Physicians declining patient enrollment in a critical care trial: a case study in thromboprophylaxis

Recruitment characteristics of randomised trials in critical care: A systematic review

BACKGROUND/AIMS

To summarise the temporal trends of recruitment and methodological characteristics of critical care randomised controlled trials with the primary outcome of mortality.

METHODS

PubMed was searched for articles meeting inclusion and exclusion criteria. Randomised controlled trials, with primary outcome of mortality, of adult and paediatric critical care patients treated in an intensive care unit, were included. Neonatal intensive care unit trials, non-English publications and conference proceedings or abstracts without full-length publications were excluded. Duplicate literature search, article selection and quality assessment were performed by two reviewers with disputes resolved through discussion. Data were extracted into a custom-designed Research Electronic Data Capture database.

RESULTS

The search identified 67,199 records of which 230 were included. The annual number of critical care randomised controlled trials published increased gradually over a 30-year period from 0 in 1990 to 19 in 2014 with stabilisation at 8-11 between 2015 and 2020. Twenty-seven percent of randomised controlled trials were low risk in all categories using the Cochrane Risk of Bias tool. Methodological characteristics such as registration on clinical trials registries and data safety monitoring committee presence significantly (p < 0.001) increased over time. The median recruitment was 376 patients (interquartile range 125-895) with significant increase (p = 0.002) from 62 (interquartile range: 33-486) in 1991 to 725 (interquartile range: 537-2600) in 2020. This was accompanied by an increase in recruitment times. Thus overall, recruitment rates did not increase. Early cessation occurred in 23% (54/230) of randomised controlled trials with no temporal trend.

CONCLUSION

The number, size and some methodological qualities of critical randomised controlled trials with primary outcome of mortality have increased over time, but rates of recruitment and early cessation have been unchanged.

An evaluation of factors that may influence clinicians' decisions not to enroll eligible patients into randomized trials in critical care

OBJECTIVES

To determine the association between intensive care unit (ICU) characteristics and clinicians' decision to decline eligible patients for randomization into a multicentered pragmatic comparative-effectiveness controlled trial.

METHODS

Screening logs from the Adjunctive Glucocorticoid Therapy in Septic Shock Trial (ADRENAL) and site-level data from the College of Intensive Care Medicine and Australia New Zealand Intensive Care Society were examined. The effects of ICU characteristics such as tertiary academic status, research coordinator availability, number of admissions, and ICU affiliations on clinicians declining to randomize eligible patients were calculated using mixed effects logistic regression modelling.

RESULTS

There were 21,818 patients screened for inclusion in the ADRENAL trial at 69 sites across five countries, out of which 5,501 were eligible, 3,800 were randomized and 659 eligible patients were declined for randomization by the treating clinician. The proportion of eligible patients declined by clinicians at individual ICUs ranged from 0 to41%. In the multivariable model, none of the ICU characteristics were significantly associated with higher clinician decline rate.

CONCLUSIONS

Neither tertiary academic status, nor other site-level variables were significantly associated with increased rate of clinicians declining eligible patients.

Criteria for Clinically Relevant Bleeding in Critically Ill Children: An International Survey

OBJECTIVES

Bleeding, a feared complication of critical illness, is frequent in critically ill children. However, the concept of clinically relevant bleeding is ill-defined in this population. There are many established diagnostic criteria for bleeding, but only one estimates bleeding in critically ill adults, and none exist for critically ill children. Our objective was to identify the factors that influence pediatric intensivists' perception of clinically relevant bleeding.

DESIGN

Self-administered, web-based survey with 9-point Likert scales, to qualify the clinical significance of 103 bleeding characteristics in critically ill children.

SETTING

Online survey.

SUBJECTS

Pediatric critical care physicians and nurse practitioners.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The response rate was 40%, with 225 respondents from 16 countries. Characteristics most frequently identified as clinically relevant were bleeding in critical locations (e.g., pericardium, pleural space, CNS, and lungs); requiring interventions; leading to physiologic repercussions, including organ failure; and of prolonged duration. Quantifiable bleeding greater than 5 mL/kg/hr for more than 1 hour was frequently considered clinically relevant. Respondents identified the following characteristics as clinically irrelevant: dressings required to be changed no less frequently than every 6 hours, streaks of blood in gastric tubes, streaks of blood in endotracheal tubes or blood in endotracheal tubes only during suctioning, lightly blood-tinged urine, quantifiable bleeding less than 1 mL/kg/hr, and noncoalescing petechiae. Perception of the clinical relevance of bleeding was not associated with the respondent's geographical location of clinical practice or years of experience.

CONCLUSIONS

This international survey provides a better understanding of the factors that influence the pediatric intensivists' assessment of the clinical relevance of bleeding in critically ill children. It provides the foundation for the development of a validated, diagnostic definition of clinically relevant bleeding in this population.

