Quantitative Research Critique by Rae Walker, PhD RN FAAN (they/them)

Emefa

2023-05-02 18:41:29 UTC

When critiquing the choice of variables ad measurement strategies, there are some key considerations to keep in mind. These considerations include validity, reliability, operational definitions, and appropriateness of the variables and measurement strategies.

For this article titled “Daytime-to-Nighttime Sleep Ratios and Cognitive Impairment in Older Intensive Care Unit Survivor”, I would focus on critiquing the author's choice of variables and measurement strategies using these key considerations. The variables used in this study were categorized into two- retrospective data and prospective data. Retrospective data included demographic characteristics, history of obstructive sleep apnea, baseline sleep quality, and ICU severity of illness. Prospective data included daytime sleep(actigraphy), daytime-to-nighttime sleep ratio(actigraphy), cognitive flexibility, and grip strength.

Reliability: The scales used to measure the variables of interest demonstrated high reliability with Cronbach's alpha. The Katz Index of Activities of Daily Living, and Dimensional Change Card Sort Test(DCCST) had Cronbach alpha coefficients ranging from 0.87 to 0.94 and 0.82 to 0.92 respectively which indicated that the instruments were reliable. The Katz Index of Daily Living is an easy-to-administer instrument and has been used in a variety of clinical and research settings, its reliability and validity have been proven to be good in measuring the functional status of older adults and individuals with disability. Therefore, it could be used to measure the functional status of the study population without the researcher indicating how the reliability and validity were established. The reliability of the other measurements including the Dimensional Change Card Sort Test(DCCST), Pittsburg Sleep Quality Index(PSQI), and Grip Strength Test(GST) which were used to measure cognitive flexibility, sleep quality, and grip strength were mentioned by the author. The reliability of these scales was good to excellent.

Overall, the instruments used to measure different variables in this study were reliable.

· Validity: The DCCST had good construct validity. The PSQI has been validated in both older men and women. The authors did not mention the validity of the other scales used to measure the other study variables.

· Operational definitions: The operational definition of each variable was provided in the measures and procedure session. This would ensure that readers either experts or non-experts in the area of cognitive impairment and sleep ratio understand what is meant by the terms and concepts that are used in this research.

· Appropriateness: From the literature review and operational definition of the variables and the rationale for the selection of measurement scales, we can determine that the measurement strategy was appropriate in measuring the variables of interest.

2023-05-02 18:42:17 UTC

-The discussion of the findings clearly and concisely summarizes the study's main findings in the beginning of the sentence where it says the study reveals the greater post-ICU daytime sleep duration was significantly associated with cognitive impairment. The discussion of the findings flow logically from the data and can be related to the lit review to a greater extent.
-The authors' interpretations of the results are well supported by the data presented in the study. The figure used which is a table also gives a clear picture of the results accompanied by the narration in the discussion section.
- The authors' conclusions are quite logical and reasonable based on their analysis of the data. The authors conclude that they found significant association between greater daytime sleep duration and post-ICU cognitive impairment in a cohort of older ICU survivors.
- The authors addressed the actual limitations of the study as lacking the pre-ICU cognitive assessment or baseline self-report which could have helped provide prognostic information about the likelihood of older adults maintaining independence after critical illness. Limitation to do with small sample size was not properly highlighted as a limitation of the study claiming that the small sample size was able to give out the results as desired. Suggested avenues for future research was also not given which was not great.
- The authors' implications of the findings for clinical practice are well-supported and plausible. The relevance reflected a clinical significance and relevance.
-I don’t see how theoretical conceptual framework is incorporated in the research study.

Results:

2023-05-02 18:46:32 UTC

miaomiaoshen — 2023-05-02 18:51:47 UTC

The target population has been clearly identified, they were hospitalized older ICU survivors (aged ≥65 years) who were functionally independent before hospital admission, had no preexisting diagnosis of dementia, and required mechanical ventilation (≥12 hours) while in the ICU.

The setting was all 12 medical-surgical floors of a level I trauma hospital.

Participants were selected through convenience sampling between November 2017 and January 2018. It was a non-probability sampling.

The sample size was 30. For correlational studies, 30 participants are sufficient to create a representative sample size. However, it would be more accurate to calculate the sample size based on the formula.

The inclusion/exclusion criteria were dearly identified.

Inclusion criteria: previously community-dwelling adults (i.e., admitted from home), aged 65 years or older, able to speak English, functionally independent before hospital admission (Katz Index is 6).

Exclusion criteria: imminent death, active palliative care or hospice orders, history or suspicion of preexisting dementia on medical record review.

Conclusion & implications

2023-05-02 18:53:14 UTC

Strengths:

1. The results have been presented in accordance with the study's objectives and purposes.

2. The researchers have acknowledged study limitations, including the lack of pre-ICU cognitive assessment or baseline self-report, as well as the potential inaccuracies in using actigraphy to measure sleep duration.

3. As a result, there is a need for a more robust longitudinal cohort study that utilizes polysomnography to further investigate these issues.

4. Applying finding in practice is suggested depend on the purpose of the study “ WE propose that improving post-ICU sleep may help prevent or mitigate post-ICU cognitive decline and thus may reduce symptom burden and health care costs among older ICU survivors.”

Limitations:

1. The information presented in the conclusion section appears to be more appropriate for the discussion section, particularly the first three sentences.

2. Although the design and sample size of the study may not support generalizability, the statement 'health care providers in post-ICU units should promote daytime activity and mobility while attempting to optimize nighttime sleep' suggests that the researchers attempted to generalize their findings.

The conclusion section does not offer any significant or relevant suggestions for future research in the area

2023-05-02 18:53:32 UTC

Used appropriate measurements:
descriptives to ration of daytime-night sleep - used means
regression models to measure relationship between sleep and cognition

showed P-values= .001 and R coefficients = <0.8 statistically significant.

Results were aligned with aims except
for Aims 1 was looking at sleep duration and cognitive impairment, whereas the results are specifically focused on daytime sleep and cognitive impairment- is that true to the original aim?

They used appropriate charts to demonstrate results.

Enrolled: 30 participants

26 participants completed the data (Greater than 50%, so this is a good response rate to minimize response bias)

The research design was mentioned, which was an exploratory study, and used cross-sectional design. The protocols of their experiments were discussed. They offered explanations of why they did what they did, and how they did. The instruments that were employed for the study were mentioned and explained in detail. Overall, all the stages of their experiment were described. They should have used 2 or more than 2 groups which they did not. Their sample was randomly assigned. Everyone received the same intervention. The cause and effect relationships were discussed

2023-05-02 19:03:30 UTC