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PubMed2006

False assumptions about psychopathology, hysteria and the MMPI-2 Restructured Clinical Scales.

The MMPI-2 Restructured Clinical scales rest on the common behavioral assumption that consistent items can be added to assess all psychopathologies. This may be the case for some unitary symptoms such as anxiety or anger, but not for complex diagnostic conditions such as Hysteria, Post Traumatic Stress Disorder, and Borderline Personality Disorder. These are better understood with a psychodynamic formulation. Psychodynamic theory assumes that internal conflicts and contradictions are a significant feature of many psychopathologies. For example, the new MMPI-2 Restructured Clinical scales eliminated a measure of hysteria. The RC3 Cynicism scale is not an improvement over the MMPI-2 Hysteria scale, as the new scale serves as an example of a failure of the behaviorism to account for complex psychopathology. Making scales more internally consistent and distinct from each other has not produced more external validity and useful measures for many of the psychopathologies found in clinical practice.

Diagnosis, Differential↗

PubMed1986

Research by regional psychiatrists, 1978-84.

An audit was undertaken of research by psychiatrists in Australia and New Zealand published in an accepted scientific journal during the seven-year period, 1978-84. The key analyses were limited to first authors only and identified 89 responsible for 372 scientific publications. Despite an increase in psychiatrists in the region there was no evidence of any increased research output during the seven years. While the distribution of researchers across the region was consistent with the overall distribution of psychiatrists, relatively strong and consistent differences in measures of quality and quantity of research output were demonstrated between geographical areas. The audit examined published research by topic, by publishing journal, and by the affiliation of the researcher. Several measures of research quality and productivity were internally and externally validated. Profiles are given of the average researcher and of those distinguished in terms of high productivity and high citation rates.

Adult↗

PubMed1983

Schizophrenic subgroups with normal and abnormal cognitive functioning on the Luria-Nebraska Neuropsychological Battery.

A new set of decision rules for identification of brain dysfunction among schizophrenic or schizoaffective disorder patients were tested with the Luria-Nebraska Neuropsychological Battery. In a sample of 100 patients from these categories with normal neurological examination findings, three groups of patients were identified. These patients respectively were identified as cognitively normal, borderline, or abnormal. These groups were subjected to a series of multivariate and univariate analyses that showed them to be associated with significantly different profiles on the Luria-Nebraska Neuropsychological Battery. Different functional systems were postulated to account for the differences in impaired scores across normal, borderline, and abnormal cognitive functioning groups. Further research with external validation criteria was encouraged.

Adult↗

PubMed1989

A review of four MMPI indices which differentiate between organicity and schizophrenia.

Reviewed studies investigating the internal and external validity of four MMPI indices differentiating between schizophrenia and CNS disorders were contrasted and critiqued. Two types of test construction methods were identified as development procedures for the indices discussed, which were the item and profile analysis approaches. Although the indices developed by the profile analysis method proved more accurate in separating patients into the two diagnostic categories, hit rates were consistently affected by the degree of overlapping symptomatology between diagnostic sample groups. Variable hit rates reported for each of the indices ultimately lead one to question the MMPI's clinical utility for distinguishing patients presenting mixed organic and schizophrenic symptoms. Results from several studies converged on the conclusion that these MMPI indices measured a general degree of disturbance factor rather than schizophrenia or organicity.

Brain Diseases↗

PubMed1988

Single case studies. An introduction.

The limitations of conventional group comparative therapeutic trials are discussed. They include: the heterogeneity problem (due to biological variations within the sample) and the extrapolation problem (i.e. the problem of external validity). These problems may to some extent be overcome by multiple cross-over studies in a single patients. Such studies may be useful in selected cases in daily clinical work, but could also be used for detecting treatment effects in rare diseases. Usually, it is necessary to measure the clinical effect by means of clinical scores, for which reason ranking methods must be used. The statistical significance may be judged by means of a permutation test. The risk of committing a type II error in single patient studies is usually high.

Clinical Trials as Topic↗

PubMed1995

Patterns of cocaine use among individuals in substance abuse treatment.

