Cognitive and Functional Change Over Time in Cognitively Healthy Individuals According to Alzheimer Disease Biomarker-Defined Subgroups

BACKGROUND AND OBJECTIVES

It is unclear to what extent cognitive outcome measures are sensitive to capture decline in Alzheimer disease (AD) prevention trials. We aimed to analyze the sensitivity to changes over time of a range of neuropsychological tests in several cognitively unimpaired, biomarker-defined patient groups.

METHODS

Cognitively unimpaired individuals from the Amsterdam Dementia Cohort and the SCIENCe project with available AD biomarkers, obtained from CSF, PET scans, and plasma at baseline, were followed over time (4.5 ± 3.1 years, range 0.6-18.9 years). Based on common inclusion criteria for clinical trials, we defined groups (amyloid, phosphorylated tau [p-tau], APOE ε4). Linear mixed models, adjusted for age, sex, and education, were used to estimate change over time in neuropsychological tests, a functional outcome, and 2 cognitive composite measures. Standardized regression coefficients of time in years (βtime) were reported as outcome of interest. We analyzed change over time with full follow-up, as well as with follow-up limited to 1.5 and 3 years.

RESULTS

We included 387 individuals (aged 61.7 ± 8.6 years; 44% female) in the following (partly overlapping) biomarker groups: APOE ε4 carriers (n = 212), amyloid-positive individuals (n = 109), amyloid-positive APOE ε4 carriers (n = 66), CSF p-tau-positive individuals (n = 127), plasma p-tau-positive individuals (n = 71), and amyloid and CSF p-tau-positive individuals (n = 50), or in a control group (normal biomarkers; n = 65). An executive functioning task showed most decline in all biomarker groups (βtime range -0.30 to -0.71), followed by delayed word list recognition (βtime range -0.18 to -0.50). Functional decline (βtime range -0.17 to -0.63) was observed in all, except the CSF and plasma tau-positive groups. Both composites showed comparable amounts of change (βtime range -0.12 to -0.62) in all groups, except plasma p-tau-positive individuals. When limiting original follow-up duration, many effects disappeared or even flipped direction.

DISCUSSION

In conclusion, functional, composite, and neuropsychological outcome measures across all cognitive domains detect changes over time in various biomarker-defined groups, with changes being most evident among individuals with more AD pathology. AD prevention trials should use sufficiently long follow-up duration and/or more sensitive outcome measures to optimally capture subtle cognitive changes over time.

What's in a score: A longitudinal investigation of scores based on item response theory and classical test theory for the Amsterdam Instrumental Activities of Daily Living Questionnaire in cognitively normal and impaired older adults

OBJECTIVE

We aimed to investigate whether item response theory (IRT)-based scoring allows for a more accurate, responsive, and less biased assessment of everyday functioning than traditional classical test theory (CTT)-based scoring, as measured with the Amsterdam Instrumental Activities of Daily Living Questionnaire.

METHOD

In this longitudinal multicenter study including cognitively normal and impaired individuals, we examined IRT-based and CTT-based score distributions and differences between diagnostic groups using linear regressions, and investigated scale attenuation. We compared change over time between scoring methods using linear mixed models with random intercepts and slopes for time.

RESULTS

Two thousand two hundred ninety-four participants were included (66.6 ± 7.7 years, 54% female): n = 2,032 (89%) with normal cognition, n = 93 (4%) with subjective cognitive decline, n = 79 (3%) with mild cognitive impairment, and n = 91 (4%) with dementia. At baseline, IRT-based and CTT-based scores were highly correlated (r = -0.92). IRT-based scores showed less scale attenuation than CTT-based scores. In a subsample of n = 1,145 (62%) who were followed for a mean of 1.3 (SD = 0.6) years, IRT-based scores declined significantly among cognitively normal individuals (unstandardized coefficient [B] = -0.15, 95% confidence interval, 95% CI [-0.28, -0.03], effect size = -0.02), whereas CTT-based scores did not (B = 0.20, 95% CI [-0.02, 0.41], effect size = 0.02). In the other diagnostic groups, effect sizes of change over time were similar.

CONCLUSIONS

IRT-based scores were less affected by scale attenuation than CTT-based scores. With regard to responsiveness, IRT-based scores showed more signal than CTT-based scores in early disease stages, highlighting the IRT-based scores' superior suitability for use in preclinical populations. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Further validation of the THINC-it tool and extension of the normative data set in a study of n = 10.019 typical controls

INTRODUCTION

We report further validation and normative data for the THINC-Integrated Tool (THINC-it), a measure of cognitive function designed for use with individuals living with Major Depressive Disorder, but which is finding use in further psychiatric and neurological diseases. THINC-it comprises four objective computerised cognitive tests based on traditional psychological paradigms and a version of the Perceived Deficits Questionnaire assessment.

METHODS

Sample size of n = 10.019 typical control study participants were tested on one to two occasions to further validate the reliability of THINC-it. Temporal reliability was assessed across 120-180 days.

RESULTS

Test-retest reliability correlations varied between r = 0.50 and 0.72 for the component measures and r = 0.75 (95% confidence intervals 0.74, 0.76) for the THINC-it composite score. Normative data categorised by Age, Sex and Years of Education were calculated and the effect on task performance was reported.

DISCUSSION

Our analysis confirms previously reported levels of reliability and validates previously reported normative data values.

Asynchronous Remote Assessment for Cognitive Impairment: Reliability Verification of the Neurotrack Cognitive Battery

Background

As evidenced by the further reduction in access to testing during the COVID-19 pandemic, there is an urgent, growing need for remote cognitive assessment for individuals with cognitive impairment. The Neurotrack Cognitive Battery (NCB), our response to this need, was evaluated for its temporal reliability and stability as part of ongoing validation testing.

Objective

The aim of this study is to assess the temporal reliability of the NCB tests (5 total) across a 1-week period and to determine the temporal stability of these measures across 3 consecutive administrations in a single day.

Methods

For test-retest reliability, a range of 29-66 cognitively healthy participants (ages 18-68 years) completed each cognitive assessment twice, 1 week apart. In a separate study, temporal stability was assessed using data collected from 31 different cognitively healthy participants at 3 consecutive timepoints in a single day.

Results

Correlations for the assessments were between 0.72 and 0.83, exceeding the standard acceptable threshold of 0.70 for temporal reliability. Intraclass correlations ranged from 0.60 to 0.84, indicating moderate to good temporal stability.

Conclusions

These results highlight the NCB as a brief, easy-to-administer, and reliable assessment for remote cognitive testing. Additional validation research is underway to determine the full magnitude of the clinical utility of the NCB.

