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. 2017 Aug 24;2017(8):CD005051. doi: 10.1002/14651858.CD005051.pub3
  Total cholesterol change
Study limitations
(risk of bias) 1. Was random sequence generation used (i.e. no potential for selection bias)? Yes
2. Was allocation concealment used (i.e. no potential for selection bias)? Unclear (half of the studies low risk and the other half unclear)
3. Was there blinding of participants and personnel (i.e. no potential for performance bias)? N/A (not applicable in lifestyle interventions)
4. Was there blinding of outcome assessment (i.e. no potential for detection bias)? No (does not affect objective outcomes)
5. Was an objective outcome used? Yes
6. Were more than 80% of participants enrolled in trials included in the analysis (i.e. no potential reporting bias)?a Yes
7. Were data reported consistently for the outcome of interest (i.e. no potential selective reporting)? Unclear
8. No other biases reported (i.e. no potential of other bias)? Possible risk of attrition bias
9. Did the trials end up as scheduled (i.e. not stopped early)? Yes
Inconsistency 1. Point estimates did not vary widely? No (some variability) (↓)
2. To what extent did confidence intervals overlap (substantial: all confidence intervals overlap at least 1 of the included studies point estimate; some: confidence intervals overlap but not all overlap at least 1 point estimate; no: at least 1 outlier, where the confidence intervals of some of the studies do not overlap with those of most included studies)? Some
3. Was the direction of effect consistent? No (↓)
4. What was the magnitude of statistical heterogeneity (as measured by I2) ‐ low (I2 < 40%), moderate (I2 40% to 60%), high (I2 > 60%)? Low
5. Was the test for heterogeneity statistically significant (P < 0.1)? No
Indirectness 1. Were the populations in included studies applicable to the decision context? Yes
2. Were the interventions in the included studies applicable to the decision context? Yes
3. Was the included outcome not a surrogate outcome? No (however relevant risk factors)
4. Was the outcome timeframe sufficient? Yes
5. Were the conclusions based on direct comparisons? Yes
Imprecision 1. Was the confidence interval for the pooled estimate not consistent with benefit and harm? No (↓)
2. What is the magnitude of the median sample size (high: 300 participants, intermediate: 100‐300 participants, low: <100 participants)?a Intermediate (103 participants)
3. What was the magnitude of the number of included studies (large: > 10 studies, moderate: 5 to 10 studies, small: < 5 studies)?a Moderate
4. Was the outcome a common event (e.g. occurs more than 1/100)? N/A
Publication bias 1. Was a comprehensive search conducted? Yes
2. Was grey literature searched? No
3. Were no restrictions applied to study selection on the basis of language? No
4. There was no industry influence on studies included in the review? Some industry support but all declared
5. There was no evidence of funnel plot asymmetry? N/A
6. There was no discrepancy in findings between published and unpublished trials? N/A
aDepends on the context of the systematic review area.
(↓): key item for potential downgrading the quality of the evidence (GRADE) as shown in the footnotes of the 'Summary of findings' table(s); N/A: not applicable