Recognition of the heterogeneity among substance abusers has led to increased attention to the issue of client-treatment matching. One approach involves identifying different patterns of use within samples of substance abusers. The present preliminary report employed a cluster analysis of various aspects of cocaine use to examine subgroups of cocaine users within a sample of individuals in treatment for substance abuse. Three clusters emerged, differentiated primarily by quantity/frequency of use and route of administration. The resulting subgroups were compared on measures of external validity. Results suggest that subgroups of cocaine use patterns do exist within a sample of substance abusers. In addition, these subgroups differ in age of cocaine use onset and the severity of negative consequences. Future research is needed to establish the clinical utility of these clusters.

Adolescent↗

PubMed1991

Combined single subject trials.

Randomized controlled single subject trials are designed as multiple crossovers between the treatments to be compared. Results from such independent trials may be combined and integrated for the purpose of extending the conclusions beyond the single subject. Unlike the conventional crossover group trial, the primary goal of the combined single subject study is not to demonstrate an overall clinical benefit of a drug, but to indicate the features typical for drug responders. The external validity of combined single subject trials depends on the same prerequisites as are employed in group trials: strict entry criteria, uniform treatment procedures, consensus targets for outcome measures, and acceptable statistical tests. In clinical research the main role of combined single subject trials should be to elucidate new insight and generate hypotheses that could optimize the design of subsequent group trials.

Data Interpretation, Statistical↗

PubMed1988

A decisional balance measure and the stages of change model for weight loss.

Two studies were conducted to explore the cognitive and motivational aspects related to progression through the stages of intentional change in weight loss and control. Study I developed a Decisional Balance Measure for comparison of the positive and negative aspects of a decision to try to lose weight. Based on principal components analysis, item analysis, and coefficient alpha, 20 items were retained, 10 for each of two orthogonal scales labeled Pros and Cons. These two components accounted for 50% of the total variance. In Study II, the Pro, Con, and Pro-Con difference scores were compared across groups representing four stages in the change process: Precontemplation, Contemplation, Action, and Maintenance. External validity for the Decisional Balance Measure was provided by significant ANOVAs for the Pro and the Pro-Con scale scores, with the Action group showing the greatest imbalance of Pros over Cons. The combination of the decisional balance and stages of change models appears to offer a powerful tool for relating two important elements in an integrated theory of how change occurs naturally, and how it could be enhanced through planned treatment.

Adolescent↗

PubMedDate not supplied

RE-AIMing research for application: ways to improve evidence for family medicine.

OBJECTIVE: To outline changes in clinical research design and measurement that should enhance the relevance of research to family medicine. METHODS: Review of the traditional efficacy research paradigm and discussion of why this needs to be expanded. Presentation of practical clinical and behavioral trials frameworks, and of the RE-AIM model for planning, evaluating, and reporting studies. RESULTS: Recommended changes to improve the external validity and relevance of research to family medicine include studying multiple clinical practices, realistic alternative program choices, heterogeneous and representative patients, and multiple outcomes including cost, behavior change of patients and staff, generalization, and quality of life. CONCLUSIONS: The methods and procedures discussed can help program planners, evaluators and readers of research articles to evaluate the replicability, consistency of effects, and likelihood of widespread adoption of interventions.

Behavioral Research↗

PubMed2003

Systematic review of endoscopic sinus surgery for nasal polyps.

