How the earplug trial was run, not what its abstract concludes, decides this NU504 Unit 5 critique of a published Belgian ICU trial, worked through the CASP randomized trial checklist. Searches like "nu 504 unit 5 assignment example", "nu504 unit 5 sample" and "nu504 unit 5 example" land here.
Confusion Fell, Delirium Did Not: A CASP Critique of the Van Rompaey Earplug Trial in Intensive Care Patients
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Purdue University Global
NU504: Scientific and Analytic Approaches to Advanced Evidence-Based Practice
Unit 5 Assignment
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[Date]
Critique of a published trial; every detail is taken from the article itself.
The Article
Van Rompaey, B., Elseviers, M. M., Van Drom, W., Fromont, V., & Jorens, P. G. (2012). The effect of earplugs during the night on the onset of delirium and sleep perception: A randomized controlled trial in intensive care patients. Critical Care, 16(3), R73.
Summary
The trial was run in the 45-bed intensive care department of a Belgian university hospital. Adults expected to stay more than 24 hours, with a Glasgow Coma Scale of at least 10, were randomized to foam earplugs worn from 2200 to 0600 or to no earplugs, for up to five nights. Patients who were sedated, delirious on admission, hearing impaired or known to have dementia were excluded. Delirium and confusion were assessed three times a day with the NEECHAM Confusion Scale, and sleep was rated each morning with five yes or no questions. Of 221 eligible patients, 136 were randomized, 69 to earplugs and 67 to control. The authors report that earplugs lowered the risk of delirium or mild confusion, with a hazard ratio of 0.47, 95% CI 0.27 to 0.82 (Van Rompaey et al., 2012). The appraisal follows the CASP checklist for randomized controlled trials (CASP, 2020), which groups eleven questions under four headings: whether the basic design is valid, whether the methods were sound, what the results are, and whether they will help locally.
Section A: Is the Basic Design Valid?
1. Did the study address a clearly focused question? Yes. Population, intervention, comparison and outcomes are stated, although two primary outcomes, delirium and sleep perception, are named.
2. Was assignment randomized? Yes. An independent nurse researcher assigned patients from a computer-generated list, and allocation was hidden in a nontransparent canister at the bedside holding either earplugs or a dummy. That arrangement is a real strength for a trial whose intervention cannot be disguised.
3. Were all participants accounted for at the conclusion? Can't tell. The flow of patients from eligibility to randomization is reported, and two patients died before the first assessment. But patients were followed for at most five nights and censored when they first scored positive, and most stayed only one night, so the trial accounts for patients mainly across a very short window.
Section B: Was the Study Methodologically Sound?
4. Were participants, investigators and assessors blinded? Partly. Patients could not be blinded; they knew whether they were wearing earplugs. The authors took care that assessors did not know: the night nurse inserted and removed the earplugs, while the NEECHAM was scored by day and evening nurses and a researcher who were asked not to be told. Patients and staff were instructed not to mention the earplugs. That is a reasonable design, but the NEECHAM includes observations of behavior, and a patient who says "I slept well with those plugs" would unblind the assessor.
5. Were the groups similar at the start? Mostly. Age, severity scores and nursing workload were similar. Two differences stand out: 65 percent of the earplug group were in intensive care for the first time against 45 percent of controls, and more of the earplug group were in paid work. Both could bear on cognition and resilience, and the direction of any bias is not clear.
6. Apart from the intervention, were the groups treated equally? Can't tell. The earplug group was observed for longer, 43 hours against 33, a difference the authors report as significant. Longer observation gives more chances to detect confusion, which would bias against earplugs, so this difference probably does not explain the benefit, but it is unexplained.
Section C: What Are the Results?
7. Were the effects reported comprehensively? Partly, and this is the critique's central finding. The trial named delirium as its primary outcome and was sized to detect a 20 percent reduction with about 46 patients per group. When results are separated by category, delirium itself was almost identical: 19 percent with earplugs and 20 percent without. The difference lies almost entirely in mild confusion, 15 percent against 40 percent, and the reported hazard ratio combines the two into "delirium or confusion." A reader of the abstract would reasonably conclude that earplugs prevented delirium; the table shows that they prevented a milder state, if anything.
8. Was the precision of the effect reported? Yes, for the combined outcome, with a hazard ratio and 95 percent interval from a Cox model adjusted for the patient characteristics in the baseline table. Variables entered the model stepwise, which risks overfitting in a sample of this size. No interval is given for delirium alone.
9. Do the benefits outweigh harms and costs? Probably. Earplugs are inexpensive, and no harms were reported. Sleep perception was better after the first night but not significantly so after the second.
Section D: Will the Results Help Locally?
