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 793 records · Page 44Linked to original sources

PubMed2006

A nomogram for staging of exclusive nonobturator lymph node metastases in men with localized prostate cancer.

OBJECTIVES: Some patients with localized prostate cancer are at risk of nonobturator lymph node invasion (NOLNI) and may require an extended pelvic lymph node dissection (ePLND). We explored the rate of exclusive NOLNI and developed a nomogram to predict it. MATERIAL AND METHODS: We mapped all ePLND specimens according to their anatomic location (obturator, external iliac, internal iliac lymph nodes) and assessed the location-specific rate of LNI in 565 patients. A multivariate logistic regression-based nomogram predicting NOLNI was then internally validated with 200 bootstrap resamples. RESULTS: Overall, 11.1% (63 of 565) had LNI and 21 (3.7%) had exclusive NOLNI. The nomogram predicting exclusive NOLNI was 80.2% accurate. The nomogram's negative predictive value was 99%, when it predicted 0-10% probability of NOLNI. This approach could allow the omission of an ePLND in 350 of 565 (61.9%) patients and still correctly stage 85.8% of NOLNI cases. CONCLUSIONS: Our nomogram-based approach offers the possibility of identifying men who are at virtually zero risk of exclusive NOLNI. In these men, an ePLND may be safely avoided.

Adult↗

PubMed2006

Prostate cancer-specific survival in men treated with hormonal therapy after failure of radical prostatectomy.

OBJECTIVES: We hypothesized that prostate cancer-specific survival (PCaSS) could be accurately predicted in men in whom radical prostatectomy (RP) failed and who received hormonal therapy (HT) after RP failure. METHODS: Between 1954 and 1994, 752 consecutive patients underwent RP without neoadjuvant therapy. Of those, 114 patients (15.2%) received HT at RP failure and represent the focus of this analysis. Cox regression models and a nomogram targeted PCaSS. The main predictor was timing of HT initiation: at prostate-specific antigen (PSA) versus local versus distant recurrence. Covariates included age at HT, pathologic T stage, surgical margin status and Gleason sum at RP, use of adjuvant or salvage radiation, and time from RP to HT. RESULTS: Mean and median follow-up periods were 5.1 and 3.9 yr; 70 deaths were recorded, of which 45 (39.8%) were due to PCa. At 1, 5, 10, and 15 yr, the estimates of PCaSS were, respectively, 97.1%, 68.3%, 49.3%, and 30.2% (median, 9.8 yr). Younger men and those with HT initiated at the time of distant recurrence had lower PCaSS. A nomogram predicting PCaSS at 2, 3, 4, and 5 yr after RP was developed and demonstrated 66% accuracy after 200-bootstrap internal validation. CONCLUSION: Despite RP failure, half the patients can expect to survive for 10 yr. The nomogram can help in discriminating between those with better versus worse PCaSS, better than relying on most educated guesses.

Aged↗

PubMed2005

HPLC and chemometric assisted spectrophotometric methods for simultaneous determination of diprophylline, phenobarbitone and papaverine hydrochloride.

Three methods are developed for the simultaneous determination of diprophylline (DP), phenobarbitone (PH) and papaverine hydrochloride (PP). The chromatographic method depends on a high performance liquid chromatographic (HPLC) separation on a reversed-phase C18 column with a mobile phase consisting of 0.02 M potassium dihydrogen phosphate, pH 3.5--acetonitrile (55:45 v/v). Quantitation was achieved with UV detection at 210 nm based on peak area. The other two chemometric methods applied were principal component regression (PCR) and partial least squares (PLS-1). These approaches were successfully applied to quantify the three drugs in the mixture using the information included in the UV absorption spectra of appropriate solutions in the range 215-245 nm with the intervals Delta lambda = 0.2 nm. The calibration PCR and PLS-1 models were evaluated by internal validation (prediction of compounds in its own designed training set of calibration), by cross-validation (obtaining statistical parameters that show the efficiency for a calibration fit model) and by external validation over laboratory-prepared mixtures and pharmaceutical preparations. The PCR and PLS-1 methods require neither any separation step, nor any priori graphical treatment of the overlapping spectra of the three drugs in a mixture. The results of PCR and PLS-1 methods were compared with HPLC method obtained in pharmaceutical formulation and a good agreement was found.