OBJECTIVES: To provide a systematic review of the clinical effectiveness of endoscopic sinus surgery (ESS) for the removal of nasal polyps. DATA SOURCES: Searches of electronic databases, websites and reference lists were made to identify relevant studies. REVIEW METHODS: An extensive search was performed to identify all articles where FESS is used for the excision of nasal polyps. Two reviewers independently screened articles for inclusion according to predefined criteria. Comparative studies were included if they were primary research, focused on FESS for the removal of nasal polyps, reported patient relevant outcomes and were published in English. In addition, case series studies were included if they met the above criteria and enrolled more than 50 patients with polyps. Data were then extracted by one reviewer and checked by a second. A structured form was used to assess the internal and external validity of included studies. Comparative data were reported where available. Excluded case series and case reports were grouped and described. A group of nine ear, nose and throat (ENT) experts were selected, then using the literature and their own experience, they generated a list of priority research questions. Existing economic evaluations were sought and described. RESULTS: Of the 33 studies included, the randomised controlled trials and controlled trials reported overall symptomatic improvement that ranged from 78 to 88% for FESS compared with 43 to 84% for similar techniques (including polypectomy, Caldwell-Luc and intranasal ethmoidectomy). Disease recurrence was 8% for FESS compared with 14% for Caldwell-Luc and polyp recurrence was 28% for endoscopic ethmoidectomy compared with 35% for polypectomy. Revision surgery was reported in one study only and was the same for FESS and Caldwell-Luc procedures. Percentage of overall complications was reported in only one comparative study and was 1.4% for FESS compared with 0.8% for conventional procedures. The case series studies reported overall symptomatic improvement for patients with nasal polyps ranging from 37 to 99% (median 89%). For the mixed patient groups (with and without polypoid disease) overall symptomatic improvement ranged from 40 to 98% (median 88%). Total complications in the case series studies ranged from 22.4 to 0.3% (median 6%). CONCLUSIONS: The majority of studies report that symptoms improve following FESS with relatively few complications; however, only a small proportion of evidence is comparative. Results from non-comparative studies do not inform the choices that need to be made by ENT surgeons and commissioners. Health economics data are also lacking and therefore cannot inform these decisions. FESS may offer some advantages in effectiveness over comparative techniques, but there is enormous variation in the range of results reported and there are severe methodological limitations. There is a clear need for quality-controlled trials in order to answer questions regarding the effectiveness of FESS. A number of priority research questions from a selection of ENT surgeons within the UK are identified and presented.

Endoscopy↗

PubMed2005

The causes and effects of socio-demographic exclusions from clinical trials.

OBJECTIVES: To investigate the exclusion from trials of women, older people and minority ethnic groups, focusing on two drug exemplars, statins and non-steroidal anti-inflammatory drugs (NSAIDs). DATA SOURCES: Medical and ethical databases. Workshops with stakeholders. REVIEW METHODS: Literature was reviewed on exclusions in healthcare research and three workshops were held with stakeholders. Twenty-seven randomised controlled trials (RCTs) of statins use for secondary prevention of coronary heart disease (CHD) and 25 NSAIDs trials for pain in osteoarthritis (OA) were analysed. Using a Scottish cohort with record-linkage, profiling was carried out for 3188 people needing secondary prevention for CHD (1993-1996), ascertaining the independent effects of statins, and 131,410 people dispensed NSAIDs (1989-1996), examining adverse effects. Routine data sources were accessed to profile the need for secondary prevention of CHD in England and usage was estimated by consulting published surveys. The Somerset and Avon Survey of Health (SASH) 1996-97 and published data were accessed for information on potential need and usage of NSAIDs in OA. For both drugs, the socio-demographic profiles of trial samples, the population in potential need and those on treatment were compared. An evidence synthesis was produced to clarify the effects of statins on women and older people and the relationship of absolute effectiveness outcomes with underlying risk levels of disease events was modelled, examining the likely effects of trial exclusions. RESULTS: The average age of statins trial participants was 58.5 years; only 16.3% were women. Statins reduced cardiovascular disease (CVD) incidence by about 25% in both men and women. Older people up to 75 years of age also benefited. Meta-analysis and two landmark trials confirmed these results. The average age of NSAIDs trial participants was 61.9 years and women were well represented (68.5%). Gastrointestinal (GI) adverse events were commonly reported, but renal side-effects were not. Outcomes were seldom reported according to socio-demographic group. For both drugs, USA trials were more inclusive than UK/European trials. Ethnicity was not well reported for either drug. Some 23% of the cohort were treated with statins. Users were younger than non-statins users (but no more likely to be male) and had superior outcomes. High current exposure to NSAIDs elevated the risk of GI side-effects by about 50% versus no current exposure and renal impairment risk by nearly 140%. Side-effect risk increased with age; being female diminished risk. Approximately 537,000 incident cases of CVD would qualify for statins use in England each year. Women constitute 45% of this population with need, two-thirds of whom are aged 65 years or over. Need varies by ethnic group. No sex bias in prescribing statins was detected, but use was commoner in younger people. For NSAIDs, 6.3% of adults aged 35+ years reported hip and/or knee pain associated with OA; 3.9% of adults used prescribed analgesics for this and they were more likely to be women and to be >65 years old. For statins, women formed almost half of the 'with need' and 'on treatment' populations, but were markedly under-represented in trials. Those aged 65+ years formed nearly two-thirds of the 'with need' population, but only one-fifth of trial samples, and were less likely to be treated than younger subjects. For NSAIDs, women formed similar proportions. Associations of side-effects with socio-demographic factors was revealed in cohort data but not in trials. CONCLUSIONS: The issue of exclusion from trials of women, older people and ethnic minorities has been relatively neglected in the UK research community, and there is confusion about diversity issues. Under-representation occurs, but in drug trials at least this may not always affect the external validity of relative effect estimates. However, measures of absolute effectiveness, absolute harm and cost-effectiveness are associated with underlying risk levels in different socio-demographic groups. Under-representation will therefore bias absolute effect estimates. The following areas are suggested for future research: multi-disciplinary assessment of realistic options for trialists to address the issue of exclusions; clarification of the use of ethnic categories in health research and of the implications of the different dimensions of ageing and sex/gender; identification of barriers and facilitators to the involvement of different population groups in research, further investigation of the susceptibility of older men to NSAID adverse events, and the development of a 'register of registries and databases' and exploration of how linked health information systems in the UK could be improved.

