Imputation of response rates from means and standard deviations in schizophrenia

Efficacy of dietary interventions in irritable bowel syndrome: a systematic review and network meta-analysis

BACKGROUND

Patients with irritable bowel syndrome (IBS) are often interested in dietary interventions as a means of managing their symptoms. However, the relative efficacy of available diets for the management of IBS is unclear. We aimed to examine the relative efficacy of various dietary interventions in IBS.

METHODS

For this systematic review and network meta-analysis we searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane Central Register of Controlled Trials from database inception to Feb 7, 2025, to identify randomised controlled trials comparing an active dietary intervention requiring changes to the intake of more than one food in IBS with either a control intervention, such as a habitual diet, sham diet, a high fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet, or alternative miscellaneous dietary advice, or any other active dietary intervention requiring changes to the intake of more than one food. We assessed efficacy using dichotomous assessments of improvement in global IBS symptoms or improvement in individual IBS symptoms, including abdominal pain, abdominal bloating or distension, and bowel habit. We pooled data using a random-effects model, with the efficacy of each intervention reported as pooled relative risks (RRs) with 95% CIs. We ranked interventions according to their P-score, which measures the mean extent of certainty that one intervention is better than another, averaged over all competing interventions.

FINDINGS

We identified 28 eligible randomised controlled trials (comprising 2338 patients) of 11 different dietary interventions compared with four control interventions, of which six (low FODMAP diet, British Dietetic Association/National Institute for Health and Care Excellence [BDA/NICE] diet, lactose-reduced diet, starch-reduced and sucrose-reduced diet, a personalised diet, and a Mediterranean diet) were studied in more than one trial. For global IBS symptoms, assessed in 28 randomised controlled trials and when considering only the dietary interventions studied in more than one trial, a starch-reduced and sucrose-reduced diet ranked first (RR of global IBS symptoms not improving 0·41 [95% CI 0·26-0·67]; P-score 0·84; two trials), a low FODMAP diet ranked fourth (0·51 [0·37-0·70]; P-score 0·71; 24 trials), and a BDA/NICE diet ranked tenth (0·62 [0·43-0·90]; P-score 0·44; eight trials), versus a habitual diet. For abdominal pain, assessed in 26 trials and when considering only the dietary interventions studied in more than one randomised controlled trial, a starch-reduced and sucrose-reduced diet ranked second (RR of abdominal pain not improving 0·54 [95% CI 0·33-0·90]; P-score 0·73; two trials), and a low FODMAP diet ranked fifth (0·61 [0·42-0·89]; P-score 0·64; 23 trials), versus a habitual diet. For abdominal bloating or distension, assessed in 26 trials and when considering only the dietary interventions studied in more than one randomised trial, only a low FODMAP diet (RR of abdominal bloating or distension not improving 0·55 [95% CI 0·37-0·80]; P-score 0·64; 23 trials) was superior to a habitual diet and ranked fourth. For bowel habit, assessed in 23 randomised trials, none of the dietary interventions was superior to any of the control interventions, but a low FODMAP diet was superior to a BDA/NICE diet (RR of bowel habit not improving 0·79 [95% CI 0·63-0·99]). All comparisons across the network were rated as low or very low confidence, except for direct comparisons between a low FODMAP diet or a starch-reduced and sucrose-reduced diet and habitual diet, both of which were rated as moderate confidence.

INTERPRETATION

In terms of dietary interventions for IBS, the most evidence exists for a low FODMAP diet, but other promising therapies are emerging and should be the subject of further study.

FUNDING

None.

Systematic Review and Meta-Analysis: Imputing Response Rates for First-Line Psychological Treatments for Posttraumatic Stress Disorder in Youth

OBJECTIVE

Meta-analyses assessing psychological therapies for posttraumatic stress disorder (PTSD) in youth have demonstrated their effectiveness using standardized mean differences. Imputation of response rates (ie, 50% or greater reduction in symptoms) may facilitate easier interpretation for clinicians.

METHOD

We searched 4 databases (MEDLINE, PsycINFO, PTSDPubs, and Web of Science) and screened 1,654 records to include 60 randomized controlled trials (52 trauma-focused cognitive-behavioral therapy [TF-CBT], 8 eye movement desensitization [EMDR]) with a total of 5,113 participants, comparing psychological therapies for PTSD against control conditions in youth. Data from randomized controlled trials of EMDR and TF-CBT for PTSD were used to impute response rates, establishing how many patients display 50% reduction, 20% reduction, and reliable improvement and deterioration (using reliable change indices) in PTSD and depression.

RESULTS

The proportion of youth exhibiting a 50% reduction in PTSD symptoms was 0.48 (95% CI = 0.41-0.55) for TF-CBT, 0.30 (0.24-0.37) for EMDR, and 0.46 (0.39-0.52) for all psychological therapies, compared to 0.20 (0.16-0.24) for youth in control conditions. Reliable improvement was displayed by 0.53 (0.45-0.61; TF-CBT 0.55 [0.46-0.64], EMDR 0.42[0.30-0.55]) of youth receiving psychological therapies, compared to 0.25 (0.20-0.30) of youth in control conditions. Reliable deterioration was seen in 0.01 (0.01-0.02) of youth receiving psychological therapies, compared to 0.13 (0.08-0.20) of youth in control conditions. There was a high degree of heterogeneity in the included studies.

CONCLUSION

Psychological therapies, in particular TF-CBT, for young people with PTSD are effective and unlikely to cause deterioration, with around half of youth receiving TF-CBT exhibiting 50% symptom reduction.