A phase 2 double-blind placebo-controlled 24-week treatment clinical study of the p38 alpha kinase inhibitor neflamapimod in mild Alzheimer's disease

BACKGROUND

In preclinical studies, p38⍺ kinase is implicated in Alzheimer's disease (AD) pathogenesis. In animal models, it mediates impaired synaptic dysfunction in the hippocampus, causing memory deficits, and is involved in amyloid-beta (Aβ) production and tau pathology.

METHODS

The REVERSE-SD (synaptic dysfunction) study was a multi-center phase 2, randomized, double-blind, placebo-controlled trial of the p38⍺ kinase inhibitor neflamapimod; conducted December 29, 2017, to June 17, 2019; 464 participants screened, and 161 randomized to either 40 mg neflamapimod (78 study participants) or matching placebo (83 study participants), orally twice daily for 24 weeks. Study participants are as follows: CSF AD-biomarker confirmed, Clinical Dementia Rating (CDR)-global score 0.5 or 1.0, CDR-memory score ≥0.5, and Mini-Mental State Examination (MMSE) 20-28. The primary endpoint was the improvement in episodic memory, assessed by combined change in Z-scores of Hopkins Verbal Learning Test-Revised (HVLT-R) Total and Delayed Recall. Secondary endpoints included change in Wechsler Memory Scale-IV (WMS) Immediate and Delayed Recall composites, CDR-SB, MMSE, and CSF biomarkers [total and phosphorylated tau (T-tau and p-tau₁₈₁), Aβ_1-40, Aβ_1-42, neurogranin, and neurofilament light chain].

RESULTS

At randomization, the mean age is 72, 50% female, 77% with CDR-global score 0.5, and mean MMSE score 23.8. The incidence of discontinuation for adverse events and serious adverse events (all considered unrelated) was 3% each. No significant differences between treatment groups were observed in the primary or secondary clinical endpoints. Significantly reduced CSF levels with neflamapimod treatment, relative to placebo, were evident for T-tau [difference (95% CI): -18.8 (-35.8, -1.8); P=0.031] and p-tau₁₈₁ [-2.0 (-3.6, -0.5); P=0.012], with a trend for neurogranin [-21.0 (-43.6, 1.6); P=0.068]. In pre-specified pharmacokinetic-pharmacodynamic (PK-PD) analyses, subjects in the highest quartile of trough plasma neflamapimod levels demonstrated positive trends, compared with placebo, in HLVT-R and WMS.

CONCLUSIONS AND RELEVANCE

A 24-week treatment with 40 mg neflamapimod twice daily did not improve episodic memory in patients with mild AD. However, neflamapimod treatment lowered CSF biomarkers of synaptic dysfunction. Combined with PK-PD findings, the results indicate that a longer duration study of neflamapimod at a higher dose level to assess effects on AD progression is warranted.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03402659 . Registered on January 18, 2018.

Cognitive Functions as Predictors of Alzheimer's Disease Biomarker Status in the European Prevention of Alzheimer's Dementia Cohort

Alterations in Alzheimer's disease (AD) biomarkers have been observed decades before the onset of dementia. Cognitive dysfunction, while central to the clinical diagnosis of AD, has long been considered as a late-stage phenomenon. This assumption is currently challenged and signals on some cognitive tests are now being observed within the preclinical stage. As part of the European Prevention of Alzheimer's Dementia (EPAD) project, a battery of cognitive tests has been proposed (the EPAD Neuropsychological Examination, ENE) which is designed to detect cognitive changes in persons without clinical signs of AD but who are at high risk. Analysis of results from the 361 participants with complete measures and without dementia recruited into the EPAD Longitudinal Cohort Study showed that the majority have elevated biomarker levels, with significant associations between an episodic verbal memory task and tau, while amyloid-β (Aβ) was associated with a central executive task. These preliminary findings suggest that profiles of cognitive performance may be specific to a given biomarker, with a primarily hippocampal task being associated with higher levels of tau and a frontal executive task being associated with higher levels of Aβ. While previous research has focused on the relationship between cognition and levels of Aβ, our findings suggest that p-tau may potentially be a more significant correlate.

Environmental Distractions during Unsupervised Remote Digital Cognitive Assessment

The current demand for cognitive assessment cannot be met with traditional in-person methods, warranting the need for remote unsupervised options. However, lack of visibility into testing conditions and effort levels limit the utility of existing remote options. This retrospective study analyzed the frequency of and factors associated with environmental distractions during a brief digital assessment taken at home by 1,442 adults aged 23–84. Automated scoring algorithms flagged low data capture. Frequency of environmental distractions were manually counted on a per-frame and per-trial basis. A total of 7.4% of test administrations included distractions. Distractions were more frequent in men (41:350) than women (65:1,092) and the average age of distracted participants (51.7) was lower than undistracted participants (57.8). These results underscore the challenges associated with unsupervised cognitive assessment. Data collection methods that enable review of testing conditions are needed to confirm quality, usability, and actionability.

Evaluation of Speech-Based Digital Biomarkers: Review and Recommendations

Speech represents a promising novel biomarker by providing a window into brain health, as shown by its disruption in various neurological and psychiatric diseases. As with many novel digital biomarkers, however, rigorous evaluation is currently lacking and is required for these measures to be used effectively and safely. This paper outlines and provides examples from the literature of evaluation steps for speech-based digital biomarkers, based on the recent V3 framework (Goldsack et al., 2020). The V3 framework describes 3 components of evaluation for digital biomarkers: verification, analytical validation, and clinical validation. Verification includes assessing the quality of speech recordings and comparing the effects of hardware and recording conditions on the integrity of the recordings. Analytical validation includes checking the accuracy and reliability of data processing and computed measures, including understanding test-retest reliability, demographic variability, and comparing measures to reference standards. Clinical validity involves verifying the correspondence of a measure to clinical outcomes which can include diagnosis, disease progression, or response to treatment. For each of these sections, we provide recommendations for the types of evaluation necessary for speech-based biomarkers and review published examples. The examples in this paper focus on speech-based biomarkers, but they can be used as a template for digital biomarker development more generally.

Commentary: Composite cognitive and functional measures for early stage Alzheimer's disease trials

In this commentary I consider the issues raised in Schneider and Goldberg's review of composite cognitive and functional measures. I find much to agree with in their commentary and especially their concerns regarding satisfactory psychometric validation of composite measures. I endorse also their provision for analysis by cognitive domain, backed by the use of statistical methods for grouping test variables. The authors helpfully mention the possibility that treatment effects may be peculiar to specific domains of cognitive function. I develop this view and argue for exploratory studies of new therapeutic interventions to include broad assessments of the cognitive domains known to be compromised in early Alzheimer's disease. I suggest that the results of exploratory studies be used to help identify target domains for confirmatory studies. Finally, I note that computerized cognitive composite assessments have often been validated in the fashion that the authors recommend for composite measures.