Adult↗

PubMed2026

Aqueous humour extracellular vesicle membrane protein profiling reveals pathological features of refractory macular edema.

BACKGROUND: Both diabetic macular edema (DME) and retinal vein occlusion-related macular edema (RVO-ME) can become refractory to anti-vascular endothelial growth factor (anti-VEGF) therapy, but the underlying mechanisms are unclear. Molecular discrimination of refractory disease could guide personalized treatment. This study examined whether aqueous humor-derived extracellular vesicle (EV) membrane proteins can characterize refractoriness and reveal etiology-specific pathways. METHODS: This prospective cohort study included 28 patients with DME or RVO-ME (14 each), further divided into treatment-naïve and refractory subgroups. Aqueous humour samples were collected before intravitreal anti-VEGF injection. EV membrane proteins were profiled using an EV Array chip targeting 435 antibodies. Differentially expressed proteins were analyzed by bioinformatics, including Gene Ontology, Kyoto encyclopaedia of genes and genomes (KEGG) pathway enrichment, Gene set enrichment analysis (GSEA), and cell-of-origin mapping using public single-cell RNA-seq data. RESULTS: VEGF/VEGFR2 were elevated in treatment-naïve DME and RVO-ME. Refractory DME showed upregulation of C5 and CD34 (complement/immune activation). Refractory RVO-ME exhibited increased CD68 and Annexin A1 with decreased PDGFR (chronic inflammation, vascular dysregulation). RANTES was commonly upregulated in refractory disease. Several EV proteins discriminated refractory cases with high accuracy (AUC 0.898-0.980). Cellular origin suggested immune cell-derived EVs in DME, retinal cell-derived EVs in RVO-ME. External validation confirmed key differences. CONCLUSION: Refractory ME involves distinct pathways: immune-inflammatory activation in DME versus chronic inflammation with vascular dysregulation in RVO-ME. EV membrane proteins from aqueous humor provide insights into therapeutic resistance and hold promise as biomarkers for personalized treatment decisions.

artificial intelligence↗

PubMed2026

Multimodal artificial intelligence and machine learning in oncology: from data integration to precision cancer care.

Cancer remains a major global health burden, with approximately 20 million new cases and 9.7 million cancer-related deaths reported globally in 2022. While advances in radiological imaging, molecular profiling, and clinical data have enhanced the interpretation of disease progression, the availability of multiple such modalities still does not meet the needs of a large patient population. This narrative review focuses on the role of multimodal artificial intelligence and machine learning in bridging the gap in interpreting heterogeneous modalities to improve risk prediction, prognostic assessment, and treatment decision-making in precision oncology. Multimodal frameworks such as Pathomic Fusion illustrate how complementary histopathological and genomic information can be integrated for cancer diagnosis and prognostic modeling. Multimodal models have demonstrated potential in virtual biopsy, cancer screening, prognostic prediction, radiotherapy planning, intraoperative guidance, and clinical-trial design using digital twins and synthetic control arms. The major limitations of incorporating multimodal artificial intelligence and machine learning in oncology include data heterogeneity, demographic or institutional biases, and reproducibility challenges that hinder translation. Accordingly, appropriate data-governance strategies, fairness audits, and privacy-preserving approaches such as federated learning should be considered where appropriate. Future progress will depend on the development of standardized benchmarking datasets, robust external validation, seamless integration with electronic health records and picture archiving and communication systems, and the implementation of explainable, secure, and clinically validated multimodal artificial intelligence frameworks that support precision oncology in routine clinical practice.

deep learning↗

PubMed2026

Association between circulating GTP cyclohydrolase 1 concentrations and acute ischemic stroke: an exploratory case-control study in a Chinese population.

