Haloperidol versus placebo for schizophrenia

How to perform a meta-analysis with R: a practical tutorial

OBJECTIVE

Meta-analysis is of fundamental importance to obtain an unbiased assessment of the available evidence. In general, the use of meta-analysis has been increasing over the last three decades with mental health as a major research topic. It is then essential to well understand its methodology and interpret its results. In this publication, we describe how to perform a meta-analysis with the freely available statistical software environment R, using a working example taken from the field of mental health.

METHODS

R package meta is used to conduct standard meta-analysis. Sensitivity analyses for missing binary outcome data and potential selection bias are conducted with R package metasens. All essential R commands are provided and clearly described to conduct and report analyses.

RESULTS

The working example considers a binary outcome: we show how to conduct a fixed effect and random effects meta-analysis and subgroup analysis, produce a forest and funnel plot and to test and adjust for funnel plot asymmetry. All these steps work similar for other outcome types.

CONCLUSIONS

R represents a powerful and flexible tool to conduct meta-analyses. This publication gives a brief glimpse into the topic and provides directions to more advanced meta-analysis methods available in R.

Haloperidol discontinuation for people with schizophrenia

BACKGROUND

Schizophrenia is a disabling serious mental illness that can be chronic. Haloperidol, one of the first generation of antipsychotic drugs, is effective in the treatment of schizophrenia but can have adverse side effects. The effects of stopping haloperidol in people with schizophrenia who are stable on their prescription are not well researched in the context of systematic reviews.

OBJECTIVES

To review the effects of haloperidol discontinuation in people with schizophrenia who are stable on haloperidol.

SEARCH METHODS

On 20 February 2015, 24 May 2017, and 12 January 2019, we searched the Cochrane Schizophrenia Group's Study-Based Register of Trials including trial registers.

SELECTION CRITERIA

We included clinical trials randomising adults with schizophrenia or related disorders who were receiving haloperidol, and were stable. We included trials that randomised such participants to either continue their current treatment with haloperidol or discontinue their haloperidol treatment. We included trials that met our selection criteria and reported usable data.

DATA COLLECTION AND ANALYSIS

We independently checked all records retrieved from the search and obtained full reports of relevant records for closer inspection. We extracted data from included studies independently. All usable data were dichotomous, and we calculated relative risks (RR) and their 95% confidence intervals (95% CI) using a fixed-effect model. We assessed risk of bias within the included studies and used GRADE to create a 'Summary of findings' table.

MAIN RESULTS

We included five randomised controlled trials (RCTs) with 232 participants comparing haloperidol discontinuation with haloperidol continuation. Discontinuation was achieved in all five studies by replacing haloperidol with placebo. The trials' size ranged between 23 and 87 participants. The methods of randomisation, allocation concealment and blinding were poorly reported.Participants allocated to discontinuing haloperidol treatment were more likely to show no improvement in global state compared with those in the haloperidol continuation group (n = 49; 1 RCT; RR 2.06, 95% CI 1.33 to 3.20; very low quality evidence: our confidence in the effect estimate is limited due to relevant methodological shortcomings of included trials). Those who continued haloperidol treatment were less likely to experience a relapse compared to people who discontinued taking haloperidol (n = 165; 4 RCTs; RR 1.80, 95% CI 1.18 to 2.74; very low quality evidence). Satisfaction with treatment (measured as numbers leaving the study early) was similar between groups (n = 43; 1 RCT; RR 0.13, 95% CI 0.01 to 2.28; very low quality evidence).No usable mental state, general functioning, general behaviour or adverse effect data were reported by any of the trials.

