Association between Breast Cancer and Sleep Determinants among Women of Western Australia: A Population-Based Case-Control Study

Epidemiology
Research Critique
General Description
The selected study is about investigating the association between breast cancer
and three sleep domains among Women of Western Australia through population-based
case control method. The basic construct of the article seems logical with adequate
reasonable headings. It is evident from the text that the paper is written in a easy,
logical, clear as well as understandable manner without any grammatical and
typographical mistakes.
Article critique
According to Polit (2016) critical appraisal is defined as the logical as well as
systematic way of evaluating the degree to which the described study-methods are
trust-worthy, relevant and adequate for its applicability in clinical practice1. The essence
of an appropriate critique lies in establishing a balanced appraisal. In this report, all the
research methods were carefully scrutinized for its positives, negatives, gaps and
consistencies to enable evidence based practice.
Title, abstract and keywords
The title should be clear and accurate and should describe the research. It
should not be too long, short or complicated but should be congruent with the text. It is
evident from the study with a clear and concise title that reflects what this study is
about.
1 Polit DF, Beck CT. Nursing Research: New Delhi; Lippincott Williams & Wilkins; 2016.
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Epidemiology
According to Moule (2013), the study’s abstract should render clear and
condensed information about the complexity of study and its applicability in nursing
practice2. It should outline the study problem, aim, methods, findings and conclusions
clearly which is evident in this study’s abstract, except few issues. It has not clarified
the focus of the research design (here, case control design). But, it details the problem
to be investigated by mentioning about the expected relationship between breast cancer
and sleep determinants. The study’s abstract provides concise description, accurate
synopsis as well as clear perception of the paper. They have given certain key words
such as case- control method, breast cancer, and sleep domains that are adequate and
appropriate.
Introduction, aims and objectives
The text suggests that the researchers have given an elaborate and clear
introduction that details the support evidences, need and objective of the study, which is
highly appropriate. The review of literature portrays the motivation of the researchers in
this study. The given worldwide and Australian statistics of breast cancer, ill-effects of
poor sleep, studies that predict direct and indirect linkage between the risk for
developing cancer and poor sleep, including a study that showed absence of
association between sleep’s quality & breast cancer, is highly acceptable and
appropriate. In 2017, Grove has suggested that the literatures used should be clear,
appropriate, recent, well-organized, summarized and comprehensive with correct
2 Moule P, Nursing Research; 2013 [Cited 2019 Oct 7]. Available from
https://books.google.co.in/books?isbn=1446293521
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Epidemiology
citations that are relevant to the study’s title, which is evidenced in this current study 3. It
is understood from the introduction that the study is original in concept. They stated a
clear, adequate and achievable aim as ‘to determine the association between breast
cancer and 3 aspects of sleep among women of Western Australia’ that follows logically
from the given literature. They have not stated any null hypothesis to predict relationship
between variables.
Materials and Methods
The researchers have selected case control design (a non-experimental design)
under quantitative research. It is employed to compare cases (clients having certain
problem requiring investigation) with control groups (similar type of clients without any
problem)4. In this study the authors have used this design as they cannot manipulate
the cause (variations in sleep domains) in western Australian women to test this
relationship with breast cancer. Additionally this design helps to test the association
between two groups (cases and controls), Therefore it is consistent with their aim as to
determine how variations in sleep domains is associated with the risk for developing
breast cancer.
3 Grove SK, Grey JR, Burns, N. Understanding nursing research: Building an evidence-
based practice. London: Elsevier; 2015
4 THS. Epidemiology- Glossary of Epidemiological and Statistical Terminology. Tropical
Health Solutions. . 2015 [Internet] (Cited 2019 Oct 7). Available from
http://www.tropicalhealthsolutions.com/statsglossary
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Epidemiology
Pilot study is performed to analyze the possibility of the study and redefine
research methods5. They too help in evaluating the adequacy of study instruments,
identifying problems of the study-design, determining how the samples are the
representativeness of the target population, reframing data gathering methods and data
analytic plan. They have not conducted pilot study being carried out in this study to test
the methodology.
Samples are the representatives of the entire population. They have selected
1,000 subjects as cases and 2,000 age-matched subjects as controls through the
calculation of expected number as well as recruitment rate of breast cancer women
along with the prevalence of exposure to shift work among women of Western Australia.
This shows that their selection of samples to both cases and control groups is
adequate.
In 2015, Gerrish has given that controls are the individuals who are similar to the
cases without condition (here, breast cancer)6. They are needed to compare with the
cases (persons with condition requiring analysis) to rule-out how breast cancer is
associated with sleep determinants. The researchers have selected controls as women
of Western Australia from the period of May ‘09 to July ‘11 through random selection
from electoral poll. They too have frequency matched the controls with the cases
(expected distribution) by 5 year age. It is noted from the text that there is no difference
5 Grove SK, Grey JR, Burns, N. Understanding nursing research: Building an evidence-
based practice. London: Elsevier; 2015.
6 Gerrish K, Lathlean J. The research process in nursing. Malden: John Wiley & Sons;
2015
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