Objectively Measured Physical Activity and Cognitive Function in Older Adults

Title

In a research article, the title is the first section that a reviewer interacts with. The reader can identify the content of the article by reading the title. Therefore, the title should comprehensively identify key variables and the population under study. The title of the article under review is efficient and adequately identifies the key variables, physical activity, and cognitive function, as well as study population, which is older adults. However, the title fails to identify the outcome of the study. However, the reviewer can establish the goal of the study through the title.

Abstract

The abstract is a clear and concise summary of the article content. The reviewer should understand the idea of the content, as well as the main sections of the study, by reading the abstract. The abstract contains a summary of the main features of the report, purpose, methods, results, and conclusions. The purpose of the study was to establish the effect of cognitive function on physical activity among older adults. The methods were a cohort study of older adults. The study revealed “a dose–response relationship between MVPA% and cognitive function in older adults, with higher levels associated with a 36% or lower risk of cognitive impairment and better maintenance of memory and executive function over time, particularly in White adults” (Zhu et al., 2016, p. 47).

Introduction

The introduction provides the background of the study, including the statement of the problem. The problem under study is clearly and unambiguously stated: the increased rate of cognitive impairment, including various types of dementia, as an individual age, causing negative health outcomes. The problem builds a convincing basis for the current study because it shows the need to understand the potential causes of the health problems related to cognitive impairment and the possible role of physical activity in improving the health of older adults. The problem is significant to nurses because of their role in providing care to aged patients who have major health problems associated with cognitive impairments. A quantitative approach is appropriate for the research problem because of the need for objective quantitative data to establish the causal relationship between physical activity and cognitive function.

Hypotheses or Research Questions

The nature of data collected for a study depends on the hypothesis or research question. Researchers collect and analyze data to test a hypothesis or answer a research question. The study has a hypothesis emerging from a review of previous research on the topic, which entails“engagement in physical activity (PA) can positively influence the health of older adults and reduce the risk of many chronic diseases” (Zhu et al., 2016, p. 47). The hypothesis is properly worded with an indication of the key variables and identification of the study population. The hypothesis is consistent with the literature review and directly emerges as part of the review and identification of the need for further study.

Literature Review

The review of literature plays a significant role in identifying the research that has been conducted on the topic. It shows the gaps in research that can be filled through the current study. Therefore, the reviewed literature should be recent to inform the study. Although the review includes mainly primary sources, many are not up-to-date because they were published before 2006, which means they were more than ten years old when the article was published in 2016. However, they are relevant to the topic and provides a state-of-the-art synthesis of evidence on the problem. It shows the outcomes of previous studies on the topic of physical activity and cognitive function. The literature shows current gaps, such as differences in the effect of physical activity on cognitive function across racial groups, justifying the current study.

Conceptual/Theoretical Framework

The article provides the conceptual definition of important concepts in the study. The section contains a definition of the participants (Black and White older adults), “Reasons for Geographic and Racial Differences in Stroke (REGARDS), study measures (ActicalTM (Mini Mitter Respironics, Inc., Bend, OR), cognitive function, sedentary behavior (SED), light-intensity PA (LPA), and moderate-to-vigorous intensity PA (MVPA) and proportions of total accelerometer wear time spent in SED (SED%), LPA (LPA%), and MVPA (MVPA%))”, and statistical analysis (Zhu et al., 2016, p. 48). The study does not have a clear conceptual/theoretical framework, rationale, and/or map. Besides, it lacks justification for the lack of the conceptual framework.

Method/Protection of Human Rights

The method of the study is identified, including the subjects used for the data collection process. The correct safeguards were used to protect the rights of the participants. For example, patients were requested if they would be willing to wear an accelerometer and complete a daily activity log for a week. The study was approved by IRB “Arizona State University, University of South Carolina, and the University of Alabama at Birmingham” (Zhu et al., 2016, p. 48). However, the article does not include the measures taken to minimize risks and maximize benefits to participants.

Research Design

The research design shows how the data was collected to test the hypothesis or answer the research question. The study used a rigorous research design aligned with the purpose of the study. The cohort study was centered on the “Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a national longitudinal study of Black and White older adults” (Zhu et al., 2016, p. 48). The research used apposite comparisons to make the data easily interpretable, such as the connection between PA and cognitive function. The Six-Item Screener (SIS) was used in the study as one suitable data collection point. The research was a baseline study designed in a way that minimized biases and threats to validity.

Population and Sample

The population of the study provides the sample from which the data is collected to test the hypothesis or answer the research question. The population for the study is indicated and its characteristics, Black and White older adults. The report includes a sample of 6452 people with  30.5% Blacks and 55.3% women. The sample was obtained purposively using older adults, enrolled in January 2003 to October 2007 in the U.S. Hence, researchers did not use deliberate means to minimize bias. The sample was adequate to provide reliable findings but did not include a power analysis for estimating the sample size.

