Quality of life among survivors of prolonged critical illness; a mixed methods study

Introduction

Survivors of prolonged critical illness (requiring ≥ 14 days ventilation) experience the highest prevalence and severest forms of critical illness-related morbidity. This study examines the degree to which generic questionnaires reflect the quality of survivors' lives following critical illness.

Methods

Twenty patients took part in semistructured interview at ≤ 6 months post ICU discharge. Patients discussed in detail the aspects of their physical and psychological recovery that concerned them most. Interviews were transcribed verbatim and were thematically analysed. Patients also completed recommended quality of life questionnaires (SF-36 and Euroqol 5D). Using 'think aloud' techniques, patients described the ways in which their responses to the fixed-choice categories of the questionnaires were constructed. Interview data were also mapped on to the developers' definitions of the domains of the SF-36, providing rich contextual information.

Results

Impaired mobility and fatigue were major concerns. Patients experienced a range of morbidity and expressed a number of concerns not captured by questionnaire. Patients often provided counter-intuitive scores by questionnaire; 'thinking aloud' revealed that individuals process and construct their responses in unanticipated ways. Patients under-reported many aspects of morbidity not considered a matter of 'health' (for example, muscle wasting), and under-reported morbidity overall because a life of impairment was 'better than being dead'. Interviews revealed the nature and extent of patients' reliance on informal carers and, importantly, the diverse adaptive processes used to minimise the interference of morbidity in everyday life. These patients, although self-selecting, presented a positive outlook akin to the survivor 'persona' known to influence the meaning and subjective evaluation of quality of life among cancer patients.

Conclusion

This research raises important questions about the use of generic quality of life measures among survivors of critical illness. Qualitative and mixed methods approaches, although analytically laborious, may yield experientially important information and clinically useful insights into the quality of survivors' lives that are inaccessible by questionnaire alone.