SEARCH · PubMed Health

Results for “Internal validation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources

PubMed1999

The design of Partners in Care: evaluating the cost-effectiveness of improving care for depression in primary care.

This paper describes a study design that blends health services and clinical research approaches to examine the cost-effectiveness of treatments and of quality improvement for depression in primary care, managed care practices. Six managed care organizations in Los Angeles (Calif.), San Antonio (Tex.), San Luis Valley (Colo.), Twin Cities (Minn.), and Columbia (Md.) participated. Primary care clinics were randomized to one of two quality improvement interventions or care as usual. Interventions included patient and provider education, nurse-assisted patient assessment, and resources to support appropriate medication management or access to cognitive behavioral therapy. Practices implemented the interventions with study support. Providers and patients selected treatment. Patients with depressive symptoms regardless of comorbidities were eligible. Over 27,000 primary care patients visiting the practices of 181 primary care clinicians were screened for depression, 14% were potentially eligible, and 1356 enrolled into the 2-year longitudinal study. Enrollees were similar to eligibles, but usual care clinic patients tended to be less severely depressed than intervention clinic patients, partly due to clinic staff enthusiasm. The result of the study showed that studying treatment effects and quality improvement in nonacademic settings is feasible, but requires relaxation of design features of experiments that protect internal validity. The trade-off between certainty of causal inference and generalizability to usual care conditions is discussed. The strengths and limitations of this study design are compared to those of clinical trials and recent clinical effectiveness studies.

Adolescent↗

PubMed2006

Acute lung injury and the coagulation pathway: Potential role of gene polymorphisms in the protein C and fibrinolytic pathways.

There is evidence that dysregulation of coagulation and fibrinolysis may participate in the pathogenesis of acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Altered concentrations of several proteins of the coagulation and fibrinolytic pathways in plasma and pulmonary edema fluid from patients with acute lung injury have been related to the severity of lung injury and clinical outcomes. Polymorphisms in the genes encoding for proteins of the protein C and fibrinolysis pathways are known to regulate the production of the respective proteins. It is plausible that these polymorphisms may be associated with the susceptibility to and severity of illness in ALI and ARDS. Well-designed studies that examine the association of these polymorphisms with susceptibility and severity of ALI and ARDS are needed to test the influence of both genetic and environmental factors on the clinical outcomes in patients with ALI and ARDS. There are several important considerations in the design of these genetic association studies, including selection of candidate genes with the most biological plausibility, definition of the phenotype, selection of appropriate controls, determination of the appropriate sample size and assessment of Hardy-Weinberg equilibrium among controls as a measure of internal validity.

Blood Coagulation↗

PubMed2004

A model of osteoporosis impact in Switzerland 2000-2020.

The aim of our study was to develop a modeling framework suitable to quantify the incidence, absolute number and economic impact of osteoporosis-attributable hip, vertebral and distal forearm fractures, with a particular focus on change over time, and with application to the situation in Switzerland from 2000 to 2020. A Markov process model was developed and analyzed by Monte Carlo simulation. A demographic scenario provided by the Swiss Federal Statistical Office and various Swiss and international data sources were used as model inputs. Demographic and epidemiologic input parameters were reproduced correctly, confirming the internal validity of the model. The proportion of the Swiss population aged 50 years or over will rise from 33.3% in 2000 to 41.3% in 2020. At the total population level, osteoporosis-attributable incidence will rise from 1.16 to 1.54 per 1,000 person-years in the case of hip fracture, from 3.28 to 4.18 per 1,000 person-years in the case of radiographic vertebral fracture, and from 0.59 to 0.70 per 1,000 person-years in the case of distal forearm fracture. Osteoporosis-attributable hip fracture numbers will rise from 8,375 to 11,353, vertebral fracture numbers will rise from 23,584 to 30,883, and distal forearm fracture numbers will rise from 4,209 to 5,186. Population-level osteoporosis-related direct medical inpatient costs per year will rise from 713.4 million Swiss francs (CHF) to CHF946.2 million. These figures correspond to 1.6% and 2.2% of Swiss health care expenditures in 2000. The modeling framework described can be applied to a wide variety of settings. It can be used to assess the impact of new prevention, diagnostic and treatment strategies. In Switzerland incidences of osteoporotic hip, vertebral and distal forearm fracture will rise by 33%, 27%, and 19%, respectively, between 2000 and 2020, if current prevention and treatment patterns are maintained. Corresponding absolute fracture numbers will rise by 36%, 31%, and 23%. Related direct medical inpatient costs are predicted to increase by 33%; however, this estimate is subject to uncertainty due to limited availability of input data.