Data Collection and Measurement

The researchers used consistent operational and conceptual definitions of key terms. The key variables were adequately operationalized using a computer-assisted telephone interview by trained interviewers. The method was important to collect follow-up information from the REGARDS study. The study used appropriate instruments that are adequately described and suitable for the study, including interviews, ancillary accelerometer, daily activity log, and Six-Item Screener (SIS). The study reveals that the data collection methods provided reliable and valid information to inform the findings.

Procedures

The study did not include an intervention, but a longitudinal study of racial differences in stroke mortality. However, the study is adequately described from the enrollment into the study and the process used to collect follow-up data, including telephone interviews. The study procedure was rigorously developed and implemented. The participants were enrolled in the program, but they did not receive any intervention. The idea of intervention fidelity was irrelevant for this study. Data was collected in a manner that reduced bias because they involved interviews with well-trained interviewers. They effectively used computer-assisted telephone interview to collect objective data from the participants.

Results: Data Analysis

Statistical analysis of the data included the use of ANOVA or chi-square tests. The analysis was conducted for the hypothesis as well as for the independent variable of MVPA% and dependent variable, and incident cognitive impairment using the SIS score. The study used suitable statistical methods, considering the level of measurement of the variables, several groups being compared, and assumptions of the tests. The study used SIS score and z-scores for the variables. ANOVA or chi-square tests were powerful analytic methods used. The study did not indicate any means of avoiding or minimizing Type I and Type II errors. The study was not based on the intervention; hence, it did not include an intention-to-treat analysis. The missing data was not mentioned in the study.

Findings

The findings indicated “demographics, accelerometer data, and cognitive function status” findings (Zhu et al., 2016, p. 49). The report includes information on statistical significance, including MVPA%. However, the researchers omit information regarding the effect of size and estimates’ precision. The report has an adequate summary of findings in the section titled RESULTS. In essence, the summary includes tables and figures that are easy to follow. The findings are presented in a way that facilitates a meta-analysis, and with sufficient information needed for evidence-based practice. The information can be incorporated into future studies and practice.

Discussion

The article has a section titled, discussion, which includes major findings interpreted and discussed within the perspective of the previous research and evidence. However, the study lacked a conceptual framework to inform baseline data of a cohort. Causal inferences are identified and discussed in the study, such as the role of physical activity in improving cognitive function and reducing cognitive impairment. The study was interpreted in a well-founded and consistent way in line with limitations, such as the utilization of hip-worn accelerometers that failed to adequately identify the kinds of physical activity or recognize the movements of upper-body. The report addresses the issue of the generalizability of the findings, suggesting that the results may not be generalizable.

Implications/Recommendations

Clinical studies are useful if they apply to clinical practice or inform future research. Regardless of the aspect that the study revealed a relationship between physical activity and cognitive function in older adults, conflicting results in the research limit its applicability to practice and indicate the need for further exploration of the effect of the SED on cognitive changes. The article lacks comprehensive and reasonable implications for future research and practice. There is a need for further research to make the research applicable.

Global Issues/Presentation

The presentation of a research report plays an important role in its usability. The report is well-written, organized, and sufficiently detailed for critical analysis. It includes well-laid-out sections that are easy to follow from the abstract to the conclusions. It is not an intervention study; therefore, it lacks a CONSORT flow chart to show the flow of participants in the study. The findings of the study are highly accessible and easy to follow for practicing nurses. The findings are presented in tables and graphs. Therefore, any reader can easily read and interpret the information from the tables and as interpreted in the text.

Researcher Credibility

The credibility of the researchers is well-established at the beginning of the report. It includes the clinical, substantive and methodological qualifications of the researchers. The information helps to enhance their credibility. The study was conducted by six researchers, Wenfei Zhu, Virginia G. Wadley, Virginia J. Howard, Brent Hutto, Steven N. Blair, and Steven P. Hooker. The academic qualifications and current institutional affiliations are indicated for each of the six researchers. “Zhu is affiliated to School of Physical Education, Shaanxi Normal University, Xian, Shaanxi, CHINA, Wadley with Department of Medicine, School of Medicine, the University of Alabama at Birmingham, Birmingham” (Zhu et al., 2016, p. 47).

Howard is based on “Department of Epidemiology, School of Public Health, the University of Alabama at Birmingham, Birmingham, while Hutto is on prevention Research Center, Arnold School of Public Health, University of South Carolina, Columbia, SC, Blair with Departments of Exercise Science and Epidemiology/Biostatistics” (Zhu et al., 2016, p. 47). Finally, Arnold is in the School of “Public Health, University of South Carolina, Columbia, while SC, and Hooker are based on Exercise Science and Health Promotion Program, College of Health Solutions, Arizona State University, Phoenix, AZ” (Zhu et al., 2016, p. 47). From the list, it is evident that those researchers are credible scholars in their respective fields of study.

Summary Assessment

Regardless of the limitations of the study, the findings appear valid and applicable to further research and practice. I have confidence in the value of the results, which reveal the positive effect of physical activity on cognitive function as well as preventing cognitive impairment. The study is a source of meaningful evidence that can be used in nursing practice and also in the nursing discipline. The results can provide evidence for the enhancement of physical activity for health improvements such as the prevention of dementia and other health conditions, including stroke.