Efficacy and Safety of Four Psychedelic-Assisted Therapies for Adults with Symptoms of Depression, Anxiety, and Posttraumatic Stress Disorder: A Systematic Review and Meta-Analysis

There has been a resurgence in psychedelic research for managing psychiatric conditions in recent years. This study aimed to present a comprehensive review of the current state of the field by applying a systematic search strategy for articles on the effectiveness and tolerability of four psychedelic-assisted therapies (psilocybin, lysergic acid diethylamide [LSD], 3,4-Methylenedioxymethamphetamine [MDMA], and ayahuasca) for adults with symptoms of depression, anxiety, and posttraumatic stress disorder (PTSD). Psychometric scores and adverse events were pooled using random-effects meta-analysis models with Hedges' g bias-corrected standardized mean differences (g) and rate ratios (RR) with 95% confidence intervals (CI). Bias evaluation followed PRISMA and Cochrane guidelines. Eighteen studies were identified, which suggested that psychedelic therapies were well tolerated and presented a large effect size for the management of depression symptoms in a transdiagnostic population with psilocybin (g = -1.92, 95% CI, -2.73 to -1.11) and MDMA (g = -0.71; 95% CI, -1.39 to -0.03). These are promising results that complement the current literature. However, evidence certainty was low to very low due to methodological limitations, small sample size, blinding, study heterogeneity, and publication bias. These results also highlight the need for more adequately powered studies exploring these novel therapies.

Systematic Review and Meta-analysis: Efficacy of Mesalamine in Irritable Bowel Syndrome

BACKGROUND & AIMS

Some patients with irritable bowel syndrome (IBS) demonstrate low-grade inflammation in the intestine. Mesalamine, which has anti-inflammatory effects, may be an efficacious treatment for IBS, but studies are conflicting. We conducted a systematic review and meta-analysis to assess efficacy and safety of mesalamine in IBS.

METHODS

We searched the medical literature up to September 14, 2022, to identify randomized controlled trials (RCTs) of mesalamine in IBS. We judged efficacy and safety using dichotomous assessments of effect on global IBS symptoms, abdominal pain, bowel habit or stool frequency, and occurrence of any adverse event. We pooled data using a random effects model, with efficacy and safety reported as pooled relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

We identified 8 eligible RCTs (820 patients). Mesalamine was more efficacious than placebo for global IBS symptoms (RR of global symptoms not improving, 0.86; 95% CI, 0.79-0.95; number needed to treat = 10; 95% CI, 6-27), but not for abdominal pain or bowel habit or stool frequency. Subgroup analyses demonstrated efficacy of mesalamine in IBS with diarrhea for global IBS symptoms (RR, 0.88; 95% CI, 0.79-0.99), but not patients with other predominant bowel habits or those with post-infection IBS. Adverse event rates were no higher with mesalamine (RR, 1.20; 95% CI, 0.89-1.63) but were reported in only 5 trials.

CONCLUSIONS

Mesalamine may be modestly efficacious for global symptoms in IBS, particularly IBS with diarrhea, but quality of evidence was low. Adequately powered high quality RCTs of mesalamine in IBS are needed.

Caregiver Burden among Caregivers of Patients with Mental Illness: A Systematic Review and Meta-Analysis

Due to the increasing importance of caregivers in the treatment outcomes of patients with mental illness, this study aimed to systematically review studies investigating the former's caregiver burden and determine its prevalence. An open search, without filters, was conducted. Articles were selected from Medline, Scopus, and PubMed from inception to 30 April 2022 using the PRISMA protocol. Subgroup analyses examined the between-group differences by study setting, measurements used, and disorder type. A total of 5034 caregivers from 23 countries were included in this review. Thirty-nine studies were included in the systematic review, and, among them, twenty-six were deemed eligible for meta-analysis. The overall pooled prevalence of caregiver burden among caregivers of individuals with mental illness was 31.67% (95% CI = 26.22-37.12). Pooled prevalence was the highest among care recipients receiving treatment in a hospital setting (36.06%; 95% CI = 22.50-49.63), followed by the community and clinic settings. Caregiver prevalence values were higher for burden measured using the Zarit Burden Interview (38.05%; 95% CI = 27.68-48.43). compared with other instruments, and for carers of care recipients with psychosis (35.88%; 95% CI = 27.03-44.72) compared with those without. Thus, targeted interventions should focus on caregivers of patients in hospital settings and with psychotic symptoms.

Response and Adverse Event Rates With Placebo in Gastroparesis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Multiple drugs have been used to treat gastroparesis symptoms, yet their therapeutic benefits are poorly understood partly due to lack of insight into response and adverse event rates with placebo in randomized controlled trials (RCTs). We evaluated these issues systematically in drug trials for gastroparesis.

METHODS

We searched the medical literature through August 2, 2022 to identify RCTs comparing active drug with placebo in patients with gastroparesis. We assessed placebo response rates according to at least one of the following endpoints: improvement according to a composite outcome, nausea, vomiting, abdominal pain, bloating, or fullness, as well as total adverse events, and adverse events leading to withdrawal. We extracted data as intention-to-treat analyses with dropouts assumed to be treatment failures. We pooled placebo response and adverse event rates using a random effects model and expressed as proportions with 95% confidence intervals (CIs).

RESULTS

Thirty-five studies were eligible. Among 23 trials reporting a composite endpoint of improvement, the pooled placebo response rate was 29.3% (95% CI, 23.7%-35.2%). Pooled placebo response rates were higher in idiopathic compared with diabetic gastroparesis (34.2% vs 28.1%), among trials that did not use validated symptom questionnaires (31.2% vs 27.4%), and in RCTs of shorter duration (<4 weeks, 32.6% vs ≥9 weeks, 23.2%). Adverse events occurred in 33.8% (95% CI, 26.4%-41.8%) of patients with placebo, in 27 trials, and were less common in idiopathic compared with diabetic gastroparesis (17.9% vs 43.4%), trials of shorter duration (<4 weeks, 33.7% vs ≥9 weeks, 40.7%), and trials with lower randomization ratios of active drug to placebo (1:1, 26.7% vs 3:1, 50.5%).

