Cost-effectiveness analysis of alternative cooling strategies following cardiac arrest

A Systematic Literature Review to Assess Fever Management and the Quality of Targeted Temperature Management in Critically Ill Patients

Targeted temperature management (TTM) has been proposed to reduce mortality and improve neurological outcomes in postcardiac arrest and other critically ill patients. TTM implementation may vary considerably among hospitals, and "high-quality TTM" definitions are inconsistent. This systematic literature review in relevant critical care conditions evaluated the approaches to and definitions of TTM quality with respect to fever prevention and the maintenance of precise temperature control. Current evidence on the quality of fever management associated with TTM in cardiac arrest, traumatic brain injury, stroke, sepsis, and critical care more generally was examined. Searches were conducted in Embase and PubMed (2016 to 2021) following PRISMA guidelines. In total, 37 studies were identified and included, with 35 focusing on postarrest care. Frequently-reported TTM quality outcomes included the number of patients with rebound hyperthermia, deviation from target temperature, post-TTM body temperatures, and number of patients achieving target temperature. Surface and intravascular cooling were used in 13 studies, while one study used surface and extracorporeal cooling and one study used surface cooling and antipyretics. Surface and intravascular methods had comparable rates of achieving target temperature and maintaining temperature. A single study showed that patients with surface cooling had a lower incidence of rebound hyperthermia. This systematic literature review largely identified cardiac arrest literature demonstrating fever prevention with multiple TTM approaches. There was substantial heterogeneity in the definitions and delivery of quality TTM. Further research is required to define quality TTM across multiple elements, including achieving target temperature, maintaining target temperature, and preventing rebound hyperthermia.

Economic burden of Cardiac Arrest in Spain: analyzing healthcare costs drivers and treatment strategies cost-effectiveness

BACKGROUND

Cardiac arrest is a major public health issue in Europe. Cardiac arrest seems to be associated with a large socioeconomic burden in terms of resource utilization and health care costs. The aim of this study is the analysis of the economic burden of cardiac arrest in Spain and a cost-effectiveness analysis of the key intervention identified, especially in relation to neurological outcome at discharge.

METHODS

The data comes from the information provided by 115 intensive care and cardiology units from Spain, including information on the care of patients with out-of-hospital cardiac arrest who had a return of spontaneous circulation. The information reported by theses 115 units was collected by a nationwide survey conducted between March and September 2020. Along with number of patients (2631), we also collect information about the structure of the units, temperature management, and prognostication assessments. In this study we analyze the potential association of several factors with neurological outcome at discharge, and the cost associated with the different factors. The cost-effectiveness of using servo-control for temperature management is analyzed by means of a decision model, based on the results of the survey and data collected in the literature, for a one-year and a lifetime time horizon.

RESULTS

A total of 109 cardiology units provided results on neurological outcome at discharge as evaluated with the cerebral performance category (CPC). The most relevant factor associated with neurological outcome at discharge was 'servo-control use', showing a 12.8% decrease in patients with unfavorable neurological outcomes (i.e., CPC3-4 vs. CPC1-2). The total cost per patient (2020 Euros) was €73,502. Only "servo-control use" was associated with an increased mean total cost per hospital. Patients treated with servo-control for temperature management gained in the short term (1 year) an average of 0.039 QALYs over those who were treated with other methods at an increased cost of €70.8, leading to an incremental cost-effectiveness ratio of 1,808 euros. For a lifetime time horizon, the use of servo-control is both more effective and less costly than the alternative.

CONCLUSIONS

Our results suggest the implementation of servo-control techniques in all the units that are involved in managing the cardiac arrest patient from admission until discharge from hospital to minimize the neurological damage to patients and to reduce costs to the health and social security system.

Cost-Effectiveness Analysis of Intravascular Targeted Temperature Management after Cardiac Arrest in England

BACKGROUND

Targeted temperature management (TTM) has been shown to improve neurological outcomes and survival in patients resuscitated from cardiac arrest; however, the cost effectiveness of multiple TTM methods is not well studied.

OBJECTIVE

This study aimed to evaluate the cost effectiveness of intravascular temperature management (IVTM) using Thermogard XP compared with surface cooling methods after cardiac arrest in the England from the perspectives of the UK national health service and Personal Social Services.

METHODS

We developed a multi-state Markov model that evaluated IVTM (Thermogard XP) compared with surface cooling using two different devices (Blanketrol III and Arctic Sun 5000) over a short-term and lifetime time horizon. Model input parameters were obtained from the literature and local databases. We assumed a hypothetical cohort of 1000 patients who required TTM after cardiac arrest per year in the England. The outcomes were costs (in £, year 2019 values) and quality-adjusted life-years (QALYs), discounted at 3.5% annually. Deterministic and probabilistic sensitivity analyses were undertaken to examine the effect of alternative assumptions and uncertainty in model parameters on the results.

