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Table 4 Risk of bias assessments

From: The effectiveness of smoking cessation interventions for socio-economically disadvantaged women: a systematic review and meta-analysis

Studies

Bias arising from the randomisation process

Bias due to deviations from intended interventions

Bias due to missing outcome data

Bias in measurement of the outcome

Bias in selection of the reported result

Overall bias

Andrews et al. 2016 [48]

Low risk

Low risk

Low risk

Some concerns: no information on blinding of outcome assessors

Some concerns: no information on whether statistical analysis was pre-planned

Some concerns

Bernstein et al. 2015 [47]

Some concerns: Some differences in baseline characteristics between groups

Low risk

Low risk

Low risk

Low risk

Some concerns

Collins et al. 2019 [49]

Low risk

Low risk

Retention rate relatively low

 

High risk: authors changed statistical analysis plan due to low retention ratea

High risk

Curry et al. 2003 [50]

Low risk

Low risk

Low risk

High risk: no biochemical validation in primary outcome

Some concerns: no information on whether statistical analysis was pre-planned

High risk

Etter et al. 2016 [51]

Some concerns: Some differences in characteristics between groups, but accounted for in analysis

Low risk

Low risk

Low risk

Some concerns: No information on whether statistical analysis was pre-planned

Some concerns

Gilbert et al. 2017 [46]

Low risk

Low risk

Low risk

Low risk

Low risk

Low risk

Glasgow et al. 2000 [52]

Low risk

Low risk

Low risk

Some concerns: no information on blinding of outcome assessors

Some concerns: no information on whether statistical analysis was pre-planned

Some concerns

Haas et al. 2015 [53]

Low risk

Low risk

Some concerns: Retention rate relatively low and higher assessment rate in control group

High risk: no biochemical validation in primary outcome

Some concerns: no information on whether statistical analysis was pre-planned

High risk

Manfredi et al. 2004 [54]

Some concerns: differences in racial characteristics between groups

Low risk

Some concerns: Retention rates low, but equally low in both groups

High risk: no biochemical validation in primary outcome

Some concerns: no information on whether statistical analysis was pre-planned

High risk

Solomon et al. 2000 [55]

Low risk

Low risk

Low risk

Some concerns: no information on blinding of outcome assessors

Some concerns: no information on whether statistical analysis was pre-planned

Some concerns

Solomon et al. 2005 [56]

Low risk

Low risk

Low risk

High risk: no biochemical validation in primary outcome

Some concerns: no information on whether statistical analysis was pre-planned

High risk

  1. aThe authors explain the change in analyses as “We planned to test the interaction between treatment and other smokers in home at p<0.05 when initial models demonstrated main effects of both variables. Although each of the predictors and outcome variables contained small numbers of missing values, an analysis of complete data only would have reduced our sample by about one third. To retain our sample and avoid bias arising from missing data, we used multiple imputation methods, which also estimate SEs that incorporate the uncertainty due to imputation