CONCLUSIONS

This meta-analysis assessed placebo response and adverse event rates in gastroparesis. To accurately assess therapeutic gain, future trials should be a minimum of 8 weeks duration, use validated questionnaires, and distinguish gastroparesis subtypes.

Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common disorders of gut-brain interaction, with a complex pathophysiology. Antispasmodics are prescribed as first-line therapy because of their action on gut dysmotility. In this regard, peppermint oil also has antispasmodic properties.

AIM

To update our previous meta-analysis to assess efficacy and safety of peppermint oil, particularly as recent studies have cast doubt on its role in the treatment of IBS METHODS: We searched the medical literature up to 2nd April 2022 to identify randomised controlled trials (RCTs) of peppermint oil in IBS. Efficacy and safety were judged using dichotomous assessments of effect on global IBS symptoms or abdominal pain, and occurrence of any adverse event or of gastro-oesophageal reflux. Data were pooled using a random effects model, with efficacy and safety reported as pooled relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

We identified 10 eligible RCTs (1030 patients). Peppermint oil was more efficacious than placebo for global IBS symptoms (RR of not improving = 0.65; 95% CI 0.43-0.98, number needed to treat [NNT] = 4; 95% CI 2.5-71), and abdominal pain (RR of abdominal pain not improving = 0.76; 95% CI 0.62-0.93, NNT = 7; 95% CI 4-24). Adverse event rates were significantly higher with peppermint oil (RR of any adverse event = 1.57; 95% CI 1.04-2.37).

CONCLUSIONS

Peppermint oil was superior to placebo for the treatment of IBS, but adverse events were more frequent, and quality of evidence was very low. Adequately powered RCTs of peppermint oil as first-line treatment for IBS are needed.

Efficacy of a low FODMAP diet in irritable bowel syndrome: systematic review and network meta-analysis

OBJECTIVE

A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is recommended for irritable bowel syndrome (IBS), if general lifestyle and dietary advice fails. However, although the impact of a low FODMAP diet on individual IBS symptoms has been examined in some randomised controlled trials (RCTs), there has been no recent systematic assessment, and individual trials have studied numerous alternative or control interventions, meaning the best comparator is unclear. We performed a network meta-analysis addressing these uncertainties.

DESIGN

We searched the medical literature through to 2 April 2021 to identify RCTs of a low FODMAP diet in IBS. Efficacy was judged using dichotomous assessment of improvement in global IBS symptoms or improvement in individual IBS symptoms, including abdominal pain, abdominal bloating or distension, and bowel habit. Data were pooled using a random effects model, with efficacy reported as pooled relative risks (RRs) with 95% CIs, and interventions ranked according to their P-score.

RESULTS

We identified 13 eligible RCTs (944 patients). Based on failure to achieve an improvement in global IBS symptoms, a low FODMAP diet ranked first vs habitual diet (RR of symptoms not improving=0.67; 95% CI 0.48 to 0.91, P-score=0.99), and was superior to all other interventions. Low FODMAP diet ranked first for abdominal pain severity, abdominal bloating or distension severity and bowel habit, although for the latter it was not superior to any other intervention. A low FODMAP diet was superior to British Dietetic Association (BDA)/National Institute for Health and Care Excellence (NICE) dietary advice for abdominal bloating or distension (RR=0.72; 95% CI 0.55 to 0.94). BDA/NICE dietary advice was not superior to any other intervention in any analysis.

CONCLUSION

In a network analysis, low FODMAP diet ranked first for all endpoints studied. However, most trials were based in secondary or tertiary care and did not study effects of FODMAP reintroduction and personalisation on symptoms.

Antipsychotic-Induced Weight Gain: Dose-Response Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Weight gain is among the most important side-effects of antipsychotics. It is, however, unclear whether it is associated with antipsychotic doses. We aimed to fill this gap with a dose-response meta-analysis.

METHODS

We searched multiple electronic databases (last update search June 2021) for all fixed-dose studies that investigated 16 second-generation antipsychotics and haloperidol in adults with acute exacerbation of schizophrenia or with negative symptoms. We estimated the dose-response curves by conducting random-effects dose-response meta-analyses. We used the restricted cubic spline to model the dose-response relationship. The primary outcome was mean weight gain in kg from baseline to endpoint, the secondary outcome was the number of patients with clinically important weight gain.

FINDINGS

Ninety-seven studies with 333 dose arms (36 326 participants) provided data for meta-analyses. Most studies were short-term with median duration of 6 weeks (range 4 to 26 weeks). In patients with acute exacerbation, amisulpride, aripiprazole, brexpiprazole, cariprazine, haloperidol, lumateperone, and lurasidone produced mild weight gain in comparison to placebo (mean difference at any dose≤1 kg), while more significant weight gain was observed by all other drugs. For most drugs, dose-response curves showed an initial dose-related increase in weight which plateaued at higher doses, while for others there was no plateau and some even had bell-shaped curves, meaning less weight gain to be associated with higher doses.

INTERPRETATION

Second-generation antipsychotics do not only differ in their propensity to produce weight gain, but also in the shapes of their dose-response curves. This information is important for dosing decisions in clinical practice.

Systematic Review and Meta-analysis: An Empirical Approach to Defining Treatment Response and Remission in Pediatric Obsessive-Compulsive Disorder

OBJECTIVE

A lack of universal definitions for response and remission in pediatric obsessive-compulsive disorder (OCD) has hampered the comparability of results across trials. To address this problem, we conducted an individual participant data diagnostic test accuracy meta-analysis to evaluate the discriminative ability of the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) in determining response and remission. We also aimed to generate empirically derived cutoffs on the CY-BOCS for these outcomes.

