A systematic review of the outcomes reported in cardiac arrest clinical trials: The need for a core outcome set

Variation in outcome of hospitalised patients with out-of-hospital cardiac arrest from acute coronary syndrome: a cohort study

Background

Each year, approximately 30,000 people have an out-of-hospital cardiac arrest (OHCA) that is treated by UK ambulance services. Across all cases of OHCA, survival to hospital discharge is less than 10%. Acute coronary syndrome (ACS) is a common cause of OHCA.

Objectives

To explore factors that influence survival in patients who initially survive an OHCA attributable to ACS.

Data source

Data collected by the Myocardial Ischaemia National Audit Project (MINAP) between 2003 and 2015.

Participants

Adult patients who had a first OHCA attributable to ACS and who were successfully resuscitated and admitted to hospital.

Main outcome measures

Hospital mortality, neurological outcome at hospital discharge, and time to all-cause mortality.

Methods

We undertook a cohort study using data from the MINAP registry. MINAP is a national audit that collects data on patients admitted to English, Welsh and Northern Irish hospitals with myocardial ischaemia. From the data set, we identified patients who had an OHCA. We used imputation to address data missingness across the data set. We analysed data using multilevel logistic regression to identify modifiable and non-modifiable factors that affect outcome.

Results

Between 2003 and 2015, 1,127,140 patient cases were included in the MINAP data set. Of these, 17,604 OHCA cases met the study inclusion criteria. Overall hospital survival was 71.3%. Across hospitals with at least 60 cases, hospital survival ranged from 34% to 89% (median 71.4%, interquartile range 60.7–76.9%). Modelling, which adjusted for patient and treatment characteristics, could account for only 36.1% of this variability. For the primary outcome, the key modifiable factors associated with reduced mortality were reperfusion treatment [primary percutaneous coronary intervention (pPCI) or thrombolysis] and admission under a cardiologist. Admission to a high-volume cardiac arrest hospital did not influence survival. Sensitivity analyses showed that reperfusion was associated with reduced mortality among patients with a ST elevation myocardial infarction (STEMI), but there was no evidence of a reduction in mortality in patients who did not present with a STEMI.

Limitations

This was an observational study, such that unmeasured confounders may have influenced study findings. Differences in case identification processes at hospitals may contribute to an ascertainment bias.

Conclusions

In OHCA patients who have had a cardiac arrest attributable to ACS, there is evidence of variability in survival between hospitals, which cannot be fully explained by variables captured in the MINAP data set. Our findings provide some support for the current practice of transferring resuscitated patients with a STEMI to a hospital that can deliver pPCI. In contrast, it may be reasonable to transfer patients without a STEMI to the nearest appropriate hospital.

Future work

There is a need for clinical trials to examine the clinical effectiveness and cost-effectiveness of invasive reperfusion strategies in resuscitated OHCA patients of cardiac cause who have not had a STEMI.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Inconsistent selection of outcomes and measurement devices found in shoulder arthroplasty research: An analysis of studies on ClinicalTrials.gov

Introduction

Recent evidence suggests a lack of standardization of shoulder arthroplasty outcomes. This issue is a limiting factor in systematic reviews. Core outcome set (COS) methodology could address this problem by delineating a minimum set of outcomes for measurement in all shoulder arthroplasty trials.

Methods

A ClinicalTrials.gov search yielded 114 results. Eligible trials were coded on the following characteristics: study status, study type, arthroplasty type, sample size, measured outcomes, outcome measurement device, specific metric of measurement, method of aggregation, outcome classification, and adverse events.

Results

Sixty-six trials underwent data abstraction and data synthesis. Following abstraction, 383 shoulder arthroplasty outcomes were organized into 11 outcome domains. The most commonly reported outcomes were shoulder outcome score (n = 58), pain (n = 33), and quality of life (n = 15). The most common measurement devices were the Constant-Murley Shoulder Outcome Score (n = 38) and American Shoulder and Elbow Surgeons Shoulder Score (n = 33). Temporal patterns of outcome use was also found.