Aged↗

PubMed2002

A repeated 28-day oral dose toxicity study of 17alpha-methyltestosterone in rats, based on the 'enhanced OECD Test Guideline 407' for screening the endocrine-disrupting chemicals.

As part of the international validation project to establish the Enhanced OECD Test Guideline 407, we performed a 28-day repeated-dose toxicity study of 17alpha-methyltestosterone, an exogenous androgen agonist. Special attention was paid to the sensitivity of additional parameters for detecting endocrine-related effects of endocrine-disrupting chemicals, based on the existing Test Guideline 407. Seven-week-old Crj:CD(SD)IGS rats were allocated to one of four groups, each consisting of ten males and ten females, and 17alpha-methyltestosterone was administered daily by gavage at doses of 0 (control), 5, 20 and 80 mg/kg body weight per day. Male rats were killed on the day after the 28th administration and females on the day of the diestrus stage during the 4 day period after the 28th administration. Male rats receiving 80 mg/kg 17alpha-methyltestosterone demonstrated decreases in testis and epididymis weights, atrophy of seminiferous tubules and Leydig cells, and degenerated pachytene spermatocytes in the testes and degenerated germ cells in the epididymides as major alterations. Female rats showed abnormal estrous cycles, decreases in ovary and adrenal weights, increase in immature follicles with decreased corpus lutea in the ovaries at doses of 5 mg/kg and higher, as well as atrophy of zona reticularis in the adrenals and increase in mammary gland secretion at 20 mg/kg and above. Dilatation of the lumina and apoptosis of endometrial cells in the uterus, mucinification in the vagina and increase in serum follicle-stimulating hormone were seen with 80 mg/kg. Among the parameters examined in the present experimental system, effects of 17alpha-methyltestosterone on endocrine-related organs were detected in organ weights and histopathological examination of both sexes, and in serum hormones and estrous cycle of females. Based on these results, the no-observed-adverse-effect level (NOAEL) in the present study was estimated to be below 5 mg/kg per day. In particular, effects were most sensitively detected by organ weights and histopathological examination of sexual organs.

Administration, Oral↗

PubMed2002

A repeated 28-day oral dose toxicity study of genistein in rats, based on the 'Enhanced OECD Test Guideline 407' for screening endocrine-disrupting chemicals.

In association with the international validation project to establish an OECD Enhanced Test Guideline 407, we performed a 28-day repeated-dose toxicity study of genistein, which is known as a phytoestrogen. Attention was paid to the sensitivity of certain additional parameters, such as histopathology observations and organ weights of endocrine related organs, sperm characteristics, serum hormone levels and estrous cycle, for detecting endocrine-related effects of endocrine-disrupting chemicals based on the existing TG 407. Seven-week-old Crj:CD(SD)IGS rats were assigned to one of four groups, each consisting of ten males and ten females, and genistein was administered once daily by gavage at doses of 0 (control), 120, 400 or 1000 mg/kg body weight per day. Male rats were killed on the day after the 28th administration. Female rats were killed on the day of the diestrus stage during the 4 days after the 28th administration. Endocrine-disrupting effects of genistein were detected in females by histopathology. The changes included vacuolation and mucinification of the vaginal epithelium in the 400 and 1000 mg/kg groups; however, the incidences of the lesion were very low. Although increased serum prolactin levels were recorded in the males of the 1000 mg/kg group, we could not determine whether this was indeed induced by genistein. General toxicological effects of genistein were detected in blood chemistry, such as increased triglycerides and total protein and a decreased albumin/globulin ratio, as well as increased liver weight and glycogen deposition in the periportal hepatocytes. Based on these results, the no-observed-adverse-effect level (NOAEL) in the present study was estimated to be 120 mg/kg per day. In particular, endocrine-related effects were most sensitively detected by histopathology examination of sexual organs. However, the findings indicate that chemicals with weak endocrine-disrupting potential like genistein must be evaluated taking into consideration the results of other test systems.

