How representative of everyday clinical populations are schizophrenia patients enrolled in clinical trials?

A novel approach to assessing disparity in representativeness of clinical trial participants within a large midwestern healthcare system

Background

Representativeness in clinical trials (CT) serves as a metric of access to healthcare and reflects differences that may determine differential efficacy of medical interventions; thus, quantifying representativeness in CT participation is critical.

Methods

This retrospective, descriptive study utilized patient demographic data extracted from the largest Midwestern non-profit healthcare system. Using data between January 1, 2019 and December 31, 2021, a CT Participant Sample of 4,537 system patients who were active CT participants was compared to a CT Patient Population of 195,726 system patients receiving care by the PI of active CTs, which represented the target population. Chi-square goodness-of-fit tests were used to test differences in distributions of demographic variables between groups, indicating disparity in CT participation. Two metrics adapted from literature - participation incidence disparity (PID) and participation incidence ratio (PIR) - were calculated to quantify absolute and relative disparity in representativeness proportions, respectively. Descriptive approaches to assessing representativeness are also provided.

Results

Results showed significant differences by race/ethnicity (χ2 = 50.64; p < 0.0001), age categories (χ2 = 56.64; p < 0.0001), and insurance (χ2 = 41.29; p < 0.0001). PID and PIR metrics revealed reduced CT participation among non-White racial/ethnic groups and increased CT participation among White Non-Hispanic patients. Further, CT participants ≥80 or Worker's Compensation were underrepresented while those with Self-Pay insurance were overrepresented as CT participants.

Conclusions

Despite progress, continued efforts to not only enroll participants into CTs that are representative of the healthcare system and region, but also to better assess representativeness quantitatively are still needed.

Clinical Trials Studying Suicide Risk Reduction: Who is Excluded From Participation

OBJECTIVE

The use of exclusion criteria in clinical trials can cause research participants to differ markedly from clinical populations, which negatively impacts generalizability of results. This study identifies and quantifies common and recurring exclusion criteria in clinical trials studying suicide risk reduction, and estimates their impact on eligibility among a clinical sample of adults in an emergency department with high suicide risk.

METHOD

Recent trials were identified by searching PubMed (terms suicide, efficacy, effectiveness, limited to clinical trials in prior 5 years). Common exclusion criteria were identified using Qualitative Content Analysis. A retrospective chart review examined a one-month sample of all adults receiving psychiatric evaluation in a large urban academic emergency department.

RESULTS

The search yielded 27 unique clinical trials studying suicide risk reduction as a primary or secondary outcome. After research fundamentals (e.g. informed consent, language fluency), the most common exclusion criteria involved psychosis (77.8%), cognitive problems (66.7%), and substance use (63.0%). In the clinical sample of adults with high suicide risk (N = 232), psychosis exclusions would exclude 53.0% of patients and substance use exclusions would exclude 67.2% of patients. Overall, 5.6% of emergency psychiatry patients would be eligible for clinical trials that use common exclusion criteria.

CONCLUSIONS

Recent clinical trials studying suicide risk reduction have low generalizability to emergency psychiatry patients with high suicide risk. Trials enrolling persons with psychosis and substance use in particular are needed to improve generalizability to this clinical population.

CLEAR - clozapine in early psychosis: study protocol for a multi-centre, randomised controlled trial of clozapine vs other antipsychotics for young people with treatment resistant schizophrenia in real world settings

BACKGROUND

Clozapine is an antipsychotic drug with unique efficacy, and it is the only recommended treatment for treatment-resistant schizophrenia (TRS: failure to respond to at least two different antipsychotics). However, clozapine is also associated with a range of adverse effects which restrict its use, including blood dyscrasias, for which haematological monitoring is required. As treatment resistance is recognised earlier in the illness, the question of whether clozapine should be prescribed in children and young people is increasingly important. However, most research to date has been in older, chronic patients, and evidence regarding the efficacy and safety of clozapine in people under age 25 is lacking. The CLEAR (CLozapine in EARly psychosis) trial will assess whether clozapine is more effective than treatment as usual (TAU), at the level of clinical symptoms, patient rated outcomes, quality of life and cost-effectiveness in people below 25 years of age. Additionally, a nested biomarker study will investigate the mechanisms of action of clozapine compared to TAU.

METHODS AND DESIGN

This is the protocol of a multi-centre, open label, blind-rated, randomised controlled effectiveness trial of clozapine vs TAU (any other oral antipsychotic monotherapy licenced in the British National Formulary) for 12 weeks in 260 children and young people with TRS (12-24 years old).

AIM AND OBJECTIVES

The primary outcome is the change in blind-rated Positive and Negative Syndrome Scale scores at 12 weeks from baseline. Secondary outcomes include blind-rated Clinical Global Impression, patient-rated outcomes, quality of life, adverse effects, and treatment adherence. Patients will be followed up for 12 months and will be invited to give consent for longer term follow-up using clinical records and potential re-contact for further research. For mechanism of action, change in brain magnetic resonance imaging (MRI) biomarkers and peripheral inflammatory markers will be measured over 12 weeks.

DISCUSSION

The CLEAR trial will contribute knowledge on clozapine effectiveness, safety and cost-effectiveness compared to standard antipsychotics in young people with TRS, and the results may guide future clinical treatment recommendation for early psychosis.

TRIAL REGISTRATION

ISRCTN Number: 37176025, IRAS Number: 1004947.

TRIAL STATUS

In set-up. Protocol version 4.0 01/08/23. Current up to date protocol available here: https://fundingawards.nihr.ac.uk/award/NIHR131175# /.

How representative are clinical trial cohorts of the general CF population? Implications for trial planning

Understanding the number of patients eligible to participate in research is important to design protocols and define research priorities. We reviewed the records of all patients with CF, age 12+, who receive care at our centre. We assessed their eligibility for trial participation based on common trial inclusion/exclusion criteria. 643 patients were included in the analysis, 31 were modulator ineligible(MI). Only 198(31 %) of the total cohort and 7(23 %) of the MI cohort were eligible for participation based on the hypothetical criteria. The most common reason for ineligibility was ppFEV1 ≥90 % followed by clinical instability, complex comorbidity and anticipated inability to adhere to the protocol. We suggest this would be a useful exercise for centres planning to either participate in, or refer subjects into, upcoming trials to undertake for their own cohort. We also make suggestions for protocol designs that optimise the number of patients who are eligible to participate.

