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. 2016 Aug 9;14(2):161–173. doi: 10.1177/1479972316661926

Table 2.

Risks of bias within trials in sarcoidosis patients reporting fatigue as an outcome measure.

Author (year) Lower et al. (2007)29 Erckens et al. (2011)30 Heij et al. (2012)13 van Rijswijk et al. (2013)31 Lower et al. (2013)32 Strookappe et al. (2015)33 Marcellis et al. (2015)34 Strookappe et al. (2015)35
Sequence generation Low risk: Random sequence computer-generated High risk: No randomization (not RCT) Low risk: Computer generated randomization code High risk: No randomization (not RCT) Unclear: No statement on randomization procedure High risk: No randomization (not RCT) High risk: No randomization (not RCT) High risk: No randomization (not RCT)
Allocation concealment Low risk: Pharmacy-controlled allocation High risk: No concealment, all patients receive drug Low risk: Pharmacy-controlled allocation High risk: No concealment, all patients received drug Unclear: No statement on allocation procedure High risk: No concealment, all patients on programme High risk: No concealment, all patients on programme High risk: No concealment, all patients on programme
Blinding of participants, personnel and outcome assessors Low risk: Double-blind with low risk of breaking blinding High risk: No blinding Low risk: Only allocating pharmacist unblinded High risk: No blinding Low risk: Double-blind with low risk of breaking blinding High risk: No blinding High risk: No blinding High risk: No blinding, including assessors of physical function pre- and post.
Incomplete outcome data Unclear: No description of missing data points or handling of missing data Unclear: No description of missing data points or handling of missing data Low risk: Missing data compensated for by taking forward last value Unclear: No description of missing data points or handling of missing data Unclear: No description of missing data points or handling of missing data Unclear: No description of missing data points or handling of missing data Unclear: No description of missing data points or handling of missing data Unclear: No description of missing data points or handling of missing data
Selective outcome reporting Low: All outcomes reported Unclear: No protocol available Unclear: No protocol available Unclear: No protocol available Low: All outcomes reported Unclear: No protocol available Unclear: No protocol available Unclear: No protocol available
Other sources of bias No other clear causes of bias identified; crossover ensures groups balanced, patients are own controls. Small sample. Study design (case series) limits conclusions – no comparator group to eliminate placebo effect. Baseline imbalance in FAS and health status score (SF36) between groups – significantly lower fatigue scores in placebo arm. Retrospective review – data collected pre- and post-intervention but high risk of bias from retrospective nature No other clear causes of bias identified; crossover ensures groups balanced, patients are own controls. Small sample. Not an RCT, also participants enrolling on programme would self-select as motivated people? generalizable Not an RCT, also participants enrolling on programme would self-select as motivated people? generalizable Patients choosing the intervention would be a self-selecting cohort; controls not randomized but refused intervention
Overall risk of bias Low – Well designed crossover trial, though only small sample High – Study design (case series) means no blinding, randomization or comparator. Low – Well designed RCT but not powered to look at change in fatigue. High – Design (retrospective case series) has no blinding, randomization or comparator. Unclear – Issues with description of randomisation allocation and concealment mean study at risk of bias High – Study design (case series) means no blinding, randomisation or comparator. High – Study design (case series) means no blinding, randomisation or comparator. High – Self-selecting intervention group, high risk of bias given control group declined intervention

RCT: randomized controlled trial.