Impact of point-of-care testing for white blood cell count on triage of patients with infection in the remote Northern Territory of Australia

The efficiency, timeliness, health outcomes and cost-effectiveness of a new aeromedical retrieval model in Central Australia: A pre- and post-implementation observational study

OBJECTIVE

To assess timeliness, efficiency, health outcomes and cost-effectiveness of the 2018 redesigned Central Australian aeromedical retrieval model.

DESIGN

Pre- and postimplementation observational study of all patients receiving telehealth consultations from remote medical practitioners (RMPs) or Medical Retrieval and Consultation Centre (MRaCC) physicians between 1/1/2015 and 29/2/2020. Descriptive and inferential statistics measuring system efficiency, timeliness, health outcomes and incremental cost-effectiveness.

FINDINGS

There were 9%-10% reductions in rates of total aeromedical retrievals, emergency department admissions and hospitalisations postimplementation, all p-values < 0.001. Usage rates for total hospital bed days and ICU hours were 17% lower (both p < 0.001). After adjusting for periodicity (12% fewer retrievals on weekends), each postimplementation year, there were 0.7 fewer retrievals/day (p = 0.002). The mean time from initial consultation to aeromedical departure declined by 18 minutes post-implementation (115 vs. 97 min, p = 0.007). The hazard of death within 365 days was nonsignificant (0.912, 95% CI 0.743-1.120). Postimplementation, it cost $302 more per hospital admission and $3051 more per year of life saved, with a 75% probability of cost-effectiveness. These costs excluded estimated savings of $744,528/year in reduced hospitalisations and the substantial social and out-of-pocket costs to patients and their families associated with temporary relocation to Alice Springs.

CONCLUSION

Central Australia's new critical care consultant-led aeromedical retrieval model is more efficient, is dispatched faster and is more cost-effective. These findings are highly relevant to other remote regions in Australia and internationally that have comparable GP-led retrieval services.

Speaking of sepsis: semantics, syntax, and slang

Medical language is in a constant state of evolution. Its grammar and vocabulary are not fixed by rigid rules. The interdisciplinary field of sepsis has become a meeting point for new insights arising from advances in systems biology, epidemiology, mechanistic understandings of disease process and antimicrobial interventions. This convergence has gained from our recent experience of SARS-CoV-2 infection and COVID-19 and possibilities inferred from emerging information technology. Biomedical descriptors have diverged along disciplinary lines creating an unfortunate disconnect between clinical and laboratory-based terminology. The resulting confusion between clinically determined sepsis and laboratory verified bloodstream infection raises practical questions that affect daily operational processes in the ward, clinic and laboratory. There is an urgent need to understand how the clinical sepsis pathway and corresponding clinical laboratory workflow can be better aligned as a single coherent entity. There is also an implicit need to understand how this process should produce actionable information in a timely and orderly manner, and identify residual obselete terminology that has crept into common usage. A widely accepted sepsis epistemology, ontology and heuristic will help us improve our clinical management of sepsis.

Diagnostic and Prognostic Value of Monocyte Distribution Width in Sepsis

Monocyte distribution width (MDW) is a blood monocyte morphological parameter that can be easily detected by an automated hemocyte analyzer and can provide clinicians with important information about cell volume variability in peripheral blood monocyte populations. The United States' Food and Drug Administration and Conformite Europeenne have both been cleared for their clinical application in the detection of sepsis and developing sepsis in adult patients in the emergency department (ED). Recently, MDW has been found to have an early diagnosis and predictive value for sepsis in neonates and COVID-19 patients. Here, we summarize the findings of the studies investigating the clinical application of MDW in sepsis. Under different stimuli, especially in infectious diseases, the activation of innate immunity is the host's first defense mechanism, and the change in monocyte volume is considered an early indicator reflecting the state of activation of innate immunity. Pivotal study data from a large multicenter patient cohort showed that abnormal MDW at presentation increases the odds of sepsis, considering the combination of MDW and White Blood Cell Count (WBC) as part of a standard sepsis assessment protocol for ED, which may increase the sensitivity and specificity of sepsis diagnosis. Meanwhile, MDW shares a diagnostic performance comparable to that of conventional biomarkers (C-reactive protein and procalcitonin) in sepsis. In addition, some evidence suggests that increased MDW, both in adults and neonates, may be associated with unfavorable short- and long-term outcomes, which indicates its prognostic value in sepsis. Taken together, MDW is a parameter of increased morphological variability of monocytes in response to infection, and numerous studies have shown that MDW could be used as a valuable diagnostic and prognostic index in patients with sepsis or suspected sepsis.