RESULTS

The cost-effectiveness analysis determined that Thermogard XP resulted in direct cost savings of £2339 and £2925 (per patient) compared with Blanketrol III and Arctic Sun 5000, respectively, and a gain of 0.98 QALYs over the patient lifetime. The probabilistic sensitivity analysis demonstrated that the probability of Thermogard XP being cost saving would be 69.2% and 65.3% versus the Arctic Sun 5000 and Blanketrol III, respectively.

CONCLUSION

Implementation of IVTM using Thermogard XP can lead to cost savings and improved patient quality of life versus surface cooling methods.

Health-Related Quality-of-Life and Cost Utility Analyses in Critical Care: A Systematic Review

OBJECTIVES

Cost utility analyses compare the costs and health outcome of interventions, with a denominator of quality-adjusted life year, a generic health utility measure combining both quality and quantity of life. Cost utility analyses are difficult to compare when methods are not standardized. It is unclear how cost utility analyses are measured/reported in critical care and what methodologic challenges cost utility analyses pose in this setting. This may lead to differences precluding cost utility analyses comparisons. Therefore, we performed a systematic review of cost utility analyses conducted in critical care. Our objectives were to understand: 1) methodologic characteristics, 2) how health-related quality-of-life was measured/reported, and 3) what costs were reported/measured.

DESIGN

Systematic review.

DATA SOURCES

We systematically searched for cost utility analyses in critical care in MEDLINE, Embase, American College of Physicians Journal Club, CENTRAL, Evidence-Based Medicine Reviews' selected subset of archived versions of UK National Health Service Economic Evaluation Database, Database of Abstracts of Reviews of Effects, and American Economic Association electronic databases from inception to April 30, 2020.

SETTING

Adult ICUs.

PATIENTS

Adult critically ill patients.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 8,926 citations, 80 cost utility analyse studies were eligible. The time horizon most commonly reported was lifetime (59%). For health utility reporting, health-related quality-of-life was infrequently measured (29% reported), with only 5% of studies reporting baseline health-related quality-of-life. Indirect utility measures (generic, preference-based health utility measurement tools) were reported in 85% of studies (majority Euro-quality-of-life-5 Domains, 52%). Methods of estimating health-related quality-of-life were seldom used when the patient was incapacitated: imputation (19%), assigning fixed utilities for incapacitation (19%), and surrogates reporting on behalf of incapacitated patients (5%). For cost utility reporting transparency, separate incremental costs and quality-adjusted life years were both reported in only 76% of studies. Disaggregated quality-adjusted life years (reporting separate health utility and life years) were described in only 34% of studies.

CONCLUSIONS

We identified deficiencies which warrant recommendations (standardized measurement/reporting of resource use/unit costs/health-related quality-of-life/methodological preferences) for improved design, conduct, and reporting of future cost utility analyses in critical care.

Cost-Effectiveness Studies in the ICU: A Systematic Review

OBJECTIVES

Cost-effectiveness analyses are increasingly used to aid decisions about resource allocation in healthcare; this practice is slow to translate into critical care. We sought to identify and summarize original cost-effectiveness studies presenting cost per quality-adjusted life year, incremental cost-effectiveness ratios, or cost per life-year ratios for treatments used in ICUs.

DESIGN

We conducted a systematic search of the English-language literature for cost-effectiveness analyses published from 1993 to 2018 in critical care. Study quality was assessed using the Drummond checklist.

SETTING

Critical care units.

PATIENTS OR SUBJECTS

Critical care patients.

INTERVENTIONS

Identified studies with cost-effectiveness analyses.

MEASUREMENTS AND MAIN RESULTS

We identified 97 studies published through 2018 with 156 cost-effectiveness ratios. Reported incremental cost-effectiveness ratios ranged from -$119,635 (hypothetical cohort of patients requiring either intermittent or continuous renal replacement therapy) to $876,539 (data from an acute renal failure study in which continuous renal replacement therapy was the most expensive therapy). Many studies reported favorable cost-effectiveness profiles (i.e., below $50,000 per life year or quality-adjusted life year). However, several therapies have since been proven harmful. Over 2 decades, relatively few cost-effectiveness studies in critical care have been published (average 4.6 studies per year). There has been a more recent trend toward using hypothetical cohorts and modeling scenarios without proven clinical data (2014-2018: 19/33 [58%]).

CONCLUSIONS

Despite critical care being a significant healthcare cost burden there remains a paucity of studies in the literature evaluating its cost effectiveness.

Targeted Temperature Management After Cardiac Arrest: Systematic Review and Meta-analyses

BACKGROUND

Targeted temperature management (TTM) with therapeutic hypothermia is an integral component of postarrest care for survivors. However, recent randomized controlled trials (RCTs) have failed to demonstrate the benefit of TTM on clinical outcomes. We sought to determine if the pooled data from available RCTs support the use of prehospital and/or in-hospital TTM after cardiac arrest.