METHOD

A systematic review of PubMed, PsycINFO, Embase and CENTRAL identified 5,401 references; 42 randomized controlled clinical trials were considered eligible, and 21 provided data for inclusion (N = 1,234). Scores of ≤2 in the Clinical Global Impressions Improvement and Severity scales were chosen to define response and remission, respectively. A 2-stage, random-effects meta-analysis model was established. The area under the curve (AUC) and the Youden Index were computed to indicate the discriminative ability of the CY-BOCS and to guide for the optimal cutoff, respectively.

RESULTS

The CY-BOCS had sufficient discriminative ability to determine response (AUC = 0.89) and remission (AUC = 0.92). The optimal cutoff for response was a ≥35% reduction from baseline to posttreatment (sensitivity = 83.9, 95% CI = 83.7-84.1; specificity = 81.7, 95% CI = 81.5-81.9). The optimal cutoff for remission was a posttreatment raw score of ≤12 (sensitivity = 82.0, 95% CI = 81.8-82.2; specificity = 84.6, 95% CI = 84.4-84.8).

CONCLUSION

Meta-analysis identified empirically optimal cutoffs on the CY-BOCS to determine response and remission in pediatric OCD randomized controlled clinical trials. Systematic adoption of standardized operational definitions for response and remission will improve comparability across trials for pediatric OCD.

Pharmacological and dietary-supplement treatments for autism spectrum disorder: a systematic review and network meta-analysis

BACKGROUND

There is still no approved medication for the core symptoms of autism spectrum disorder (ASD). This network meta-analysis investigated pharmacological and dietary-supplement treatments for ASD.

METHODS

We searched for randomized-controlled-trials (RCTs) with a minimum duration of seven days in ClinicalTrials.gov, EMBASE, MEDLINE, PsycINFO, WHO-ICTRP (from inception up to July 8, 2018), CENTRAL and PubMed (up to November 3, 2021). The co-primary outcomes were core symptoms (social-communication difficulties-SCD, repetitive behaviors-RB, overall core symptoms-OCS) measured by validated scales and standardized-mean-differences (SMDs). Associated symptoms, e.g., irritability/aggression and attention-deficit/hyperactivity disorder (ADHD) symptoms, dropouts and important side-effects, were investigated as secondary outcomes. Studies in children/adolescents and adults were analyzed separately in random-effects pairwise and network meta-analyses.

RESULTS

We analyzed data for 41 drugs and 17 dietary-supplements, from 125 RCTs (n = 7450 participants) in children/adolescents and 18 RCTs (n = 1104) in adults. The following medications could improve at least one core symptom domain in comparison with placebo: aripiprazole (k = 6 studies in analysis, SCD: SMD = 0.27 95% CI [0.09, 0.44], RB: 0.48 [0.26, 0.70]), atomoxetine (k = 3, RB:0.49 [0.18, 0.80]), bumetanide (k = 4, RB: 0.35 [0.09, 0.62], OCS: 0.61 [0.31, 0.91]), and risperidone (k = 4, SCM: 0.31 [0.06, 0.55], RB: 0.60 [0.29, 0.90]; k = 3, OCS: 1.18 [0.75, 1.61]) in children/adolescents; fluoxetine (k = 1, RB: 1.20 [0.45, 1.96]), fluvoxamine (k = 1, RB: 1.04 [0.27, 1.81]), oxytocin (k = 6, RB:0.41 [0.16, 0.66]) and risperidone (k = 1, RB: 0.97 [0.21,1.74]) in adults. There were some indications of improvement by carnosine, haloperidol, folinic acid, guanfacine, omega-3-fatty-acids, probiotics, sulforaphane, tideglusib and valproate, yet imprecise and not robust. Confidence in these estimates was very low or low, except moderate for oxytocin. Medications differed substantially in improving associated symptoms, and in their side-effect profiles.

LIMITATIONS

Most of the studies were inadequately powered (sample sizes of 20-80 participants), with short duration (8-13 weeks), and about a third focused on associated symptoms. Networks were mainly star-shaped, and there were indications of reporting bias. There was no optimal rating scale measuring change in core symptoms.

CONCLUSIONS

Some medications could improve core symptoms, although this could be likely secondary to the improvement of associated symptoms. Evidence on their efficacy and safety is preliminary; therefore, routine prescription of medications for the core symptoms cannot be recommended. Trial registration PROSPERO-ID CRD42019125317.

Humour-based interventions for people with schizophrenia

BACKGROUND

Humour-based interventions are defined as any intervention that promotes health and wellness by stimulating a playful discovery, expression, or appreciation of the absurdity or incongruity of life's situations. Humour-based interventions can be implemented in different settings, including hospitals, nursing homes and day care centres. They have been posed as an adjunct to usual care for people with schizophrenia, but a summary of the evidence is lacking.

OBJECTIVES

To examine the effects of humour-based interventions as an add-on intervention to standard care for people with schizophrenia.

SEARCH METHODS

On 31 July 2019 and 10 February 2021 we searched the Cochrane Schizophrenia Group's study-based register of trials, which is based on CENTRAL, CINAHL, ClinicalTrials.Gov, Embase, ISRCTN, MEDLINE, PsycINFO, PubMed, and WHO ICTRP.

SELECTION CRITERIA

We included all randomised controlled trials comparing humour-based interventions with active controls, other psychological interventions, or standard care for people with schizophrenia. We excluded studies fulfilling our prespecified selection criteria but without useable data from further quantitative synthesis.