AUTHORS' CONCLUSIONS

This review provides limited evidence derived from small, short-term studies. The longest study was for one year, making it difficult to generalise the results to a life-long disorder. Very low quality evidence shows that discontinuation of haloperidol is associated with an increased risk of relapse and a reduction in the risk of 'global state improvement'. However, participant satisfaction with haloperidol treatment was not different from participant satisfaction with haloperidol discontinuation as measured by leaving the studies early. Due to the very low quality of these results, firm conclusions cannot be made. In addition, the available studies did not report usable data regarding the adverse effects of haloperidol treatment.Considering that haloperidol is one of the most widely used antipsychotic drugs, it was surprising that only a small number of studies into the benefit and harm of haloperidol discontinuation were available. Moreover, the available studies did not report on outcomes that are important to clinicians and to people with schizophrenia, particularly adverse effects and social outcomes. Better designed trials are warranted.

Dose equivalents for second-generation antipsychotics: the minimum effective dose method

BACKGROUND

Clinicians need to know the right antipsychotic dose for optimized treatment, and the concept of dose equivalence is important for many clinical and scientific purposes.

METHODS

We refined a method presented in 2003, which was based on the minimum effective doses found in fixed-dose studies. We operationalized the selection process, updated the original findings, and expanded them by systematically searching more recent literature and by including 13 second-generation antipsychotics. To qualify for the minimum effective dose, a dose had to be significantly more efficacious than placebo in the primary outcome of at least one randomized, double-blind, fixed-dose trial. In a sensitivity analysis, 2 positive trials were required. The minimum effective doses identified were subsequently used to derive olanzapine, risperidone, haloperidol, and chlorpromazine equivalents.

RESULTS

We reviewed 73 included studies. The minimum effective daily doses/olanzapine equivalents based on our primary approach were: aripiprazole 10 mg/1.33, asenapine 10 mg/1.33, clozapine 300 mg/40, haloperidol 4 mg/0.53, iloperidone 8 mg/1.07, lurasidone 40 mg/5.33, olanzapine 7.5 mg/1, paliperidone 3 mg/0.4, quetiapine 150 mg/20, risperidone 2 mg/0.27, sertindole 12 mg/1.60, and ziprasidone 40 mg/5.33. For amisulpride and zotepine, reliable estimates could not be derived.

CONCLUSIONS

This method for determining antipsychotic dose equivalence entails an operationalized and evidence-based approach that can be applied to the various antipsychotic drugs. As a limitation, the results are not applicable to specific populations such as first-episode or refractory patients. We recommend that alternative methods also be updated in order to minimize further differences between the methods and risk of subsequent bias.

Haloperidol versus placebo for schizophrenia

BACKGROUND

Haloperidol was developed in the late 1950s for use in the field of anaesthesia. Research subsequently demonstrated effects on hallucinations, delusions, aggressiveness, impulsiveness and states of excitement and led to the introduction of haloperidol as an antipsychotic.

OBJECTIVES

To evaluate the clinical effects of haloperidol for the management of schizophrenia and other similar serious mental illnesses compared with placebo.

SEARCH METHODS

Initially, we electronically searched the databases of Biological Abstracts (1985-1998), CINAHL (1982-1998), The Cochrane Library (1998, Issue 4), The Cochrane Schizophrenia Group's Register (December 1998), EMBASE (1980-1998), MEDLINE (1966-1998), PsycLIT (1974-1998), and SCISEARCH. We also checked references of all identified studies for further trial citations and contacted the authors of trials and pharmaceutical companies for further information and archive material.For the 2012 update, on 15 May 2012, we searched the Cochrane Schizophrenia Group's Trials Register.

SELECTION CRITERIA

We included all relevant randomised controlled trials comparing the use of haloperidol (any oral dose) with placebo for those with schizophrenia or other similar serious, non-affective psychotic illnesses (however diagnosed). Our main outcomes of interest were death, loss to follow-up, clinical and social response, relapse and severity of adverse effects.

DATA COLLECTION AND ANALYSIS

We evaluated data independently and extracted, re-inspected and quality assessed the data. We analysed dichotomous data using risk ratio (RR) and calculated their 95% confidence intervals (CI). For continuous data, we calculated mean differences (MD). We excluded continuous data if loss to follow-up was greater than 50% and inspected data for heterogeneity. We used a fixed-effect model for all analyses. For the 2012 update, we assessed risk of bias of included studies and used the GRADE approach to create a 'Summary of findings' table.