Age-Dependent Biomarkers for Prediction of In-Hospital Mortality in COVID-19 Patients

Background: Several biomarkers and models have been proposed to predict in-hospital mortality among COVID-19 patients. However, these studies have not examined the association in sub-populations. The present study aimed to identify the association between the two most common inflammatory biomarkers in the emergency department and in-hospital mortality in subgroups of patients. Methods: A historical cohort study of adult patients who were admitted to acute-care hospital between March and December 2020 and had a diagnosis of COVID-19 infection. Data on age, sex, Charlson comorbidity index, white blood cell (WBC) count, C-reactive protein (CRP), and in-hospital mortality were collected. Discrimination ability of each biomarker was observed and the CHAID method was used to identify the association in subgroups of patients. Results: Overall, 762 patients (median age 70.9 years, 59.7% males) were included in the study. Of them, 25.1% died during hospitalization. In-hospital mortality was associated with higher CRP (median 138 mg/L vs. 85 mg/L, p < 0.001), higher WBC count (median 8.5 vs. 6.6 K/µL, p < 0.001), and higher neutrophil-to-lymphocyte ratio (NLR) (median 9.2 vs. 5.4, p < 0.001). The area under the ROC curve was similar among all biomarkers (WBC 0.643, NLR 0.677, CRP 0.646, p > 0.1 for all comparisons). The CHAID method revealed that WBC count was associated with in-hospital mortality in patients aged 43.1−66.0 years (<11 K/µL: 10.1% vs. 11+ K/µL: 27.9%), NLR in patients aged 66.1−80 years (≤8: 15.7%, >8: 43.3%), and CRP in patients aged 80.1+ years (≤47 mg/L: 18.8%, 47.1−149 mg/L: 43.1%, and 149.1+: 71.7% mortality). Conclusions: WBC, NLR, and CRP present similar discrimination abilities. However, each biomarker should be considered as a predictor for in-hospital mortality in different age groups.

Scope and quality of economic evaluations of Aboriginal and Torres Strait Islander health programs: a systematic review

OBJECTIVES

Identify the number, type, scope and quality of economic evaluations of Aboriginal and Torres Strait Islander health programs.

METHODS

A systematic review of peer-reviewed and grey literature was conducted for articles published from 2010 to 2020 that reported a full economic evaluation of Aboriginal and Torres Strait Islander health programs. Data extraction included: type of economic evaluation, comparators, data sources and concerns, and outcome measures. Methodological quality was assessed using the Drummond checklist.

RESULTS

Thirteen publications met inclusion criteria: two cost-consequence analyses, two cost-effectiveness analyses, five cost-utility analyses, and four cost-benefit/return on investment analyses. Most studies (n=10) adopted a health system perspective and used a range of key data sources for economic analyses. Ten studies identified data access limitations that restricted analyses and two studies identified data quality concerns. Twelve studies were of good methodological quality and one was of average quality.

CONCLUSIONS

Despite significant investment in strategies to close the gap in health outcomes for Aboriginal and Torres Strait Islander people, there is limited evidence about what constitutes a cost-effective investment in Aboriginal and Torres Strait Islander healthcare.

IMPLICATIONS FOR PUBLIC HEALTH

More economic evaluation is required to justify the significant investment in health programs for Aboriginal and Torres Strait Islander people.