The Cognitive-Functional Composite is sensitive to clinical progression in early dementia: Longitudinal findings from the Catch-Cog study cohort

INTRODUCTION

In an attempt to capture clinically meaningful cognitive decline in early dementia, we developed the Cognitive-Functional Composite (CFC). We investigated the CFC's sensitivity to decline in comparison to traditional clinical endpoints.

METHODS

This longitudinal construct validation study included 148 participants with subjective cognitive decline, mild cognitive impairment, or mild dementia. The CFC and traditional tests were administered at baseline, 3, 6, and 12 months. Sensitivity to change was investigated using linear mixed models and r 2 effect sizes.

RESULTS

CFC scores declined over time (β = -.16, P < .001), with steepest decline observed in mild Alzheimer's dementia (β = -.25, P < .001). The CFC showed medium-to-large effect sizes at succeeding follow-up points (r 2 = .08-.42), exhibiting greater change than the Clinical Dementia Rating scale (r 2 = .02-.12). Moreover, change on the CFC was significantly associated with informant reports of cognitive decline (β = .38, P < .001).

DISCUSSION

By showing sensitivity to decline, the CFC could enhance the monitoring of disease progression in dementia research and clinical practice.

The clinical promise of biomarkers of synapse damage or loss in Alzheimer's disease

BACKGROUND

Synapse damage and loss are fundamental to the pathophysiology of Alzheimer's disease (AD) and lead to reduced cognitive function. The goal of this review is to address the challenges of forging new clinical development approaches for AD therapeutics that can demonstrate reduction of synapse damage or loss. The key points of this review include the following: Synapse loss is a downstream effect of amyloidosis, tauopathy, inflammation, and other mechanisms occurring in AD.Synapse loss correlates most strongly with cognitive decline in AD because synaptic function underlies cognitive performance.Compounds that halt or reduce synapse damage or loss have a strong rationale as treatments of AD.Biomarkers that measure synapse degeneration or loss in patients will facilitate clinical development of such drugs.The ability of methods to sensitively measure synapse density in the brain of a living patient through synaptic vesicle glycoprotein 2A (SV2A) positron emission tomography (PET) imaging, concentrations of synaptic proteins (e.g., neurogranin or synaptotagmin) in the cerebrospinal fluid (CSF), or functional imaging techniques such as quantitative electroencephalography (qEEG) provides a compelling case to use these types of measurements as biomarkers that quantify synapse damage or loss in clinical trials in AD.

CONCLUSION

A number of emerging biomarkers are able to measure synapse injury and loss in the brain and may correlate with cognitive function in AD. These biomarkers hold promise both for use in diagnostics and in the measurement of therapeutic successes.

No evidence of neurocognitive adverse events associated with alirocumab treatment in 3340 patients from 14 randomized Phase 2 and 3 controlled trials: a meta-analysis of individual patient data

Aims

Despite patient reports of neurocognitive disorders with lipid-lowering treatments (LLTs), large clinical trials have found no significant association between neurocognitive disorders and LLTs. We assessed incidence of neurocognitive treatment-emergent adverse events (TEAEs) from 14 Phase 2 and 3 trials of the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor alirocumab.

Methods and results

Patients (most on background maximally tolerated statin) received alirocumab 75/150 mg every 2 weeks (n = 3340; 4029 patient-years of exposure), placebo (n = 1276), or ezetimibe (n = 618). Data were pooled by the control used. Neurocognitive TEAEs were reported by 22 (0.9%) alirocumab-treated patients vs. 9 (0.7%) with placebo in placebo-controlled trials [hazard ratio (HR) 1.24, 95% confidence interval (CI) 0.57–2.68] and 10 (1.2%) with alirocumab vs. 8 (1.3%) with ezetimibe in ezetimibe-controlled trials (HR 0.81, 95% CI 0.32–2.08). Rates of neurocognitive TEAEs were similar in patients receiving alirocumab with LDL cholesterol (LDL-C) levels <25 mg/dL (<0.65 mmol/L; n = 5/839; 0.6%; 0.5/100 patient-years) vs. ≥25 mg/dL (n = 26/2501; 1.0%; 0.8/100 patient-years). One patient (0.1%; ezetimibe-controlled pool) receiving alirocumab had a neurocognitive TEAE leading to discontinuation vs. two (0.2%) patients receiving placebo and three (0.4%) patients receiving ezetimibe. Neurocognitive TEAE incidence was also similar between alirocumab and controls when stratified by age.

Conclusions

Neurocognitive TEAE incidences were low (≤1.2%), with no significant differences between alirocumab vs. controls up to 104 weeks. No association was found between neurocognitive TEAEs and LDL-C <25 mg/dL based on the completed Phase 2 and 3 trials examined, although long-term effects of very low LDL-C levels induced by PCSK9 inhibitors are currently unknown.

Psychometric Evaluation of the Neuropsychological Test Battery in Individuals with Normal Cognition, Mild Cognitive Impairment, or Mild to Moderate Alzheimer's Disease: Results from a Longitudinal Study

BACKGROUND

The Neuropsychological Test Battery (NTB) is a combination of widely used clinical neuropsychological tests measuring memory and executive function and was designed to overcome some of the limitations of the traditionally used Alzheimer's disease Assessment Scale - Cognitive subscale (ADAS-Cog). A previously reported account indicated high levels of NTB reliability in patients with mild-to-moderate Alzheimer's disease (AD) and mild cognitive impairment (MCI).

OBJECTIVES

We examined capacity of the Neuropsychological Test Battery (NTB) and its component subtests to measure cognitive change over time. Correlations with other cognitive and functional assessments were also determined. Design, Settings, Participants: This was a multicentre, prospective, non-interventional, longitudinal cohort study involving patients with mild-to-moderate AD (n=196), MCI (n=70), or cognitively normal control participants (NC, n=75).

INTERVENTION

The NTB, as well as other Clinical Outcome Assessments including, ADAS-Cog, other cognitive measures, functional/behavioral questionnaires, health outcome questionnaires, and resource utilization tools were administered.

RESULTS

Mean change from baseline for the NTB composite score and the six individual NTB subtests showed greater reductions in performance over time in the AD and MCI groups, compared with NC group. The ADAS-Cog was found to be more sensitive to change than the NTB in all three populations.