Detailed systematic analysis of recruitment strategies in randomised controlled trials in patients with an unscheduled admission to hospital

OBJECTIVES

To examine the design and findings of recruitment studies in randomised controlled trials (RCTs) involving patients with an unscheduled hospital admission (UHA), to consider how to optimise recruitment in future RCTs of this nature.

DESIGN

Studies within the ORRCA database (Online Resource for Recruitment Research in Clinical TriAls; www.orrca.org.uk) that reported on recruitment to RCTs involving UHAs in patients >18 years were included. Extracted data included trial clinical details, and the rationale and main findings of the recruitment study.

RESULTS

Of 3114 articles populating ORRCA, 39 recruitment studies were eligible, focusing on 68 real and 13 hypothetical host RCTs. Four studies were prospectively planned investigations of recruitment interventions, one of which was a nested RCT. Most recruitment papers were reports of recruitment experiences from one or more 'real' RCTs (n=24) or studies using hypothetical RCTs (n=11). Rationales for conducting recruitment studies included limited time for informed consent (IC) and patients being too unwell to provide IC. Methods to optimise recruitment included providing patients with trial information in the prehospital setting, technology to allow recruiters to cover multiple sites, screening logs to uncover recruitment barriers, and verbal rather than written information and consent.

CONCLUSION

There is a paucity of high-quality research into recruitment in RCTs involving UHAs with only one nested randomised study evaluating a recruitment intervention. Among the remaining studies, methods to optimise recruitment focused on how to improve information provision in the prehospital setting and use of screening logs. Future research in this setting should focus on the prospective evaluation of the well-developed interventions to optimise recruitment.

Characteristics and Outcomes of Eligible Nonenrolled Patients in a Mechanical Ventilation Trial of Acute Respiratory Distress Syndrome

RATIONALE

Patients eligible for randomized controlled trials may not be enrolled for various reasons. Nonenrollment may affect study generalizability and lengthen the time required for trial completion.

OBJECTIVES

To describe characteristics and outcomes of eligible nonenrolled (ENE) patients in a multicenter trial of mechanical ventilation strategies.

METHODS

Within the OSCILLATE trial of high-frequency oscillation (HFO) versus conventional ventilation (CV) in adults with adult respiratory distress syndrome, and with approval from research ethics boards, we collected a minimal dataset on patients who satisfied eligibility criteria but were not enrolled. We categorized ENE patients as ENE-HFO and ENE-CV based on receipt of HFO at any time. We used multivariable logistic regression to assess the association between ENE status and mortality.

MEASUREMENTS AND MAIN RESULTS

A total of 548 patients were randomized, and 546 were ENE. The most common reasons for ENE were no consent (42%), physician refusal (24%), missed randomization window (15%), and current HFO use (14%). Compared with randomized patients in respective arms of the trial, ENE-HFO patients were younger and had worse lung injury, whereas ENE-CV patients had lower illness severity. ENE status was independently associated with mortality (adjusted odds ratio, 1.39; 95% confidence interval, 1.06-1.84; P = 0.02), with no significant interaction with ventilation treatment group.

CONCLUSIONS

Nonenrollment was common, with approximately one ENE patient for every randomized patient. Our study suggests that enrollment in trials of mechanical ventilation may be associated with improved outcomes compared with standard care and highlights the need for prospective tracking and transparent reporting of ENE patients as part of trial management.

Comparison of standard and accelerated initiation of renal replacement therapy in acute kidney injury

In patients with severe acute kidney injury (AKI) but no urgent indication for renal replacement therapy (RRT), the optimal time to initiate RRT remains controversial. While starting RRT preemptively may have benefits, this may expose patients to unnecessary RRT. To study this, we conducted a 12-center open-label pilot trial of critically ill adults with volume replete severe AKI. Patients were randomized to accelerated (12 h or less from eligibility) or standard RRT initiation. Outcomes were adherence to protocol-defined time windows for RRT initiation (primary), proportion of eligible patients enrolled, follow-up to 90 days, and safety in 101 fully eligible patients (57 with sepsis) with a mean age of 63 years. Median serum creatinine and urine output at enrollment were 268 micromoles/l and 356 ml per 24 h, respectively. In the accelerated arm, all patients commenced RRT and 45/48 did so within 12 h from eligibility (median 7.4 h). In the standard arm, 33 patients started RRT at a median of 31.6 h from eligibility, of which 19 did not receive RRT (6 died and 13 recovered kidney function). Clinical outcomes were available for all patients at 90 days following enrollment, with mortality 38% in the accelerated and 37% in the standard arm. Two surviving patients, both randomized to standard RRT initiation, were still RRT dependent at day 90. No safety signal was evident in either arm. Our findings can inform the design of a large-scale effectiveness randomized control trial.

