Introduction

Although mortality and survival are easy to understand and measure, survival alone is an incomplete endpoint for the recovery from critical illness or major surgery. Therefore, patient outcome from critical care treatment is not only described in terms of longer term survival (‘mortality’ outcomes), but also incorporates quality of life and neuropsychological and functional status (‘nonmortality’ outcomes). Assessment of these broader long-term outcome measures requires organized long-term follow-up that often extends to 12 months after hospital discharge. Critical care follow-up clinics have highlighted the variety of physical, psychological and psychosocial complaints experienced by patients as they recover from their critical care experience and treatment.

Patients requiring more than a 2- to 3-day critical care stay after cardiothoracic surgery tend to experience similar long-term outcomes as noncardiac patients. This chapter focuses on some of these long-term, patient-centred outcomes.

Mortality

In the United Kingdom, the mortality at critical care discharge exceeds 20%, and at hospital discharge, it exceeds 30%. Longer term survival rates are commonly represented by a Kaplan–Meier survival curve.

A very simplistic survival curve for a critical care population shows a very high initial mortality that gradually diminishes with time. The effects of critical illness and the underlying pathophysiological process on mortality are no longer present when the survival curve parallels that of a comparable patient cohort. The survival time corresponding to any proportion of the patient cohort is easily calculated, and survival curves of different cohorts can be compared.