CONCLUSIONS

The NTB showed high correlation with the ADAS-Cog and appears to be a sensitive and reliable assessment tool for measuring cognitive decline in patients with mild-to-moderate AD. However, the ADAS-Cog was found to be more sensitive to change over time in both the AD and MCI populations.

Assessing cognition and daily function in early dementia using the cognitive-functional composite: findings from the Catch-Cog study cohort

Background

The cognitive-functional composite (CFC) was designed to improve the measurement of clinically relevant changes in predementia and early dementia stages. We have previously demonstrated its good test-retest reliability and feasibility of use. The current study aimed to evaluate several quality aspects of the CFC, including construct validity, clinical relevance, and suitability for the target population.

Methods

Baseline data of the Capturing Changes in Cognition study was used: an international, prospective cohort study including participants with subjective cognitive decline (SCD), mild cognitive impairment (MCI), Alzheimer’s disease (AD) dementia, and dementia with Lewy bodies (DLB). The CFC comprises seven existing cognitive tests focusing on memory and executive functions (EF) and the informant-based Amsterdam Instrumental Activities of Daily Living Questionnaire (A-IADL-Q). Construct validity and clinical relevance were assessed by (1) confirmatory factor analyses (CFA) using all CFC subtests and (2) linear regression analyses relating the CFC score (independent) to reference measures of disease severity (dependent), correcting for age, sex, and education. To assess the suitability for the target population, we compared score distributions of the CFC to those of traditional tests (Alzheimer’s Disease Assessment Scale–Cognitive subscale, Alzheimer’s Disease Cooperative Study–Activities of Daily Living scale, and Clinical Dementia Rating scale).

Results

A total of 184 participants were included (age 71.8 ± 8.4; 42% female; n = 14 SCD, n = 80 MCI, n = 78 AD, and n = 12 DLB). CFA showed that the hypothesized three-factor model (memory, EF, and IADL) had adequate fit (CFI = .931, RMSEA = .091, SRMR = .06). Moreover, worse CFC performance was associated with more cognitive decline as reported by the informant (β = .61, p < .001), poorer quality of life (β = .51, p < .001), higher caregiver burden (β = − .51, p < .001), more apathy (β = − .36, p < .001), and less cortical volume (β = .34, p = .02). Whilst correlations between the CFC and traditional measures were moderate to strong (ranging from − .65 to .83, all p < .001), histograms showed floor and ceiling effects for the traditional tests as compared to the CFC.

Conclusions

Our findings illustrate that the CFC has good construct validity, captures clinically relevant aspects of disease severity, and shows no range restrictions in scoring. It therefore provides a more useful outcome measure than traditional tests to evaluate cognition and function in MCI and mild AD.

Electronic supplementary material

The online version of this article (10.1186/s13195-019-0500-5) contains supplementary material, which is available to authorized users.

FDA position statement "Early Alzheimer's disease: Developing drugs for treatment, Guidance for Industry"

Despite billions of dollars invested in clinical trials to develop novel therapeutics for Alzheimer's disease, no approved treatments have been developed in the past 15 years. In that span, new classes of drugs have been developed and tested, including monoclonal antibodies, γ-secretase modulators, γ-secretase inhibitors, BACE inhibitors, RAGE inhibitors, nicotinic agonists, 5HT6 antagonists, and others. The one constant for all of these clinical trials programs is the use of the ADAS-cog as the primary scale to determine efficacy. The question that needs to be considered is whether it is the target engagement of the drug or the clinical trial measure testing the efficacy. The FDA put out a new position statement in 2018 informing the field on possible considerations for demonstrating efficacy to open the path for approval. Here, we propose and comment on a variety of approaches that are alternatives to the ADAS for FDA-specified stage 3 and 4 Alzheimer's disease. These novel outcomes are being validated in current clinical trials and could be used as efficacy measures moving forward.

Stability, reliability, and validity of the THINC-it screening tool for cognitive impairment in depression: A psychometric exploration in healthy volunteers

OBJECTIVES

There is a need for a brief, reliable, valid, and sensitive assessment tool for screening cognitive deficits in patients with Major Depressive Disorders. This paper examines the psychometric characteristics of THINC-it, a cognitive assessment tool composed of four objective measures of cognition and a self-rated assessment, in subjects without mental disorders.

METHODS

N = 100 healthy controls with no current or past history of depression were tested on four sequential assessments to examine temporal stability, reliability, and convergent validity of the THINC-it tests. We examined temporal reliability across 1 week and stability via three consecutive assessments. Consistency of assessment by the study rater (intrarater reliability) was calculated using the data from the second and third of these consecutive assessments.

RESULTS

Test-retest reliability correlations varied between Pearson's r = 0.75 and 0.8. Intrarater reliability between 0.7 and 0.93. Stability for the primary measure for each test yielded within-subject standard deviation values between 5.9 and 11.23 for accuracy measures and 0.735 and 17.3 seconds for latency measures. Convergent validity for three tasks was in the acceptable range, but low for the Symbol Check task.

CONCLUSIONS

Analysis shows high levels of reliability and stability. Levels of convergent validity were modest but acceptable in the case of all but one test.

Cognition comes of age: comments on the new FDA draft guidance for early Alzheimer's disease

Background

The FDA have recently published draft guidance for the development of treatments for early Alzheimer’s disease. Key features of this guidance are the advocacy of sensitive cognitive measures and a taxonomy of disease severity. Whilst desirable patterns of cognitive-functional improvement are included, specific measures, and the magnitude of required effects, are not described.

Main section

We describe key elements of the guidance content, especially with regard targeting key cognitive domains and the means by which they might be efficiently indexed in the disease stages included in the guidance. We discuss also the opportunities to assess cognitive performance in ‘Stage 2’ and ‘Stage 3’ patients, as well as the possibilities for effectively assessing function in the latter category. In this section we review candidate cognitive assessments that we judge are capable of delivering on the guidance specification for sensitive neuropsychological measures. This includes detailed consideration of the ADCS-PACC and Catch-Cog initiatives. With respect to the magnitude of effects, we propose that standardised effect sizes of 0.3 represent a reasonable level of efficacy based on the observation that already marketed drugs on average deliver this level of improvement.

Conclusions

We propose the use of cognitive measures in stage 2 patients to index the cognitive skills known to be compromised early in the Alzheimer’s disease process. We recommend extending the traditional interest in episodic memory to include sensitive, reliable and valid measures of attention, working memory and aspects of executive function. We propose a focus on these additional cognitive abilities based on evidence that performance on tests of these domains is moderately well related to functional skills.