Selection bias in clinical studies of first-episode psychosis: A follow-up study

OBJECTIVES

Selection bias is a concern in studies on psychotic disorders due to high dropout rates and many eligibility criteria for inclusion. We studied how representative the first-episode psychosis study sample in the Turku Early Psychosis Study (TEPS) was.

METHODS

We screened 3772 consecutive admissions to the clinical psychiatric services of Turku Psychiatry, Finland, between October 2011 and June 2016. A total of 193 subjects had first-episode psychosis and were suitable for TEPS. Out of 193 subjects, 101 participated (PA) and 92 did not participate (NPA) in TEPS due to refusal or contact problems. We retrospectively used patient register data to study whether NPA and PA groups differed in terms of clinical outcomes during 1-year follow-up.

RESULTS

In overall sample, the NPA group had a significantly higher rate of discontinuation of clinical treatment than the PA group (48.9 % vs 29.7 %, p = 0.01). In the hospital-treated subsample chi-square tests did not indicate statistically significant differences between the NPA and PA groups in the rate of involuntary care (69.7 % vs 62.7 %, p = 0.34), coercive measures (36.0 % vs 22.7 %, p = 0.06), and readmissions during the follow-up (41.5 % vs 33.8 %, p = 0.31), respectively.

CONCLUSION

The differences in clinical outcomes and treatment characteristics in the non-participating and participating groups were relatively modest. The results do not support a major sample selection bias that would complicate the interpretation of results in this first-episode psychosis study.

Representation and Outcomes of Individuals With Schizophrenia Seen in Everyday Practice Who Are Ineligible for Randomized Clinical Trials

IMPORTANCE

Most evidence about efficacy and safety of antipsychotics in schizophrenia spectrum disorders relies on randomized clinical trials (RCTs). However, owing to their strict eligibility criteria, RCTs represent only a part of the real-world population (ie, unselected patients seen in everyday clinical practice), which may result in an efficacy-effectiveness gap.

OBJECTIVE

To quantify the proportion of real-world individuals with schizophrenia spectrum disorders who would be ineligible for participation in RCTs, and to explore whether clinical outcomes differ between eligible and ineligible individuals.

DESIGN, SETTING, AND PARTICIPANTS

This study applied eligibility criteria typically used in RCTs for relapse prevention in schizophrenia spectrum disorders to real-world populations. Individuals with diagnoses of schizophrenia spectrum disorders recorded in national patient registries in Finland and Sweden were identified. Individuals who had used antipsychotics continuously for 12 weeks in outpatient care were selected. Individuals were followed up for up to 1 year while they were receiving maintenance treatment with any second-generation antipsychotic (excluding clozapine). Follow-up was censored at treatment discontinuation, initiation of add-on antipsychotics, death, and end of database linkage.

MAIN OUTCOMES AND MEASURES

Proportions of RCT-ineligible individuals with schizophrenia spectrum disorders owing to any and specific RCT exclusion criteria. The risk of hospitalization due to psychosis within 1-year follow-up in ineligible vs eligible persons were compared using hazard ratios (HR) and corresponding 95% CIs.

RESULTS

The mean (SD) age in the Finnish cohort (n = 17 801) was 47.5 (13.8) years and 8972 (50.4%) were women; the mean (SD) age in the Swedish cohort (n = 7458) was 44.8 (12.5) years and 3344 (44.8%) were women. A total of 20 060 individuals (79%) with schizophrenia spectrum disorders would be ineligible for RCTs (Finnish cohort: 14 221 of 17 801 [79.9%]; Swedish cohort: 5839 of 7458 [78.3%]). Most frequent reasons for ineligibility were serious somatic comorbidities and concomitant antidepressant/mood stabilizer use. Risks of hospitalization due to psychosis was higher among ineligible than eligible individuals (Finnish cohort: 18.4% vs 17.2%; HR, 1.14 [95% CI, 1.04-1.24]; Swedish cohort: 20.1% vs 14.8%; HR, 1.47 [95% CI, 1.28-1.92]). The largest risks of hospitalization due to psychosis were observed in individuals ineligible owing to treatment resistance, tardive dyskinesia, and history of suicide attempts. Finally, with more ineligibility criteria met, larger risks of hospitalization due to psychosis were observed in both countries.

CONCLUSIONS AND RELEVANCE

RCTs may represent only about a fifth of real-world individuals with schizophrenia spectrum disorders. Underrepresented (ineligible) patients with schizophrenia spectrum disorders have moderately higher risks of admission due to psychosis while receiving maintenance treatment than RCT-eligible patients. These findings set the stage for future studies targeting real-world populations currently not represented by RCTs.

Factors affecting participant recruitment and retention in borderline personality disorder research: a feasibility study

Background

Previous studies have shown that stigma is a major barrier to participation in psychiatric research and that individuals who participate in psychiatric research may differ clinically and demographically from non-participants. However, few studies have explored research recruitment and retention challenges in the context of personality disorders.

Aim

To provide an analysis of the factors affecting participant recruitment and retention in a study of borderline personality disorder among general psychiatric inpatients.

Methods

Adult inpatients in a tertiary psychiatric hospital were approached about participating in a cross-sectional study of borderline personality disorder. Recruitment rates, retention rates, and reasons for declining participation or withdrawing from the study were collected. Demographic characteristics were compared between participants and non-participants and between patients who remained in the study and those who withdrew.

Results

A total of 71 participants were recruited into the study between January 2018 and March 2020. Recruitment and retention rates were 45% and 70%, respectively. Lack of interest was the most commonly cited reason for non-participation, followed by scheduling conflicts and concerns regarding mental/physical well-being. Age and sex were not predictors of study participation or retention.

Conclusions

More research is needed to explore patients’ perspectives and attitudes towards borderline personality disorder diagnosis and research, determine effects of different recruitment strategies, and identify clinical predictors of recruitment and retention in personality disorder research.

How do participants in clinical trials compare with other patients with schizophrenia?

We aimed to explore the clinical relevance of a multicentre, pragmatic randomised trial of antipsychotic reduction in people diagnosed with schizophrenia or psychosis The sample recruited for the antipsychotic reduction study (n = 69 people) was compared with the population of patients with an eligible diagnosis undergoing treatment in the same service (n = 3067 people), using routinely-collected, anonymised data. The trial sample was found to resemble the wider population in terms of the number of past admissions, the likelihood of having been subject to legal detention and the level of risk the patient was perceived to pose to themselves or others. There was a lower proportion of people from minority ethnic backgrounds in the trial sample. The results provide some reassurance that trial recruits were similar to the wider population in terms of the severity of their condition and did not comprise a highly select sample of people with milder problems. The different ethnic composition of the research sample is consistent with other research.