10. Can the results be applied to our population? Only in part. The sample excluded anyone receiving sedation, which removes many of the patients at highest risk of delirium in a mixed ICU. The confusion scale used is not the CAM-ICU, which was validated for ventilated and nonverbal patients (Ely et al., 2001) and which most American units use, so results would not map directly onto our screening data.
11. Would the intervention provide greater value than current care? Possibly, as one part of a sleep bundle, but this trial alone does not show that earplugs prevent delirium.
Where the Trial Sits in the Wider Evidence
This trial matters beyond its own size because it is one of the few randomized studies of earplugs with a cognitive outcome, and it was among the studies pooled in a later meta-analysis that associated earplug use with a lower risk of delirium, a relative risk of 0.59 (Litton et al., 2016). A reader using that pooled figure should know that one of its randomized inputs measured delirium and mild confusion together and found no difference in delirium alone. The meta-analysis also judged all of its included studies to carry a high risk of bias, a finding consistent with the concerns raised here.
Verdict
Moderate trustworthiness for the combined outcome; low for delirium alone. The design has real strengths, especially concealed allocation and a serious effort at blinded assessment. Its weaknesses sit in how the outcome was defined and reported, in the short observation window and in the exclusion of sedated patients. The trial can contribute to a practice decision as evidence that earplugs may reduce early, milder confusion in alert ICU patients, and as a reason to include earplugs in a bundle that is then measured carefully. It cannot, by itself, support the claim that earplugs prevent delirium.
References
Critical Appraisal Skills Programme. (2020). CASP randomised controlled trial standard checklist. https://casp-uk.net/casp-tools-checklists/
Ely, E. W., Inouye, S. K., Bernard, G. R., Gordon, S., Francis, J., May, L., Truman, B., Speroff, T., Gautam, S., Margolin, R., Hart, R. P., & Dittus, R. (2001). Delirium in mechanically ventilated patients: Validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU). JAMA, 286(21), 2703-2710. https://doi.org/10.1001/jama.286.21.2703
Litton, E., Carnegie, V., Elliott, R., & Webb, S. A. R. (2016). The efficacy of earplugs as a sleep hygiene strategy for reducing delirium in the ICU: A systematic review and meta-analysis. Critical Care Medicine, 44(5), 992-999. https://doi.org/10.1097/CCM.0000000000001557
Van Rompaey, B., Elseviers, M. M., Van Drom, W., Fromont, V., & Jorens, P. G. (2012). The effect of earplugs during the night on the onset of delirium and sleep perception: A randomized controlled trial in intensive care patients. Critical Care, 16(3), R73. https://doi.org/10.1186/cc11330
How this NU504 Unit 5 example is structured
The critique appraises a published Belgian trial of nighttime earplugs and follows the CASP randomized trial checklist in its own order, answering each question yes, no or can't tell and defending the answer from the methods section. Its central finding comes under the results questions: the reported hazard ratio combines delirium with mild confusion, and delirium alone was almost identical between groups. Blinding by a closed bedside canister is credited as a strength, and the short observation window, baseline differences and the exclusion of sedated patients are weighed against it. A section places the trial in the later meta-analysis that pooled it, and the verdict separates moderate trustworthiness for the combined outcome from low trustworthiness for delirium.
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Which article has your section assigned, or did you pick your own? Its full text or citation, the Unit 5 instructions and rubric, and the appraisal tool named, whether CASP, JBI or another, will do. The critique returns answered item by item from the methods section. First custom sample free, with delivery in 24-48h. The paper above is an original model document written by our desk, not a submitted student paper and not an official Purdue University Global document.
NU504 Unit 5 questions, answered
Why does blinding the outcome assessor matter so much here?
Because delirium screening involves judgment. A nurse who knows a patient wore earplugs overnight may, without intending to, read an ambiguous inattention test more generously. When participants cannot be blinded, as with earplugs, blinding the people who measure the outcome is the main protection left, and its absence is usually the most serious bias in trials of this kind.
What is allocation concealment, and how is it different from blinding?
Concealment protects the assignment before enrollment: the person enrolling a patient cannot know or influence which group comes next. Blinding protects the trial after assignment, by keeping participants, clinicians or assessors unaware of group. A trial can conceal allocation well and still be unblinded, as earplug trials must be. Central randomization by phone or web is the usual gold standard for concealment.
Can a critique conclude that a flawed study is still useful?
Yes, and the stronger ones often do. Few trials are free of bias, and the question is whether the flaws are large enough to overturn the finding or only to widen the uncertainty around it. A verdict such as promising but not decisive, with the reasons stated, is more useful to a later synthesis than either uncritical acceptance or blanket rejection.