Effect Size Analyses of Souvenaid in Patients with Alzheimer's Disease

Background: Souvenaid^® (uridine monophosphate, docosahexaenoic acid, eicosapentaenoic acid, choline, phospholipids, folic acid, vitamins B12, B6, C, and E, and selenium), was developed to support the formation and function of neuronal membranes.

Objective: To determine effect sizes observed in clinical trials of Souvenaid and to calculate the number needed to treat to show benefit or harm.

Methods: Data from all three reported randomized controlled trials of Souvenaid in Alzheimer’s disease (AD) dementia (Souvenir I, Souvenir II, and S-Connect) and an open-label extension study were included in analyses of effect size for cognitive, functional, and behavioral outcomes. Effect size was determined by calculating Cohen’s d statistic (or Cramér’s V method for nominal data), number needed to treat and number needed to harm. Statistical calculations were performed for the intent-to-treat populations.

Results: In patients with mild AD, effect sizes were 0.21 (95% confidence intervals: –0.06, 0.49) for the primary outcome in Souvenir II (neuropsychological test battery memory z-score) and 0.20 (0.10, 0.34) for the co-primary outcome of Souvenir I (Wechsler memory scale delayed recall). No effect was shown on cognition in patients with mild-to-moderate AD (S-Connect). The number needed to treat (6 and 21 for Souvenir I and II, respectively) and high number needed to harm values indicate a favorable harm:benefit ratio for Souvenaid versus control in patients with mild AD.

Conclusions: The favorable safety profile and impact on outcome measures converge to corroborate the putative mode of action and demonstrate that Souvenaid can achieve clinically detectable effects in patients with early AD.

Cognitive Impairment Associated with Cancer: A Brief Review

This brief review explores the areas of cognitive impairment that have been observed in cancer patients and survivors, the cognitive assessment tools used, and the management of the observed cognitive changes. Cognitive changes and impairment observed in patients with cancer and those in remission can be related to the direct effects of cancer itself, nonspecific factors or comorbid conditions that are independent of the actual disease, and/or the treatments or combination of treatments administered. Attention, memory, and executive functioning are the most frequently identified cognitive domains impacted by cancer. However, the prevalence and extent of impairment remains largely unknown due to marked differences in methodology, definitions of cognitive impairment, and the assessment measures used. Assessment of cognitive functioning is an important and necessary part of a comprehensive oncological care plan. Research is needed to establish a better understanding of cognitive changes and impairments associated with cancer so that optimal patient outcomes can be achieved.

Which Cognitive Domains are Improved by Treatment with Vortioxetine?

BACKGROUND

These post hoc analyses evaluated vortioxetine efficacy on cognitive dysfunction in depression. Data were from a double-blind, randomized, fixed-dose, placebo-controlled, 8-week depression study in adults aged 18-65 years (n = 602) with DSM-IV-defined major depressive disorder (MDD). Subjects were randomized (1:1:1) to vortioxetine 10mg/day or 20mg/day or placebo.

METHODS

Cognitive function was assessed at baseline, Week 1 (10mg/day only) and Week 8 using Digit Symbol Substitution Test (DSST) number of correct symbols, Rey Auditory Verbal Learning Test, Trail Making Test, Stroop test, Simple Reaction Time, and Choice Reaction Time tests. The cognition variables were standardized and used for constructing composite Z-scores for the cognitive domains of executive function, attention/speed of processing, and memory.

RESULTS

At Week 1, vortioxetine 10mg/day separated from placebo for attention/speed of processing (standardized composite Z-score = 0.21; p = 0.0238) and DSST number of correct symbols (standardized effect size = 0.18; p = 0.0458) and for executive function (standardized composite Z-score = 0.20; p = 0.0274). At Week 8, vortioxetine 10mg/day and 20mg/day separated from placebo for executive function and attention/speed of processing, with standardized composite Z-scores ranging from 0.35 to 0.49 (all p < 0.01). Standardized composite Z-scores for memory were 0.31 ( p = 0.0036, 10mg/day) and 0.22 ( p = 0.0349, 20mg/day). Standardized effect sizes for DSST were 0.51 ( p < 0.0001, 10mg/day) and 0.52 ( p < 0.0001, 20mg/day). Results are limited by the post hoc nature of the analyses and the absence of an active reference in the original study.

CONCLUSIONS

Vortioxetine (10 and 20mg/day) had a multi-domain beneficial effect on cognitive performance, as evidenced by improvements in measures of executive function, attention/speed of processing, and memory. The effect on the DSST may be due to improvements in several cognitive skills.

Alzheimer's Disease Assessment Scale-Cognitive subscale variants in mild cognitive impairment and mild Alzheimer's disease: change over time and the effect of enrichment strategies

Background

Development of new treatments for Alzheimer’s disease (AD) has broadened into early interventions in individuals with modest cognitive impairment and a slow decline. The 11-item version of the Alzheimer’s Disease Assessment Scale–Cognitive subscale (ADAS-Cog) was originally developed to measure cognition in patients with mild to moderate AD. Attempts to improve its properties for early AD by removing items prone to ceiling and/or by adding cognitive measures known to be impaired early have yielded a number of ADAS-Cog variants. Using Alzheimer’s Disease Neuroimaging Initiative data, we compared the performance of the 3-, 5-, 11- and 13-item ADAS-Cog variants in subjects with early AD. Given the interest in enrichment strategies, we also examined this aspect with a focus on cerebrospinal fluid (CSF) markers.

Methods

Subjects with mild cognitive impairment (MCI) and mild AD with available ADAS-Cog 13 and CSF data were analysed. The decline over time was defined by change from baseline. Direct cross-comparison of the ADAS-Cog variants was performed using the signal-to-noise ratio (SNR), with higher values reflecting increased sensitivity to detect change over time.

Results

The decline over time on any of the ADAS-Cog variants was minimal in subjects with MCI. Approximately half of subjects with MCI fulfilled enrichment criteria for positive AD pathology. The impact of enrichment was detectable but subtle in MCI. The annual decline in mild AD was more pronounced but still modest. More than 90 % of subjects with mild AD had positive AD pathology. SNRs were low in MCI but greater in mild AD. The numerically largest SNRs were seen for the ADAS-Cog 5 in MCI and for both the 5- and 13-item ADAS-Cog variants in mild AD, although associated confidence intervals were large.

Conclusions

The possible value of ADAS-Cog expansion or reduction is less than compelling, particularly in MCI. In mild AD, adding items known to be impaired at early stages seems to provide more benefit than removing items on which subjects score close to ceiling.

Electronic supplementary material

The online version of this article (doi:10.1186/s13195-016-0170-5) contains supplementary material, which is available to authorized users.

