Table 2 Indicators of study quality
Quality indicator | Sittitavornwong, 2005[21] | Susarla, 2011[22] | Mandal, 2004[23] | |
|---|---|---|---|---|
Was the objective of the study clearly described? | Yes | Yes | Yes | Yes |
Are the main outcomes to be measured clearly described? | Yes | Yes | Yes | Yes |
Are the characteristics of the included subjects clearly described? | Yes | No | Partial | No |
Was there a clearly defined point in time when the intervention occurred? | Yes | Yes | Yes | No |
Are the interventions of interest clearly described? | Yes | No | Yes | Yes |
Are possible confounders clearly described? | Partial | Partial | Partial | No |
Are the main findings of the study clearly described? | Yes | Yes | Yes | Yes |
Are estimates of the random variability in the data provided? | Yes | Yes | Yes | No |
Are all adverse events that may be a consequence of the intervention reported? | Unclear | Unclear | Unclear | Unclear |
Are the characteristics of patients lost to follow-up described? | NA | Yes | NA | No |
Were losses of patients to follow up accounted for? | NA | Yes | NA | No |
Are the actual probability values reported for the main outcomes? | Yes | No | Yes | No |
Were attempts made to blind outcome assessors to the intervention? | NA | No | NA | NA |
Were the groups recruited from the same population? | No | Yes | Yes | Yes |
Were the groups recruited over the same period of time? | No | Yes | Yes | Unclear |
Was a representative sample of the population approached? | Yes | Yes | Unclear | Unclear |
Was the intervention unlikely to affect data collection? | Yes | Yes | Yes | Yes |
Was there reliable compliance with the intervention? | Partial | Yes | NA | Yes |
Were the main outcome measures used valid and reliable? | Yes | Yes | Yes | No |
Was the study free from selective outcome reporting? | Unclear | Unclear | Unclear | Unclear |
Were baseline characteristics similar between groups? | Unclear | Unclear | Unclear | Unclear |