Conclusion

Our study suggests the need for greater standardization of outcomes and instruments. The lack of consistency across trials indicates that developing a core outcome set for shoulder arthroplasty trials would be worthwhile. Such standardization would allow for more effective comparison across studies in systematic reviews, while at the same time consider important outcomes that may be underrepresented otherwise. This review of outcomes provides an evidence-based foundation for the development of a COS for shoulder arthroplasty.

Comparison of Clinical Trial and Systematic Review Outcomes for the 4 Most Prevalent Eye Diseases

Importance

Suboptimal overlap in outcomes reported in clinical trials and systematic reviews compromises efforts to compare and summarize results across these studies.

Objectives

To examine the most frequent outcomes used in trials and reviews of the 4 most prevalent eye diseases (age-related macular degeneration [AMD], cataract, diabetic retinopathy [DR], and glaucoma) and the overlap between outcomes in the reviews and the trials included in the reviews.

Design, Setting, and Participants

This cross-sectional study examined all Cochrane reviews that addressed AMD, cataract, DR, and glaucoma; were published as of July 20, 2016; and included at least 1 trial and the trials included in the reviews. For each disease, a pair of clinical experts independently classified all outcomes and resolved discrepancies. Outcomes (outcome domains) were then compared separately for each disease.

Main Outcomes and Measures

Proportion of review outcomes also reported in trials and vice versa.

Results

This study included 56 reviews that comprised 414 trials. Although the median number of outcomes per trial and per review was the same (n = 5) for each disease, the trials included a greater number of outcomes overall than did the reviews, ranging from 2.9 times greater (89 vs 30 outcomes for glaucoma) to 4.9 times greater (107 vs 22 outcomes for AMD). Most review outcomes, ranging from 14 of 19 outcomes (73.7%) (for DR) to 27 of 29 outcomes (93.1%) (for cataract), were also reported in the trials. For trial outcomes, however, the proportion also named in reviews was low, ranging from 19 of 107 outcomes (17.8%) (for AMD) to 24 of 89 outcomes (27.0%) (for glaucoma). Only 1 outcome (visual acuity) was consistently reported in greater than half the trials and greater than half the reviews.

Conclusions and Relevance

Although most review outcomes were reported in the trials, most trial outcomes were not reported in the reviews. The current analysis focused on outcome domains, which might underestimate the problem of inconsistent outcomes. Other important elements of an outcome (ie, specific measurement, specific metric, method of aggregation, and time points) might have differed even though the domains overlapped. Inconsistency in trial outcomes may impede research synthesis and indicates the need for disease-specific core outcome sets in ophthalmology.

Post-admission outcomes of participants in the PARAMEDIC trial: A cluster randomised trial of mechanical or manual chest compressions

BACKGROUND

The PARAMEDIC cluster randomised trial evaluated the LUCAS mechanical chest compression device, and did not find evidence that use of mechanical chest compression led to an improvement in survival at 30 days. This paper reports patient outcomes from admission to hospital to 12 months after randomisation.

METHODS

Information about hospital length of stay and intensive care management was obtained through linkage with Hospital Episode Statistics and the Intensive Care National Audit and Research Centre. Patients surviving to hospital discharge were approached to complete questionnaires (SF-12v2, EQ-5D, MMSE, HADS and PTSD-CL) at 90days and 12 months. The study is registered with Current Controlled Trials, number ISRCTN08233942.

RESULTS

377 patients in the LUCAS arm and 658 patients in the manual chest compression were admitted to hospital. Hospital and intensive care length of stay were similar. Long term follow-up assessments were limited by poor response rates (53.7% at 3 months and 55.6% at 12 months). Follow-up rates were lower in those with worse neurological function. Among respondents, long term health related quality of life outcomes and emotional well-being was similar between groups. Cognitive function, measured by MMSE, was marginally lower in the LUCAS arm mean 26.9 (SD 3.7) compared to control mean 28.0 (SD 2.3), adjusted mean difference -1.5 (95% CI -2.6 to -0.4).