Administration, Oral↗

PubMed2006

A repeated 28-day oral dose toxicity study of nonylphenol in rats, based on the 'Enhanced OECD Test Guideline 407' for screening of endocrine-disrupting chemicals.

A 28-day repeated oral dose toxicity study of nonylphenol (NP) was performed for an international validation of the 'Enhanced OECD Test Guideline 407' paying particular attention to the sensitivity of individual endocrine-related parameters. Sprague-Dawley rats, each group consisting of ten males and ten females, were administered NP once daily by gavage at doses of 0 (control), 10, 50, or 250 mg/kg body weight. At 250 mg/kg, three females died or became moribund during the experiment. At this dose, hepatic and renal toxicity was evident in both sexes with increase of relative liver and kidney weights as well as histopathological changes, such as centrilobular liver cell hypertrophy and a variety of renal tubular lesions, and alteration of serum biochemical parameters, some of them being evident from 50 mg/kg in females (glucose and inorganic phosphates). Hematologically, development of anemia was evident at 250 mg/kg in both sexes. Regarding endocrine-related effects, increase of thyroid weight in males was detected from 50 mg/kg. At 250 mg/kg, males exhibited reduction of relative weights of the ventral prostate and seminal vesicles, and females developed irregular estrous cyclicity and vaginal mucosal hyperplasia. Although changes in serum hormone levels were detected in both sexes, magnitude of the changes was small to be regarded as a low toxicological significance. In summary, repeated oral doses of NP to rats for 28 days resulted in hepato-renal toxicity from 50 mg/kg and anemia at 250 mg/kg. Effects on the endocrine system were observed from 50 mg/kg, and assessment of weights and histopathology of endocrine-related organs and estrous cyclicity may be valid in a battery for detecting endocrine effects of NP. The no-observed-adverse-effect level of NP was estimated to be 10 mg/kg per day.

Administration, Oral↗

PubMed2000

Repeated dose (28 days) oral toxicity study of flutamide in rats, based on the draft protocol for the 'Enhanced OECD Test Guideline 407' for screening for endocrine-disrupting chemicals.

In association with the international validation project to establish a test protocol for the 'Enhanced OECD Test Guideline 407', we performed a preliminary 28-day, repeated-dose toxicity study of flutamide, a non-steroidal androgen antagonist, and assessed the sensitivity of a list of parameters for detecting endocrine-related effects of endocrine-disrupting chemicals (EDCs). Seven-week-old CD(SD)IGS rats were divided into four groups, each consisting of 10 males and 10 females, and administered flutamide once daily by oral gavage at doses of 0 (control), 0.25, 1 and 4 mg/kg body weight/day. Male rats were killed 1 day after the 28th administration. Female rats were killed on the day they entered the diestrus stage in the estrous cycle following the last treatment. Male rats receiving flutamide at dose levels of 1 and 4 mg/kg showed lobular atrophy of the mammary gland and a decrease in epididymal weight. In addition, 4 mg/kg flutamide-treated males exhibited raised serum testosterone and estradiol levels and decreased weight of the accessory sex glands. In females, a slight prolongation of the estrous cycle was also observed in the 4 mg/kg flutamide-treated group. No dose-related changes could be detected by haematology, serum biochemistry and sperm analysis. Thus, among the parameters tested in the present experimental system, the weight of endocrine-linked organs and their histopathological assessment, serum hormone levels, and estrous cycle stage allowed the detection of endocrine-related effects of flutamide.

Administration, Oral↗

PubMed2001

A repeated 28-day oral dose toxicity study of methoxychlor in rats, based on the 'enhanced OECD test guideline 407' for screening endocrine-disrupting chemicals.