MAIN RESULTS

Twenty-five trials randomising 4651 people are now included in this review. We chose seven main outcomes of interest for the 'Summary of findings' table. More people allocated haloperidol improved in the first six weeks of treatment than those given placebo (4 RCTs n = 472, RR 0.67 CI 0.56 to 0.80, moderate quality evidence). A further eight trials also found a difference favouring haloperidol across the six weeks to six months period (8 RCTs n = 307 RR 0.67 CI 0.58 to 0.78, moderate quality evidence). Relapse data from two trials favoured haloperidol at < 52 weeks but the evidence was very low quality (2 RCTs n = 70, RR 0.69 CI 0.55 to 0.86). Moderate quality evidence showed about half of those entering studies failed to complete the short trials (six weeks to six months), although, at up to six weeks, 16 studies found a difference that marginally favoured haloperidol (n = 1812, RR 0.87 CI 0.80 to 0.95). Adverse effect data does, nevertheless, support clinical impression that haloperidol is a potent cause of movement disorders, at least in the short term. Moderate quality evidence indicates that haloperidol caused parkinsonism (5 RCTs n = 485, RR 5.48 CI 2.68 to 11.22), akathisia (6 RCTs n = 695, RR 3.66 CI 2.24 to 5.97, and acute dystonia (5 RCTs n = 471, RR 11.49 CI 3.23 to 10.85). Discharge from hospital was equivocal between groups (1 RCT n = 33, RR 0.85 CI 0.47 to 1.52, very low quality evidence). Data were not reported for death and patient satisfaction.

AUTHORS' CONCLUSIONS

Haloperidol is a potent antipsychotic drug but has a high propensity to cause adverse effects. Where there is no treatment option, use of haloperidol to counter the damaging and potentially dangerous consequences of untreated schizophrenia is justified. However, where a choice of drug is available, people with schizophrenia and clinicians may wish to prescribe an alternative antipsychotic with less likelihood of adverse effects such as parkinsonism, akathisia and acute dystonias. Haloperidol should be less favoured as a control drug for randomised trials of new antipsychotics.

Benzodiazepines alone or in combination with antipsychotic drugs for acute psychosis

BACKGROUND

Acute psychotic illness, especially when associated with agitated or violent behaviour, can require urgent pharmacological tranquillisation or sedation. In several countries, clinicians often use benzodiazepines (either alone or in combination with antipsychotics) for this outcome.

OBJECTIVES

To estimate the effects of benzodiazepines, alone or in combination with antipsychotics, when compared to placebo or antipsychotics, to control disturbed behaviour and reduce psychotic symptoms.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's register (October 2002 and April 2005), inspected reference lists of included and excluded studies and contacted authors of relevant studies.

SELECTION CRITERIA

We included all randomised clinical trials comparing benzodiazepines, alone or in combination with antipsychotics, with placebo or sole use of antipsychotics, for people with acute psychotic illnesses.

DATA COLLECTION AND ANALYSIS

We reliably selected studies, quality assessed them and extracted data. For binary outcomes we calculated standard estimates of relative risk (RR) and their 95% confidence intervals (CI), and weighted number needed to treat or harm (NNT/NNH) statistics. For continuous outcomes we estimated a weighted mean difference between groups. If heterogeneity was found, we used a random effects model.