CONCLUSION

There were no clinically important differences identified in outcomes at long term follow-up between those allocated to the mechanical chest compression compared to those receiving manual chest compression.

Randomised crossover trial of rate feedback and force during chest compressions for paediatric cardiopulmonary resuscitation

OBJECTIVE

To determine the effect of visual feedback on rate of chest compressions, secondarily relating the forces used.

DESIGN

Randomised crossover trial.

SETTING

Tertiary teaching hospital.

SUBJECTS

Fifty trained hospital staff.

INTERVENTIONS

A thin sensor-mat placed over the manikin's chest measured rate and force. Rescuers applied compressions to the same paediatric manikin for two sessions. During one session they received visual feedback comparing their real-time rate with published guidelines.

OUTCOME MEASURES

Primary: compression rate. Secondary: compression and residual forces.

RESULTS

Rate of chest compressions (compressions per minute (compressions per minute; cpm)) varied widely (mean (SD) 111 (13), range 89-168), with a fourfold difference in variation during session 1 between those receiving and not receiving feedback (108 (5) vs 120 (20)). The interaction of session by feedback order was highly significant, indicating that this difference in mean rate between sessions was 14 cpm less (95% CI -22 to -5, p=0.002) in those given feedback first compared with those given it second. Compression force (N) varied widely (mean (SD) 306 (94); range 142-769). Those receiving feedback second (as opposed to first) used significantly lower force (adjusted mean difference -80 (95% CI -128 to -32), p=0.002). Mean residual force (18 N, SD 12, range 0-49) was unaffected by the intervention.

CONCLUSIONS

While visual feedback restricted excessive compression rates to within the prescribed range, applied force remained widely variable. The forces required may differ with growth, but such variation treating one manikin is alarming. Feedback technologies additionally measuring force (effort) could help to standardise and define effective treatments throughout childhood.

A review of patient and carer participation and the use of qualitative research in the development of core outcome sets

Background

To be meaningful, a core outcome set (COS) should be relevant to all stakeholders including patients and carers. This review aimed to explore the methods by which patients and carers have been included as participants in COS development exercises and, in particular, the use and reporting of qualitative methods.

Methods

In August 2015, a search of the Core Outcomes Measures in Effectiveness Trials (COMET) database was undertaken to identify papers involving patients and carers in COS development. Data were extracted to identify the data collection methods used in COS development, the number of health professionals, patients and carers participating in these, and the reported details of qualitative research undertaken.

Results

Fifty-nine papers reporting patient and carer participation were included in the review, ten of which reported using qualitative methods. Although patients and carers participated in outcome elicitation for inclusion in COS processes, health professionals tended to dominate the prioritisation exercises. Of the ten qualitative papers, only three were reported as a clear pre-designed part of a COS process. Qualitative data were collected using interviews, focus groups or a combination of these. None of the qualitative papers reported an underpinning methodological framework and details regarding data saturation, reflexivity and resource use associated with data collection were often poorly reported. Five papers reported difficulty in achieving a diverse sample of participants and two reported that a large and varied range of outcomes were often identified by participants making subsequent rating and ranking difficult.

Conclusions

Consideration of the best way to include patients and carers throughout the COS development process is needed. Additionally, further work is required to assess the potential role of qualitative methods in COS, to explore the knowledge produced by different qualitative data collection methods, and to evaluate the time and resources required to incorporate qualitative methods into COS development.

Quality and acceptability of measures of exercise adherence in musculoskeletal settings: a systematic review

Objective

To recommend robust and relevant measures of exercise adherence for application in the musculoskeletal field.

