The
Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies
in meta-analyses
Nonrandomised studies, including case-control and cohort
studies, can be challenging to implement and conduct. Assessment of the quality
of such studies is essential for a proper understanding of nonrandomised
studies. The Newcastle-Ottawa Scale (NOS) is an ongoing collaboration between
the Universities of Newcastle, Australia and Ottawa, Canada. It was developed
to assess the quality of nonrandomised studies with its design, content and
ease of use directed to the task of incorporating the quality assessments in
the interpretation of meta-analytic results.