MAIN RESULTS

We included eleven studies with a total of 648 participants. When comparing benzodiazepines with placebo, sedation was equally prevalent (n=102, 1 RCT, RR 1.67 CI 0.4 to 6.6), however, fewer people allocated lorazepam remained excited at 24 hours (n=102, RR 0.62 CI 0.4 to 1.0, NNT 5 CI 3 to 59). The lorazepam and placebo group experienced similar non-significant, low levels of adverse effects. In the comparison of benzodiazepines versus use of antipsychotics without use of anticholinergics/antihistamines, people allocated benzodiazepines did not clearly need additional medication compared with those given antipsychotics (n=216, 2 RCTs, RR 1.28 CI 0.5 to 3.2). Numbers sedated were also equivocal between groups (n=324, 6 RCTs, RR 0.76 CI 0.5 to 1.2) as were mental state ratings. Extrapyramidal symptoms were significantly higher in the antipsychotic treatment group (n=391, 7 RCTs, RR 0.17 CI 0.1 to 0.4, NNT 6 CI 2 to 17). Two trials (total n=83) comparing lorazepam plus haloperidol with lorazepam alone found no clear difference for the need of additional medication (n=83, 2 RCTs, RR 1.02 CI 0.8 to 1.3) or 'not improved' at one hour (n=20, 1 RCT, RR 1.47 CI 0.66 to 3.25). There was no difference in the incidence of extrapyramidal symptoms (n=83, 2 RCTs, RR 1.94 CI 0.2 to 20.3). Finally when the benzodiazepine plus antipsychotic combination was compared with antipsychotics alone (2 RCTs, n=95) there was no difference between groups in the need for additional medications (n=67, 1 RCT, RR 0.95 CI 0.8 to 1.2) or for mental state measures. Extrapyramidal symptoms were significantly lower for people receiving both benzodiazepines and antipsychotics compared with those receiving antipsychotics alone (n=95, 2 RCTs, RR 0.45 CI 0.2 to 0.9, NNH 2 CI 1 to 5). There was no significant difference in the number of participants unfit for early discharge (n=28, 1 RCT, RR 0.90 CI 0.54 to 1.5).

AUTHORS' CONCLUSIONS

There is insufficient data from these studies to support or refute the use of benzodiazepines with or without antipsychotics where emergency drugs are needed. The sole use of older antipsychotics unaccompanied by anticholinergic drugs may be problematic, but studies in this review are not large enough to identify any serious adverse effects of benzodiazepines such as respiratory depression. Larger, more informative studies are needed before definite conclusions can be drawn as to the efficacy of benzodiazapines.

The European First Episode Schizophrenia Trial (EUFEST): rationale and design of the trial

BACKGROUND

Most studies comparing second generation antipsychotics with classical neuroleptics have been conducted in more or less chronic schizophrenia patients. Such studies were usually conducted in highly selected samples, and were generally designed and financed by the manufacturer of the drug tested. These and other facts have stimulated discussions regarding the effectiveness of the new generation of antipsychotics.

AIMS

The aim of the European First Episode Schizophrenia Trial (EUFEST) is to compare treatment with amisulpride, quetiapine, olanzapine and ziprasidone to a low dose of haloperidol in an unselected sample of first episode schizophrenia patients with minimal prior exposure to antipsychotics.

METHODS

500 patients between the ages of 18-40 meeting DSM-IV criteria for schizophrenia, schizoaffective disorder or schizophreniform disorder are randomly allocated to one year of treatment with one of the drugs under study. The primary outcome measure is retention in treatment, defined as time to discontinuation of study drug. Loss of retention can be the result of insufficient clinical effect, or lack of tolerability or acceptance. Secondary measures include changes in different dimensions of psychopathology, side effects, compliance, social needs, quality of life, substance abuse and cognitive functions.

CONCLUSIONS

At present, more than 400 patients have been recruited and randomized in the following countries: Austria, Belgium, Bulgaria, Czech Republic, Germany, France, Israel, Italy, the Netherlands, Poland, Rumania, Spain, Sweden and Switzerland: The study should be finished by the end of 2006 and it is expected that results will yield relevant clinical information with regard to the effectiveness of the second generation antipsychotics. This effort represents the first independently designed trans-European schizophrenia treatment trial.

Risperidone versus olanzapine for schizophrenia

BACKGROUND

Antipsychotic medication is a mainstay of treatment for schizophrenia and risperidone and olanzapine are the most popular treatment choice of the new generation drugs.