Method

A systematic review of measures was conducted in two phases. Phase 1 sought to identify all reproducible measures used to assess exercise adherence in a musculoskeletal setting. Phase 2 identified published evidence of measurement and practical properties of identified measures. Eight databases were searched (from inception to February 2016). Study quality was assessed against the Consensus-based Standards for the Selection of Health Measurement Instruments guidelines. Measurement quality was assessed against accepted standards.

Results

Phase 1: from 8511 records, 326 full-text articles were reviewed; 45 reproducible measures were identified. Phase 2: from 2977 records, 110 full-text articles were assessed for eligibility; 10 articles provided evidence of measurement/practical properties for just seven measures. Six were exercise adherence-specific measures; one was specific to physical activity but applied as a measure of exercise adherence. Evidence of essential measurement and practical properties was mostly limited or not available. Assessment of relevance and comprehensiveness was largely absent and there was no evidence of patient involvement during the development or evaluation of any measure.

Conclusion

The significant methodological and quality issues encountered prevent the clear recommendation of any measure; future applications should be undertaken cautiously until greater clarity of the conceptual underpinning of each measure is provided and acceptable evidence of essential measurement properties is established. Future research should seek to engage collaboratively with relevant stakeholders to ensure that exercise adherence assessment is high quality, relevant and acceptable.

Identifying Important Gaps in Randomized Controlled Trials of Adult Cardiac Arrest Treatments: A Systematic Review of the Published Literature

BACKGROUND

Cardiac arrest is a major public health concern worldwide. The extent and types of randomized controlled trials (RCT)-our most reliable source of clinical evidence-conducted in these high-risk patients over recent years are largely unknown.

METHODS AND RESULTS

We performed a systematic review, identifying all RCTs published in PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library from 1995 to 2014 that focused on the acute treatment of nontraumatic cardiac arrest in adults. We then extracted data on the setting of study populations, types and timing of interventions studied, risk of bias, outcomes reported, and how these factors have changed over time. Over this 20-year period, 92 RCTs were published containing 64 309 patients (median, 225.5 per trial). Of these, 81 RCTs (88.0%) involved out-of-hospital cardiac arrest, whereas 4 (4.3%) involved in-hospital cardiac arrest and 7 (7.6%) included both. Eighteen RCTs (19.6%) were performed in the United States, 68 (73.9%) were performed outside the United States, and 6 (6.5%) were performed in both settings. Thirty-eight RCTs (41.3%) evaluated drug therapy, 39 (42.4%) evaluated device therapy, and 15 (16.3%) evaluated protocol improvements. Seventy-four RCTs (80.4%) examined interventions during the cardiac arrest, 15 (16.3%) examined post cardiac arrest treatment, and 3 (3.3%) studied both. Overall, reporting of the risk of bias was limited. The most common outcome reported was return of spontaneous circulation: 86 (93.5%) with only 22 (23.9%) reporting survival beyond 6 months. Fifty-three RCTs (57.6%) reported global ordinal outcomes, whereas 15 (16.3%) reported quality-of-life. RCTs in the past 5 years were more likely to be focused on protocol improvements and postcardiac arrest care.

CONCLUSIONS

Important gaps in RCTs of cardiac arrest treatments exist, especially those examining in-hospital cardiac arrest, protocol improvement, postcardiac arrest care, and long-term or quality-of-life outcomes.

What change in outcomes after cardiac arrest is necessary to change practice? Results of an international survey

BACKGROUND

Efficient trials of interventions for patients with out-of-hospital cardiac arrest (OHCA) should have adequate but not excess power to detect a difference in outcomes. The minimum clinically important difference (MCID) is the threshold value in outcomes observed in a trial at which providers should choose to adopt a treatment. There has been limited assessment of MCID for outcomes after OHCA. Therefore, we conducted an international survey of individuals interested in cardiac resuscitation to define the MCID for a range of outcomes after OHCA.

