Table 6 Critical appraisal criteria to assess studies in the full text stage
Factor | Low | Medium | High |
|---|---|---|---|
Study design | Experimental studies (includes also quasi-experimental studies) | Observational studies | Case studies |
Sampling | Large sample size Sampling method suitable for the population of interest Properly conducted randomisation of study areas Random sampling of study subjects Control and intervention areas matched | Small to medium sample size Sampling method suitable for the population of interest Control and intervention areas comparable based on their ecological characteristics | Sampling method not suitable for collecting data on the population of interest |
Accounting for heterogeneity and potential effect modifiers | Effect modifiers identified, and data collected on them | Effect modifiers identified and considered in relation to the results | Effect modifiers not identified or considered |
Data analysis methods | Methods appropriate | Methods appropriate | Methods not appropriate |