Summary of findings 2. H2 antagonists compared to placebo for prevention of weight gain in people with schizophrenia.
| H2 antagonists compared to placebo for prevention of weight gain in people with schizophrenia | ||||||
| Patient or population: people with schizophrenia with antipsychotic‐induced weight gain Setting: inpatients or outpatients Intervention: H2 antagonists Comparison: placebo | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with placebo | Risk with H2 antagonists | |||||
| Weight: clinically important change in weight (kg) | Study population | Not estimable | (0 RCTs) | ‐ | No data available | |
| Not estimable | Not estimable | |||||
| Weight: average endpoint/change in body weight (kg) | Average endpoint/change in body weight ranged from 4.18 to 4.88 | MD 1.32 lower (2.09 lower to 0.56 lower) | ‐ | 248 (3 RCTs) | ⊕⊕⊝⊝ Lowa,b | |
| Weight: clinically important change in BMI (kg/m2) | Study population | Not estimable | (0 RCTs) | ‐ | No data available | |
| Not estimable | Not estimable | |||||
| Weight: average endpoint/change in BMI (kg/m2) | Average endpoint/change in BMI was 1.82 | MD 0.66 lower (0.99 lower to 0.33 lower) | ‐ | 79 (2 RCTs) | ⊕⊝⊝⊝ Very lowa,b | |
| Leaving the study early: for any reason | Study population | RR 1.07 (0.72 to 1.57) | 189 (2 RCTs) | ⊕⊕⊝⊝ Lowa,b | ||
| 343 per 1000 | 367 per 1000 (247 to 539) | |||||
| Compliance with treatment | Study population | Not estimable | (0 RCTs) | ‐ | No data available | |
| Not estimable | Not estimable | |||||
| Reports of nausea | Study population | RR 1.13 (0.34 to 3.68) | 175 (1 RCT) | ⊕⊕⊝⊝ Lowa,b | ||
| 67 per 1000 | 75 per 1000 (23 to 245) | |||||
| *The risk in the intervention group (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). BMI: body mass index; CI: confidence interval; MD: mean difference; RCT: randomised controlled trial; RR: risk ratio | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect. | ||||||
aThe risk of bias is uncertain for most studies included in this comparison. bThe total number of participants included in the review is less than the number of participants required for a single, adequately powered study.