In association with the international validation project to establish an OECD Enhanced Test Guideline 407, we performed a 28-day repeated-dose toxicity study of methoxychlor, a chlorinated hydrocarbon pesticide with pro-estrogenic and anti-androgenic activities. Attention was paid to the sensitivity of certain additional parameters for detecting endocrine related effects of endocrine disrupting chemicals based on the existing TG 407. Seven-week-old Crj:CD(SD)IGS rats were allocated to one of four groups, each consisting often males and ten females, and methoxychlor was administered once daily by gavage at doses of 0 (control), 20, 100 or 500 mg/kg body weight per day. Male rats were killed on the day after the 28th administration. Female rats were killed on the day of the diestrus stage during 4 days after the 28th administration. Male rats receiving methoxychlor showed mainly atrophy of mammary acinus in the 20 mg/ kg and higher groups, together with decreases in prostate and seminal vesicle weights, and atrophy of epididymis, prostate, seminal vesicle and coagulating gland in the 100 and 500 mg/kg groups. In addition, decrease in serum testosterone level, increase in follicle-stimulating hormone level, decrease in testis and epididymis weights, atrophy of semiferous tubules and Leydig cells, decrease in the number of sperm in the caudal epididymis and their motility were observed in the 500 mg/kg group. Female rats receiving methoxychlor showed mainly abnormal estrous cycles, decrease in serum luteinizing hormone level, decrease in ovary weight, proliferation of mammary acinus, atrophy of ovary due to decrease in follicles and corpus luteum in histopathology, hypertrophy of endometrial epithelium of uterus and vagina epithelium in the 100 and 500 mg/kg groups. Among the parameters tested in the present experimental system, effects of methoxychlor on endocrine-related organs were detected with regard to serum hormone, organ weights, histopathological examination in both sexes, estrus cycle in females and sperm examination in males. Based on these results, a no-observed-adverse-effect level (NOAEL) in the present study was estimated to be below 20 mg/kg per day. In particular, the adverse effects were effectively detected in organ weights of accessory sex organs and histopathological examination.

Administration, Oral↗

PubMed2005

How to appraise a prognostic study.

Prognostic studies are studies that examine selected predictive variables or risk factors and assess their influence on the outcome of a disease. They allow clinicians to understand better the natural history of a disease, guide clinical decision-making by facilitating the selection of appropriate treatment options, and allow more accurate prediction of disease outcomes. Appraising prognostic studies involves determining the internal validity of the study design and evaluating the influence of systemic errors or bias. In studies examining multiple prognostic variables, care must be taken to minimize the confounding influence each variable would have on the other parameters. Evaluating the results of appropriate statistical analysis enables conclusions to be made that may influence clinical practice. Care must be taken to ensure that the conditions under which the prognostic study were conducted resemble circumstances in the local institution so as to allow the conclusions to be applied to local practices.

Confounding Factors, Epidemiologic↗

PubMed2026

Quality over quantity: biopsy-anchored CT radiogenomics models outperform all-lesion training in a multi-tumour cohort despite a smaller sample size.

OBJECTIVE: Radiogenomics aims to non-invasively predict tumour genotypes from imaging, but most studies assume molecular homogeneity by assigning a single biopsy-derived label to all lesions within a patient. This approach risks substantial label noise given well-documented interlesional heterogeneity. We investigated whether anchoring training to biopsy-confirmed lesions improves radiogenomic model performance and generalisability. MATERIALS AND METHODS: We retrospectively analysed 1646 patients (11473 segmented lesions) with contrast-enhanced CT and EGFR mutation status from next-generation sequencing at the Netherlands Cancer Institute, alongside an external NSCLC radiogenomics cohort (n = 158). All visible lesions were segmented, and the exact biopsy site was matched to its segmentation. Radiomic features were extracted, and machine learning models were trained with three lesion selection strategies: all lesions, non-biopsied lesions only, and biopsy-confirmed lesions only. To disentangle label quality from sample size, we created size-matched variants (one lesion per patient) for all-lesion and non-biopsied strategies. RESULTS: All models achieved significant discrimination of EGFR status on internal validation (AUC = 0.62-0.68). However, performance of the all-lesion and non-biopsied models declined on external validation (AUC = 0.55-0.63), while the biopsy-anchored model maintained stable performance (AUC = 0.62), despite having only 1/10th of the training sample size. When training sets were size-matched, the biopsy-anchored approach significantly outperformed a model trained on all available lesions on external validation (p = 0.037). CONCLUSIONS: Radiogenomic models trained on biopsy-confirmed lesions outperform conventional all-lesion strategies in external validation, despite using an order of magnitude fewer samples. Prioritising lesion-level label fidelity can mitigate heterogeneity-driven noise, enhancing robustness and clinical translation of imaging-based genomic prediction. KEY POINTS: Question Does assigning biopsy-derived molecular labels to all lesions introduce heterogeneity-driven label noise that reduces the generalisability of radiogenomic models? Findings Models trained exclusively on biopsy-confirmed lesions demonstrated superior external generalisability compared with all-lesion approaches, despite being trained on substantially fewer samples. Clinical relevance Biopsy-anchored radiogenomics improves the reliability of non-invasive mutation prediction by accounting for tumour heterogeneity, potentially supporting clinical decision-making when tissue sampling is limited or molecular results are discordant across lesions.

