The overriding hypothesis is that preoperative cognitive impairment is a risk factor for poor surgical outcomes in seniors and that preoperative screening is superior to standard or systematic clinical processes for identifying at-risk patients. The first objective is to assess the marginal benefit of structured preoperative cognitive screening relative to standard or systematic preoperative evaluation for identifying seniors with likely cognitive impairment. The second objective is to determine whether preoperative cognitive impairment predicts postoperative outcome. This project is designed as a prospective, single-center observational study. The cohort will consist of 250 consenting subjects ≥ 65 years of age who present to the BWH Weiner Center for Preoperative Evaluation (CPE) prior to elective lower extremity joint replacement surgery. These surgeries are selected because they are common in this age group, associated with significant morbidity, and along with dementia are considered a priority area (bone and joint conditions) by AHRQ. These ages are chosen as significant clinical data demonstrate increased cognitive impairment in community dwelling elders. Eligibility criteria include: patients ≥ 65 years of age with an ASA physical status of I-IV presenting for elective joint replacement. Exclusion criteria will include planned ICU admission postoperatively, uncorrected vision or hearing impairment (unable to see pictures or read or hear instructions); limited use of the dominant hand (limited ability to draw); and or inability to speak, read, or understand English. Study staff will use the CPE computerized scheduling system, which is updated continuously in real time and captures relevant information such as age and procedure, to identify potential subjects. When patients check in with the receptionist in the CPE for their appointment they will be notified that they (and their surrogate) may be eligible to participate in a study in the CPE involving patients over the age of 65. The receptionist will then provide them with a brochure about the study that includes information about the purpose of the study, the risks to the patient, and the potential benefits to society. The patient will then be asked if they are willing to speak with one of the study investigators and only those patients that agree to speak with a study investigator will be approached. Patients with known cognitive impairment will be included in the study to determine whether this information is included in the preoperative evaluation form. They will sign their own consent if they are capable and going to sign their surgical procedure consent. In the event that the patient is not capable of signing their own consent a surrogate will be asked to provide consent with assent from the patient. In our prior studies with similar patient populations less than 1% had documented cognitive impairment. The staff member will then describe the goals and risks of the study in a quiet room in the PATC and ask the patient (and their surrogate where appropriate) if they choose to participate. After all questions have been answered and the patient has the opportunity to read the consent form, written consent will be obtained by one of the study investigators. After obtaining consent, study staff will gain information about the patient's age and years of education. Study staff will administer standard instruments to assess health and functional status (basic and instrumental activities of daily living [ADLs and IADLs, respectively, and the WHODAS]). The World Health Organization Disability Scale 2.0 (WHODAS) is an alternative to the SF36 to measure physical health and disability.