METHODS

A brief survey instrument was developed and modified by consensus. Included were open-ended responses. The survey included an illustrative example of a hypothetical randomized study with distributions of outcomes based on those in a public use datafile from a previous trial. Elicited information included the minimum significant difference required in an outcome to change clinical practice. The population of interest was emergency physicians or other practitioners of acute cardiovascular research.

RESULTS

Usable responses were obtained from 160 respondents (50% of surveyed) in 46 countries (79% of surveyed). MCIDs tended to increase as baseline outcomes increased. For a population of patients with 25% survival to discharge and 20% favorable neurologic status at discharge, the MCID were median 5 (interquartile range [IQR] 3, 10) percent for survival to discharge; median 5 (IQR 2, 10) percent for favorable neurologic status at discharge, median 4 (IQR 2, 9) days of ICU-free survival and median 4 (IQR 2, 8) days of hospital-free survival.

CONCLUSION

Reported MCIDs for outcomes after OHCA vary according to the outcome considered as well as the baseline rate of achieving it. MCIDs of ICU-free survival or hospital-free survival may be useful to accelerate the rate of evidence-based change in resuscitation care.

Comparison of health-related quality of life and functional recovery measurement tools in out-of-hospital cardiac arrest survivors

INTRODUCTION

Although a number of validated health-related quality of life (HR-QOL) instruments exist for critical care populations, a standardised approach to assessing the HR-QOL of out-of-hospital cardiac arrest (OHCA) survivors has not been developed. We sought to compare the responses of 12-month OHCA survivors to three HR-QOL and functional recovery instruments, and assess instrument validity.

METHODS

The Victorian Ambulance Cardiac Arrest Registry invited 12-month OHCA survivors to participate in telephone follow-up between January 2011 and December 2015. Responders provided answers to the 12 Item Short Form Health Survey (SF-12), Three-Level EuroQol-5D (EQ-5D-3L) and the Glasgow Outcome Scale-Extended (GOSE). The SF-12 was also used to derive the SF-6D. Responses were used to assess the interpretability and construct validity of the instruments.

RESULTS

A total of 1188 patients and proxies responded. Large ceiling effects were observed for the EQ-5D-3L (patients=46%, proxies=23%). Substantial variability was also observed in SF-6D responses for patients who reported full health according to the EQ-5D-3L. For patient responders, the strongest correlations were observed between the EQ-5D-3L index score and SF-6D (ρ=0.65, p<0.001), and between the SF-6D and SF-12 physical component (ρ=0.69, p<0.001). The distribution of the SF-6D and EQ-5D-3L differed significantly for patients reporting a lower or upper moderate GOSE outcome and lower or upper good recovery (p<0.001 for all comparisons).

CONCLUSIONS

The EQ-5D-3L demonstrated limited interpretability due to the presence of ceiling effects. However, the measurement properties of the SF-12, SF-6D and GOSE suggest that these may be useful measures of HR-QOL and functional recovery in OHCA survivors.

Association between therapeutic hypothermia and long-term quality of life in survivors of cardiac arrest: A systematic review

OBJECTIVES

Therapeutic hypothermia (TH) has increasingly become a part of the current standard of care for treating patients with cardiac arrest (CA). However, little is known regarding the association between TH and long-term quality of life (QoL) in adult survivors of CA. We conducted a systematic review to investigate the association between TH implementation and long-term QoL outcomes in adult survivors of CA following hospital discharge.

METHODS

We systematically searched MEDLINE and Cochrane databases to identify randomized and observational studies from January 2005 to January 2016 investigating the relationship between TH implementation immediately post-CA and long-term QoL in CA survivors post-hospital discharge.

RESULTS

We included 9 studies with a total of 801 patients. Six of these were prospective cohort studies, 2 were substudies of randomized controlled trials, and 1 was a retrospective cohort study. Six studies included patients only with out-of-hospital CA while 3 included patients with both in-hospital and out-of-hospital CA. There was marked between-study heterogeneity with respect to study population, TH implementation, and QoL assessment tool. TH was not associated with long-term QoL in this population.

