Summary of findings 1. Oral magnesium compared with placebo/no treatment for treating leg cramps in pregnancy.
| Oral magnesium compared with placebo/no treatment for treating leg cramps in pregnancy | ||||||
| Patient or population: treating leg cramps in pregnancy Settings: outpatient clinics in Norway, Sweden and Thailand Intervention: oral magnesium Comparison: placebo/no treatment | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Assumed risk with placebo/ no treatment | Corresponding risk with oral magnesium | |||||
| Frequency of leg cramps during treatment | The mean frequency of leg cramps during treatment in the control group was 7.7 | The mean frequency of leg cramps during treatment in the intervention group was 1.8 higher (1.32 lower to 4.92 higher) | ‐ | 38 (1 RCT) | ⊕⊕⊝⊝ LOW 1 | |
| Frequency of leg cramps after treatment: never | Study population | RR 5.66 (1.35 to 23.68) | 69 (1 RCT) | ⊕⊕⊝⊝ LOW 2,3 | ||
| 57 per 1000 | 323 per 1000 (77 to 1000) | |||||
| Frequency: 50% reduction in number of leg cramps | Study population | RR 1.42 (1.09 to 1.86) | 86 (1 RCT) | ⊕⊕⊝⊝ LOW 4,5 | ||
| 605 per 1000 | 859 per 1000 (659 to 1000) | |||||
| Intensity of pain during treatment: mean total scale points The degree of pain was noted in the form, on a scale from 0 to 4 measured over 4 days and nights (0 = no pain, 1 = light pain, 2 = medium pain, 3=strong pain, 4=extreme pain) |
The mean intensity of pain during treatment: mean total scale points in the control group was 11.4 | The mean intensity of pain during treatment: mean total scale points in the intervention group was 1.8 higher (3.1 lower to 6.7 higher) | ‐ | 38 (1 RCT) | ⊕⊕⊝⊝ LOW 1 | |
| Intensity of pain: 50% reduction in pain score 100‐mm visual analogue scale (0 = no pain, 100 = worst pain) |
Study population | RR 1.43 (0.99 to 2.06) | 86 (1 RCT) | ⊕⊝⊝⊝ VERY LOW 1,4 | ||
| 488 per 1000 | 698 per 1000 (483 to 1000) | |||||
| Intensity of pain: visual analogue scale 100 mm Visual analogue scale where 0=insignificant and 100 = extremely painful. |
The mean intensity of pain: visual analogue scale in the control group was 47.8 | The mean intensity of pain: visual analogue scale in the intervention group was 17.5 lower (34.68 lower to 0.32 lower) | ‐ | 69 (1 RCT) | ⊕⊕⊝⊝ LOW 2,5 | |
| Duration of leg cramps: persisting symptoms after night‐time cramps Always |
Study population | RR 0.23 (0.05 to 0.98) | 69 (1 RCT) |
⊕⊕⊝⊝ LOW 2,3 | ||
| 257 per 1000 | 59 per 1000 (13 to 252) |
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| Duration of leg cramps: persisting symptoms after night‐time cramps Sometimes |
Study population | RR 0.59 (0.19 to 1.83) | 69 (1 RCT) |
⊕⊝⊝⊝ VERY LOW 1,2 | ||
| 200 per 1000 | 118 per 1000 (38 to 366) |
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| Composite outcome: symptoms of leg cramps (intensity and frequency) Partial improvement: decrease in intensity and frequency |
Study population | RR 1.07 (0.71 to 1.61) |
42 (1 RCT) |
⊕⊝⊝⊝ VERY LOW 1,2 | ||
| 667 per 1000 | 713 per 1000 (473 to 1000) |
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| Composite outcome: symptoms of leg cramps (intensity and frequency) Complete recovery: no leg cramps after treatment |
Study population | RR 3.00 (0.68 to 13.20) |
42 (1 RCT) |
⊕⊝⊝⊝ VERY LOW 1,2 | ||
| 95 per 1000 | 286 per 1000 (65 to 1000) |
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| Side effects ‐ nausea | Study population | RR 1.83 (0.75 to 4.51) |
86 (1 RCT) |
⊕⊕⊝⊝ LOW 1 | ||
| 140 per 1000 | 255 per 1000 (105 to 629) |
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| Side effects ‐ diarrhoea | Study population | RR 6.00 (0.75 to 47.76) |
86 (1 RCT) |
⊕⊕⊝⊝ LOW 1 | ||
| 23 per 1000 | 140 per 1000 (17 to 1000) |
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| Side effects ‐ any | Study population | RR 0.96 (0.36 to 2.52) |
45 (1 RCT) |
⊕⊕⊝⊝ LOW 1 | ||
| 273 per 1000 | 262 per 1000 (98 to 687) |
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| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: risk ratio | ||||||
| GRADE Working Group grades of evidence High certainty: further research is very unlikely to change our confidence in the estimate of effect. Moderate certainty: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low certainty: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low certainty: we are very uncertain about the estimate. | ||||||
1Wide CI crossing the line of no effect and small sample size (‐2).
2Design limitations (‐1).
3Few events and small sample size (‐1).
4Outcome is assessed using an arbitrary cut‐off (‐1).
5Small sample size (‐1).