Table 2.
Quality of article included in this review using Downs and Black scale.
| Measures | Ebnezar et al., 2012 [16] | Ebnezar et al., 2012 [17] | Ebnezar and Yogitha, 2012 [18] | Cheung et al., 2014 [19] | Kolasinski et al., 2005 [20] | Brenneman et al., 2015 [21] | Ebnezar et al., 2012 [22] | Nambi and Shah, 2013 [23] | Ghasemi et al., 2013 [24] |
|---|---|---|---|---|---|---|---|---|---|
| Clear description of the following? | |||||||||
| (1) Hypothesis/aim/objective | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| (2) Main outcome | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| (3) Characteristics of participants | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| (4) Intervention of interest | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| (5) Distribution of principal confounders in each group | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 |
| (6) Main findings | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| (7) Estimates of random variability for main outcomes | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| (8) All important adverse events that may be a consequence of intervention | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 0 |
| (9) Characteristics of patients lost to follow-up | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 |
| (10) Actual probability values for main outcomes | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| External validity | |||||||||
| (11) Were invitees representative of the population from which they were recruited? | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| (12) Were subjects who were prepared to participate representative of the population from which recruited? | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 |
| (13) Were the staff, places, and facilities representative of the treatment that the majority of subjects received? | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 0 |
| Internal validity | |||||||||
| (14) Was an attempt made to blind subjects to the intervention they received? | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| (15) Was an attempt made to blind those measuring main outcomes of the intervention? | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| (16) If any results were based on “data dredging,” was this made clear? | 0 | 0 | 0 | 1 | 1 | 1 | 0 | 1 | 1 |
| (17) In trials and cohort studies, did analyses adjust for length of follow-up? Or, in case-control studies, was the period between intervention and outcome the same for cases and controls? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 |
| (18) Were appropriate statistical tests used to assess the main outcomes? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 |
| (19) Was compliance with the intervention reliable? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
| (20) Were main outcome measures reliable and valid? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 |
| Internal validity-confounding (selection bias) | |||||||||
| (21) For trials and cohort studies, were patients in different intervention groups? For case-control studies, were cases and controls recruited from the same population? | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 |
| (22) For trials and cohort studies, were subjects in different intervention groups? For case-control studies, were cases and controls recruited over same period of time? | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| (23) Were subjects randomized to intervention groups? | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 |
| (24) Was the randomized intervention assignment concealed from both patients and staff until recruitment was complete? Was it irrevocable? | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 |
| (25) Was there adequate adjustment for confounding in analyses from which main findings were drawn? | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| (26) Were losses of subjects to follow-up taken into account? | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 0 |
| Power | |||||||||
| (27) Was there sufficient power to detect a clinically important effect when p < 0.05? | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Total score (maximum 32) | 17 | 17 | 17 | 23 | 18 | 16 | 17 | 11 | 13 |
A score of 23 or higher indicates good-quality article with low risk of bias.
A score between 22 and 13 indicates medium-quality article with moderate risk of bias.
A score of 12 or lower represents a poor-quality article with high risk of bias [25].