Bronchodilator Agents↗

PubMed2004

Identification of carboxypeptidase E and gamma-glutamyl hydrolase as biomarkers for pulmonary neuroendocrine tumors by cDNA microarray.

Pulmonary neuroendocrine tumors vary dramatically in their malignant behavior. Their classification, based on histological examination, is often difficult. In search of molecular and prognostic markers for these tumors, we used cDNA microarray analysis of human transcripts against reference RNA from a well-characterized immortalized bronchial epithelial cell line, BEAS-2B. Tumor cells were isolated by laser-capture microdissection from primary tumors of 17 typical carcinoids, small cell lung cancers, and large cell neuroendocrine carcinomas. An unsupervised, hierarchical clustering algorithm resulted in a precise classification of each tumor subtype according to the proposed histological classification. Selection of genes, using supervised analysis, resulted in the identification of 198 statistically significant genes (P <.004) that also accurately discriminated between 3 predefined tumor subtypes. Two-by-two comparisons of these genes identified classifier genes that distinguished each tumor subtype from the others. Changes in expression of selected differentially expressed genes for each tumor subtype were internally validated by real-time reverse-transcription polymerase chain reaction. Expression of 2 potential classifier gene products, carboxypeptidase E (CPE) and gamma-glutamyl hydrolase (GGH), was validated by immunohistochemistry and cross-validated on additional archival samples of pulmonary neuroendocrine tumors. Kaplan-Meier survival analysis revealed that immunostaining for CPE was a statistically significant predictor of good prognosis, whereas GGH expression correlated with poor prognosis. Thus, cDNA microarray analysis led to the identification of 2 novel biomarkers that should facilitate molecular diagnosis and further study of pulmonary neuroendocrine tumors.

Biomarkers, Tumor↗

PubMed2026

Pragmatic gynecologic cancer clinical trials: statements and roadmap from the Gynecologic Cancer InterGroup Chicago Brainstorming Meeting.

Randomized controlled trials remain fundamental to evidence generation in oncology but are increasingly complex, costly, and often misaligned with real-world practice. Traditional explanatory trials, designed under ideal, controlled conditions, frequently enroll highly selected populations, limiting generalizability and underrepresenting key groups such as older adults, patients with comorbidities, and those from low- and middle-income countries. Pragmatic clinical trials offer an alternative by evaluating interventions under routine care conditions, with broader eligibility, simplified procedures, and patient-centered outcomes. To address these challenges, the Gynecologic Cancer InterGroup convened an international brainstorming meeting in May 2025 with multi-disciplinary experts, patients, and advocates to define priorities and develop a roadmap for pragmatic trials in gynecologic oncology. Key discussions emphasized embedding trial design within routine care, aligning eligibility criteria and procedures with standard practice, minimizing non-essential data collection, and prioritizing outcomes meaningful to patients, including quality of life. Innovative designs such as registry-based randomized trials, trials-within-cohorts, and cluster randomization were highlighted as feasible approaches to improve efficiency while preserving internal validity. Integration of patient-reported outcomes and real-world data was considered achievable when carefully streamlined. Major challenges identified included regulatory heterogeneity, consent complexity, data interoperability, and funding limitations, particularly in multi-national settings. Proposed solutions include simplified consent models, centralized ethics processes, hybrid funding strategies, and the responsible use of artificial intelligence to enhance patient identification, recruitment, and potential development of synthetic control arms. Patient engagement was recognized as essential to ensure relevance, feasibility, and equity. Incorporation of patient-reported outcomes was discussed as key to informing acceptance and tolerability. In summary, pragmatic trials within Gynecologic Cancer InterGroup represent a critical pathway to generate efficient, inclusive, and practice-changing evidence in gynecologic cancers across diverse health care settings.

Humans↗

PubMed2004

Genetic programming outperformed multivariable logistic regression in diagnosing pulmonary embolism.

