Table 1 Quality assessment and scores of included studies using Downs and Black quality checklist
From: A systematic review of enteric dysbiosis in chronic fatigue syndrome/myalgic encephalomyelitis
Reference | |||||||
|---|---|---|---|---|---|---|---|
Armstrong et al. (2016) | Frémont et al. (2016) | Giloteaux et al. (2016) | Mandarono et al. (2015) | Rao et al. (2014) | Sheedy et al. (2010) | Shukla et al. (2009) | |
1 Objective of the study clearly described | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
2 Outcomes of interest clearly stated | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
3 Patient characteristics clearly described | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
4 Interventions of interest clearly described | – | – | – | – | 1 | – | – |
5 Are the distributions of principle confounders in each group of subjects to be compared clearly described? | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
6 Main findings of the study clearly described | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
7 Does the study provide estimates of random variability in the data | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
8 Have all important adverse events that may be a consequence of the intervention been reported? | – | – | – | – | 1 | – | – |
9 Have the characteristics of patients lost to follow-up been described? | – | – | – | – | 1 | – | – |
10 Have actual probability values been reported for the main outcomes | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
11 Were the subjects asked to participate in the study representative of the entire population from which they were recruited | 1 | 1 | 0 | 0 | 0 | 1 | 1 |
12 Were those subjects who participated representative of the entire population from which they were recruited | 1 | 1 | 0 | 0 | 0 | 1 | 1 |
13 Were the staff, places and facilities where the patients were treated representative of the treatment the majority of patients receive | – | – | – | – | 0 | – | |
14 Was an attempt made to blind study subjects to the intervention they received? | – | – | – | – | 1 | – | – |
15 Was an attempt made to blind those measuring the main outcomes of the intervention | – | – | – | – | 0 | – | – |
16 If any of the results were based on “data dredging”, was this made clear? | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
17 Do the analyses adjust for different lengths of follow-up of patients | – | – | – | – | 1 | – | – |
18 Were the statistical tests used to assess the main outcomes appropriate? | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
19 Was compliance with the intervention reliable? | – | – | – | – | 1 | – | – |
20 Were the main outcome measures used accurate (valid and reliable)? | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
21 Were the patients recruited from the same population? | 1 | 1 | 0 | 0 | 1 | 1 | 1 |
22 Were subjects recruited over the same period of time? | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
23 Were study subjects randomised to intervention groups? | – | – | – | – | 1 | – | – |
24 Was the randomised intervention assignment concealed from both patients and healthcare staff until recruitment was complete and irrevocable? | – | – | – | – | 0 | – | – |
25 Was there adequate adjustment for confounding in the analyses from which the main findings were drawn? | – | – | – | – | 0 | – | – |
26 Were the losses of patient to follow-up taken into account? | – | – | – | – | 1 | – | – |
27 Did the study have sufficient power to detect a clinically important effect where the probability value for a difference being due to chance is less than 5%? | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Score | 73% | 67% | 47% | 47% | 56% | 80% | 80% |