Critical Appraisal Methods
The usage of a good quality critical appraisal tool allows a structured approach to the assessment of the rigor of the studies being reviewed(20). The choice of an appropriate critical appraisal tool is considered to be an integral aspect of conducting a systematic review and of evidence-based practice (21). Additionally, it is important to identify that, due to the wide variation in critical appraisal tools that are available, the quality of the evaluation that results from a review when using different tools will also vary, even when applied to the same literature. Design-specific tools are tailored to highlight potential methodological issues or bias that is unique to the study design; therefore The Critical Appraisal Skills Programme (CASP) tools for cohort studies (qualitative and quantitative) were chosen. CASP is a reputable organisation whose tools are free and easy to access, making this review easily reproducible and minimising the potential for varied evaluations of these pieces of literature.