Unwell in hospital but not incapable: cross-sectional study on the dissociation of decision-making capacity for treatment and research in in-patients with schizophrenia and related psychoses

BACKGROUND

Consent to research with decision-making capacity for research (DMC-R) is normally a requirement for study participation. Although the symptoms of schizophrenia and related psychoses are known to affect decision-making capacity for treatment (DMC-T), we know little about their effect on DMC-R.AimsWe aimed to determine if DMC-R differs from DMC-T in proportion and associated symptoms in an in-patient sample of people with schizophrenia and related psychoses.

METHOD

Cross-sectional study of psychiatric in-patients admitted for assessment and/or treatment of schizophrenia and related psychoses. We measured DMC-R and DMC-T using 'expert judgement' clinical assessment guided by the MacArthur Competence Assessment Tool for Clinical Research, the MacArthur Competence Assessment Tool for Treatment and the legal framework of the Mental Capacity Act (2005), in addition to symptoms of psychosis.

RESULTS

There were 84 participants in the study. Half the participants had DMC-R (51%, 95% CI 40-62%) and a third had DMC-T (31%, 95% CI 21-43%) and this difference was statistically significant (P < 0.01). Thought disorder was most associated with lacking DMC-R (odds ratio 5.72, 95% CI 2.01-16.31, P = 0.001), whereas lack of insight was most associated with lacking DMC-T (odds ratio 26.34, 95% CI 3.60-192.66, P = 0.001). With the exception of improved education status and better DMC-R, there was no effect of sociodemographic variables on either DMC-R or DMC-T.

CONCLUSIONS

We have shown that even when severely unwell, people with schizophrenia and related psychoses in in-patient settings commonly retain DMC-R despite lacking DMC-T. Furthermore, different symptoms have different effects on decision-making abilities for different decisions. We should not view in-patient psychiatric settings as a research 'no-go area' and, where appropriate, should recruit in these settings.Declaration of interestNone.

The Representativeness of Participants With Severe Mental Illness in a Psychosocial Clinical Trial

Introduction: Cardiovascular morbidity and mortality are increased in severe mental illnesses (SMI). Trials of psychosocial health interventions to improve physical health in SMI, including in treatment-resistant schizophrenia, have shown some benefit. However, the representativeness of participants in such trials has not been determined. Method: We utilized an anonymised case register to determine if participants in a randomized controlled trial (RCT) of a novel psychosocial health intervention aiming to improve physical health in SMI had similar severity of illness to eligible non-participants. A retrospective database analysis was performed, using Health of the Nation Outcome Scale (HoNOS) data from the sample of patients participating in the IMPaCT (Improving Physical health and reducing substance use in Psychosis) RCT (n = 293) compared to all eligible participants with a psychotic illness (n = 774). Results: The mean total HoNOS score in the eligible comparator population (Mean = 9.09, SD = 5.8, range = 0-30) was significantly greater than that of the IMPaCT RCT participants (Mean = 7.16, SD = 4.7, range = 0-26), (t = 3.810, p = 0.006), as was the degree of overall illness severity and functional impairment, as measured by HoNOS. Conclusion: This study shows for the first time that the patient population participating in an RCT of a lifestyle intervention for those with SMI had a better mental health status at entry to the trial, than the total eligible population, although there was no difference in physical health needs. This has relevance to the applicability of RCTs of lifestyle interventions in service planning and suggests that when people are more unwell, greater effort may be needed to include them in psychosocial interventions. A more careful and focused recruitment approach should be followed to improve the participation of the more severely ill patients in psychosocial interventions in order to enhance the external validity of such studies.

A Review of the Impact of Exclusion Criteria on the Generalizability of Schizophrenia Treatment Research

Treatment research studies employ criteria that determine which patients are eligible to participate and which are not. When such exclusion criteria produce a treatment research sample that is a small and unrepresentative subset of all patients with a particular disease, clinicians may be hesitant to apply the research results in front-line clinical practice. Accordingly, the present paper reviews the English-language literature on exclusion criteria in schizophrenia treatment research and draws initial conclusions about their impact. Empirically derived estimates of the rate of exclusion vary widely (31.0-98.2%), but the best available evidence suggests that about 4 in 5 patients with schizophrenia would be ineligible to enroll in a typical treatment research study. Women are particularly likely to be excluded from schizophrenia treatment research, which is problematic from both a clinical and social justice viewpoint. Excluded patients also tend to be older than eligible patients, and, though it has been examined in only a few studies, they also tend to have more severe problems at baseline and different outcomes over time than patients who are allowed to participate in research. More limited use of exclusion criteria in schizophrenia treatment research would be beneficial in terms of increasing generalizability, but would also potentially involve costs, particularly a need for larger samples. More modest steps that would improve treatment outcome research reports include requiring a full description of the rationale for, and nature of, any exclusion criteria, and, having a designated place in the discussion section which draws attention to the proper scope of generalization.

A literature review on the representativeness of randomized controlled trial samples and implications for the external validity of trial results

Randomized controlled trials (RCTs) are conducted under idealized and rigorously controlled conditions that may compromise their external validity. A literature review was conducted of published English language articles that reported the findings of studies assessing external validity by a comparison of the patient sample included in RCTs reporting on pharmaceutical interventions with patients from everyday clinical practice. The review focused on publications in the fields of cardiology, mental health, and oncology. A range of databases were interrogated (MEDLINE; EMBASE; Science Citation Index; Cochrane Methodology Register). Double-abstract review and data extraction were performed as per protocol specifications. Out of 5,456 de-duplicated abstracts, 52 studies met the inclusion criteria (cardiology, n = 20; mental health, n = 17; oncology, n = 15). Studies either performed an analysis of the baseline characteristics (demographic, socioeconomic, and clinical parameters) of RCT-enrolled patients compared with a real-world population, or assessed the proportion of real-world patients who would have been eligible for RCT inclusion following the application of RCT inclusion/exclusion criteria. Many of the included studies concluded that RCT samples are highly selected and have a lower risk profile than real-world populations, with the frequent exclusion of elderly patients and patients with co-morbidities. Calculation of ineligibility rates in individual studies showed that a high proportion of the general disease population was often excluded from trials. The majority of studies (n = 37 [71.2 %]) explicitly concluded that RCT samples were not broadly representative of real-world patients and that this may limit the external validity of the RCT. Authors made a number of recommendations to improve external validity. Findings from this review indicate that there is a need to improve the external validity of RCTs such that physicians treating patients in real-world settings have the appropriate evidence on which to base their clinical decisions. This goal could be achieved by trial design modification to include a more representative patient sample and by supplementing RCT evidence with data generated from observational studies. In general, a thoughtful approach to clinical evidence generation is required in which the trade-offs between internal and external validity are considered in a holistic and balanced manner.