Humans↗

PubMed2004

Placebo-controlled trials in major depression are necessary and ethically justifiable: how to improve the communication between researchers and ethical committees.

Despite numerous placebo-controlled clinical trials with antidepressants were conducted in humans and a large amount of data was already published in the last two decades, the members of the 4th European Expert Forum on Ethical Evaluation of Placebo-Controlled Studies in Depression were agreed that placebo-controlled trials with antidepressants also in the future are essential. Placebo-controlled studies measure the effect size in a reliable way and establish sensitivity and internal validity. They are scientifically sound and interpretable in terms of efficacy and are, therefore, clinically more relevant than non-placebo-controlled clinical trials. The "Note of Clarification" of the Declaration of Helsinki opens up where such trials are acceptable. This statement of the members of the 4th European Expert Forum is directed to academia, members of Ethic Committees, regulators, and industry to facilitate their decisions towards clinical studies with antidepressants. "Checklists" for the contents of patients information are given as well as for the investigator.Placebo-controlled clinical trials are scientifically necessary, ethical and feasible. The administration of the placebo is in itself a non-specific treatment and experts agree that there appears to be no increased suicidal risk in the placebo-group of carefully selected and monitored study patients.

Antidepressive Agents↗

PubMed2003

Cerebral microdialysis as a monitoring method in subarachnoid hemorrhage patients, and correlation with clinical events--a systematic review.

BACKGROUND: One of the goals in treating subarachnoid hemorrhage patients is to prevent or minimize vasospasm-induced ischemia. Intracerebral microdialysis is a rapidly developing tool to monitor physiological and pathophysiological changes in chemical processes associated with ischemia. OBJECTIVE: To determine the diagnostic accuracy of microdialysis in detecting ischemia or ischemic events in patients with subarachnoid hemorrhage. METHODS: A systematic review of clinical studies regarding microdialysis as a monitoring method in patients in the acute stage of subarachnoid hemorrhage was conducted by performing a MEDLINE search using the terms "subarachnoid hemorrhage", "brain ischemia", "intracranial aneurysm", "cerebrovascular accident" and "stroke". These were combined with a search on "microdialysis". The methodological quality of the studies was assessed independently by two reviewers. For each study the grades of recommendation were determined. RESULTS: The search yielded 73 publications of which 13 studies were analysed. The methodological quality of the studies was low,with only 3 studies fulfilling more than 50% of the criteria. Consequently the level of evidence was low. Of the internal validity criteria the characteristics of study populations were similar in most of the studies. The technical assessment varied considerably. A quantitative analysis (meta-analysis) could not be performed because of lack of sufficient data. A qualitative analysis yielded a positive impression with regard to the diagnostic accuracy of microdialysis in detecting ischemic events. CONCLUSION: There is a positive tendency to use microdialysis as a diagnostic tool for monitoring of ischemic events in subarachnoid hemorrhage patients. However, there is insufficient evidence for the routine use of microdialysis.

Cerebral Cortex↗

PubMed2005

Dexamethasone and prognostic factors in adults with bacterial meningitis.

