p450 abnormalities
4. To examine whether delirium persistence is impacted by types of medications administered during their hospital stay.

Delirium is a costly and devastating illness affecting older patients in the hospital. Its prevalence increases as patients get older and sicker. There is scientific evidence that delirium affects cognitive function for a prolonged period of time and in many cases irreversibly. The economic burden on health care and emotional burden on the caregivers of patients with delirium is tremendous. We think that our study may contribute to developing prevention strategies for delirium in the hospital. We propose genetic testing of older patients to determine their ability to metabolize commonly used medications in the hospital. This will give medical professionals and pharmacists an ability to adjust dosages of medications based on the patient's genetic profile.

Inclusion Criteria:

1. Patients age 18 and older admitted to the ALGH (Advocate Lutheran General Hospital) rehabilitation unit

2. One or more of the Following Principle Diagnosis:

   Principle stroke diagnosis Principle Cardiac-Post cardiac surgery Principle Spinal surgery

3. Non-English speakers are not anticipated. However, there is an available interpreter services already on the unit and this interpreter's services will be utilized. https://www.languageline.com/ However, we will utilize that AHC IRB approved short forms if a potential subject presents itself.

Exclusion Criteria:

1. Stroke patients with any diagnosed aphasia
2. Spinal surgery, as a result of trauma
3. Pregnant women
4. Prisoners
5. Patients with dementia (score of greater than 3.3 on short IQCODE questionnaire) (Long Term Cognitive Impairment after Critical Illness, NEJM, 2013, Pandharipande et al.)
6. Patients with cirrhosis and liver failure
7. Patients with renal failure requiring dialysis
8. Recent blood transfusion

Patients admitted to the Rehabilitation Unit at Lutheran General Hospital will be approached to participate in this case-control study. Patients will be assigned to the case group once identified with delirium by the Psychology staff. Control group will consist of patients without delirium upon assessment by the Psychology staff. The Delirious patients will then be matched to a control patient hospitalized in the Rehabilitation Lutheran General Unit.

We will de-identify the data once the study is completed.