When children suffer from a critical-illness, the investigators focus on resuscitating and saving lives. Once these children leave the pediatric intensive care unit, very little is known about what happens to them - how long it takes for them to recover, how families cope, and what factors that impede their recovery. The specific objective of this research project is to evaluate how children and their families recover after a critical illness.

Research Hypotheses: Following a critical illness in children, 1) the rate and degree of health and functional recovery is influenced by the following factors: age, pre-admission co-morbid status, critical illness severity, discharge functional status, and time to initiating acute rehabilitation; 2) functional recovery is influenced by caregiver burden and health-related quality-of-life (HRQoL).

The Specific Objective of this study is to evaluate the trajectory of health and functional outcomes in children following a critical illness, define poor functional recovery, and evaluate predictors of poor recovery.

The Research Questions for this study are: 1) What are the health and functional outcomes in children affected by a critical illness, at 3 and 6 months following Pediatric Intensive Care Unit (PICU) discharge? 2) What defines poor functional recovery? 3) What are predictors of poor functional recovery in critically ill children? 4) What are the most important and relevant outcomes in critically ill children, from the patient and caregiver's point of view?

Study Design: Prospective Observational Mixed Methods Longitudinal Cohort Study Study Setting: Two Academic Pediatric Centres in Canada - McMaster Children's Hospital and London Health Sciences Centre.

Inclusion Criteria:

• Age over 12 months to 17 years
• Admitted to PICU for at least 48 hours
• ≥ one organ dysfunction on admission
• Informed consent of patient/substitute decision maker, and patient assent were appropriate

Exclusion Criteria:

• Patients transferred directly from a neonatal intensive care unit prior to discharge home
• Patients who are already mobilizing well, or are at baseline functional status at time of screening
• Previous enrolment into this study
• Language barrier (i.e. no access to translation services)

In order to enrol children at potential risk for the outcomes of interest, and avoid "healthier" participants with short PICU stays, we considered the following: the patient should have: a) a minimum age (when one is expected to be ambulatory/mobilizing), and b) a threshold severity of illness. In order to understand how different subsets of PICU populations are affected by critical illness, we chose not to restrict the selection of patients to a specific diagnosis, nor did we exclude patients with underlying functional or cognitive abnormalities at baseline. This study will evaluate the epidemiology of recovery in a general critically ill pediatric population over time.