Considerations in psychotropic treatments in dementia--can polypharmacy be avoided?

Physicians treating demented individuals are confronted with complex clinical presentations. This complexity results from the multi-factorial nature of clinical phenomena, the aetiologies of these phenomena, which differ from similar symptoms in younger populations, limited physiological reserves and the multiple co-morbidities and medications. This intricacy is well exemplified within the clinical presentation and management of psychological and behavioural symptoms of dementia. The latter are associated with a poor quality of life, increased burden for both patient and caregivers. A further challenge and source for frustration is the fact that many of the medications used to treat cognitive and behavioural symptoms of dementia are only marginally effective or not effective at all, on the one hand, and associated with increased risk for morbidity and mortality on the other hand. In the present review, we discuss these factors in the context of polypharmacy and suggest further clinical and research strategies that may enable more accurate and less harmful therapeutic strategies.

Early improvement as a predictor of treatment response and remission in patients with schizophrenia: a pooled, post-hoc analysis from the asenapine development program

OBJECTIVE

The purpose of this study was to assess whether early symptom improvement predicts later treatment outcome in patients with schizophrenia.

METHODS

Data were pooled from intent-to-treat (ITT) populations of three six-week randomized controlled studies with fixed doses of asenapine (ASE; n=470), olanzapine (OLA; n=95), risperidone (RIS; n=56), haloperidol (HAL; n=112), or placebo (PLA; n=275). Early improvement was defined as a 20% reduction of Positive and Negative Syndrome Scale (PANSS) total score at week 2, compared to baseline (primary criterion). Treatment outcome at week 6 was defined as response (PANSS: ≥50% score reduction) or remission (PANSS item score ≤3 on selected items at week 6). Odds ratios (ORs) and predictive performance statistics were calculated.

RESULTS

Statistically significant associations between early improvement (at week 2) and treatment outcome (at week 6) were observed for all treatment groups except OLA; as evidenced by increased ORs for response. Analysis of associations between early improvement and remission, as defined by Andreasen et al. (2005), revealed a statistically significant relationship for ASE and PLA-treated patients only. Predictive performance statistics revealed higher negative predictive value (NPV) and sensitivity rates, and comparably lower positive predictive value (PPV) and specificity rates across treatment groups for both response and remission.

CONCLUSION

It is suggested that absence of improvement within two weeks of treatment may predict the unlikely success of subsequent pharmacological intervention.

The potential role of Marginal Structural Models (MSMs) in testing the effectiveness of antidepressants in the treatment of patients with major depression in everyday clinical practice

OBJECTIVES

To better evaluate the effectiveness of antidepressant drugs in the treatment of major depression in clinical practice.

METHODS

A simulation experiment was used to illustrate an application of marginal structural models (MSMs) via inverse probability of treatment weighting (IPTW) approach in the context of non-randomized data on N = 1,000 depressed subjects, initially subjected to "watchful waiting". In simulation we assumed that subjects with worse intermediate outcome have a higher probability of being subsequently assigned to antidepressant treatment while those who receive antidepressant treatment are more likely to reach remission and less likely to reach relapse state. The outcomes from multiple (500) simulated data sets are analyzed using simple unadjusted analysis based on logistic regression and using MSM.

RESULTS

In contrast to unadjusted analysis, but consistent with the treatment assumptions, using MSM via IPTW results in strong evidence of the effectiveness of the antidepressant treatment. Furthermore MSM via IPTW substantially reduces the probability of wrongly rejecting the null hypothesis. However, the instability of weights due to the sparse data and incorrectly specified MSM may still result in inflation of Type I error rates.

CONCLUSIONS

MSMs may allow evaluating the causal effects associated with antidepressant treatment from the data observed in clinical practice.

Veteran subjects willingness to participate in schizophrenia clinical trials

Predictive characteristics of subjects agreeing to be randomized into clinical trials for the treatment of schizophrenia and schizoaffective disorder have been little studied. In this study, we used data from the recruitment phase of a randomized trial that compared long acting injectable (LAI) risperidone to oral antipsychotic medications. Basic socio-demographic and clinical data were gathered from eligible patients and clinicians at the time of screening for trial entry. Bivariate comparisons and multivariate logistic regression were used to compare those who agreed to participate and those who refused. Altogether 446 veterans were eligible on preliminary screening, of these 382 (86 %) agreed to participate and 64 (14 %) declined. Eligible patients who agreed to be randomized were more willing to change medications without regard to their level of satisfaction with their current medication. Subjects reported as currently taking LAI medication and taking risperidone, in particular, were more likely to agree to participate. Factors that did not significantly predict participation included age, years on current medication, reported medication compliance, race, and gender. Veterans with schizophrenia or schizoaffective disorder who were actually more satisfied with their current medications and who were currently taking the experimental agent were more likely to agree to participate in this randomized clinical trial in contrast to expectations that individuals who are unsatisfied with their current treatment would be more likely to enroll in such studies.

[Eligibility of schizophrenia inpatients to participate in clinical trials]

INTRODUCTION

This study assesses the potential eligibility of patients admitted to a psychiatric hospitalisation unit to take part in the major clinical trials based on schizophrenia treatment in clinical practice (CATIE, CUtLASS and EUFEST).

MATERIAL AND METHODS

A retrospective evaluation by consulting the medical records of 241 subjects (59.8% males and 40.2% females, mean age 39.7±13.0 years), admitted consecutively over one year to psychiatric hospitalisation unit with a diagnosis of schizophrenia or another psychosis. The influence of the factors involved in the non-eligibility in each of the clinical trials is analysed using logistic regression analysis.

RESULTS

Only 20.7%, 22.3%, and 22.5% of patients with schizophrenia or another psychosis would be eligible to participate in the CATIE, CUtLASS and EUFEST studies, respectively. The main factors involved in the non-eligibility were polytherapy with anti-psychotics (2 or more) (Odds Ratio (OR): 7.64, 95% confidence interval (CI): 3.06-19.06, P<.001), mental retardation (OR: 16.67, 95% CI: 1.75-166.67, P=.014), and resistance, intolerance or contraindication to any of the anti-psychotics of the study (OR: 3.68, 95% CI: 1.13-11.99, P=.030).