OBJECTIVE: To determine the effect of dexamethasone on prognostic factors in adults with bacterial meningitis. DESIGN AND SETTING: A post hoc multivariate analysis of the European Dexamethasone Study. PATIENTS AND PARTICIPANTS: Dexamethasone-treated patients in the European Dexamethasone Study. As internal validation we performed an identical analysis on patients in the placebo group. MEASUREMENTS AND RESULTS: Only focal cerebral abnormalities on admission were predictive for unfavourable outcome in patients treated with early adjunctive dexamethasone (Odds ratio 3.22; 95% confidence interval 1.11-9.35; P=0.03). Other potential prognostic factors failed to achieve statistical significance. An analysis on patients in the placebo group showed prognostic factors comparable with those found in the literature without routine use of dexamethasone. CONCLUSIONS: Routine use of dexamethasone therapy may lead towards new risk stratification in adults with bacterial meningitis.

Adult↗

PubMed2005

Development and evaluation of the Parkinson Psychosis Questionnaire A screening-instrument for the early diagnosis of drug-induced psychosis in Parkinson's disease.

OBJECTIVE: Drug-induced psychosis is a frequent side-effect in the treatment of advanced Parkinson's disease (PD). We sought to develop and evaluate a brief instrument for early recognition of drug-induced psychosis in PD. METHODS: We developed the "Parkinson Psychosis Questionnaire" (PPQ), which consists of screening questions for typical early signs and psychotic symptoms in PD and which quantifies the frequency and severity of four clinical categories-sleep disturbances, hallucinations/illusions, delusions and orientation. We performed an internal validation of the PPQ in 50 unselected patients with parkinsonism. The Brief Psychiatric Rating Scale (BPRS) and the "Structurized Clinical Interview" (SCID) for DSM IV were applied to the same patients as external references. RESULTS: Of 50 subjects, 49 suffered from idiopathic PD and one from probable MSA-P. Hoehn and Yahr stages in "on" ranged from 1.5 to 4. Sensitivity of the PPQ test for drug-induced psychosis according to SCID was 100 % (95 % CI: 73.5%, 100%); while specificity was 92.1 % (95% CI: 78.6%, 98.3 %). The PPQ severity score was highly correlated with BPRS. We derived a linear prediction formula, which transformed PPQ into BPRS scores. CONCLUSION: The PPQ appears to be a suitable, and easily administered instrument for early diagnosis of drug induced psychosis in routine PD care. Whether the PPQ could also be a valuable tool for monitoring follow-up studies and therapeutic intervention trials remains to be tested.

Antiparkinson Agents↗

PubMed2003

Occupational issues of allergic contact dermatitis.

Occupational contact dermatitis is often of multifactorial origin, and it is difficult to determine the relative significance of the various contributing factors. Contact allergies are relevant in 20-50% of recognised occupational contact dermatitis cases. The reported frequency in different studies varies, depending on differences in how occupational diseases are notified and recognised, in types of occupation in a geographical area, and the "quality" of the dermatological examination, including the accuracy of the diagnostic patch-test investigation. However, the clinical relevance of the reported contact allergies is often uncertain. Many occupational contact dermatitis patients with documented contact allergies develop chronic eczema, in spite of work changes and attempted allergen avoidance. Recognition/non-recognition of a notified case may be based on circumstantial evidence, because of difficulties in the establishing of a firm proof of work exposure and subsequent development of skin disease. Reliable quantitative exposure measuring techniques are needed. Methods are developed for the measurement of exposure to allergens such as nickel and acrylates, which makes it possible for exposure-effect relationships to be established with increased certainty. For prevention of allergic contact dermatitis it was a major step forward, with mandatory ingredient labelling of cosmetic products. However, improved labelling of the presence of contact allergens in household and industrial products is needed. For the identification of hazardous contact allergenic compounds, guinea pig or mice assays are still required. The local lymph node assay (LLNA), which is an objective and sensitive mouse assay has now been internationally validated and accepted.

Dermatitis, Allergic Contact↗

PubMed2004

Conversion rates in laparoscopic colorectal surgery: a predictive model with, 1253 patients.