METHODS

A comprehensive search of SCOPUS, Elsevier's abstract and citation database of peer-reviewed literature, from 1966 to November 2016 was performed using predefined criteria. Therapeutic hypothermia was defined as any strategy that aimed to cool post-cardiac arrest survivors to a temperature ≤34°C. Normothermia was temperature of ≥36°C. We compared mortality and neurologic outcomes in patients by categorizing the studies into 2 groups: (1) hypothermia versus normothermia and (2) prehospital hypothermia versus in-hospital hypothermia using standard meta-analytic methods. A random effects modeling was utilized to estimate comparative risk ratios (RR) and 95% confidence intervals (CIs).

RESULTS

The hypothermia and normothermia strategies were compared in 5 RCTs with 1389 patients, whereas prehospital hypothermia and in-hospital hypothermia were compared in 6 RCTs with 3393 patients. We observed no difference in mortality (RR, 0.88; 95% CI, 0.73-1.05) or neurologic outcomes (RR, 1.26; 95% CI, 0.92-1.72) between the hypothermia and normothermia strategies. Similarly, no difference was observed in mortality (RR, 1.00; 95% CI, 0.97-1.03) or neurologic outcome (RR, 0.96; 95% CI, 0.85-1.08) between the prehospital hypothermia versus in-hospital hypothermia strategies.

CONCLUSIONS

Our results suggest that TTM with therapeutic hypothermia may not improve mortality or neurologic outcomes in postarrest survivors. Using therapeutic hypothermia as a standard of care strategy of postarrest care in survivors may need to be reevaluated.

A novel scoring system for predicting the neurologic prognosis prior to the initiation of induced hypothermia in cases of post-cardiac arrest syndrome: the CAST score

BACKGROUND

The aim of this study was to develop a scoring system for identifying the post-cardiac arrest syndrome (PCAS) patients with a good potential for recovery prior to the initiation of induced therapeutic hypothermia.

METHODS

A multi-center, retrospective, observational study was performed. Data of a total of 151 consecutive adults who underwent induced hypothermia after cardiac arrest (77 learning cases from two hospitals and 74 validation cases from two other hospitals) were analyzed.

RESULTS

In the learning set, 8 factors (initial rhythm, witnessed status and time until return of spontaneous circulation, pH, serum lactate, motor score according to the Glasgow Coma Scale (GCS), gray matter attenuation to white matter attenuation ratio (GWR), serum albumin, and hemoglobin) were found to be strongly correlated with the neurological outcomes. A tentative scoring system was created from the learning data using these factors, and the predictive accuracy (sensitivity and specificity) was evaluated in terms of both internal validation (0.85 and 0.84) and external validation (cutoff 50%: 0.95 and 0.90, 30%: 0.87 and 0.98, 15%: 0.67 and 1.00). Finally, using all the data, we established a post-Cardiac Arrest Syndrome for induced Therapeutic hypothermia (CAST) score to predict the neurologic prognosis prior to initiation of induced hypothermia.

CONCLUSIONS

The CAST score was developed to predict the neurological outcomes of PCAS patients treated by induced hypothermia. The likelihood of good recovery at 30 days was extremely low in PCAS patients with a CAST score of ≤15%. Prospective validation of the score is needed in the future.

Global cerebral ischemia due to circulatory arrest: insights into cellular pathophysiology and diagnostic modalities

Circulatory arrest (CA) remains a major unresolved public health problem in the United States; the annual incidence of which is ~0.50 to 0.55 per 1000 population. Despite seminal advances in therapeutic approaches over the past several decades, brain injury continues to be the leading cause of morbidity and mortality after CA. In brief, CA typically results in global cerebral ischemia leading to delayed neuronal death in the hippocampal pyramidal cells as well as in the cortical layers. The dynamic changes occurring in neurons after CA are still unclear, and predicting these neurological changes in the brain still remains a difficult issue. It is hypothesized that the "no-flow" period produces a cytotoxic cascade of membrane depolarization, Ca²⁺ ion influx, glutamate release, acidosis, and resultant activation of lipases, nucleases, and proteases. Furthermore, during reperfusion injury, neuronal death occurs due to the generation of free radicals by interfering with the mitochondrial respiratory chain. The efficacy of many pharmacological agents for CA patients has often been disappointing, reflecting our incomplete understanding of this enigmatic disease. The primary obstacles to the development of a neuroprotective therapy in CA include uncertainties with regard to the precise cause(s) of neuronal dysfunction and what to target. In this review, we summarize our knowledge of the pathophysiology as well as specific cellular changes in brain after CA and revisit the most important neurofunctional, neuroimaging techniques, and serum biomarkers as potent predictors of neurologic outcome in CA patients.