Table 4 Checklist of quality assessment and risk of bias evaluation of included studies according to Fowkes and Fulton [26]
From: Association of cerebral malaria and TNF-α levels: a systematic review
Checklist | Akinori et al., 2000 [62] | Armah et al., 2005b [53] | Cabantous et al., 2006 [54] | Kinra and Dutta , 2013 [31] | Kwiatkowski et al., 1990 [28] | Prakash et al.,2006 [32] | Sahu et al., 2013 [33] | Thuma et al., 2011 [29] | |
|---|---|---|---|---|---|---|---|---|---|
Is the study design appropriate to objectives? | Objective common design | ||||||||
Prevalence e Cross-sectional | |||||||||
Prognosis Cohort | |||||||||
Treatment Controlled trial | |||||||||
Cohort, case-control, cross-sectional | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Study sample representative? | Source of sample | 0 | 0 | 0 | ++ | 0 | 0 | 0 | 0 |
Sampling method | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Sample size | ++ | ++ | ++ | ++ | + | ++ | ++ | ++ | |
Entry criteria/exclusion | 0 | 0 | 0 | + | + | + | 0 | 0 | |
Non-respondents | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Control group acceptable? | Definition of controls | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Source of controls | 0 | 0 | 0 | ++ | 0 | 0 | 0 | 0 | |
Matching/randomization | + | ++ | + | + | + | + | + | + | |
Comparable characteristics | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Quality of measurements and outcomes? | Validity | 0 | ++ | 0 | 0 | 0 | 0 | 0 | 0 |
Reproducibility | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Blindness | ++ | ++ | ++ | ++ | ++ | ++ | ++ | ++ | |
Quality control | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Completeness | Compliance | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Drop outs | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Deaths | NA | NA | NA | NA | NA | NA | NA | NA | |
Missing data | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Distorting influences? | Extraneous treatments | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Contamination | NA | NA | NA | NA | NA | NA | NA | NA | |
Changes over time | NA | NA | NA | NA | NA | NA | NA | NA | |
Confounding factors | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Distortion reduced by analysis | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Summary questions | Bias: | ||||||||
Are the results erroneously biased in a certain direction? | NO | NO | NO | NO | NO | NO | NO | NO | |
Confounding: | |||||||||
Are there any serious confusing or other distorting influences? | NO | NO | NO | NO | NO | NO | NO | NO | |
Chance: | |||||||||
Is it likely that the results occurred by chance? | NO | NO | NO | NO | NO | NO | NO | NO |