CONCLUSIONS

Three out of every four patients with schizophrenia or another psychosis admitted to a psychiatric hospitalisation unit are not represented in the major clinical trials on schizophrenia treatment.

Equipercentile linking of the Brief Psychiatric Rating Scale and the Clinical Global Impression Scale in a catchment area

Recent analyses tried to explain the meaning of the Brief Psychiatric Rating Scale total score (BPRS) and its percentage change from baseline by equipercentile linking with the Clinical Global Impression Scale (CGI). A major limitation was that they were conducted in clinical trial populations limiting generalisability to 'real-world' patients. We therefore replicated the findings in a large sample covering patients admitted to a state hospital with a catchment area. BPRS and CGI ratings at admission (n=1772) and at discharge from all patients with schizophrenic disorders (ICD-10 F20.0-F20.9) admitted between 2005 and 2008 were compared using equipercentile linking. Being considered "mildly ill" according to the CGI severity score approximately corresponded to a BPRS total score of 25, "moderately ill" to a BPRS of 33-35, "markedly ill" to a BPRS of 50 and severely ill to a BPRS of 70. To be "minimally improved" according to the CGI change score was associated with a mean BPRS reduction of 13%; and "much improved" with 50% BPRS reduction. The linking functions were not identical, but overall comparable to those in previous randomised trial samples. The suggestion that a 50% BPRS reduction from baseline is a clinically meaningful definition of response in acutely ill patients was reinforced.

How close is evidence to truth in evidence-based treatment of mental disorders?

Given the importance of the term 'evidence' in evidence-based medicine (EBM), the meaning of this term is evaluated, going back to the philosophical tradition and current meaning of the terms 'evidence' and 'truth'. Based on this, current problems in the definition of evidence and in the grading of evidence in EBM are described, taking examples from the field of psychiatry and especially pharmacopsychiatry. These problems underline that the use of the term evidence in EBM is inconsistent and inconclusive. This should be fairly stated in all EBM-related publications, especially in EBM-based guidelines, to avoid severe misunderstandings in and outside the field of psychiatry. Although EBM might have increased empirically driven rational decision-making in psychiatry/medicine, the current limitations should be carefully considered.

What is causing the reduced drug-placebo difference in recent schizophrenia clinical trials and what can be done about it?

On September 18, 2007, a collaborative session between the International Society for CNS Clinical Trials and Methodology and the International Society for CNS Drug Development was held in Brussels, Belgium. Both groups, with membership from industry, academia, and governmental and nongovernmental agencies, have been formed to address scientific, clinical, regulatory, and methodological challenges in the development of central nervous system therapeutic agents. The focus of this joint session was the apparent diminution of drug-placebo differences in recent multicenter trials of antipsychotic medications for schizophrenia. To characterize the nature of the problem, some presenters reported data from several recent trials that indicated higher rates of placebo response and lower rates of drug response (even to previously established, comparator drugs), when compared with earlier trials. As a means to identify the possible causes of the problem, discussions covered a range of methodological factors such as participant characteristics, trial designs, site characteristics, clinical setting (inpatient vs outpatient), inclusion/exclusion criteria, and diagnostic specificity. Finally, possible solutions were discussed, such as improving precision of participant selection criteria, improving assessment instruments and/or assessment methodology to increase reliability of outcome measures, innovative methods to encourage greater subject adherence and investigator involvement, improved rater training and accountability metrics at clinical sites to increase quality assurance, and advanced methods of pharmacokinetic/pharmacodynamic modeling to optimize dosing prior to initiating large phase 3 trials. The session closed with a roundtable discussion and recommendations for data sharing to further explore potential causes and viable solutions to be applied in future trials.

Safety and efficacy of long-acting injectable risperidone in daily practice: an open-label, noninterventional, prospective study in schizophrenia and related disorders

This postauthorization safety study evaluated the long-term safety, tolerability, and efficacy of risperidone long-acting injectable (RLAI) in routine clinical practice. In this 6-month, multicenter, European, naturalistic study, patients were included if, during routine clinical practice, long-term antipsychotic therapy with RLAI was deemed necessary by the treating physician. Efficacy measures included Clinical Global Impression-Severity and Global Assessment of Functioning. Safety was evaluated by recording treatment-emergent adverse events (AE). RLAI was initiated in 5134 patients (aged 14-94 years); predominantly male (58.6%) with paranoid schizophrenia (69.8%). RLAI initial doses were 25 mg every 2 weeks (37.0% patients), 37.5 mg (18.0%), and 50 mg (44.4%). Treatment was completed by 4314 patients (84.0%). RLAI was discontinued on account of loss to follow-up (n=346; 6.7%), insufficient response (n=116; 2.3%), and AEs (n=106; 2.1%). Clinical Global Impression-Severity significantly improved from baseline to endpoint (P<0.001). Patient functioning on the Global Assessment of Functioning scale also significantly improved from baseline to endpoint (45.4 + or - 16.0 vs. 62.4 + or - 17.7, respectively, P<0.001). Treatment-emergent AEs were recorded by 1018 (20%) of patients. AEs occurring in > or = 5% of patients were akathisia, extrapyramidal disorders, depression, psychotic disorder, anxiety, and weight gain. Serious AEs were reported by 384 (8%) patients. This study confirms good safety, tolerability, and efficacy with RLAI in routine clinical practice.

Appraising evidence for intervention effectiveness in early psychosis: conceptual framework and review of evaluation approaches

The literature that is relevant to evaluation of treatment effectiveness is large, scattered and difficult to assemble for appraisal. This scoping review first develops a conceptual framework to help organize the field, and second, uses the framework to appraise early psychosis intervention (EPI) studies. Literature searches were used to identify representative study designs, which were then sorted according to evaluation approach. The groupings provided a conceptual framework upon which a map of the field could be drawn. Key words were cross-checked against definitions in dictionaries of scientific terms and the National Library of Medicine Medical Subject Headings (MeSH) browser. Using the final list of key words as search terms, the EPI evaluation literature was appraised. Experimental studies could be grouped into two classes: efficacy and effectiveness randomized controlled trials. Non-experimental studies could be subgrouped into at least four overlapping categories: clinical epidemiological; health service evaluations; quality assurance studies; and, quasi-experimental assessments of treatment effects. Applying this framework to appraise EPI studies indicated promising evidence for the effectiveness of EPI irrespective of study design type, and a clearer picture of where future evaluation efforts should be focused. Reliance on clinical trials alone will restrict the type of information that can inform clinical practice. There is convergent evidence for the benefits of specialized EPI service functions across a range of study designs. Greater investment in health services research and quality assurance approaches in evaluating EPI effectiveness should be made, which will involve scaling up of study sizes and development of an EPI programme fidelity rating template. The degree of complexity of the evaluation field suggests that greater focus on research methodology in the training of Australasian psychiatrists is urgently needed.