Probiotics: Prevention of Severe Pneumonia and Endotracheal Colonization Trial-PROSPECT: protocol for a feasibility randomized pilot trial

BACKGROUND

Probiotics are defined as live microorganisms that may confer health benefits when ingested. Meta-analysis of probiotic trials suggests a 25 % lower ventilator-associated pneumonia (VAP) and 18 % lower infection rates overall when administered to patients in the intensive care unit (ICU). However, prior trials are small, largely single center, and at high risk of bias. Before a large rigorous trial is launched, testing whether probiotics confer benefit, harm, or have no impact, a pilot trial is needed. The aim of the PROSPECT Pilot Trial is to determine the feasibility of performing a larger trial in mechanically ventilated critically ill patients investigating Lactobacillus rhamnosus GG. A priori, we determined that the feasibility of the larger trial would be based on timely recruitment, high protocol adherence, minimal contamination, and an acceptable VAP rate.

METHODS/DESIGN

Patients ≥18 years old in the ICU who are anticipated to receive mechanical ventilation for ≥72 hours will be included. Patients are excluded if they are at increased risk of probiotic-associated infection, have strict enteral medication contraindications, are pregnant, previously enrolled in a related trial, or are receiving palliative care. Following informed consent, patients are randomized in variable unspecified block sizes in a fixed 1:1 ratio, stratified by ICU, and medical, surgical, or trauma admitting diagnosis. Patients receive 1 × 1010 colony forming units of L. rhamnosus GG (Culturelle, Locin Industries Ltd) or an identical placebo suspended in tap water administered twice daily via nasogastric tube in the ICU. Clinical and research staff, patients, and families are blinded.

DISCUSSION

The primary outcomes for this pilot trial are the following: (1) recruitment success, (2) ≥90 % protocol adherence, (3) ≤5 % contamination, and (4) ~10 % VAP rate. Additional clinical outcomes are VAP, other infections, diarrhea (total, antibiotic associated, and Clostridium difficile), ICU and hospital length of stay, and mortality. The morbidity, mortality, and cost of VAP underscore the need for cost-effective prophylactic interventions. The PROSPECT Pilot Trial is the initial step toward rigorously evaluating whether probiotics decrease nosocomial infections, have no effect, or actually cause infections in critically ill patients.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT01782755.

PROF-ETEV study: prophylaxis of venous thromboembolic disease in critical care units in Spain

PURPOSE

Venous thromboembolic disease (VTE) in critically ill patients has a high incidence despite prophylactic measures. This fact could be related to an inappropriate use of these measures due to the absence of specific VTE risk scores. To assess the current situation in Spain, we have performed a cross-sectional study, analyzing if the prophylactic measures were appropriate to the patients' VTE risk.

METHODS

Through an electronic questionnaire, we carried out a single day point prevalence study on the VTE prophylactic measures used in several critical care units in Spain. We performed a risk stratification for VTE in three groups: low, moderate-high, and very high risk. The American College of Chest Physicians guidelines were used to determine if the patients were receiving the recommended prophylaxis.

RESULTS

A total of 777 patients were included; 62% medical, 30% surgical, and 7% major trauma patients. The median number of the risk factors for VTE was four. According to the proposed VTE risk score, only 2% of the patients were at low risk, whereas 83% were at very high risk. Sixty-three percent of patients received pharmacological prophylaxis, 12% mechanical prophylaxis, 6% combined prophylaxis, and 19% did not receive any prophylactic measure. According to criteria suggested by the guidelines, 23% of medical, 71% of surgical, and 70% of major trauma patients received an inappropriate prophylaxis.

CONCLUSIONS

Most critically ill patients are at high or very high risk of VTE, but there is a low rate of appropriate prophylaxis. The efforts to improve the identification of patients at risk, and the implementation of appropriate prevention protocols should be enhanced.

Clonidine in the sedation of mechanically ventilated children: a pilot randomized trial

PURPOSE

Clonidine is often used as a sedative in critically ill children, but its effectiveness has not been evaluated in a large, rigorous randomized controlled trial. Our objectives in this pilot trial were to assess the feasibility of a larger trial with respect to (1) effective screening, (2) recruitment, (3) timely drug administration, and (4) protocol adherence.

MATERIALS AND METHODS

This is a randomized, blinded, placebo-controlled pilot trial. Mechanically ventilated children received enteral clonidine 5 μg/kg or placebo every 6 hours; additional sedatives were at the discretion of attending physicians.

RESULTS

We enrolled 50 children. The median interquartile range (IQR) age was 2.5 (0.7-5.2) years, and Pediatric Risk of Mortality score on pediatric intensive care unit admission was 12 (8-15). In terms of feasibility outcomes, 90 (87%) of 104 eligible patients were approached for consent, and on average, 1.7 children were enrolled per month. Thirty-five (70%) were enrolled within 1 day of becoming eligible (mean, 1.2 days). Thereafter, 94% of doses were administered by protocol. Clinical outcomes and adverse effects were not significantly different between the groups.

CONCLUSIONS

This pilot trial demonstrated feasibility of a larger randomized controlled trial. Some important challenges emerged, allowing refinement of the study protocol and enrolment estimates. We recommend that future trials capitalize on the experience gained and use these results to design a larger trial focusing on clinically important outcomes.