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Critical Appraisal of Quantitative and Qualitative Research in Health Practice
Introduction
The ability to critically appraise research is fundamental for evidence-based health practice. Appraisal allows practitioners to assess methodological rigour, evaluate reliability and validity, and determine the applicability of findings to practice (Polit & Beck, 2017). This paper critically appraises two peer-reviewed studies: one quantitative and one qualitative, using appropriate critical appraisal tools to evaluate strengths, limitations, and implications for healthcare practice.
Article 1: Quantitative Research
Study Identification
The quantitative study selected is a randomized controlled trial (RCT) examining the effectiveness of a nurse-led intervention to reduce hospital readmissions in patients with chronic heart failure (Smith et al., 2020).
Critical Appraisal Tool
The CASP Randomised Controlled Trial Checklist (Critical Appraisal Skills Programme, 2018) was selected because it provides structured guidance for evaluating RCTs, including study validity, bias, and applicability.
Strengths of the Study
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Randomisation reduced selection bias and improved internal validity.
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Clear inclusion and exclusion criteria enhanced reproducibility.
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Use of objective outcome measures (readmission rates) increased reliability.
Limitations of the Study
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Sample size was relatively small (n=80), limiting generalisability.
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Blinding of participants was not possible, introducing potential performance bias.
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Short follow-up duration (3 months) may not reflect long-term effectiveness.
Implications for Practice
The study provides evidence that nurse-led interventions can reduce hospital readmissions. Practitioners can consider incorporating structured discharge planning and follow-up strategies while acknowledging limitations in sample size and follow-up duration.
Article 2: Qualitative Research
Study Identification
The qualitative study selected explored the lived experiences of breastfeeding mothers managing postnatal depression (Jones et al., 2019). A phenomenological approach was used to understand the emotional and practical challenges faced by participants.
Critical Appraisal Tool
The CASP Qualitative Checklist (Critical Appraisal Skills Programme, 2018) was chosen because it provides structured evaluation of qualitative research, including credibility, relevance, ethical considerations, and clarity of findings.
Strengths of the Study
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Use of in-depth semi-structured interviews facilitated rich, detailed data.
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Clear description of analytical process enhanced credibility and transparency.
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Ethical approval and informed consent processes were robust.
Limitations of the Study
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Small sample size (n=12) limits transferability to broader populations.
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Researcher reflexivity was not fully addressed, potentially influencing interpretation.
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Findings are context-specific and may not be generalisable to mothers outside the study setting.
Implications for Practice
The study highlights the importance of psychosocial support for breastfeeding mothers with postnatal depression. Health practitioners can implement tailored support programs and enhance communication strategies to improve maternal wellbeing.
Comparative Discussion
Quantitative studies provide numerical evidence and facilitate generalisability, while qualitative studies offer in-depth understanding of patient experiences (Polit & Beck, 2017). Critical appraisal tools, such as CASP checklists, provide structured frameworks to evaluate methodological quality, ethical adherence, and applicability to practice. Integrating findings from both research types supports comprehensive evidence-based decision-making in healthcare.