Natural rubber latex allergy: implications for the orthodontist

Natural rubber latex (NRL) allergy can have potentially serious consequences, and reports of orthodontic patients reacting to NRL have increased significantly over recent years. It is therefore important for the orthodontist to know how to manage patients with an NRL allergy and how to deal with possible reactions to NRL. Safe and effective practice depends on recognizing patients who are at risk of NRL allergy, and an awareness of materials and equipment that contain NRL and the availability of suitable NRL-free alternatives.

Clinical trials in orthodontics II: assessment of the quality of reporting of clinical trials published in three orthodontic journals between 1989 and 1998

AIMS

To test the hypothesis that the quality of reporting of orthodontic clinical trials is insufficient to allow readers to assess the validity of the trial.

DESIGN

A retrospective observational study.

SETTING

The American Journal of Orthodontics and Dentofacial Orthopedics (AJODO), the British Journal of Orthodontics (BJO) and European Journal of Orthodontics (EJO).

DATA SOURCE

Clinical trials published between 1989 and 1998.

METHOD

A hand search was performed to identify all clinical trials. The concealment of allocation, whether the trial was randomized, double blind, and whether there was a description of withdrawals and dropouts was recorded.

RESULTS

One hundred and fifty-five trial reports were identified of which 4 (2.6%) were adequately concealed, 85 (54.8%) were described as being randomized, 10 (6.5%) as double-blind, and 44 (28.4%) gave a description of withdrawals and drop-outs from the trial. The type of randomization was considered appropriate in 78 (50.3%) reports and in 57 (36.8%) reports the level of blinding was considered appropriate. When assessed for the risk of bias in the reported trials,(1) one trial (0.6%) had a low risk of bias, 17 (11%) a moderate risk, and 137 (88.4%) a high risk.

CONCLUSIONS

In general the quality of reporting orthodontic clinical trials was insufficient to allow readers to assess the validity of the trials. Reporting of clinical trials could be improved by orthodontic journals adopting the CONSORT statement(2,)(3) to ensure that all relevant information is provided.

How readable are orthodontic patient information leaflets?

OBJECTIVE

To assess the readability of published orthodontic patient information leaflets (PILs) and their eligibility for the Plain English Campaign's Crystal Mark.

DESIGN

A retrospective, observational study.

SETTING

PILs available from professional organizations and commercial companies.

MATERIALS AND METHODS

Twenty-six orthodontic PILs were assessed. The entire text of each leaflet was reproduced in Microsoft Word, 2000. Readability statistics were obtained via the 'Tools' menu. The design elements of each leaflet were assessed. The leaflets were sent to the Plain English Campaign for assessment of their eligibility for the Crystal Mark.

OUTCOME MEASURES

Leaflet and sentence length, passive percentage, Flesch Reading Ease score, Flesch Kincaid Grade Level, design percentage and eligibility for the Plain English Campaign's Crystal Mark.

RESULTS

Overall, nearly half of the leaflets (42.3%) were rated as 'fairly difficult' or 'difficult' to read. However, the BOS PILs were significantly better than the AAO leaflets in all but one outcome with the BOS leaflets being rated as 'standard' or 'fairly easy' to read, meaning that 70-80% of the UK population would be able to understand them. None of the PILs were eligible for the Plain English Campaign's Crystal Mark.

CONCLUSIONS

The orthodontic PILs assessed were difficult to read and none were eligible for the Plain English Campaign's Crystal Mark. However, the BOS leaflets were much easier to read and better designed than those produced by the AAO making them a useful tool to improve patients' understanding of different treatment options and allowing them to be used in the informed consent process.

The evaluation of cognitive function in the dementias: methodological and regulatory considerations

Impairment of cognitive function is the central feature of dementia. Although, clinically, the cognitive deficit most often manifests itself as memory problems, a number of other areas of cognition are affected, and memory is but one of the cognitive skills compromised in dementia. Dementia with Lewy bodies, for example, accounts for 15% to 25% of all dementias and does not have memory deficits as a core feature. Our cognitive facilities underlie our abilities to engage successfully in the activities of daily living (ADL) and it follows thai enhancement of cognitive function will facilitate performance of ADL The assessment and understanding of these impairments are crucial to any treatment of the disorder. Unfortunately, the principal instrument used to assess cognitive function in most of the major clinical trials of Alzheimer's disease in recent years, the Alzheimer's Disease Assessment Scale-Cognitive Subsection (ADAS-COG), primarily assesses aspects of memory, which has resulted in other important cognitive deficits in dementia being overlooked. Automated cognitive tests are now available that can identify an earlier onset of improvements in dementia in smaller samples than the ADAS, Regulatory authorities should encourage - or even require - the use of automated procedures alongside the ADAS in pivotal trials to help determine the relative utility of the instruments in the fairest way possible. Whatever the outcome, this will be of long-term benefit to patients, carers, drug developers, clinicians, and regulators in this important area.

A validation study of appropriate phonological verbal fluency stimulus letters for use with croatian speaking individuals

The aim of this study is to determine the word frequency for all thirty letters of the Croatian alphabet and to collect normative data for the letter fluency task in Croatian speakers. Ninety two healthy participants were given each of the Croatian letters, and asked to generate as many words as possible in 60 seconds for each letter Results suggested that participants generated most frequently words starting with the letters as follows: "K", "P", "S" and "M".

WAY-318068: a novel, potent and selective noradrenaline re-uptake inhibitor with activity in rodent models of pain and depression

BACKGROUND AND PURPOSE

Antidepressants, which raise the CNS concentrations of 5-HT and noradrenaline, are frequently used in the treatment of chronic pain; however, it is not known if increasing CNS noradrenaline levels alone is sufficient for efficacy, in part resulting from a lack of small molecules with sufficient selectivity.

EXPERIMENTAL APPROACH

In this report, we present the in vitro pharmacological and in vivo pharmacokinetic and pharmacological properties of the novel, orally available and CNS penetrant inhibitor of the noradrenaline transporter (NET), WAY-318068 (1-[(1S,2R)-1-(3,5-difluorophenyl)-2-hydroxy-3-(methylamino)propyl]-7-fluoro-3,3-dimethyl-1,3-dihydro-2H-indol-2-one).

