Critical Appraisal of a Research Paper on the Association between Obstetric Complications and Risk of Schizophrenia

Running head: EPIDEMIOLOGY
Epidemiology
Name of the student:
Name of the University:
Author’s note

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Introduction:
Critical appraisal is the systematic process of review and analysis of research findings
based on research question and assessment of trustworthiness, value and relevance of research
for a particular context. Critical appraisal is an important skill to engage in evidence based
practice and find ideas for improvement in quality of care. It emphasized on the review of a
research paper to identify whether it can facilitate practice improvement and application in target
setting or not (Elwood, 2017). The main purpose of this report to conduct a critical appraisal of
the research by Byrne et al. (2007) and evaluate the research paper based on internal and external
validity and analyzes causal association between exposure and outcome.
Overview of the paper:
The main purpose of the research article by Byrne et al. (2007) was to investigate about
the risk of schizophrenia due to exposure to range of obstetric events. The paper is focusing on
the issue of obstetric complications (OC) like abnormal fetal growth, pregnancy complication
and complications of delivery. The paper justifies the need for conducting such study by giving
evidence regarding the risk of schizophrenia due to OC. The literature review suggested
prevalence of OCs during pregnancies and interaction of OCs with family history to increase risk
of schizophrenia. It also suggested lack of clarity regarding impact of OCs on schizophrenia risk.
The study was done in 2007 and the literatures between 1999 to 2002 were used to indicate gap
in past research and justify the rationale for doing the research. Current research literature
suggests that environmental and genetics factors play a role in etiology of schizophrenia. The
risk of schizophrenia increases due to perinatal factors like OC, environment and parental
influence on the fetus during pregnancy (Jenkins, 2013). The novel approach that the study took
was that to confirm the risk of the disease due to OCs, the study aimed to explore confound
effects of socioeconomic factors and family history of psychiatric illness. The study helped to
define whether parental aged, socioeconomic status, family history, place of birth and maternal
citizenship leads to development of schizophrenia or not.
Exposure or intervention for the study:

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Although the paper does not evaluate any intervention, however the main exposure that
the study is evaluating includes risk of schizophrenia due to exposure to OCS. The study
compared different demographic factors to predict risk of schizophrenia.
Study design:
The study used national population nested case-control study to investigate about the
impact of range of OCs in risk of schizophrenia. Nested case-control research design includes
that research design in which case and control groups are taken from a recognized cohort. The
case groups involved those sample groups which are exposed to exposure of interest and control
group consist of controlled case. The advantage of using this research design is that it
particularly measures time dependent variables. However, the disadvantages of nested case-
control study includes reduces precision and chances of flaws in the sample design (Breslow &
Weiss, 2018). Since the paper aims to evaluate exposure to OC, use of this design is appropriate.
The Danish national register was used to collect information on case population and control
population
Study population:
The study was based on two population group which is the case and control population.
The case population consisted of group who were exposed to OC and schizophrenia. From the
review of persons above 15 years visiting Danish psychiatric facility between 1981 and 1998,
total of 1039 persons with schizophrenia were identified. In addition, the criteria for selection of
control population include those who never visited psychiatric facility.
Main findings and future directions:
The review of result finding revealed no statistically significant association between
obstetric factors and family history of psychiatric illness was found. In addition, the comparison
of OC with other confounding factors revealed very moderate associated maternal behavior and
maternal infections on risk of later development of schizophrenia. The review of national
population data revealed that risk significantly increased when mothers revealed no previous
antenatal visits, experiences of premature deliver and sepsis of child birth. The paper did not
directly discussed about the key implications of the research findings. However, it suggested the