OBJECTIVES

To determine the clinical effects, safety and cost effectiveness of risperidone compared with olanzapine for treating schizophrenia.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's Register (June 2004) which is based on regular searches of, amongst others, BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO. References of all identified studies were inspected for further trials. We also contacted relevant pharmaceutical companies for additional information.

SELECTION CRITERIA

We included all clinical randomised trials comparing risperidone with olanzapine for schizophrenia and schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For homogenous dichotomous data we calculated random effects, relative risk (RR), 95% confidence intervals (CI) and, where appropriate, numbers needed to treat/harm (NNT/H) on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (WMD).

MAIN RESULTS

We found no difference for the outcome of unchanged or worse in the short term (n=548, 2 RCTs, RR 1.00 CI 0.88 to 1.15). One study, sponsored by the manufactures of olanzapine, favoured this drug for the outcome of relapse/rehospitalisation by 12 months (n=279, RR 2.16 CI 1.31 to 3.54, NNT 7 CI 4 to 25). Most mental state data showed the two drugs to as effective as each other (n=552, 2 RCTs, RR 'no <20% decrease PANSS by eight weeks' 1.01 CI 0.87 to 1.16). At least two thirds of people given risperidone or olanzapine experienced an adverse event (n=300, 2 RCTs, RR 1.16 CI 0.70 to 1.94). About 20% had anticholinergic symptoms (n=719, 3 RCTs, RR 1.12 CI 0.77 to 1.63) and 20% of both groups experienced insomnia (n=594, 3 RCTs, RR 1.33 CI 0.95 to 1.85) and approximately 33% sleepiness (n=719, 4 RCTs, 0.99 CI 0.79 to 1.23). One third of people given either drug experienced some extrapyramidal symptoms (n=893, 3 RCTs, RR 1.18 CI 0.75 to 1.88) but 25% of people using risperidone require medication to alleviate extrapyramidal adverse effects (n=419, 2 RCTs, RR 1.76 CI 1.25 to 2.48, NNH 8 CI 4 to 25). People allocated to risperidone were less likely to gain weight compared with those given olanzapine and the weight gain resulting from olanzapine can be considerable and of rapid onset (n=377, 1 RCT, RR gain more than 7% of their baseline weight 0.40 CI 0.23 to 0.70, NNT 8 CI 6 to 17). Risperidone may cause more sexual dysfunction than olanzapine (n=370, 2 RCTs, RR abnormal ejaculation 4.36 CI 1.38 to 13.76, NNH 20 CI 6 to 176; n=31, 1 RCT, RR impotence 2.43 CI 0.24 to 24.07). Within trials both drugs are associated with equal attrition (n=1217, 7 RCTs, RR leaving the study early 1.17 CI 0.92 to 1.49).

AUTHORS' CONCLUSIONS

Data regarding quality of life and economic outcomes are difficult to interpret, and for both these highly marketed new drugs we know very little from evaluative studies regarding service outcomes, general functioning and behaviour, engagement with services and treatment satisfaction. There is little to differentiate between risperidone and olanzapine except on the issue of adverse effects and both these drugs have unpleasant adverse effects. Risperidone is particularly associated with movement disorders and sexual dysfunction. Olanzapine can cause considerable rapid weight gain.This review highlights the need for large, independent, well designed, conducted and reported pragmatic randomised studies.

Rapid tranquillisation for agitated patients in emergency psychiatric rooms: a randomised trial of midazolam versus haloperidol plus promethazine

OBJECTIVE

To compare two widely used drug treatments for people with aggression or agitation due to mental illness.

DESIGN

Pragmatic, randomised clinical trial.

SETTING

Three psychiatric emergency rooms in Rio de Janeiro, Brazil.

SUBJECTS

301 aggressive or agitated people.

INTERVENTIONS

Open treatment with intramuscular midazolam or intramuscular haloperidol plus promethazine.

MAIN OUTCOME MEASURES

Patients tranquil or sedated at 20 minutes.