DATA COLLECTION AND ANALYSIS

Two review authors independently inspected citations, selected studies, extracted data and appraised study quality, following the guidance from the Cochrane Handbook for Systematic Reviews of Interventions. For binary outcomes we calculated risk ratios (RRs) and their 95% confidence intervals (CIs). For continuous outcomes we calculated the mean differences (MDs) and their 95% CIs. We assessed risks of bias for included studies and created summary of findings tables using the GRADE approach.

MAIN RESULTS

We included three studies in this review for qualitative synthesis, although one study did not report any relevant outcomes. We therefore include two studies (n = 96) in our quantitative synthesis. No data were available on the following prespecified primary outcomes: clinically-important change in general mental state, clinically-important change in negative symptoms, clinically-important change in overall quality of life, and adverse effects. As compared with active control, humour-based interventions may not improve the average endpoint score of a general mental state scale (Positive and Negative Syndrome Scale (PANSS) total score: MD -1.70, 95% CI -17.01 to 13.61; 1 study, 30 participants; very low certainty of evidence); positive symptoms (PANSS positive symptom score: MD 0.00, 95% CI -2.58 to 2.58; 1 study, 30 participants; low certainty of evidence), negative symptoms (PANSS negative symptom score: MD -0.70, 95% CI -4.22 to 2.82; 1 study, 30 participants; very low certainty of evidence) and anxiety (State-Trait Anxiety Inventory (STAI): MD -2.60, 95% CI -5.76 to 0.56; 1 study, 30 participants; low certainty of evidence). Due to the small sample size, we remain uncertain about the effect of humour-based interventions on leaving the study early as compared with active control (no event, 1 study, 30 participants; very low certainty of evidence). On the other hand, humour-based interventions may reduce depressive symptoms (Beck Depression Inventory (BDI): MD -6.20, 95% CI -12.08 to -0.32; 1 study, 30 participants; low certainty of evidence). Compared with standard care, humour-based interventions may not improve  depressive symptoms (BDI second edition: MD 0.80, 95% CI -2.64 to 4.24; 1 study, 59 participants; low certainty of evidence). We are uncertain about the effect of humour-based interventions on leaving the study early for any reason compared with standard care (risk ratio 0.38, 95% CI 0.08 to 1.80; 1 study, 66 participants; very low certainty of evidence).

AUTHORS' CONCLUSIONS

We are currently uncertain whether the evidence supports the use of humour-based interventions in people with schizophrenia. Future research with rigorous and transparent methodology investigating clinically important outcomes is warranted.

Imputing the Number of Responders from the Mean and Standard Deviation of CGI-Improvement in Clinical Trials Investigating Medications for Autism Spectrum Disorder

INTRODUCTION

Response to treatment, according to Clinical Global Impression-Improvement (CGI-I) scale, is an easily interpretable outcome in clinical trials of autism spectrum disorder (ASD). Yet, the CGI-I rating is sometimes reported as a continuous outcome, and converting it to dichotomous would allow meta-analysis to incorporate more evidence.

METHODS

Clinical trials investigating medications for ASD and presenting both dichotomous and continuous CGI-I data were included. The number of patients with at least much improvement (CGI-I ≤ 2) were imputed from the CGI-I scale, assuming an underlying normal distribution of a latent continuous score using a primary threshold θ = 2.5 instead of θ = 2, which is the original cut-off in the CGI-I scale. The original and imputed values were used to calculate responder rates and odds ratios. The performance of the imputation method was investigated with a concordance correlation coefficient (CCC), linear regression, Bland-Altman plots, and subgroup differences of summary estimates obtained from random-effects meta-analysis.

RESULTS

Data from 27 studies, 58 arms, and 1428 participants were used. The imputation method using the primary threshold (θ = 2.5) had good performance for the responder rates (CCC = 0.93 95% confidence intervals [0.86, 0.96]; β of linear regression = 1.04 [0.95, 1.13]; bias and limits of agreements = 4.32% [-8.1%, 16.74%]; no subgroup differences χ2 = 1.24, p-value = 0.266) and odds ratios (CCC = 0.91 [0.86, 0.96]; β = 0.96 [0.78, 1.14]; bias = 0.09 [-0.87, 1.04]; χ2 = 0.02, p-value = 0.894). The imputation method had poorer performance when the secondary threshold (θ = 2) was used.

DISCUSSION

Assuming a normal distribution of the CGI-I scale, the number of responders could be imputed from the mean and standard deviation and used in meta-analysis. Due to the wide limits of agreement of the imputation method, sensitivity analysis excluding studies with imputed values should be performed.

Short-acting intramuscular second-generation antipsychotic drugs for acutely agitated patients with schizophrenia spectrum disorders. A systematic review and network meta-analysis

BACKGROUND

Psychomotor agitation is a common condition in patients with psychotic disorders. One treatment possibility is intramuscular (IM) second-generation antipsychotics. Yet their efficacy in this formulation and for this aim is unclear. This network meta-analysis aims to evaluate the efficacy of short-acting IM second-generation antipsychotic drugs, haloperidol and placebo in patients with diagnosis of schizophrenia and schizophrenia-like disorders that present acute agitation.

METHODS

We searched the Cochrane Schizophrenia Group Controlled Trials Register, MEDLINE, EMBASE, PsycINFO, Cochrane Library, PubMed, BIOSIS, ClinicalTrials.gov and WHO ICTRP up to November 2018 and PubMed until March 2020. Study selection and outcome extraction were performed independently by two reviewers. Pairwise and network meta-analyses were conducted to compare the different IM second-generation antipsychotics among themselves and with IM haloperidol and placebo. The primary outcome was the number of responders at 2 h after the first injection. Responders at 24 h were also analysed.

