This is a novel observational study with the overarching aim of evaluating the association between poor sleep health and poor quality of recovery in a surgical setting. It hopes to assess and optimize the perioperative sleep health of patients so significant improvements in their quality of recovery and health outcomes may be achieved.

Surgery and pain may cause sleep disturbances that affect both physical and mental well-being of patients. Sleep disturbance can cause an increased risk of confusion after surgery, increased pain needing some or more medication, untoward events (heart and breathing problems), delayed recovery and increased lengths of hospital stay.

Hospitalization interferes with sleep patterns, causing poor quality sleep due to noise, light, pain, medication administration and nursing checks. The circadian rhythm, which is the "body clock" is a 24-hour cycle that tells our bodies when to sleep and rise. This in turn helps in regulating many physiological processes in the body. Sleep disruption affects the body clock, thereby changing hormone levels that may be responsible for poor wound healing. This study aims to evaluate sleep problems before disruption post-operatively and also evaluate the relation between poor sleep health and quality of recovery utilizing sleep health measurements such as sleep quality, sleep timing, and sleep efficiency.

Objectives of the study:

1. To examine the associations between specific pre-operative sleep-health parameters, predicting poor sleep health, and patient-centered outcomes such as pain control, delirium, sleep-related quality of life, and quality of recovery scores in the peri-operative period.
2. To estimate the association between presence of intrinsic sleep disorders and patient centric outcomes such as pain control, delirium, sleep-related quality of life and quality of recovery scores in the post-operative period.
3. To validate a set of subjective and objective measures of various sleep health domains in the post-operative period.

Inclusion Criteria:

1. Adult patients (>18 years).
2. ASA physical status I - IV.
3. Undergoing elective primary or revision lower limb joint replacement surgeries (such as total or partial hip or knee replacement).

Exclusion Criteria:

1. Patients undergoing emergency surgeries; cardiac, trauma, organ transplantation or organ retrieval, obstetric or intracranial neurosurgeries.
2. Pregnant or lactating patients.
3. Inability to wear study-related monitoring devices per instruction or provide informed consent limiting adherence to protocol.

260 patients will be recruited from the preoperative clinics at major academic centers: Women's College Hospital (WCH) - Coordinating center, Toronto Western Hospital (TWH) - University Health Network (UHN); and St. Michaels Hospital (SMH), Toronto, Ontario.