SECONDARY OUTCOMES

patients tranquil or asleep by 40, 60, and 120 minutes; restrained or given extra drugs within 2 hours; severe adverse events; another episode of agitation or aggression; needing extra visits from doctor during first 24 hours; overall antipsychotic load in first 24 hours; and not discharged by two weeks.

RESULTS

151 patients were randomised to midazolam, and 150 to haloperidol-promethazine mix. Follow up for the primary outcome was available for 298 (99%): 134/151 (89%) of patients given midazolam were tranquil or asleep after 20 minutes compared with 101/150 (67%) of those given haloperidol plus promethazine (relative risk 1.32 (95% confidence interval 1.16 to 1.49)). By 40 minutes, midazolam still had a statistically and clinically significant 13% relative advantage (1.13 (1.01 to 1.26)). After 1 hour, about 90% of both groups were tranquil or asleep. One important adverse event occurred in each group: a patient given midazolam had transient respiratory depression, and one given haloperidol-promethazine had a grande mal seizure.

CONCLUSIONS

Both treatments were effective. Midazolam was more rapidly sedating than haloperidol-promethazine, reducing the time people are exposed to aggression. Adverse effects and resources to deal with them should be considered in the choice of the treatment.

Short-acting parenteral antipsychotics drive choice for classical versus atypical agents

OBJECTIVE

The objective of this study was to investigate which antipsychotics (classical versus atypical) are prescribed in a psychiatric hospital and which determinants affect the choice for one of these two classes of antipsychotics in newly admitted patients.

METHODS

In a retrospective cohort design, 522 newly admitted patients were followed from the date of admission until discharge from the hospital. In the cohort of newly admitted patients treated with an oral antipsychotic, a nested case-control study was conducted considering recipients of an atypical agent as cases. Controls were all other cohort members. The association of patient characteristics and the choice between classical versus atypical antipsychotics was studied using logistic regression analysis. The same analysis was performed with adjustment for possible confounding factors (age group, gender, DSM-IV diagnoses, use of short-acting parenteral antipsychotic, global assessment of functioning score, involuntary admissions and involuntary measures).

RESULTS

Patients treated with classical oral antipsychotics were more often previously treated with short-acting parenteral antipsychotics than patients treated with atypical antipsychotics (40.8% vs 15.2%; adjusted OR=0.20 95% CI=0.09-0.44). No statistically significant difference was found between patients with different severities of disease.

DISCUSSION

Availability of injectable forms seems to drive the choice for oral antipsychotic agents. Future introductions of short-acting parenteral atypical antipsychotics may have a large impact on first-choice oral antipsychotic treatment.

TREC-Rio trial: a randomised controlled trial for rapid tranquillisation for agitated patients in emergency psychiatric rooms [ISRCTN44153243]

BACKGROUND

Agitated or violent patients constitute 10% of all emergency psychiatric treatment. Management guidelines, the preferred treatment of clinicians and clinical practice all differ. Systematic reviews show that all relevant studies are small and none are likely to have adequate power to show true differences between treatments. Worldwide, current treatment is not based on evidence from randomised trials. In Brazil, the combination haloperidol-promethazine is frequently used, but no studies involving this mix exist.

METHODS

TREC-Rio (Tranquilização Rápida-Ensaio Clínico [Translation: Rapid Tranquillisation-Clinical Trial]) will compare midazolam with haloperidol-promethazine mix for treatment of agitated patients in emergency psychiatric rooms of Rio de Janeiro, Brazil. TREC-Rio is a randomised, controlled, pragmatic and open study. Primary measure of outcome is tranquillisation at 20 minutes but effects on other measures of morbidity will also be assessed. TREC-Rio will involve the collaboration of as many health care professionals based in four psychiatric emergency rooms of Rio as possible. Because the design of this trial does not substantially complicate clinical management, and in several aspects simplifies it, the study can be large, and treatments used in everyday practice can be evaluated.