RESULTS

10 studies with 1964 patients were included in the meta-analysis. Ziprasidone, olanzapine, aripiprazole and haloperidol were more efficacious than placebo in calming patients at 2 h after administration. Furthermore, olanzapine was superior to aripiprazole. The results at 24 h confirmed the superiority of aripiprazole, olanzapine and haloperidol over placebo, while for ziprasidone no data were available.

CONCLUSIONS

All second-generation antipsychotics available as intramuscular medications were effective in reducing agitation in people with schizophrenia. Olanzapine was somewhat more efficacious than aripiprazole.

Comparative efficacy of racemic ketamine and esketamine for depression: A systematic review and meta-analysis

BACKGROUND

Ketamine appears to have a therapeutic role in certain mental disorders, most notably depression. However, the comparative performance of different formulations of ketamine is less clear.

OBJECTIVES

This study aimed to assess the comparative efficacy and tolerability of racemic and esketamine for the treatment of unipolar and bipolar major depression.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched PubMed, MEDLINE, Embase, PsycINFO, the Cochrane Central Register of Controlled Clinical Trials, and the Cochrane Database of Systematic Reviews for relevant studies published since database inception and December 17, 2019.

STUDY ELIGIBILITY CRITERIA

We considered randomized controlled trials examining racemic or esketamine for the treatment of unipolar or bipolar major depression.

OUTCOMES

Primary outcomes were response and remission from depression, change in depression severity, suicidality, retention in treatment, drop-outs, and drop-outs due to adverse events.

ANALYSIS

Evidence from randomized controlled trials was synthesized as rate ratios (RRs) for treatment response, disorder remission, adverse events, and withdrawals and as standardized mean differences (SMDs) for change in symptoms, via random-effects meta-analyses.

FINDINGS

24 trials representing 1877 participants were pooled. Racemic ketamine relative to esketamine demonstrated greater overall response (RR = 3.01 vs. RR = 1.38) and remission rates (RR = 3.70 vs. RR = 1.47), as well as lower dropouts (RR = 0.76 vs. RR = 1.37).

CONCLUSIONS

Intravenous ketamine appears to be more efficacious than intranasal esketamine for the treatment of depression.

Antipsychotic drugs v. barbiturates or benzodiazepines used as active placebos for schizophrenia: a systematic review and meta-analysis

BACKGROUND

Comparisons of antipsychotics with placebo can be biased by unblinding due to side effects. Therefore, this meta-analysis compared the efficacy of antipsychotics for acute schizophrenia in trials using barbiturates or benzodiazepines as active placebos.

METHODS

Randomized controlled trials (RCTs) in acute schizophrenia with at least 3 weeks duration and comparing any antipsychotic with barbiturates or benzodiazepines were eligible. ClinicalTrials.gov, CENTRAL, EMBASE, MEDLINE, PsycINFO, PubMed, WHO-ICTRP as well as previous reviews were searched up to 9 January 2018. Two separate meta-analyses, one for barbiturates and one for benzodiazepines, were conducted using random-effects models. The primary outcome was response to treatment, and mean values of schizophrenia rating scales and dropouts were analyzed as secondary outcomes. This study is registered with PROSPERO (CRD42018086263).

RESULTS

Seven barbiturate-RCTs (number of participants n = 1736), and two benzodiazepine-RCTs (n = 76) were included in the analysis. The studies were published between 1960 and 1968 and involved mainly chronically ill patients. More patients on antipsychotics in comparison to barbiturates achieved a 'good' response (36.2% v. 16.8%; RR 2.15; 95% CI 1.36-3.41; I2 = 48.9) and 'any' response (57.4% v. 27.8%; RR 2.07; 95% CI 1.35-3.18; I2 = 68.2). In a single small trial (n = 60), there was no difference between antipsychotics and benzodiazepines on 'any' response (74.7% v. 65%; RR 1.15; 95% CI 0.82-1.62).

CONCLUSIONS

Antipsychotic drugs were more efficacious than barbiturates, based on a large sample size. Response ratios were similar to those observed in placebo-controlled trials. The results on benzodiazepines were inconclusive due to the small number of studies and participants.

Placebo response in pharmacological and dietary supplement trials of autism spectrum disorder (ASD): systematic review and meta-regression analysis

Background

Placebo response in autism spectrum disorder (ASD) might dilute drug-placebo differences and hinder drug development. Therefore, this meta-analysis investigated placebo response in core symptoms.

Methods

We searched ClinicalTrials.gov, CENTRAL, EMBASE, MEDLINE, PsycINFO, WHO-ICTRP (up to July 8, 2018), and PubMed (up to July 4, 2019) for randomized pharmacological and dietary supplement placebo-controlled trials (RCTs) with a minimum of seven days of treatment. Single-group meta-analyses were conducted using a random-effects model. Standardized mean changes (SMC) of core symptoms in placebo arms were the primary outcomes and placebo positive response rates were a secondary outcome. Predictors of placebo response were investigated with meta-regression analyses. The protocol was registered with PROSPERO ID CRD42019125317.

Results

Eighty-six RCTs with 2360 participants on placebo were included in our analysis (87% in children/adolescents). The majority of trials were small, single-center with a duration of 8–12 weeks and published after 2009. Placebo response in social-communication difficulties was SMC = − 0.32, 95% CI [− 0.39, − 0.25], in repetitive behaviors − 0.23[− 0.32, − 0.15] and in scales measuring overall core symptoms − 0.36 [− 0.46, − 0.26]. Overall, 19%, 95% CI [16–22%] of participants were at least much improved with placebo. Caregiver (vs. clinician) ratings, lower risk of bias, flexible-dosing, larger sample sizes and number of sites, less recent publication year, baseline levels of irritability, and the use of a threshold of core symptoms at inclusion were associated with larger placebo response in at least a core symptom domain.

