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Table 1 Examples of unclear supporting explanations

From: Assessments of attrition bias in Cochrane systematic reviews are highly inconsistent and thus hindering trial comparability

Study number Unclear supporting explanation Judgment
2 All participants were accounted for Low
12 Outcomes reported for all women randomized Low
20 Primary outcomes were reported Low
26 None found Low
54 Analysed the same number of participants in both groups Low
66 Expected outcomes reported. Response rates reduced in patients over 4 surveys Low
80 No study protocol was available Low
82 It appears that all participants completed the study and contributed data for each outcome at all relevant time points Low
2 Unclear Unclear
4 Losses to follow-up were unclear Unclear
6 It was unclear whether or not there was attrition, or loss to follow-up at final follow-up based on the results section Unclear
29 No information Unclear
31 Insufficient information to permit judgment of low risk or high risk Unclear
32 May be participants randomized who did not complete Unclear
41 Few data available in conference abstract only Unclear
66 Unknown Unclear
442 High attrition (41%) Unclear
13 Number of drop-outs reported, but no details High
25 Not all raw data were provided High
52 Not clear how many withdrew High