A novel approach for identifying and addressing case-mix heterogeneity in individual participant data meta-analysis.

Case-mix heterogeneity across studies complicates meta-analyses. As a result of this, treatments that are equally effective on patient subgroups may appear to have different effectiveness on patient populations with different case mix. It is therefore important that meta-analyses be explicit for what patient population they describe the treatment effect. To achieve this, we develop a new approach for meta-analysis of randomized clinical trials, which use individual patient data (IPD) from all trials to infer the treatment effect for the patient population in a given trial, based on direct standardization using either outcome regression (OCR) or inverse probability weighting (IPW). Accompanying random-effect meta-analysis models are developed. The new approach enables disentangling heterogeneity due to case mix from that due to beyond case-mix reasons.

Efficacy and tolerability of pharmacological and non-pharmacological interventions in older patients with major depressive disorder: A systematic review, pairwise and network meta-analysis.

As there is currently no comprehensive evaluation about the efficacy and safety of interventions in elderly patients with major depressive disorder, we did a systematic review and network meta-analysis about all interventions in this population. We searched the specialised register of the Cochrane common mental disorders group, MEDLINE, EMBASE, PsycINFO, CochraneLibrary, ClinicalTrials.gov and the WHO registry until Dec 12, 2017 to identify all randomized controlled trials about the treatment of major depressive disorder in patients over an age of 65. The primary outcome was response defined as reduction of at least 50% on the Hamilton Depression Scale or any other validated depression scale. Secondary outcomes were remission, depressive symptoms, dropouts total, dropouts owing to inefficacy and dropouts due to adverse events, quality of life and social functioning. Additionally, we analysed 116 adverse events. We identified 129 references from 53 RCTs with 9274 participants published from 1990 to 2017. The mean participant age was 73.7 years. In terms of the primary outcome response to treatment the network-meta-analysis showed significant superiority compared to placebo for quetiapine and duloxetine; in addition, agomelatine, imipramine and vortioxetine outperformed placebo in pairwise meta-analyses, and there were also significant superiorities of several antidepressants compared to placebo in secondary efficacy outcomes. Very limited evidence suggests that competitive memory training, geriatric home treatment group and detached mindfulness condition reduce depressive symptoms. Several antidepressants and quetiapine have been shown to be efficacious in elderly patients with major depressive disorder, but due to the comparably few available data, the results are not robust. Differences in the multiple side-effects analysed should also be considered in drug choice. Although there were significant effects for some non-pharmacological treatments, the overall evidence for non-pharmacological treatments in major depressive disorder is insufficient, because it is based on a few trials with usually small sample sizes.

Dietary Supplements and Risk of Cause-Specific Death, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis of Primary Prevention Trials.

Our aim was to assess the efficacy of dietary supplements in the primary prevention of cause-specific death, cardiovascular disease (CVD), and cancer by using meta-analytical approaches. Electronic and hand searches were performed until August 2016. Inclusion criteria were as follows: 1) minimum intervention period of 12 mo; 2) primary prevention trials; 3) mean age ≥18 y; 4) interventions included vitamins, fatty acids, minerals, supplements containing combinations of vitamins and minerals, protein, fiber, prebiotics, and probiotics; and 5) primary outcome of all-cause mortality and secondary outcomes of mortality or incidence from CVD or cancer. Pooled effects across studies were estimated by using random-effects meta-analysis. Overall, 49 trials (69 reports) including 287,304 participants met the inclusion criteria. Thirty-two trials were judged as low risk-, 15 trials as moderate risk-, and 2 trials as high risk-of-bias studies. Supplements containing vitamin E (RR: 0.88; 95% CI: 0.80, 0.96) significantly reduced cardiovascular mortality risk, whereas supplements with folic acid reduced the risk of CVD (RR: 0.81; 95% CI: 0.70, 0.94). Vitamins D, C, and K; selenium; zinc; magnesium; and eicosapentaenoic acid showed no significant risk reduction for any of the outcomes. On the contrary, vitamin A was linked to an increased cancer risk (RR: 1.16; 95% CI: 1.00, 1.35). Supplements with ß-carotene showed no significant effect; however, in the subgroup with ß-carotene given singly, an increased risk of all-cause mortality by 6% (RR: 1.06; 95% CI: 1.02, 1.10) was observed. Taken together, we found insufficient evidence to support the use of dietary supplements in the primary prevention of cause-specific death, incidence of CVD, and incidence of cancer. The application of some supplements generated small beneficial effects; however, the heterogeneous types and doses of supplements limit the generalizability to the overall population.