Limitations

About 40% of the trials had an apparent focus on core symptoms. Investigation of the differential impact of predictors on placebo and drug response was impeded by the use of diverse experimental interventions with essentially different mechanisms of action. An individual-participant-data meta-analysis could allow for a more fine-grained analysis and provide more informative answers.

Conclusions

Placebo response in ASD was substantial and predicted by design- and participant-related factors, which could inform the design of future trials in order to improve the detection of efficacy in core symptoms. Potential solutions could be the minimization and careful selection of study sites as well as rigorous participant enrollment and the use of measurements of change not solely dependent on caregivers.

Efficacy and acceptability of pharmacological and non-pharmacological interventions for non-specific chronic low back pain: a protocol for a systematic review and network meta-analysis

BACKGROUND

Despite the enormous financial and humanistic burden of chronic low back pain (CLBP), there is little consensus on what constitutes the best treatment options from a multitude of competing interventions. The objective of this network meta-analysis (NMA) is to determine the relative efficacy and acceptability of primary care treatments for non-specific CLBP, with the overarching aim of providing a comprehensive evidence base for informing treatment decisions.

METHODS

We will perform a systematic search to identify randomised controlled trials of interventions endorsed in primary care guidelines for the treatment of non-specific CLBP in adults. Information sources searched will include major bibliographic databases (MEDLINE, Embase, CENTRAL, CINAHL, PsycINFO and LILACS) and clinical trial registries. Our primary outcomes will be patient-reported pain ratings and treatment acceptability (all-cause discontinuation), and secondary outcomes will be functional ability, quality of life and patient/physician ratings of overall improvement. A hierarchical Bayesian class-based NMA will be performed to determine the relative effects of different classes of pharmacological (NSAIDs, opioids, paracetamol, anti-depressants, muscle relaxants) and non-pharmacological (exercise, patient education, manual therapies, psychological therapy, multidisciplinary approaches, massage, acupuncture, mindfulness) interventions and individual treatments within a class (e.g. NSAIDs: diclofenac, ibuprofen, naproxen). We will conduct risk of bias assessments and threshold analysis to assess the robustness of the findings to potential bias. We will compute the effect of different interventions relative to placebo/no treatment for both short- and long-term efficacy and acceptability.

DISCUSSION

While many factors are important in selecting an appropriate intervention for an individual patient, evidence for the analgesic effects and acceptability of a treatment are key factors in guiding this selection. Thus, this NMA will provide an important source of evidence to inform treatment decisions and future clinical guidelines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registry number: CRD42019138115.

Response rates in patients with schizophrenia and positive symptoms receiving cognitive behavioural therapy: a systematic review and single-group meta-analysis

BACKGROUND

Cognitive behavioural therapy has been used for schizophrenia, but to which extent it is effective is still controversial. Results of existing meta-analyses are of difficult interpretation, because they mainly present effect sizes in the form of standardized mean differences between intervention and control groups based on rating scales, which are of unclear clinical meaning. No meta-analysis has considered the number of patients responding to treatment yet. Based on this ground, we present the first meta-analysis examining the response rates of patients with schizophrenia and positive symptoms to cognitive behavioural therapy.

METHODS

We searched multiple databases for randomized controlled trials on psychological interventions of schizophrenia including patients with positive symptoms, and included for this analysis the studies on cognitive behavioural therapy (last search: January 2018). We applied a validated imputation method to calculate the number of responders from rating scales for the outcomes overall symptoms and positive symptoms, based on two criteria, at least 20% and at least 50% reduction from baseline on PANSS or BPRS total scores. Data were pooled in a single-group summary meta-analysis using R software. Additionally, several potential moderators of response to cognitive behavioural therapy were examined by subgroup and meta-regression analyses. The protocol has been registered in PROSPERO (CRD42017067795).

RESULTS

We included 33 studies with a total of 1142 participants receiving cognitive behavioural therapy. On average, 44.5 and 13.2% of the patients reached a 20% (minimally improved) and 50% (much improved) reduction of overall symptoms. Similarly, 52.9 and 24.8% of the patients reached a 20%/50% reduction of positive symptoms. Subgroup and meta-regression analyses revealed a better treatment response in overall symptoms for patients that were not treatment resistant and in studies with researchers' allegiance. Of borderline significance was the better response in studies employing expert therapists and in patients that were more severely ill at baseline. Blinding of outcome assessor, number of sessions, treatment duration, age and gender were not significant moderators of response.

CONCLUSIONS

Our findings suggest that adding cognitive behavioural therapy to pharmacotherapy brings about a minimal improvement in overall symptoms among 44.5% of its recipients. Several study and patients characteristics can moderate response rates.

How well do patients with a first episode of schizophrenia respond to antipsychotics: A systematic review and meta-analysis

It is often stated that first-episode patients tend to respond better to antipsychotics than chronic patients, but the exact numbers and moderators of response in this population are unclear. We, therefore, present the first systematic review on response rates of first episode patients with schizophrenia in randomized trials. We searched multiple databases for randomized-controlled trials of antipsychotics in acutely ill patients with a first episode of schizophrenia (last search: November 17, 2016). The outcomes were response rate based on two criteria, at least 50% PANSS or BPRS total score reduction from baseline and at least 20% reduction. Data were pooled in a single-group summary meta-analysis using Comprehensive Meta-Analysis software. Moreover, several potential moderators of response to antipsychotics were examined by meta-regression. We included 17 studies with a total of 3156 participants. On the average, 81.3%/51.9% of the first-episode patients reached an at least 20%/50% PANSS or BPRS reduction from baseline, respectively. Meta-regressions revealed a better treatment response in female patients, in more severely ill patients at baseline, in antipsychotic naïve patients, in patients with a shorter illness duration and in open studies. Study duration and dosage were no significant moderators of response. Our finding suggest that more than 80% of first-episode patients achieved 20% PANSS/BPRS reduction from baseline and around 50% achieved a 50% PANSS/BPRS reduction. Several patient characteristics moderated response rates.