Evidence-based medicine in psychopharmacotherapy: possibilities, problems and limitations

Psychopharmacotherapy should now be regulated in the sense of evidence-based medicine, as is the case in other areas of clinical treatment in medicine. In general this is a meaningful development, which principally will have a positive impact on routine health care in psychiatry. But several related problems should not be ignored. So far consensus on an internationally accepted evidence graduation could not be reached due to several difficulties related to this. For example, focussing on the results of meta-analyses instead of considering relevant single studies results in a decision-making logic which is in conflict with the rationale applied by drug authorities in the licensing process. Another example is the relevance of placebo-controlled trials: if randomized placebo-controlled phase-III studies are prioritized in the evidence grading, the evidence possibly deviates too far from the conditions of routine clinical care due to the special selection of patients in those studies. However, a grading primarily based on active comparator trials could lead to wrong conclusions about efficacy. This concerns especially the so-called "effectiveness" studies and other forms of phase-IV studies with their less restrictive methodological rigidity. Attempts to regulate psychopharmacotherapy in the sense of evidence-based medicine come closer to their limits the more complex the clinical situation and the respective decision-making logic are. Even in times of evidence-based medicine a large part of complex clinical decision-making in psychopharmacotherapy still relies more on clinical experience and a consensus on clinical experience, traditions and belief systems than on results of efficacy oriented phase-III and effectiveness-oriented phase-IV clinical studies.

Principle standards and problems regarding proof of efficacy in clinical psychopharmacology

Proof of efficacy of a psychotropic medicinal product is the key point of clinical psychopharmacology. This especially concerns the licensing of a new compound, but apart from this special case, lots of efficacy questions need to be answered in clinical psychopharmacology, such as, e.g. the question of the efficacy of a combination therapy. The methodology of the scientific proof of efficacy has already had a long tradition and has been developed further in the recent past under different aspects. Especially the double-blind randomised parallel group comparison has been developed as a design of highest methodological standard. However, often designs have their place and justification under certain conditions and in relation to certain questions. Although in the recent past, with the over-emphasis of so-called effectiveness studies, the inherent methodological limitations of these studies have not been addressed properly (Möller in Eur Arch Psychiatry Clin Neurosci 258:257-270, 2008), which in consequence devaluated the scientific merits of the classical double-blind randomised control group study designs in the view of those colleagues, who are not that experienced in study design issues. Therefore, it seems to be timely and necessary to review the principle standards and problems concerning the proof of efficacy in clinical psychopharmacology.

Is evidence sufficient for evidence-based medicine?

Psychopharmacotherapy should now be regulated in the sense of evidence-based medicine (EBM), as is the case in other areas of clinical treatment in medicine. In general this is a meaningful development, which will principally have a positive impact on routine health care in psychiatry. But several related problems should not be ignored. So far consensus on an internationally accepted evidence graduation could not be reached, due to several difficulties related to this. A principle question is also whether it is sufficient to base EBM primarily on the results of phase III trials with their high internal validity. Restrictions to generalise findings of phase III trials suggest the need for additional sources of evidence, amongst others "effectiveness" studies and other kinds of phase IV studies with their less restrictive methodological standards. Attempts to regulate psychopharmacotherapy in the sense of evidence-based medicine come closer to their limits the more complex the clinical situation and the respective decision-making logic are. Even in times of evidence-based medicine we are faced with the situation that a large part of complex clinical decision-making in psychopharmacotherapy still relies more on personal clinical experience and a group consensus about clinical experience, traditions and belief systems than on results of efficacy oriented phase III and effectiveness-oriented phase IV clinical studies.

Antipsychotic Drug Treatment for Patients with Schizophrenia: Theoretical Background, Clinical Considerations and Patient Preferences

The cornerstone in treatment of psychosis is antipsychotic drugs. Treatment options have increased over the years; newer antipsychotic drugs with a proposed increased efficacy regarding negative and cognitive symptoms, but also a shift in side-effects from neurological side-effects to metabolic side-effects have arisen as the new challenge. The basis of successful pharmacological treatment is a fundamental understanding of the mechanisms of action, the desired effects and side-effects of antipsychotic drugs, a good relationship with the patient and a thorough monitoring of the patient before and during treatment. The clinically relevant aspects of antipsychotic drug treatment are reviewed; mechanism of antipsychotic drug action, clinical considerations in treatment, switching antipsychotic drugs, polypharmacy, safety and patient preference.

Eligibility, recruitment, and retention of African Americans with severe mental illness in community research

Data that addresses severely mentally ill (SMI) African Americans (AAs) likelihood to participate in clinical research is limited. This study's purpose was to determine if differences exist between races regarding eligibility, recruitment, and retention in a community-based clinical trial. The sample included 293 participants. Data sources included clinical records and interviews. Logistic regression was used for analysis. AAs were as likely to participate and to complete followup interviews as Whites. In contrast to studies about non-mentally ill AAs, AAs with SMI appeared to be as willing to consent to and to remain in clinical research studies as Whites.

How effective are second-generation antipsychotic drugs? A meta-analysis of placebo-controlled trials

We conducted a systematic review and meta-analysis of randomized controlled trials that compared second-generation antipsychotic (SGA) drugs with placebo in schizophrenic patients and which considered 13 different outcome measures. Thirty-eight randomized controlled trials with 7323 participants were included. All SGA drugs were more effective than placebo, but the pooled effect size (ES) for overall symptoms (primary outcome) was moderate (-0.51). The absolute difference (RD) in responder rates was at 18% (41% responded to drug compared with 24% to placebo, number needed to treat=6). Similar ESs were found for the other efficacy parameters: negative symptoms (ES=-0.39), positive symptoms (ES=-0.48), depression (ES=-0.26), relapse (RD 20%) and discontinuation due to inefficacy (RD 17%). Curiously, the efficacy of haloperidol for negative and depressive symptoms was similar to that of the SGA drugs. In contrast to haloperidol, there was no difference in terms of EPS between any SGA drugs and placebo, and there was also no difference in terms of dropouts due to adverse events. Meta-regression showed a decline in treatment response over time, and a funnel plot suggested the possibility of publication bias. We conclude that the drug versus placebo difference of SGA drugs and haloperidol in recent trials was moderate, and that there is much room for more efficacious compounds. Whether methodological issues account in part for the relatively low efficacy ESs and the scarcity of adverse event differences compared with placebo needs to be established.

