The value of shock index, modified shock index and age shock index to predict mortality and hospitalisation in a district level emergency centre

Introduction

Triage is the most important step in patients' journey through an Emergency Centre (EC) and directly impacts time to critical actions. Triage tools, like the South African Triage Scale, are however not designed to predict patient outcomes. The shock index (SI), modified shock index (MSI) and age shock index (ASI) are clinical markers derived from vital signs and correlate with tissue perfusion in critically ill patients. This study aimed to assess the value of SI, MSI and ASI to predict mortality and the need for hospitalisation in all adult patients presenting to a district level emergency centre in South Africa.

Methods

This diagnostic study was performed as a retrospective observational study, using data from an existing electronic registry at a district level hospital emergency centre over a period of 24 months. All adult patients who presented to Mitchells Plain Hospital were eligible for inclusion. Sensitivity, specificity and likelihood ratios were calculated for each variable as a predictor of mortality and hospitalisation with pre-determined thresholds.

Results

During the study period of 24 months, a total of 61 329 patients ≥ 18 years old presented to the EC with 60 599 included in the final sample. A red SATS triage category (+LR = 7.2) and SI ≥1.3 (+LR = 4.9) were the only two predictors with any significant clinical value. The same two markers performed well for both patients with and without trauma and specifically for patients who died while under the care of the emergency centre.

Discussion

The study demonstrated that patients with a SI≥1.3 at triage have a significantly higher likelihood to die or require hospitalisation, whether the presenting complaint is trauma related or not, especially to predict mortality while under the care of the EC. Incorporating this marker as a triage alert could expedite the identification of patients requiring time critical interventions and improve patient throughput in the emergency centre.

Routine investigations for patients with mental and behavioural disturbances

Background

The process of medical clearance aims to exclude a general medical condition as an underlying cause for mental and behavioural disorders and involves routine screening with special investigations. Current evidence, however, suggests that clinician gestalt should guide the need for special investigations and that there is no benefit to routine screening.

Aim

This study aimed to determine the effectiveness of and adherence to the Western Cape (WC) provincial guidelines for routine investigations of adult patients with behavioural disturbances.

Setting

This study was conducted at Mitchells Plain Hospital in Cape Town, South Africa.

Methods

This descriptive study was conducted at Mitchells Plain Hospital in Cape Town, South Africa. Data were collected from existing electronic registries over a 6-month period. Adult mental healthcare users were risk stratified into the probability of having a general medical condition and the results of their special investigations were described against their outcome.

Results

Of the 688 patients included in this study, 66% had abnormal vital signs and of the 312 patients who received special investigations, 56% were abnormal, including 18% who were clinically significantly abnormal. Abnormal special investigations changed the clinical outcome for 3 (<1%) patients. Adherence to the guidelines was reasonable (82%) but non-adherence resulted in unnecessary investigations.

Conclusion

The results of this study support the existing evidence that clinical assessment and clinician gestalt should guide the need for special investigations and that there is no benefit to routine screening in the emergency centre (EC). The results also demonstrate that non-adherence rarely changed patient outcomes.

Contribution

This study provides information on the value of routine screening investigations in ECs.

Risk Factors for Coronavirus Disease 2019 (COVID-19) Death in a Population Cohort Study from the Western Cape Province, South Africa

BACKGROUND

Risk factors for coronavirus disease 2019 (COVID-19) death in sub-Saharan Africa and the effects of human immunodeficiency virus (HIV) and tuberculosis on COVID-19 outcomes are unknown.

METHODS

We conducted a population cohort study using linked data from adults attending public-sector health facilities in the Western Cape, South Africa. We used Cox proportional hazards models, adjusted for age, sex, location, and comorbidities, to examine the associations between HIV, tuberculosis, and COVID-19 death from 1 March to 9 June 2020 among (1) public-sector "active patients" (≥1 visit in the 3 years before March 2020); (2) laboratory-diagnosed COVID-19 cases; and (3) hospitalized COVID-19 cases. We calculated the standardized mortality ratio (SMR) for COVID-19, comparing adults living with and without HIV using modeled population estimates.

RESULTS

Among 3 460 932 patients (16% living with HIV), 22 308 were diagnosed with COVID-19, of whom 625 died. COVID-19 death was associated with male sex, increasing age, diabetes, hypertension, and chronic kidney disease. HIV was associated with COVID-19 mortality (adjusted hazard ratio [aHR], 2.14; 95% confidence interval [CI], 1.70-2.70), with similar risks across strata of viral loads and immunosuppression. Current and previous diagnoses of tuberculosis were associated with COVID-19 death (aHR, 2.70 [95% CI, 1.81-4.04] and 1.51 [95% CI, 1.18-1.93], respectively). The SMR for COVID-19 death associated with HIV was 2.39 (95% CI, 1.96-2.86); population attributable fraction 8.5% (95% CI, 6.1-11.1).

CONCLUSIONS

While our findings may overestimate HIV- and tuberculosis-associated COVID-19 mortality risks due to residual confounding, both living with HIV and having current tuberculosis were independently associated with increased COVID-19 mortality. The associations between age, sex, and other comorbidities and COVID-19 mortality were similar to those in other settings.