Table 2 Expert judgements made on mortality rates by care category in the excess mortality sub-model
Assumption within capacity | Assumption with noICUbeds | Assumption with noICUor ward beds | |
|---|---|---|---|
General ward care | (1%) Very low mortality as these patients are un-escalatedand so will only occur with non-respiratory failure deaths or sudden deaths | (1%) Very low mortality as these patients are un-escalated andso will only occur with non-respiratory failuredeaths or sudden deaths | (3%) The risk remains low but will be greater than the mortality rate ward-based care |
Ward care O2 > 35% | (1%) This is a group of people who would be escalated to ICUif they deteriorated, so will only include sudden deaths | (1%) Those who deteriorate may get CPAP on the ward, so the CPAP mortality rate from NIV/CPAP on ICU has been used | (50%) Assume substantial mortality as use ofO2 > 35% indicates severe disease and risk to life. Assume that there will be no O2 outside of hospital. Set at 50% after discussion with ICU consultant |
Ward care O2 > 35% (Ceiling) | (40%) Assumption that this cohort will be frail with a CFS of 6–9. Mortality is about 40% at 28 days [11] | (40%)Assumption that this cohort will be frailwith a CFS of 6–9. Mortality is about 40% at 28 days [11]. Assume unaffected by ICU absence | (95%) This is a group of frail people who will have no medical support despite needing unusually high O2 flows to remain stable. Assume there will be no O2 outside of hospital |
Supportive/HFO on ICU | (1%) Assume the same as for NIV/CPAP on ICU | (2%) Assume the same as for NIV/ CPAP on ICU | (75%) With an assumption that no O2 available outside hospital, mortality in this group is likely to be high without it. Identified at having a risk to life by their need for admission toICU |
NIV/CPAP on ICU | (1%) There were 31 patients who received NIV only on ICU, none of whom died suggesting the mortality rate is below 3–4%. Deaths are only likely to occur if from non-respiratory causes such as sepsis or non-respiratory organ failure, otherwise they would have been escalated to IMV/ECMO [10] | (2%) Assume that CPAP therapy cancontinue on the ward, but mortality rate is double the 'within capacity' mortality rate because ofreduction in supportive care | (95%) Assume the vast majority would die without CPAP, otherwise they would have remained on high flow oxygen. Also assume that there will be no O2 outside hospital |
NIV/CPAP on ICU(Ceiling) | (83%) 20 out of 24 patients who received NIV died. These patients were frail with a mean CFS of 6 and would not have been considered for escalation of care [10] | (90%) Assume that CPAP therapy cancontinue onthe ward, but mortality rate increasesdue to a reduction in supportive care | (100%) Assumption that in the absence of any hospital bed, there would be no NIV and no chance of survival |
IMV ± ECMO on ICU | (40%) Since 1st September2020 mortality rate in those ventilated within 24hrs after admission is 40%. Assumption that the mortality rate is similar for those mechanically ventilated after24hrs [12] | (100%) It is a reasonably safe assumption that the mortality rate would be close to 100% as IMV/ECMO are dangerous but potentially lifesaving procedures; only carried out if considered life-saving in this circumstance | (100%) It is a reasonably safe assumption that the mortality rate would be close to 100% as IMV/ECMO are dangerous but potentially life-saving procedures; only carried out if consideredlife-saving in this circumstance |