Clinical, functional, and economic ramifications of early nonresponse to antipsychotics in the naturalistic treatment of schizophrenia

OBJECTIVE

Early nonresponse to antipsychotics appears to predict subsequent nonresponse to treatment when assessed in randomized controlled trials of predominately acute inpatients treated for schizophrenia. This study assessed the predictive accuracy of early nonresponse to treatment and its clinical, functional, and economic ramifications in the naturalistic treatment of predominately chronic outpatients treated for schizophrenia.

METHODS

This post hoc analysis used data from a 1-year, randomized, open-label study of olanzapine, risperidone, and typical antipsychotics in the treatment of schizophrenia. If clinically warranted, patients could switch antipsychotics following 8 weeks of treatment. Patients completing 8 weeks of treatment (n = 443 of 664 enrollees) were included. Patients with early response (> or = 20% improvement from baseline on the Positive and Negative Syndrome Scale at 2 weeks) were compared with early nonresponders on symptom remission, functionality, perceptions of medication influence, and total health care costs at 8 weeks.

RESULTS

Early response/nonresponse at 2 weeks predicted subsequent response/nonresponse at 8 weeks with a high level of accuracy (72%) and specificity (89%). After 8 weeks, early nonresponders were less likely to achieve symptom remission (P < .001), improved less on functional domains (P < .05), perceived medication as less beneficial (P = .004), and incurred total heath care costs over twice that of early responders ($4349 vs $2102, P = .010).

CONCLUSIONS

In the usual care of schizophrenia patients, early nonresponse appears to reliably predict subsequent nonresponse to continued treatment with the same medication to be associated with poorer outcomes and higher health care costs. Identifying early nonresponders may minimize prolonging exposure to suboptimal or ineffective treatment strategies.

Non-participation in a field survey with respect to psychiatric disorders

Aims: Higher rates of psychiatric morbidity among non-participants may lead to biased estimates of prevalence and incidence in epidemiological studies of psychiatric disorders. We had a unique opportunity to explore psychiatric morbidity and non-participation in a large epidemiological survey including questionnaires and a clinical examination. Methods: Members of the Northern Finland 1966 Birth Cohort were included in the study. In phase I, a postal questionnaire was mailed to all those with a known address in 1997 (N=11,540). In phase II, all subjects living in northern Finland or the Helsinki area (N=8463) were invited to a clinical examination. In phase III, clinical examination participants were given a questionnaire with psychological subscales to be filled in at home and returned by mail. The data on hospital-treated psychiatric disorders were obtained from the Finnish Hospital Discharge Register. Educational level was obtained from Statistics Finland. Results: The participation rates were 76%, 71% and 61% in phases I, II and III, respectively. Subjects with any psychiatric disorder participated less actively than those without any psychiatric disorder in all phases, in both genders and at all educational levels. Participation was not found to vary across specific disorders. Gender or education did not explain the association of psychiatric disorders with participation. Conclusions: Owing to non-participation, the true prevalence of psychiatric disorders may be higher than the prevalence estimated from epidemiological field surveys.

Predicting antipsychotic drug response - replication and extension to six weeks in an international olanzapine study

OBJECTIVE

To use the degree of response after 2 weeks of treatment to predict non-response at 4 to 6 weeks.

METHOD

Post-hoc re-analysis of a large multi-centered double-blind trial including 1996 patients with schizophrenia using receiver-operator curves and logistic regression analyses to predict non-response at 4 weeks and at 4-6 weeks from the percentage BPRS change at weeks 1 and 2. The primary non-response criterion was a less than 25% BPRS reduction from baseline.

RESULTS

A 0% BPRS reduction at 2 weeks predicted non-response at 4 weeks with a positive predictive value of 77.1%; and sustained non-response at weeks 4, 5 and 6 with a positive predictive value of 75.8%. In a secondary last-observation-carried forward-analysis a less stringent cutoff of < or =15% BPRS reduction was associated with an acceptable positive predictive value (75%), with even higher sensitivity (76%).

CONCLUSIONS

Those patients who showed little to no reduction of symptoms at week 2 were unlikely to show even minimal response at weeks 4 to 6. There is increasing evidence that such patients may benefit from a change in treatment.

Methodological issues in current antipsychotic drug trials

Every year numerous reports on antipsychotic drug trials are being published in neuropsychiatric journals, adding new information to our knowledge in the field. The information however is often hard for the reader to interpret, sometimes contradictory to comparable available studies and leaves more questions open than it actually answers. Although the overall quality of the studies is rather good, there are manifold options for further improvement in the conception, conduct, and reporting of antipsychotic drug trials. In this survey, we address methodological challenges such as the limited generalizability of outcomes due to patient selection and sample size; the vague or even lacking definition of key outcome parameters such as response, remission or relapse, insufficient blinding techniques, the pitfalls of surrogate outcomes and their assessment tools; the varying complex statistical approaches; and the challenge of balancing various ways of reporting outcomes. The authors present practical examples to highlight the current problems and propose a concrete series of suggestions on how to further optimize antipsychotic drug trials in the future.

Comorbid substance abuse and neurocognitive function in recent-onset schizophrenia

Despite the high prevalence of comorbid substance use disorder (SUD) up to 65% in schizophrenia there is still few knowledge about the influence of substance abuse on neurocognitive function. In a prospective design we recruited 68 patients (aged 18-40 years) diagnosed as recent-onset schizophrenia or schizoaffective disorder consecutively admitted to hospital. The patients received standardized psychopathological evaluation of schizophrenic symptoms [Brief Psychiatric Rating Scale (BPRS), Scale for the Assessment of Negative Symptoms (SANS)], depressive symptoms [Montgomery Asberg Depression Rating Scale, (MADRS)] and global ratings [Clinical Global Impressions Scale (CGI), Global Assessment of Functioning Scale (GAF)]. Out of this sample 44 subjects underwent after stabilization (4-6 weeks after admission) neuropsychological investigation focusing on early information processing (Trail-Making-Test A, Digit Span), visuo-spatial ability (Corsi Block Tapping), verbal fluency (Verbal Fluency Test, semantic and letter category), and executive functioning and cognitive flexibility [Trail-Making-Test B, Wisconsin Card Sorting Test (WCST)]. About 36% of patients reported drug abuse [European Addiction Severity Index (EuropASI)] with a high prevalence for cannabis. Compared with nonabusers the sample of substance abusers was younger, predominantly male and had lower socioeconomic status. Attentional impairment according to the SANS subscale was less in abusers than in nonabusers on admission, no other psychopathological differences could be detected. Schizophrenic patients without substance abuse demonstrated significantly better performance only in a few neurocognitive tasks (Verbal Fluency, letter category and at trend level Digit Span, backwards), while there tended to be an advantage for substance abusers in executive functioning (WCST, not significant). These results are consistent with other studies of first-episode patients. The lack of higher cognitive disturbance in young schizophrenic patients with comorbid substance abuse may encourage clinicians to develop integrated treatment programmes using cognitive strategies of drug therapy.

