Figure 1:

Potential impact of pre-existing frailty on outcomes after minor and major illness. The green line represents the medical course of an individual who is not frail (Clinical Frailty Score [CFS] 1–3, independent with basic and instrumental activities of daily living [BADLs and IADLs]): a minor illness may cause a transient reduction in physical or cognitive function, but the individual recovers to baseline. A major illness requiring admission to intensive care may cause substantial reduction in function and impairment in ADLs, but a patient who is not frail may improve close to baseline by 6 months. The yellow line represents the medical course of an individual with mild frailty (CFS 4–5): a minor illness may cause a disproportionate reduction in function, and the individual may not return to baseline. A major illness requiring admission to intensive care may cause further substantial reduction in function, from which the individual recovers only partially by 6 months. The orange line represents the medical course of an individual with moderate to severe frailty (CFS 6–8): a minor illness is likely to cause further disproportionate reduction in already limited function without return to baseline, and a major illness is likely to result in substantial reduction in function that does not improve by 6 months, assuming the individual is able to survive the index critical illness (in-hospital mortality for CFS 8 is reported at 48%,³¹ and 12-month survival for CFS 6–7 is 35%³⁷). Note: ICU = intensive care unit.