KEY RESULTS

WAY-318068 is a potent and effective inhibitor of the NET with a K(i) of 8.7 nM in a binding assay, and an IC(50) of 6.8 nM in an assay of transporter function, without significant binding to the dopamine transporter. Furthermore, the compound has only weak activity at the 5-HT transporter, leading to a functional selectivity of greater than 2500-fold. It is orally bioavailable with substantial quantities of the compound found in the CNS after oral dosing. As measured by microdialysis in rats, the compound causes a robust and significant increase in cortical noradrenaline levels without affecting 5-HT. WAY-318068 was effective in models of acute, visceral, inflammatory, osteoarthritic, neuropathic, diabetic and bone cancer pain, as well as in traditional models of depression at doses that do not cause motor deficits.

CONCLUSIONS AND IMPLICATIONS

Collectively, the present results support the conclusion that selectively increasing CNS levels of noradrenaline is sufficient for efficacy in models of depression and pain.

Accuracy of external cause-of-injury coding in hospital records

OBJECTIVE

To appraise the published evidence regarding the accuracy of external cause-of-injury codes in hospital records.

DESIGN

Systematic review.

DATA SOURCES

Electronic databases searched included PubMed, PubMed Central, Medline, CINAHL, Academic Search Elite, Proquest Health and Medical Complete, and Google Scholar. Snowballing strategies were used by searching the bibliographies of retrieved references to identify relevant associated articles.

SELECTION CRITERIA

Studies were included in the review if they assessed the accuracy of external cause-of-injury coding in hospital records via a recoding methodology.

METHODS

The papers identified through the search were independently screened by two authors for inclusion. Because of heterogeneity between studies, meta-analysis was not performed.

RESULTS

Very limited research on the accuracy of external cause coding for injury-related hospitalisation using medical record review and recoding methodologies has been conducted, with only five studies matching the selection criteria. The accuracy of external cause coding using ICD-9-CM ranged from approximately 64% when exact code agreement was examined to approximately 85% when agreement for broader groups of codes was examined.

CONCLUSIONS

Although broad external cause groupings coded in ICD-9-CM can be used with some confidence, researchers should exercise caution for very specific codes until further research is conducted to validate these data. As all previous studies have been conducted using ICD-9-CM, research is needed to quantify the accuracy of coding using ICD-10-AM, and validate the use of these data for injury surveillance purposes.

Orthodontic treatment for prominent upper front teeth in children

BACKGROUND

Prominent upper front teeth are an important and potentially harmful type of orthodontic problem. This condition develops when the child's permanent teeth erupt and children are often referred to an orthodontist for treatment with dental braces to reduce the prominence of the teeth. If a child is referred at a young age, the orthodontist is faced with the dilemma of whether to treat the patient early or to wait until the child is older and provide treatment in early adolescence. When treatment is provided during adolescence the orthodontist may provide treatment with various orthodontic braces, but there is currently little evidence of the relative effectiveness of the different braces that can be used.

OBJECTIVES

To assess the effectiveness of orthodontic treatment for prominent upper front teeth, when this treatment is provided when the child is 7 to 9 years old or when they are in early adolescence or with different dental braces or both.

SEARCH STRATEGY

The Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE and EMBASE were searched. The handsearching of the key international orthodontic journals was updated to December 2006. There were no restrictions in respect to language or status of publication. Date of most recent searches: February 2007.

SELECTION CRITERIA

Trials were selected if they met the following criteria: design - randomised and controlled clinical trials; participants - children or adolescents (age < 16 years) or both receiving orthodontic treatment to correct prominent upper front teeth; interventions - active: any orthodontic brace or head-brace, control: no or delayed treatment or another active intervention; primary outcomes - prominence of the upper front teeth, relationship between upper and lower jaws; secondary outcomes: self esteem, any injury to the upper front teeth, jaw joint problems, patient satisfaction, number of attendances required to complete treatment.

DATA COLLECTION AND ANALYSIS

Information regarding methods, participants, interventions, outcome measures and results were extracted independently and in duplicate by two review authors. The Cochrane Oral Health Group's statistical guidelines were followed and mean differences were calculated using random-effects models. Potential sources of heterogeneity were examined.

MAIN RESULTS

The search strategy identified 185 titles and abstracts. From this we obtained 105 full reports for the review. Eight trials, based on data from 592 patients who presented with Class II Division 1 malocclusion, were included in the review.Early treatment comparisons: Three trials, involving 432 participants, compared early treatment with a functional appliance with no treatment. There was a significant difference in final overjet of the treatment group compared with the control group of -4.04 mm (95% CI -7.47 to -0.6, chi squared 117.02, 2 df, P < 0.00001, I(2) = 98.3%). There was a significant difference in ANB (-1.35 mm; 95% CI -2.57 to -0.14, chi squared 9.17, 2 df, P = 0.01, I(2) = 78.2%) and change in ANB (-0.55; 95% CI -0.92 to -0.18, chi squared 5.71, 1 df, P = 0.06, I(2) = 65.0%) between the treatment and control groups. The comparison of the effect of treatment with headgear versus untreated control revealed that there was a small but significant effect of headgear treatment on overjet of -1.07 (95% CI -1.63 to -0.51, chi squared 0.05, 1 df, P = 0.82, I(2) = 0%). Similarly, headgear resulted in a significant reduction in final ANB of -0.72 (95% CI -1.18 to -0.27, chi squared 0.34, 1 df, P = 0.56, I(2) = 0%). No significant differences, with respect to final overjet, ANB, or ANB change, were found between the effects of early treatment with headgear and the functional appliances. Adolescent treatment (Phase II): At the end of all treatment we found that there were no significant differences in overjet, final ANB or PAR score between the children who had a course of early treatment, with headgear or a functional appliance, and those who had not received early treatment. Similarly, there were no significant differences in overjet, final ANB or PAR score between children who had received a course of early treatment with headgear or a functional appliance. One trial found a significant reduction in overjet (-5.22 mm; 95% CI -6.51 to -3.93) and ANB (-2.27 degrees; 95% CI -3.22 to -1.31, chi squared 1.9, 1 df, P = 0.17, I(2) = 47.3%) for adolescents receiving one-phase treatment with a functional appliance versus an untreated control.A statistically significant reduction of ANB (-0.68 degrees; 95% CI -1.32 to -0.04, chi squared 0.56, 1 df, P = 0.46, I(2) = 0%) with the Twin Block appliance when compared to other functional appliances. However, there was no significant effect of the type of appliance on the final overjet.

AUTHORS' CONCLUSIONS

The evidence suggests that providing early orthodontic treatment for children with prominent upper front teeth is no more effective than providing one course of orthodontic treatment when the child is in early adolescence.

Measuring cognitive change in Alzheimer's disease clinical drug trials

In the following paper the cognitive measures used in clinical trials of drugs for Alzheimer's disease are reviewed. The potential benefits of employing innovative tests that map cognitive domains poorly indexed by traditional measures such as the ADAS-cog are considered. Finally, issues pertaining to the cognitive breadth of any proposed new instrument are discussed, as well as the clinical relevance of cognitive change.