CONCLUSIONS

In this systematic review, the included studies do not suggest any association between TH implementation in CA with long-term QoL in CA survivors. Further larger scale studies are needed to investigate the sustainability of TH effects long term in this patient population.

Establishing the Aus-ROC Australian and New Zealand out-of-hospital cardiac arrest Epistry

INTRODUCTION

Out-of-hospital cardiac arrest (OHCA) is a global health problem with low survival. Regional variation in survival has heightened interest in combining cardiac arrest registries to understand and improve OHCA outcomes. While individual OHCA registries exist in Australian and New Zealand ambulance services, until recently these registries have not been combined. The aim of this protocol paper is to describe the rationale and methods of the Australian Resuscitation Outcomes Consortium (Aus-ROC) OHCA epidemiological registry (Epistry).

METHODS AND ANALYSIS

The Aus-ROC Epistry is designed as a population-based cohort study. Data collection started in 2014. Six ambulance services in Australia (Ambulance Victoria, SA Ambulance Service, St John Ambulance Western Australia and Queensland Ambulance Service) and New Zealand (St John New Zealand and Wellington Free Ambulance) currently contribute data. All OHCA attended by ambulance, regardless of aetiology or patient age, are included in the Epistry. The catchment population is approximately 19.3 million persons, representing 63% of the Australian population and 100% of the New Zealand population. Data are collected using Utstein-style definitions. Information incorporated into the Epistry includes demographics, arrest features, ambulance response times, treatment and patient outcomes. The primary outcome is 'survival to hospital discharge', with 'return of spontaneous circulation' as a key secondary outcome.

ETHICS AND DISSEMINATION

Ethics approval was independently sought by each of the contributing registries. Overarching ethics for the Epistry was provided by Monash University HREC (Approval No. CF12/3938-2012001888). A population-based OHCA registry capturing the majority of Australia and New Zealand will allow risk-adjusted outcomes to be determined, to enable benchmarking across ambulance providers, facilitate the identification of system-wide strategies associated with survival from OHCA, and allow monitoring of temporal trends in process and outcomes to improve patient care. Findings will be shared with participating ambulance services and the academic community.

Mechanical chest compression devices at in-hospital cardiac arrest: A systematic review and meta-analysis

AIM

To summarise the evidence in relation to the routine use of mechanical chest compression devices during resuscitation from in-hospital cardiac arrest.

METHODS

We conducted a systematic review of studies which compared the effect of the use of a mechanical chest compression device with manual chest compressions in adults that sustained an in-hospital cardiac arrest. Critical outcomes were survival with good neurological outcome, survival at hospital discharge or 30-days, and short-term survival (ROSC/1-h survival). Important outcomes included physiological outcomes. We synthesised results in a random-effects meta-analysis or narrative synthesis, as appropriate. Evidence quality in relation to each outcome was assessed using the GRADE system.

DATA SOURCES

Studies were identified using electronic databases searches (Cochrane Central, MEDLINE, EMBASE, CINAHL), forward and backward citation searching, and review of reference lists of manufacturer documentation.

RESULTS

Eight papers, containing nine studies [689 participants], were included. Three studies were randomised controlled trials. Meta-analyses showed an association between use of mechanical chest compression device and improved hospital or 30-day survival (odds ratio 2.34, 95% CI 1.42-3.85) and short-term survival (odds ratio 2.14, 95% CI 1.11-4.13). There was also evidence of improvements in physiological outcomes. Overall evidence quality in relation to all outcomes was very low.

CONCLUSIONS

Mechanical chest compression devices may improve patient outcome, when used at in-hospital cardiac arrest. However, the quality of current evidence is very low. There is a need for randomised trials to evaluate the effect of mechanical chest compression devices on survival for in-hospital cardiac arrest.