NR 516 Week 4 Design Identification Exercise Example

Design Identification Exercise: Three Studies on Flushing Peripheral Catheters, the Label Each Uses, the Name Its Methods Actually Force, and the Sentences That Force It

Student Name

College of Nursing, Chamberlain University

NR 516: Basic Research and Evidence-based Practice

Instructor Name

Month Day, Year

Design Identification Exercise: Three Studies on Flushing Peripheral Catheters, the Label Each Uses, the Name Its Methods Actually Force, and the Sentences That Force It

How the Exercise Works

For each of three studies found in the Week 2 search, this exercise records the design the authors name on the title page, then reads the methods section for the sentences that decide what the design really is. The design is then named in ordinary research language, and the deciding sentences are quoted or closely paraphrased so the label rests on the paper rather than on the authors' choice of words. Where the title and the methods agree, that is noted too; agreement is not the same as precision. Table 1 summarizes the results, and the sections that follow give the reasoning.

Table 1

Title-Page Labels Compared With the Designs the Methods Support

Keogh et al. (2016): The Label Is Right, and Pilot Is the Word That Matters

The title calls this a pilot, factorial randomized controlled trial, and the methods support each word. Randomized: patients were allocated by a centralized web-based service in a 1:1:1:1 ratio to four groups. Factorial: the four groups cross two volumes, 3 and 10 mL, with two frequencies, every 6 and every 24 hours, so each patient contributes to both comparisons. Controlled: each intervention is compared with an alternative, not with no treatment, since every patient received some flushing (Keogh et al., 2016).

The word that most changes how the study should be read is pilot. The methods state that the outcomes were collected to establish the feasibility of the protocol, and the discussion reports that, calculated afterward, the trial had 40% power to find a volume effect and only 14% for a frequency effect. A trial with that little power is not designed to answer the clinical question, whatever its p-values show. A reader who skipped the word pilot would take a nonsignificant result as evidence of no difference, which the trial cannot support.

One further design detail is forced by the methods though not by the title: the trial was not masked. The article states that the flush orders could not be hidden from patients, clinical staff or research nurses. That places it among open-label trials, with the risk of biased outcome assessment that the authors themselves acknowledge.

Schreiber et al. (2015): Randomized, but the Title Hides the Question It Asked

The title says only that this was a randomized controlled trial, and the abstract confirms that children aged 1 to 17 were randomly assigned to saline flushing every 12 hours or every 24 hours. What the title does not say, and the methods do, is that the trial was designed to test noninferiority. The authors set a noninferiority margin of minus 4% for catheter patency before the trial, and they report that the difference in patency was 3.1 percentage points in favor of the 24-hour group, with a 95% confidence interval of minus 1.6% to 7.7% (Schreiber et al., 2015). Because the lower limit of that interval did not cross minus 4%, they concluded that once-daily flushing was not worse.

Naming the design correctly matters because a noninferiority trial answers a different question from a superiority trial. It asks whether a simpler or cheaper option is acceptably close to the usual one, not whether it is better. The authors' own conclusion, that one flush per day maintains patency without more complications, is exactly the claim a noninferiority design can make. A reader who called it simply a randomized trial might expect it to show that less flushing is better, which it did not attempt.

Xu et al. (2024): A Framework in the Title, a Descriptive Design in the Methods

The title calls this a qualitative study built on a behavior change framework, which names the theory rather than the design. The methods name the design directly as qualitative descriptive. Participants were chosen by purposive sampling, and 25 nurses and doctors from two Australian emergency departments took part in one-to-one semistructured interviews between February and August 2023, face to face or online, lasting 15 to 60 minutes. Interviews stopped when the team agreed that data saturation had been reached. The analysis began deductively, coding to existing behavior change frameworks, and then allowed themes to emerge inductively (Xu et al., 2024).

Qualitative descriptive is the right name because the study describes participants' accounts of barriers and facilitators in terms close to their own words, without building a new theory, as grounded theory would, or interpreting lived meaning in depth, as phenomenology would. The behavior change framework shapes the analysis but does not change the design.

What the Exercise Shows

All three titles were accurate as far as they went. The design names that the methods force were more precise in each case, and the precise name changed how the findings should be used. The adult trial is a feasibility study that cannot settle the flushing question. The pediatric trial tested whether once-daily flushing is acceptably close to twice daily, and it concluded that it is. The qualitative study describes why clinicians may not follow standards, which bears on how a change in our unit's flushing routine would be introduced, not on whether it should be.

The exercise also warns against sorting studies into an evidence hierarchy by label alone. On a typical hierarchy, both trials would sit above the qualitative study, and the adult trial would seem the strongest source for an adult unit. Read by design, the adult trial is the weakest of the three for answering the clinical question, because it was never powered to answer it, while the pediatric noninferiority trial answers a narrower question well but in a different population. A study's place on any hierarchy follows from its purpose, and the methods section is where that purpose is fixed.

References

Keogh, S., Flynn, J., Marsh, N., Mihala, G., Davies, K., & Rickard, C. (2016). Varied flushing frequency and volume to prevent peripheral intravenous catheter failure: A pilot, factorial randomised controlled trial in adult medical-surgical hospital patients. Trials, 17(1), Article 348. https://doi.org/10.1186/s13063-016-1470-6

Schreiber, S., Zanchi, C., Ronfani, L., Delise, A., Corbelli, A., Bortoluzzi, R., Taddio, A., & Barbi, E. (2015). Normal saline flushes performed once daily maintain peripheral intravenous catheter patency: A randomised controlled trial. Archives of Disease in Childhood, 100(7), 700-703. https://doi.org/10.1136/archdischild-2014-307478

Xu, H., Bowdery, J., To, Y., Duff, J., Griffin, B., Ullman, A. J., Rickard, C. M., & Plummer, K. (2024). Peripheral intravenous catheter clinical care standard adherence in emergency departments: A qualitative study underpinned by the behaviour change wheel. Journal of Advanced Nursing, 81(11), 7659-7673. https://doi.org/10.1111/jan.16409