Species-specific in vitro pharmacological effects of the cannabinoid receptor 2 (CB2) selective ligand AM1241 and its resolved enantiomers

BACKGROUND AND PURPOSE

Racemic (R,S) AM1241 is a cannabinoid receptor 2 (CB(2))-selective aminoalkylindole with antinociceptive efficacy in animal pain models. The purpose of our studies was to provide a characterization of R,S-AM1241 and its resolved enantiomers in vitro and in vivo.

EXPERIMENTAL APPROACH

Competition binding assays were performed using membranes from cell lines expressing recombinant human, rat, and mouse CB(2) receptors. Inhibition of cAMP was assayed using intact CB(2)-expressing cells. A mouse model of visceral pain (para-phenylquinone, PPQ) and a rat model of acute inflammatory pain (carrageenan) were employed to characterize the compounds in vivo.

KEY RESULTS

In cAMP inhibition assays, R,S-AM1241 was found to be an agonist at human CB(2), but an inverse agonist at rat and mouse CB(2) receptors. R-AM1241 bound with more than 40-fold higher affinity than S-AM1241, to all three CB(2) receptors and displayed a functional profile similar to that of the racemate. In contrast, S-AM1241 was an agonist at all three CB(2) receptors. In pain models, S-AM1241 was more efficacious than either R-AM1241 or the racemate. Antagonist blockade demonstrated that the in vivo effects of S-AM1241 were mediated by CB(2) receptors.

CONCLUSIONS AND IMPLICATIONS

These findings constitute the first in vitro functional assessment of R,S-AM1241 at rodent CB(2) receptors and the first characterization of the AM1241 enantiomers in recombinant cell systems and in vivo. The greater antinociceptive efficacy of S-AM1241, the functional CB(2) agonist enantiomer of AM1241, is consistent with previous observations that CB(2) agonists are effective in relief of pain.

Delay and failure to publish dental research

OBJECTIVE

To investigate the incidence and time taken to full publication of abstracts presented at dental scientific meetings.

DESIGN

A retrospective observational study.

SETTING

All abstracts from the 1993 proceedings of the European Orthodontic Society (EOS) and European Organisation for Caries Research (ORCA) and a 10% random sample of abstracts from the International Association for Dental Research (IADR) conferences.

METHODS

A cross-referenced Medline search of abstract title and authors was undertaken to determine whether abstracts had been published as full papers. Searches were censored 1 year prior to and 5 years post publication as an abstract. Publication rate was compared between abstracts presented orally and as posters.

MAIN OUTCOME MEASURES

Publication as a full paper and time taken to publication.

RESULTS

546 abstracts were investigated. 252 abstracts (46.1%) were found as full reports. Median time to publication of all abstracts was 18 months (IQR 9, 30 months). 99 of the oral abstracts (57%) and 153 (41%) of the poster abstracts were published. Relative Risk Oral vs Poster=1.37 CI (1.19, 1.55).

CONCLUSION

More than half of the research presented at EOS, IADR and ORCA in 1993 remained unpublished 5 years after presentation at the conference. Oral presentations were published more frequently than poster presentations.

Diagnosis based injury severity scaling: investigation of a method using Australian and New Zealand hospitalisations

OBJECTIVE

To assess the performance of the International Classification of Diseases (ICD) based injury severity score, ICISS, when applied to two versions of the 10th edition of ICD, ICD-10 and ICD-10-AM.

DESIGN

ICISS was assessed on its ability to predict threat to life using logistic regression modelling. Models used ICISS and age as predictors and survival as the outcome.

SETTING

Australia and New Zealand. Patients or

SUBJECTS

Hospitalisations with an ICD-10-AM principal diagnosis in the range S00-T89 from 1 July 1999 to 30 June 2001 (Australia) or 1 July 1999 to 31 December 2001 (New Zealand).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The models were assessed in terms of their discrimination, measured by the concordance score, and calibration, measured using calibration curves and the Hosmer-Lemeshow statistic.

RESULTS

523 633 Australian and 124 767 New Zealand hospitalisations were selected, including 7230 and 1565 deaths respectively. Discrimination was high in all the fitted models with concordance scores of 0.885 to 0.910. Calibration results were also promising with all calibration curves being close to linear, though ICISS appeared to underestimate mortality somewhat for cases with an ICISS score less than 0.6. Overall ICISS performed better when applied to the Australian than the New Zealand hospitalisations. Australian and New Zealand hospitalisations were very similar. ICISS was also only a little more successful when ICD-10-AM rather than mapped ICD-10 was used.

CONCLUSIONS

ICISS appears to be a reasonable way to estimate severity for databases using ICD-10 or ICD-10-AM. It is also likely to work well for other clinical variants of ICD-10.

Publication bias: raising awareness of a potential problem in dental research

With the development of evidence-based dentistry it is important to consider how accurate and representative our published pool of evidence is. In this article we will describe publication bias and discuss the causes and potential effects it may have upon the pool of scientific evidence available in dentistry.

Clinical trials in orthodontics I: demographic details of clinical trials published in three orthodontic journals between 1989 and 1998

AIM

To test the hypothesis that there is insufficient evidence available, from clinical trials, to allow evidence-based decisions to be made on the effectiveness of orthodontic treatment.

OBJECTIVES

To identify reports of orthodontic clinical trials and assess their demographic characteristics.

DESIGN

A retrospective, observational study.

SETTING

The American Journal of Orthodontics and Dentofacial Orthopedics, British Journal of Orthodontics, and European Journal Orthodontics.

DATA SOURCE

Clinical trials published between 1989 and 1998.

METHOD

A hand-search was performed to identify all clinical trials. The journal and year of publication, research method, interventions, and sample size of the trials reported were recorded.

RESULTS

One-hundred-and-fifty-five trial reports were identified of which 56 (36.1%) were published from 1989 to 1993 and 99 (69%) from 1994 to 1998. Ninety-nine (69%) reports were published in the AJO-DO, 18 (11.6%) in the BJO and 38 (24.5%) in the EJO. Eighty-five (54.8%) were reports of randomized controlled trials and 70 (45.2%) of controlled clinical trials. The interventions most frequently assessed were bonding materials (21.9%), growth modification treatments (21.3%), and oral hygiene procedures (9.0%). The median sample size was 32 (IQR 19.5, 50).

CONCLUSION

There is sufficient evidence available from clinical trials to warrant doing systematic reviews of orthodontic clinical trials to aid decision-making.