BACKGROUND AND OBJECTIVE: Ischemic stroke (IS) is a leading global cause of disability and mortality, characterized by cerebral hypoxia and tissue necrosis. GTP cyclohydrolase 1 (GCH1) regulates endothelial function and oxidative stress; however, whether circulating GCH1 concentrations are altered in acute ischemic stroke (AIS) remains unclear. This exploratory case-control study aimed to investigate plasma GCH1 levels and their associations with clinical characteristics in patients with AIS. METHODS: Seventy-one patients with AIS and 92 controls undergoing routine health examinations were recruited at the Affiliated Hospital of Youjiang Medical University for Nationalities (January 2024-May 2025). Clinical and biochemical data including lipid profiles, C-reactive protein, homocysteine, and National Institutes of Health Stroke Scale (NIHSS) scores (only for patients with AIS) were collected. Plasma GCH1 levels were measured using an enzyme-linked immunosorbent assay. Statistical analyses were performed to evaluate differences between groups and to examine the associations between plasma GCH1 levels and clinical characteristics. Receiver operating characteristic curve analysis was conducted to assess the discriminatory performance of circulating GCH1. RESULTS: Plasma GCH1 concentrations were significantly lower in AIS patients (6.51 ± 3.59 ng/mL vs. 14.32 ± 3.29 ng/mL, p < 0.001). Binary logistic regression analysis showed that lower plasma GCH1 levels were independently associated with AIS (OR = 0.496, 95% CI: 0.385-0.644, p < 0.001), while multiple linear regression analysis demonstrated that AIS was independently associated with lower plasma GCH1 levels (B = -7.687, 95% CI: -9.011 to -6.362, p < 0.001). Plasma GCH1 showed strong discrimination between the two groups (AUC = 0.924, 95% CI: 0.871-0.978) but was not associated with NIHSS scores (Spearman's rho = -0.034, p = 0.778). CONCLUSION: Plasma GCH1 concentrations were lower in patients with AIS than in health-examination controls and showed high apparent discrimination in this dataset. Because GCH1 was measured after stroke onset and the sample-derived threshold was derived in the same case-control sample, these findings do not establish temporality, causality, or clinical diagnostic utility. Prospective multicenter studies including clinically relevant disease controls and independent external validation are required.

Humans↗

PubMed2026

Mechanism-Driven Diagnostic Development: A Specimen-Aware Framework Illustrated by Colorectal Cancer and Solid Tumours.

Translational oncology has moved rapidly from histopathology and single-analyte biomarkers toward multi-dimensional molecular profiling. Yet many clinically deployed tests still use reductionist biomarker strategies that under-represent cancer complexity. This review examines whether a mechanistic, multi-layered, and specimen-aware approach can improve cancer detection, classification, prognosis, minimal residual disease (MRD) assessment, and therapeutic selection. Evidence across solid tumours shows that genomic alterations alone incompletely explain tumour state, metastatic behaviour, immune evasion, or therapeutic vulnerability. Integrated genome and transcriptome analyses, proteogenomics, single-cell atlases, fragmentomic, methylation based cell-free DNA assays, metabolomics and microbiome assessments reveal clinically relevant biology that single modality tests cannot determine. Minimally invasive collected specimens can extend access to screening, diagnosis and longitudinal monitoring, but the choice of specimen should be matched to disease biology and analytes that represent mechanisms of oncogenesis. However, translation remains constrained by pre-analytical variability, contamination, differences in tumour shedding behaviour, clonal haematopoiesis, translation of generated models, incomplete external validation and uncertain downstream clinical utility for emerging platforms. This review provides a commentary on the future of cancer diagnostics, the considerations and barriers to clinical translation, the relationship between utility and dimensionality of biomarkers assessed and the emerging rationale towards mechanistically grounded integrated models.

biomarkers↗

PubMed2026

C-Reactive Protein-Based Composite Indices for Predicting Tumor Overgrowth Restenosis After Partially Covered Duodenal Stenting in Gastric Cancer: A Cohort Study.