Quetiapine immediate release v. placebo for schizophrenia: systematic review, meta-analysis and reappraisal

BACKGROUND

Immediate-release (IR) quetiapine has been used to treat schizophrenia since 1997, although all the principal placebo-controlled trials have >50% missing outcome data. New studies with relatively lower rates of participant withdrawal have since been published.

AIMS

To assess the efficacy and adverse effects of quetiapine IR for schizophrenia, with consideration of outcome quality and clinical meaningfulness of results, and to examine the potential impact of missing data on the main efficacy findings.

METHOD

We conducted a systematic review and meta-analysis of randomised controlled trials comparing quetiapine IR and placebo (or subtherapeutic dose in relapse prevention trials) for the treatment of schizophrenia (PROSPERO registration CRD4201100165). Primary outcomes were change in overall symptoms and response rates. We also examined whether high rates of participant withdrawal (≥50%) attenuated effect sizes, and assessed the impact of making different assumptions about these people's outcomes.

RESULTS

We identified 15 relevant trials (including 2 unpublished), providing the first 12-week data for this drug and the first data on self-reported quality of life. We found quetiapine IR to have a weighted mean difference (WMD) of 6.5 points (95% CI -8.9 to -4) on Positive and Negative Syndrome Scale (PANSS) total scores, which corresponds to a standardised mean difference (SMD) of -0.33 (95% CI -0.46 to -0.21). Longer trials reported larger mean differences favouring quetiapine IR, but the overall estimate was smaller if more conservative assumptions about the outcomes of people who left the trial early were made. Approximately 21 people needed to take quetiapine IR for 1 person to experience at least a 50% improvement in PANSS score. No difference in quality of life was observed (two RCTs), although small to moderate improvements in social functioning were found (three RCTs). Quetiapine IR caused sedation and increased rates of clinically significant weight gain, but no extrapyramidal effects were observed.

CONCLUSIONS

Quetiapine IR has a small beneficial effect on overall psychotic symptoms over 2-12 weeks, but also leads to weight gain and sedation.

The pharmacological and non-pharmacological treatment of attention deficit hyperactivity disorder in children and adolescents: protocol for a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders of children and adolescents, with a significant impact on health services and the community in terms of economic and social burdens. The objective of this systematic review will be to evaluate the comparative efficacy and safety of pharmacological and non-pharmacological treatments in children and adolescents with ADHD.

METHODS

Searches involving PubMed/MEDLINE and the Cochrane Database of Systematic Reviews will be used to identify related systematic reviews and relevant randomized trials. Search results will be supplemented by reports from the regulatory and health technology agencies, clinical trials registers and by data requested from trialists and/or pharmaceutical companies. We will consider studies evaluating pharmacological interventions (e.g. stimulants, non-stimulants, antidepressants), psychological interventions (e.g. behavioural interventions, cognitive training and neurofeedback) and complementary and alternative medicine interventions (e.g. dietary interventions, supplement with fatty acids, vitamins, minerals, aminoacids, herbal treatment, homeopathy, and mind-body interventions including massage, chiropractic, acupuncture, yoga, meditation, Tai chi). Eligible control conditions will be placebo, waitlist, no treatment and usual care. Randomized controlled trials of a minimum of 3 weeks duration will be included. The primary outcomes of interest will be the proportion of patients who responded to treatment and who dropped out of the allocated treatment, respectively. Secondary outcomes will include treatment discontinuation due to adverse events, as well as the occurrences of serious adverse events and specific adverse events (decreased weight, anorexia, insomnia and sleep disturbances, anxiety, syncope and cardiovascular events). Two reviewers will independently screen references identified by the literature search, as well as potentially relevant full-text articles in duplicate. Data will be abstracted and risk of bias will be appraised by two team members independently. Conflicts at all levels of screening and abstraction will be resolved through discussion. Random-effects pairwise meta-analyses and Bayesian network meta-analyses will be conducted where appropriate.

DISCUSSION

This systematic review and network meta-analysis will compare the efficacy and safety of treatments used for ADHD in children and adolescents. The findings will assist patients, clinicians and healthcare providers to make evidence-based decisions regarding treatment selection.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014015008 .

Odds ratios of treatment response were well approximated from continuous rating scale scores for meta-analysis

OBJECTIVES

To empirically evaluate the performance of methods for estimating odds ratios and their corresponding standard errors from continuous end point data for meta-analysis.

STUDY DESIGN AND SETTING

A database of randomized controlled trials of chronic depression treatments was used. Trials that reported both continuous and dichotomous end points for symptom improvement were considered. Odds ratios and standard errors were calculated from the dichotomous data and estimated from the continuous data using currently available methods: Hasselblad and Hedges (HH), Cox and Snell (CS), Furukawa (F), Suissa (S), and Kraemer and Kupfer (KK). Single and meta-analytically pooled observed and estimated values were compared.

RESULTS

A total of 26 trials were included. At the trial level, four of five (HH, CS, F, and S) and three of four (HH, F, and S) methods for estimating odds ratios and standard errors performed well, respectively. We found considerable differences in the performance of all methods across trials with more accurate estimates for smaller treatment effects. At the level of meta-analysis, three of four methods (CS, F, and S) performed acceptably.

CONCLUSION

Odds ratios and standard errors can be approximated from continuous end points, but we recommend sensitivity and subgroup analyses to test robustness of the findings.