EBVM Toolkit 7: cross sectional study checklist

Introduction

Critical appraisal is a process which is used to help you identify the strengths and weakness of a research paper.  Understanding how appropriate the study design is for the question you are seeking to answer, how well the study was carried out, and how good the reporting in the paper is helps you to assess whether the paper is likely to provide reliable evidence.  

This page is designed to help you appraise the report of a cross sectional study. Answering the questions will help you to reflect on how valid the results might be, how well reported they are and whether they are applicable to your local circumstances.

Cross sectional study checklist

For each question think about whether the answer is yes, no or not sure and what your reasoning is for that answer.

1. Did the study address a clearly focused issue?

Think about whether there is there a clear question. Can you identify the PICO?

2. Was an appropriate method used to answer the question?

Is the use of a cross sectional study method appropriate?

3. Were the subjects recruited in an appropriate way?

Did the subjects represent a defined population? Was there a reliable system for selecting the subjects? Was the sample representative of a defined population?

4. Were outcomes accurately measured to reduce bias?

Were the measures objective or subjective? Does it matter? Were the measures appropriate and validated?

5. Was the data collected in a way that addresses the research issue?

Can you tell how the data were collected e.g use of interviews, questionnaire, and professional diagnosis? Were the methods explicit?

6. Was the study large enough to be sure of a reliable result?

Look for confidence intervals, very wide confidence intervals should raise concern. Was a power calculation carried out to estimate how many subjects would be needed?

7. How are the results presented and what are the main results?

Are results presented as a proportion or relative risk or are they mean or median differences? How large is it? What is the bottom line result?

8. Was the data analysis rigorous?

Is there a description of what was done? Is there enough data to support the bottom line?

9. Is there a clear statement of findings?

Is there a discussion on the meaning and credibility of the findings? Are the findings put into the context of the original research question?

10. Can the results be applied to your local population?

Are the subjects similar to your population? Does your setting differ significantly? Can you gauge benefit and harm for your local situation?

11. Do the results fit with other available evidence?

Consider evidence from other study designs for consistency.

Try it out yourself

You could use the following paper to try out the questions:

Wylie, C.E. et al (2013) Demographics and management practices of horses and ponies in Great Britain: a cross-sectional study. Research in Veterinary Science, 95 (2), pp 410-417. DOI: https://doi.org/10.1016/j.rvsc.2013.05.004