Health Economic Evidence of Point-of-Care Testing: A Systematic Review

OBJECTIVE

Point-of-care testing (POCT) has become an essential diagnostic technology for optimal patient care. Its implementation, however, still falls behind. This paper reviews the available evidence on the health economic impact of introducing POCT to assess if poor POCT uptake may be related to lacking evidence.

STUDY DESIGN

The Scopus and PubMed databases were searched to identify publications describing a health economic evaluation of a point-of-care (POC) test. Data were extracted from the included publications, including general and methodological characteristics as well as the study results summarized in either cost, effects or an incremental cost-effectiveness ratio. Results were sorted into six groups according to the POC test's purpose (diagnosis, screening or monitoring) and care setting (primary care or secondary care). The reporting quality of the publications was determined using the CHEERS checklist.

RESULTS

The initial search resulted in 396 publications, of which 44 met the inclusion criteria. Most of the evaluations were performed in a primary care setting (n = 31; 70.5%) compared with a secondary care setting (n = 13; 29.5%). About two thirds of the evaluations were on POC tests implemented with a diagnostic purpose (n = 28; 63.6%). More than 75% of evaluations concluded that POCT is recommended for implementation, although in some cases only under specific circumstances and conditions. Compliance with the CHEERS checklist items ranged from 20.8% to 100%, with an average reporting quality of 72.0%.

CONCLUSION

There were very few evaluations in this review that advised against the implementation of POCT. However, the uptake of POCT in many countries remains low. Even though the evaluations included in this review did not always include the full long-term benefits of POCT, it is clear that health economic evidence across a few dimensions of value already indicate the benefits of POCT. This suggests that the lack of evidence on POCT is not the primary barrier to its implementation and that the low uptake of these tests in clinical practice is due to (a combination of) other barriers. In this context, aspects around organization of care, support of clinicians and quality management may be crucial in the widespread implementation of POCT.

Does point-of-care testing in general practice for leucocyte and differential count change use of antimicrobial medicines? A pilot study

Diagnostic uncertainty when considering prescription of antimicrobials ('antibiotics') in primary care contributes to the major problem of microbial resistance. We conducted a feasibility evaluation of rapid testing for leucocyte and differential count in two urban general practices, surveying the GPs online and interviewing them. GPs reported that the machines were easy to use, the test results influenced their care and they would adopt the system if costs were off-set. Feasibility, acceptability and perceived benefit justify a randomised trial to test the effect on antibiotic prescribing rates and quality of care, with an economic evaluation to inform the cost-benefit.

Clinical evaluation of SARS-CoV-2 point-of-care antibody tests

The aim of this study was to assess the analytic and clinical performance of four rapid lateral flow point-of-care tests (POCTs) for identifying SARS-CoV-2-specific antibodies. A retrospective study was conducted between 22 January and 30 March 2020 on 132 serum samples for SARS-CoV-2-specific antibody detection referred to a tertiary referral hospital laboratory in New South Wales. Multiple sera were tested from 20 confirmed or suspected COVID-19 patients with SARS-CoV-2-specific antibodies detected by immunofluorescence (IFA) or neutralisation, and 71 SARS-CoV-2 uninfected individuals. We measured the sensitivity and specificity for detection of SARS-CoV-2 IgM and IgG antibodies for each POCT in comparison to positive SARS-CoV-2-specific IFA and viral neutralisation, our current laboratory benchmark tests.

All POCTs were found to have a low analytic sensitivity for SARS-CoV-2 antibodies, ranging from 27.3% to 58.2%, with a specificity between 88.3% and 100%, and a low clinical sensitivity from 45% to 65%, with a clinical specificity between 87.3% and 100%. All POCTs had an increased sensitivity when specimens were collected more than 14 days from onset of symptoms. The detection using point-of-care testing of SARS-CoV-2-specific antibodies after disease onset lagged behind IFA by a range of 0–9 days.

POCTs promise the benefit of providing quick easy testing for SARS-CoV-2-specific antibodies. However, their poor sensitivity and delayed antibody detection make them unsuitable as a diagnostic or screening tool alone.