Cohen‐Hagai 2018.
| Study characteristics | ||
| Methods | Double‐blind, parallel‐group RCT | |
| Participants | 29 adults (mean age 62.0 years) attending Israeli outpatient clinics with liver cirrhosis (mainly from viral hepatitis and non‐alcoholic fatty liver disease) and no hepatic encephalopathy | |
| Interventions | Either 520 mg magnesium oxide daily versus identical‐appearing placebo tablets. Presumably given for the full 8‐week observation period, although this is not explicitly stated | |
| Outcomes | Primary outcome not explicitly stated but study appears focused on measures of cognition Secondary outcomes are drawn from a "quality of life questionnaire that included eight parameters including fatigue level, concentration ability, frequency of muscle cramps, and daily physical performance" |
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| Conflicts of interest | Conflicts of interest not reported | |
| Funding | Funding not reported. However, does say investigator‐initiated, so possibly independent funding | |
| Notes | Published. Participants recruited between November 2013 and January 2014 | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Process not described but says randomized |
| Allocation concealment (selection bias) | Unclear risk | Not described |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Matched placebo |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Not described. Probably adequate |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Of the 29 participants enrolled, only 22 completed the trial, 8 in the intervention group and 14 in the placebo group. This imbalance resulted from 6 participants dropping out of the magnesium group (42.8%), while only 1 participant dropped out of the placebo group (6.7%). Only a per protocol analysis is carried out |
| Selective reporting (reporting bias) | High risk | Regarding cramps: the authors state that they are collecting cramp frequency and cramp pain ‒ but report only that "Improvement in the severity and frequency of muscle cramps was not significant (P = 0.438 and 0.483, respectively)." The only numbers which are reported pertain to whether muscle cramps are occurring ‒ with percentages given for each group and a nonsignificant statistical test being indicated. An e‐mail request was sent to the authors asking for more information but no response was obtained |
| Cramp diary (recall bias) | Unclear risk | It is not stated whether or not a cramp diary was used ‒ but this seems unlikely as cramping was not the focus of the study |
| Other bias | Low risk | No obvious other bias |