4b

Template for Article Critique Reports Week 4 – Assignment 4a – Barlow

Part Question Answer Points Title Title of the article, journal name, your

name Title (1): Association Between Sitting Time and Cardiometabolic Risk Factors After Adjustment for Cardiorespiratory Fitness, Cooper Center Longitudinal Study, 2010–2013 Journal (1): Preventing Chronic Disease Your name (1) 3

Purpose/Research problem

What is the purpose of the study? Is it clearly identified? Is the research problem important?

Primary goal To examine the association between sitting time and cardiometabolic risk factors after adjustment for cardiorespiratory fitness (CRF) (3) Secondary goals - To examine whether CRF confounded or modified the associations

between sitting time and cardiometabolic risk factors (1) - To explore whether the role of CRF differed by sex (1)

Yes the purpose is clearly identified (0.25 bonus). Yes, this is an important research problem given the high prevalence of extended sitting times in our society (deskwork, TVs, computers, video games, etc.) (0.25 bonus) 5

Identify the dependent variable(s) Cardiometabolic risk factors 3 Identify the independent variable(s) Sitting time 3

Literature review Are the cited sources relevant to the study?

Yes. 3

Does the literature review offer a balanced critical analysis of the literature?

Yes. 3

Are the cited studies recent? Yes. All are all from the past 10 years. 3 Theoretical framework

Has a conceptual or theoretical framework been identified?

No theoretical framework was identified. 3

If yes, is the framework adequately described?

Not applicable. 3

Design and procedures

Identify the study design used in this study?

Cross sectional 5

Is the study design appropriate to answer the research question?

Yes, given that the objective is to assess the association and not the causality. 3

What type of sampling design was used? Not clearly indicated but it seems like a convenience sample (no indication of random selection of participants or consecutive sampling) 5

Was the sample size justified on the basis of a power analysis or other rationale?

No, sample size was not justified on the basis of a power analysis. 5

Are the inclusion and exclusion criteria clearly identified?

Inclusion criteria - Adults (0.5) - Generally healthy Cooper clinic patients (0.5) - Receiving preventive medical examination (0.5) Exclusion criteria - personal history of cardiovascular disease (0.5), stroke (0.5), or

diabetes (0.5) - not reaching 85% of predicted maximal heart rate on the treadmill

test (1) - missing data on some of the covariates (1) 5

What measurement tools were used for the dependent variable(s)?

Cardiometabolic risk factors were measured using the following: - Body mass index: height measured on a stadiometer; weight on a

standard physician’s scale; BMI = weight in kilograms divided by height in meters squared; BMI of 30 kg/m2 or higher classified as obese (0.5)

- Waist girth measured with a plastic tape at the level of the umbilicus following a normal exhalation; elevated waist girth ≥102 cm for men and ≥88 cm for women (0.5)

- Percentage of body fat measured at 7 skinfold sites with calipers and inserting the sum of these skinfold measurements in a generalized body density equation to estimate percentage of body fat. Sex- specific cut points of percentage of body fat (<25% or ≥25% for men and <32% or ≥32% for women) were used to classify patients as obese (0.5)

- Lipids: o Elevated total cholesterol higher than 200 mg/dL (0.5) o Elevated LDL cholesterol higher than 100 mg/dL (0.5) o Low HDL cholesterol less than 40 mg/dL for men and less

than 50 mg/dL for women (0.5) o Elevated triglycerides ≥ 150 mg/dL; (0.5) o Elevated glucose if fasting blood glucose ≥100 mg/dL (0.5)

- Elevated blood pressure: defined as a systolic blood pressure 130 mm Hg or higher or diastolic blood pressure 85 mm Hg or higher, or both (0.5)

- Metabolic syndrome defined as meeting 3 or more of the following criteria: abdominal obesity; high triglycerides; low HDL; high blood pressure; and high glucose (0.5) 5

What measurement tools were used for the independent variable(s)?

Sitting time was measured by a question, assessing the proportion of time spent sitting during work, school, and housework during waking hours on a typical day (3.5). Response options were (1.5) 1) almost none of the time (about 0%) 5

2) approximately one-quarter of the time (about 25%) 3) approximately half of the time (about 50%) 4) approximately three quarters of the time (about 75%) 5) almost all of the time (about 100%).

Were validity and reliability issues discussed?

Dependent variables: measurements were taken according to standard (1) procedures by trained (1) technicians. This enhances the validity and reliability of the measures. Independent variable: Sitting time question was derived from the Canada Fitness Survey. However, that measure has not been validated (1). The reliability of the measure was not addressed (1). 4

Ethical considerations

Were the participants fully informed about the nature of the research?

Given the IRB approval, it is assumed that the participants were informed about the nature of the study. 3

Were the participants protected from harm?

Reporting on sitting time and having standard health measurements collected in a clinical environment is not likely to result in harm to participants. This is supported by the exempt status of the study, which implies that there is minimal risk associated with participation. 2

Was ethical permission granted for the study?

Yes. The Cooper Institutes institutional review board reviewed and approved the overall study. The study also received exempt status from the University of Texas Health Science Center at Houston’s Committee for the Protection of Human Subjects. 3

Data analysis What type of data and statistical analysis was undertaken?

Logistic regressions models adjusted for various covariates. 3

Was the statistical analysis appropriate to address the research question?

Yes. Logistic regressions allow for examining associations between sitting time and cardiometabolic risk factors. It also allows for the calculation of odds ratios.

Note: It is OK if the answer is not clear since evaluation of these advanced statistical analyses is beyond the scope of this course. 2

Results What are the results of the study? Did the results answer the research question(s)?

- Men: Prolonged sitting is associated with high levels of adiposity after accounting for cardiorespiratory fitness. Other cardiometabolic risk factors (elevated lipids, blood glucose, triglycerides, and blood pressure; low levels of HDL; and the presence of metabolic syndrome) were not significantly associated with sitting time.

- Women: The relationship between self-reported sitting time and adiposity as well as with any individual cardiometabolic risk factor was not found. 5

Discussion Were the findings linked back to the literature review?

Yes. The authors critically explore the similarities and differences in findings between their study and the literature. 3

Did the authors identify study limitations? What were they?

The authors identify the following limitations: - Self-reported measure of sitting time has not been validated (1.5) 5

- Sample characteristics (healthy, non-Hispanic whites, well educated) are not representative of the population. This may limit the generalizability of the findings (1.5)

- Cross-sectional study design does not establish causality (2) Do you think the limitations are serious enough to impact the internal and external validity* of the study?

The limitations of the study do not pause a serious threat to the internal validity of the study (1.5). However, the homogeneous sample does pause questions about the generalizability of study findings to other population groups (minorities, people with health conditions, those with lower educational attainment, etc.) (1.5).

*From your Week 3 PPT slides: The validity of a study, in contrast to the validity of measurements, is the degree to which study results are accurate and well-founded, when account is taken of study methods, representativeness of study sample, and nature of the population from which it is drawn. - Internal validity (results are attributed to hypothesized effect and not

sample differences) - External validity (generalizability) 3

Overall What is your overall assessment of the *Answers may vary. assessment study? This study addresses a very important research question given our

society’s sedentary lifestyle that supports extended periods of sitting down. The large sample size supports the inferences made. However, there is a need to replicate this study in different population groups and to utilize a different research design that supports establishing causality rather than mere associations. 5

Total 100

Source: Coughlan M1, Cronin P, Ryan F. Step-by-step guide to critiquing research. Part 1: quantitative research. Br J Nurs. 2007;16(11):658-63.