ABSTRACT
OBJECTIVE: External validation of the Oldham Composite Covid-19 associated Mortality Model (OCCAM), a prognostic model for Covid-19 mortality in hospitalised patients comprised of age, history of hypertension, current or previous malignancy, admission platelet count < 150 × 103/µL, admission CRP ≥ 100 µg/mL, acute kidney injury (AKI), and radiographic evidence of > 50% total lung field infiltrates. PATIENTS AND METHODS: Retrospective study assessing discrimination (c-statistic) and calibration of OCCAM for death in hospital or within 30 days of discharge. 300 adults admitted to six district general and teaching hospitals in North West England for treatment of Covid-19 between September 2020 and February 2021 were included. RESULTS: Two hundred and ninety-seven patients were included in the validation cohort analysis, with a mortality rate of 32.8%. The c-statistic was 0.794 (95% confidence interval 0.742-0.847) vs. 0.805 (95% confidence interval 0.766 - 0.844) in the development cohort. Visual inspection of calibration plots demonstrate excellent calibration across risk groups, with a calibration slope for the external validation cohort of 0.963. CONCLUSION: The OCCAM model is an effective prognostic tool that can be utilised at the time of initial patient assessment to aid decisions around admission and discharge, use of therapeutics, and shared decision-making with patients. Clinicians should remain aware of the need for ongoing validation of all Covid-19 prognostic models in light of changes in host immunity and emerging variants.
ABSTRACT
Understanding risk factors for death from Covid-19 is key to providing good quality clinical care. We assessed the presenting characteristics of the 'first wave' of patients with Covid-19 at Royal Oldham Hospital, UK and undertook logistic regression modelling to investigate factors associated with death. Of 470 patients admitted, 169 (36%) died. The median age was 71 years (interquartile range 57-82), and 255 (54.3%) were men. The most common comorbidities were hypertension (n = 218, 46.4%), diabetes (n = 143, 30.4%) and chronic neurological disease (n = 123, 26.1%). The most frequent complications were acute kidney injury (AKI) (n = 157, 33.4%) and myocardial injury (n = 21, 4.5%). Forty-three (9.1%) patients required intubation and ventilation, and 39 (8.3%) received non-invasive ventilation. Independent risk factors for death were increasing age (odds ratio (OR) per 10 year increase above 40 years 1.87, 95% confidence interval (CI) 1.57-2.27), hypertension (OR 1.72, 95% CI 1.10-2.70), cancer (OR 2.20, 95% CI 1.27-3.81), platelets <150 × 103/µl (OR 1.93, 95% CI 1.13-3.30), C-reactive protein ≥100 µg/ml (OR 1.68, 95% CI 1.05-2.68), >50% chest radiograph infiltrates (OR 2.09, 95% CI 1.16-3.77) and AKI (OR 2.60, 95% CI 1.64-4.13). There was no independent association between death and gender, ethnicity, deprivation level, fever, SpO2/FiO2, lymphopoenia or other comorbidities. These findings will inform clinical and shared decision making, including use of respiratory support and therapeutic agents.