Non-participation may bias the results of a psychiatric survey: an analysis from the survey including magnetic resonance imaging within the Northern Finland 1966 Birth Cohort

OBJECTIVE

A major reason for limited validity of research is non-participation. Subjects with severe mental illness tend to cumulate in the group of non-participants, causing selection bias. We tested the hypothesis that severe psychosis is linked to non-participation in a field survey including magnetic resonance imaging (MRI) of the brain, psychiatric interviews and cognitive testing among subjects with psychosis. Furthermore, we wanted to explore other associative factors expected to affect non-participation.

METHODS

Members of the Northern Finland 1966 Birth Cohort with a lifetime diagnosis of psychosis (N = 145) were invited to participate in the survey conducted in 1999-2001. Non-participation was determined by refusal or loss of contact. Data were gathered in earlier phases of the follow-up study or using register data.

RESULTS

Ninety-one (63%) subjects attended the study. Compared to participants, non-participants were more often patients with schizophrenia and had more psychiatric hospitalisations, they had more positive psychosis symptoms during their illness course and they were more often on disability pension. Married subjects participated more often than those who were not married.

CONCLUSION

This study suggests that among subjects with psychosis, particularly those subjects who have the most severe course of illness are less willing to participate. This may lead to biased estimates when studying subjects with severe mental disorders.

Bias in psychopathology research

PURPOSE OF REVIEW

Biases are frequently invoked in psychopathology research, either as core features of particular forms of psychopathology or as errors and distortions that affect psychiatric assessment, diagnosis, treatment, and research methodology. This review provides an overview of recent research on the forms of bias that are commonly examined in the field.

RECENT FINDINGS

Recent research has made a number of advances in the analysis of cognitive and affective biases underpinning psychopathology: the effect of rating and other biases on psychiatric assessment and diagnosis; the role of race and gender in psychiatric practice; financial and institutional influences on psychiatric services; and several biases affecting research methodology, study design, and statistical inference.

SUMMARY

Bias has several distinct meanings, and encompasses a disparate set of phenomena, so no over-arching conclusion about the place of bias in psychopathology research can be drawn. Recent work, however, makes solid progress toward a better understanding of systematic distortions and how they can be recognized and reduced.

Translating research into clinical practice: critical interpretation of clinical trials in schizophrenia

Translating research into clinical practice has in part been hampered by practitioners' difficulties in interpreting statistical measures. The main part of this article aims to bridge the gap between research and practice by describing frequently occurring problems in the methodology and reporting of clinical trials. Basic methodological concepts and statistical measures, such as different trial designs, randomization, blinding, case numbers, eligibility criteria, internal and external validity, efficacy versus effectiveness, the meaning of rating scales, choice of comparators, effect size versus P-value and the interpretation of risk measures, are explained and their use illustrated. The text further presents the outcome from a workshop on 'Translating Clinical Studies into Practice' held at an international conference on schizophrenia and bipolar disorder in June 2005. The participants suggested more emphasis on additional secondary endpoints in clinical trials such as patients' self assessments and indicators of well-being. Better training of clinicians in the interpretation of scientific results and the use of more meaningful clinical outcomes are both needed to effectively translate research into clinical practice.

Clinical trial design in schizophrenia: implications for clinical decisions

PURPOSE OF REVIEW

Results from clinical trials do not necessarily provide information for decisions in clinical practice. This review aims to present strengths and limitations of different methodological types of clinical trials and to offer an overview of how knowledge from clinical trails can be distilled for clinical practice. Selected key questions in the treatment of schizophrenia are presented, with a focus on the possibilities and restrictions of translating trial results into real-world practice.

RECENT FINDINGS

Randomized controlled trials are the gold standard for proving efficacy of a diagnostic or therapeutic procedure. They have a high degree of internal validity and a clear-cut message when conducted to good-quality standards but suffer from a lack of generalizability (external validity). Effectiveness studies evaluate effects of treatments under conditions approximating usual care. They may include patient-centred outcomes or health economic evaluations. According to the type of trial, specific problems arise in the interpretation of results. Typical examples are given for the treatment of acute exacerbations of schizophrenia, for relapse prevention and for the treatment of cognitive impairment.

SUMMARY

Clinical decisions have to be made upon the best knowledge. Therefore, well conducted studies addressing all major issues from all relevant perspectives are needed. The assessment of a treatment regimen for clinical utility requires both efficacy and effectiveness studies. An understanding of the design, analysis and conventions of both study types is essential for the interpretation of results and their translation to the clinical decision-making process.

How do psychiatrists choose among different antipsychotics?

OBJECTIVE

We attempted to determine the decision rules psychiatrists use in the choice of antipsychotic drugs for inpatients with schizophrenia.

METHODS

Interviews were conducted with 50 hospital psychiatrists in Southern Germany. Each physician was interviewed with respect to the reasons for his antipsychotic drug choice in the cases of three patients with a diagnosis of schizophrenia. Interviews were audiotaped and subsequently analyzed using a standardized coding scheme.

RESULTS

The clinical decision rules identified are highly complex, with a mean of eight categories cited per patient. Categories named included the patient's past treatment response, side effects, intended route of administration and co-morbidities. Moreover, psychiatrists strongly take the patient's target symptoms and the assumed efficacy of certain compounds into account in their choice of medication.

CONCLUSION

Psychiatrists' explanations for their antipsychotic drug choice seem for the most part reasonable and overlap substantially with drug-choice algorithms of clinical guidelines. However, psychiatrists additionally use indicators that--in their view--might predict treatment response. For these indicators, which are derived from personal experience, it is still unclear whether they are valid and simply have not yet been proven in clinical trials or whether they merely represent unfounded assumptions on the part of the doctors.