BACKGROUND/OBJECTIVES: Partially covered duodenal stents rapidly relieve malignant gastric outlet obstruction, but tumor overgrowth restenosis limits durability. We compared six preprocedural inflammatory, nutritional, and immune indices for predicting this outcome in patients with gastric cancer. METHODS: We retrospectively analyzed 68 consecutive patients from a prospectively maintained cohort. The primary endpoint was endoscopically or radiologically confirmed tumor overgrowth restenosis. Discrimination was assessed using receiver operating characteristic curves (pairwise DeLong tests with Bonferroni correction) and time-dependent areas under the curve (AUCs) accounting for death as a competing risk. Multivariable cause-specific Cox models were restricted to preprocedural covariates; post-stenting chemotherapy or radiotherapy was examined in time-dependent sensitivity analyses. RESULTS: Technical and clinical success rates were 100% and 94.1%. Seventeen patients (25.0%) developed restenosis at a median of 66 days. The C-reactive protein-albumin-lymphocyte (CALLY) index showed the highest AUC (0.859), followed by the C-reactive protein-to-albumin ratio (CAR; 0.822) and neutrophil-to-lymphocyte ratio (0.774); these three indices did not differ significantly. At an exploratory, internally derived cutoff of ≤0.110, CALLY had 76.5% sensitivity and 84.3% specificity and remained associated with restenosis after adjustment for stenosis site and stent length (adjusted hazard ratio, 12.30; 95% confidence interval, 3.89-38.83; C-index, 0.836), with consistent results in continuous, time-dependent, and tumor-covariate-adjusted analyses. The 180-day cumulative incidence was 52.4% with low CALLY versus 4.3% with high CALLY. CONCLUSIONS: C-reactive protein-based indices showed the highest numerical discrimination, although pairwise differences among CALLY, CAR, and NLR were not statistically significant. CALLY is a promising exploratory biomarker for restenosis risk stratification, but its cutoff should not guide clinical decisions until externally validated.

C-reactive protein↗

PubMed2001

Ability in perceiving nonnative contrasts: performance on natural and synthetic speech stimuli.

The perception of the distinction between /r/ and /l/ by native speakers of American English and of Japanese was studied using natural and synthetic speech. The American subjects were all nearly perfect at recognizing the natural speech sounds, whereas there was substantial variation among the Japanese subjects in their accuracy of recognizing /r/ and /l/ except in syllable-final position. A logit model, which additively combined the acoustic information conveyed by F1-transition duration and by F3-onset frequency, provided a good fit to the perception of synthetic /r/ and /l/ by the American subjects. There was substantial variation among the Japanese subjects in whether the F1 and F3 cues had a significant effect on their classifications of the synthetic speech. This variation was related to variation in accuracy of recognizing natural /r/ and /l/, such that greater use of both the F1 cue and the F3 cue in classifying the synthetic speech sounds was positively related to accuracy in recognizing the natural sounds. However, multiple regression showed that use of the F1 cue did not account for significant variance in natural speech performance beyond that accounted for by the F3 cue, indicating that the F3 cue is more important than the F1 cue for Japanese speakers learning English. The relation between performance on natural and synthetic speech also provides external validation of the logit model by showing that it predicts performance outside of the domain of data to which it was fit.

Adult↗

PubMed2003

Web-based research: methodological variables' effects on dropout and sample characteristics.

Previous research has made a beginning in addressing the importance of methodological differences in Web-based research. The present paper presents four studies investigating whether sample type, financial incentives, time when personal information is requested, table design, and method of obtaining informed consent influence dropout and sample characteristics (both demographics and measured attitudes). Undergraduates were less likely to drop out than nonstudents, and nonstudents offered a financial incentive were less likely to drop out than those offered no incentive. Complex tables, tables that were too wide, requests for personal information on the first page, and the imposing of additional informed consent procedures each provoked early dropout. As was expected, nonstudents and those presented with complex tables showed more measurement error and attitude differences. Asking for personal information and imposing additional consent procedures affected the demographic makeup, raising challenges to external validity.

Adult↗