BACKGROUND: This study aimed all develop a mathematical model for predicting the conversion rate for patients undergoing laparoscopic colorectal surgery. METHOD: This descriptive single-center study used routinely collected clinical data from 1,253 patients undergoing laparoscopic surgery between November 1991 and April 2003. A two-level hierarchical regression model was used to identify patient, surgeon, and procedure-related factors associated with conversion of laparoscopic to open surgery. The model was internally validated and tested using measures of discrimination and calibration. Exclusion criteria for laparoscopic colectomy included a body mass greater than 50, lesion diameter exceeding 15 cm, and multiple prior major laparotomies (exclusive of appendectomy, hysterectomy, and cholecystectomy). RESULTS: The average conversion rate for the study population was 10.0% (95% confidence interval [CI], 8.3-11.7%). The independent predictors of conversion of laparoscopic to open surgery were the body mass index (odds ratio [OR], 2.1 per 10 Americans Society of Anesthesiology units increase), (ASA) grade 3 or 4, 1 or 2 (OR, 3.2, 5.8), type of resection (low rectal, left colorectal, right colonic vs small/other bowel procedures; OR, 8.82, 4.76, 2.98), presence of intraoperative abscess (OR, 3.60) or fistula (OR, 4.73), and surgeon seniority (junior vs senior staff OR, 1.56). The model offered adequate discrimination (area under receiver operator characteristic curve, 0.74) and excellent agreement (p = 0.384) between observed and model-predicted conversion rates (range of calibration, 3-32% conversion rate). CONCLUSIONS: Laparoscopic conversion rates are dependent on a multitude of factors that require appropriate adjustment for case mix before comparisons are made between or within centers. The Cleveland Clinic Foundation (CCF) laparoscopic conversion rate model is a simple additive score that can be used in everyday practice to evaluate outcomes for laparoscopic colorectal surgery.

Adolescent↗

PubMed2003

The importance of clinical practice guidelines (CPGs) for the quality and development of supportive care in Central and Eastern European (CEE) countries.

Supportive care CPGs are intended to improve the quality of supportive care received by cancer patients. They hold potential benefits for health-care professionals, health-care organizations and patients. In order to provide an effective influence of CPGs on supportive care development in CEE countries their validity and successful implementation in clinical practice must be ensured. This would involve several important steps: (1) achievement of a consensus across Europe about what constitutes supportive care in cancer; (2) identification of supportive care priorities in CEE countries to be covered by the guidelines; and (3) searching existing CPGs relevant to previously identified priorities. Valid international CPGs could then be translated and adapted to local resources and circumstances in CEE countries and used to prepare national supportive care CPGs which could assist in the development of national supportive care standards. Skills, expertise and additional investment are required for local adaptation, dissemination and implementation of international supportive care CPGs.

Clinical Competence↗

PubMed2026

Multimodal features and prognostic risk assessment in locally advanced gastric cancer patients following neoadjuvant therapy based on machine learning algorithms: a multicenter study.

BACKGROUND: Neoadjuvant therapy (NAT) is recommended for locally advanced gastric cancer (LAGC), but some patients respond poorly. We aimed to construct a multimodal model integrating CT images, transcriptomic sequencing, and clinicopathological data to assess prognosis in LAGC patients receiving NAT. MATERIALS AND METHODS: This multicenter study included 505 LAGC patients who underwent NAT. Radiomic features were extracted from preoperative CT images of 505 patients. RNA-seq was performed on 277 post-NAT specimens, with additional data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases (n = 804). Patients were divided into training (168 cases), internal validation (72 cases), and external validation cohorts. Machine learning algorithms identified key radiomic, molecular, and clinical features associated with NAT response, which were then integrated into a multimodal model to predict overall survival (OS) and disease-free survival (DFS). RESULTS: Six radiomic and three molecular features significantly associated with NAT response were selected. Radiomic risk (hazard ratio [HR]: 4.0, P < 0.001) and molecular risk (HR: 7.1, P < 0.001) were independent prognostic factors. By integrating radiomic risk, molecular risk, and clinical characteristics, a multimodal model (MuMo) was constructed.The C-index results (OS, C-index = 0.855; DFS, C-index = 0.786) demonstrated that MuMo outperformed the single-modality models and ypTNM staging.Mechanistic analysis suggested that the efficacy of neoadjuvant therapy was significantly enriched in immune-inflammatory pathways. CONCLUSIONS: MuMo can effectively predict postoperative survival risk in LAGC patients receiving NAT, serving as a powerful tool for optimizing prognostic assessment.

Humans↗