9 Five of the six studies evaluating the efficacy of humour therapy in nursing home residents reported some benefit, 10 15 albeit limited by small sample sizes, relatively low-quality methodology and lack of flexibility in matching humour techniques to residents' abilities and preferences.
Furthermore, the small trials were of low quality in methodology compared with large trials, which may partly account for the small-study effects.
However, knowledge on this topic is still preliminary, as demonstrated by the presence of low quality studies due to weak methodology, small number of patients and short-term follow-up.
Four RCTs were considered to have a good quality methodology score (≥50), and three RCTs had a low score.
One point was awarded for the specification of each of the above criteria; the maximum score for a study is 5. High quality RCTs score more than 2 points, while low quality RCTs score 2 or fewer points, according to the reported methodology.
According to the GRADE system of classification of evidence sources [ 90], randomised controlled trial methodology automatically assumes the highest evidence grade, with observational studies low quality and other forms of evidence very low.
Our application of GRADE methodology led us to conclude that the accumulated evidence is of low quality for mortality and neurological outcome.
This paper describes the methodology of building a predictive model for the purpose of marine pollution monitoring, based on low quality biomarker data.
Two studies was defined low quality [ 20, 23], while seven studies were high quality [ 11– 14, 21, 22, 24, 25], suggesting acceptable methodology quality.
Methodology in all the studies included scored less than 6 points, scoring all of them as low quality (Table 2).
They are also generally low quality.
