NURS 225 Week 7 Research Critique Part 1 Example

Research Critique Part 1: Problem, Purpose, Literature and Hypothesis in a Trial of Clinically Indicated IV Catheter Replacement

The Article

This critique examines Kang et al. (2026), a non-inferiority, cluster-randomized crossover trial conducted on eight wards of a large tertiary hospital in South Korea, comparing routine replacement of peripheral IV catheters every 96 hours with replacement only when clinically indicated. I chose it because routine replacement is a practice I have watched cause repeated needle sticks, and the study tests whether stopping it is safe. Following the first part of the critique table in Boswell and Cannon (2017), this paper evaluates the title and abstract, problem, purpose, hypothesis, literature review, framework and variables.

Title and Abstract

The title names the comparison, the population and the design, which allows a reader to judge relevance at once. The structured abstract reports the design, dates, setting, sample size, primary outcome, non-inferiority margin, main results with a confidence interval and the conclusion. This is a strength: a nurse scanning the literature could assess the study's design and main finding from the abstract alone. One weakness is that the abstract does not mention that the trial was open-label, a design feature that matters for a subjective outcome such as phlebitis.

Problem and Significance

The authors present the problem clearly: catheter-related complications, especially phlebitis, threaten patient safety, and routine replacement became common in an effort to prevent them. They establish significance by noting that routine replacement adds patient discomfort and nursing workload and has been described in the Choosing Wisely campaign as potentially low-value care. The problem is relevant to nursing practice, since nurses insert, monitor and remove these catheters. The statement of the gap is narrower than it first appears: the authors argue that large-scale randomized evidence from Korean practice is scarce and that no cluster-randomized trial in that setting had tested dwell times beyond 96 hours. This is a legitimate gap, but it concerns applicability to a particular setting rather than an unanswered question in the field.

Purpose, Research Question and Hypothesis

The purpose, to evaluate the safety of clinically indicated compared with routine replacement in a Korean tertiary hospital, is stated in the final paragraph of the introduction. The research question is implied rather than written as a question, and the hypothesis is not stated in words; instead, the non-inferiority margin in the methods section expresses it: clinically indicated replacement would not increase phlebitis by more than 5 percentage points. Boswell and Cannon (2017) describe hypotheses as predictions of the relationship between variables, and readers would benefit from seeing the hypothesis stated directly. The margin itself is justified with precedent from earlier trials and the investigators' clinical judgment, which is a strength, although a 5-point margin is wider than the 3-point margin used in at least one earlier trial they cite, so a skeptical reader might ask whether a smaller increase in phlebitis was truly acceptable.

Review of the Literature

The introduction summarizes guidance from the CDC's 2011 infection guideline, the Infusion Nurses Society, the British NICE guidance and the Korean Hospital Nurses Association, notes inconsistent findings from earlier trials and cites the Choosing Wisely campaign. The review is current for guidelines but brief on trial evidence, describing earlier findings as "inconsistent" without summarizing them. Recent comparison sources suggest the picture is more settled than that word implies. Charles et al. (2026), updating a Cochrane review to include 14 randomized trials with 11,428 participants, found that clinically indicated removal likely makes little or no difference to bloodstream infection compared with routine removal, with low-certainty evidence because of bias and imprecision. Jiang et al. (2026) analyzed 1,805 older adults from a multicenter trial in China and found longer dwell times with clinically indicated removal. A fuller review would have positioned the Korean trial as confirming an established direction in a new setting, which is in fact its main contribution.

Theoretical Framework

No theoretical or conceptual framework is identified. For a pragmatic clinical trial testing a practice policy, this is common and does not weaken the design, but a framework such as a model of evidence-based practice or of catheter-related complications could have explained why dwell time might, or might not, increase phlebitis risk.

Variables and Definitions

The independent variable, the replacement strategy, is defined clearly for each arm, including the clinical reasons that trigger removal. The primary dependent variable, phlebitis, is operationally defined using the Infusion Nurses Society phlebitis scale, and secondary outcomes such as bloodstream infection follow published criteria. Clear operational definitions are a major strength, because they allow other researchers to replicate the measures. The first half of this article is strongest where it defines what it measured and weakest where it tells the story of the evidence that came before it.

Summary

Overall, the first half of the article is clear and well organized, with a focused problem, an appropriate purpose and precise definitions. Its weaknesses are an implied rather than stated hypothesis, a relatively wide non-inferiority margin and a literature review that understates the consistency of prior evidence. Part 2 will evaluate the design, sample, ethics, data collection, analysis and conclusions.

References

Boswell, C., & Cannon, S. (2017). Introduction to nursing research: Incorporating evidence-based practice (4th ed.). Jones & Bartlett Learning.

Charles, K. R., Schults, J. A., Marsh, N., Osborne, S. R., Rees, S., Mihala, G., Smith, S., & Rickard, C. M. (2026). Clinically indicated removal versus routine removal of peripheral venous catheters. Cochrane Database of Systematic Reviews, 2026(1), CD007798. https://doi.org/10.1002/14651858.CD007798.pub6

Jiang, X. Y., Wang, L. J., Wei, T., Li, X. Y., Tan, Y., Lin, Q., Yuan, Z., & Wang, T. Y. (2026). Clinically indicated versus routine replacement of peripheral intravenous cannulas in elderly patients: Secondary analysis of a multi-center randomized controlled trial in mainland China. Geriatric Nursing, 72, 104100. https://doi.org/10.1016/j.gerinurse.2026.104100

Kang, N., Kim, H. L., Choi, H. R., & Kim, J. (2026). Routine versus clinically indicated replacement of peripheral intravenous catheters in adults: A non-inferiority cluster-randomised crossover trial. Healthcare, 14(13), 1825. https://doi.org/10.3390/healthcare14131825