OBJECTIVE: Genetic programming is a search method that can be used to solve complex associations between large numbers of variables. It has been used, for example, for myoelectrical signal recognition, but its value for medical prediction as in diagnostic and prognostic settings, has not been documented. STUDY DESIGN AND SETTING: We compared genetic programming and the commonly used logistic regression technique in the development of a prediction model using empirical data from a study on diagnosis of pulmonary embolism. Using part (67%) of the data, we developed and internally validated (using bootstrapping techniques) a diagnostic prediction model by genetic programming and by logistic regression, and compared both on their predictive ability in the remaining data (validation set). RESULTS: In the validation set, the area under the ROC curve of the genetic programming model was significantly larger (0.73; 95%CI: 0.64-0.82) than that of the logistic regression model (0.68; 0.59-0.77). The calibration of both models was similar, indicating a similar amount of overoptimism. CONCLUSION: Although the interpretation of a genetic programming model is less intuitive and this is the first empirical study quantifying its value for medical prediction, genetic programming seems a promising technique to develop prediction rules for diagnostic and prognostic purposes.

Adult↗

PubMed2005

Back belt use for prevention of occupational low back pain: a systematic review.

BACKGROUND: Back pain continues to be the leading overall cause of morbidity and lost productivity in the workplace. Recently, there has been a renewed interest in the use of back belts by industry to reduce occupational low back pain (LBP). OBJECTIVES: To examine the literature and evaluate the effectiveness of back belt use for the primary prevention of occupational LBP. METHODS: MEDLINE, CINAHL, EMBASE, and HEALTHSTAR were searched for relevant articles published up to July 2003. Studies were included if participants were material handlers, and outcomes included the incidence and/or duration of lost time of reported LBP among workers who wore back belts compared with those who did not. The quality of the evidence was scored independently by 2 reviewers using a double rating method, first according to research design followed by an internal validity rating. Final synthesis of the evidence was performed in which the evidence was classified as good, fair, conflicting, or insufficient. RESULTS: Ten epidemiologic studies meeting inclusion criteria were identified. Of 5 randomized controlled trials, 3 showed no positive results with back belt use; 2 cohort studies had conflicting results; and 2 nonrandomized controlled studies and 1 survey showed positive results. CONCLUSIONS: Currently, because of conflicting evidence and the absence of high-quality trials, there is no conclusive evidence to support back belt use to prevent or reduce lost time from occupational LBP.

Humans↗

PubMed2026

Association of time-averaged systemic immune-inflammation indices with in-hospital mortality after intracerebral hemorrhage: a retrospective study.

BACKGROUND: Systemic inflammation plays a central role in secondary brain injury following intracerebral hemorrhage (ICH). Although inflammatory indices such as the neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) are linked to poor outcomes, their associations with mortality are commonly assumed to be linear, potentially overlooking nonlinear patterns where mortality risk rises steeply at higher levels. METHODS: We conducted a retrospective study using the MIMIC-IV database, including 440 patients with non-traumatic ICH who were alive and remained in the ICU for at least 72 h after admission. Mean NLR, SII, and SIRI were calculated from measurements obtained during this period. Multivariable logistic regression and restricted cubic spline (RCS) analyses were applied to assess their independent and nonlinear associations with in-hospital mortality. Model discrimination and calibration were internally validated using 1,000 bootstrap resamples. RESULTS: The in-hospital mortality rate was 26.1%. After multivariable adjustment, NLR and SIRI remained independently associated with mortality. Patients in the highest SIRI quartile had the highest risk of death (aOR = 5.12; 95% CI: 2.57-12.24; p < 0.001). RCS analysis revealed a significant nonlinear association between SIRI and mortality (p-nonlinearity < 0.05), showing a steep risk increase at higher SIRI levels. Adding SIRI to the base model provided a modest improvement in discrimination (AUC 0.762 to 0.785, p = 0.045) and significantly improved risk reclassification (cNRI = 0.4778, p < 0.001; IDI = 0.0240, p = 0.0151). CONCLUSIONS: Among patients with ICH who met the 72-hour eligibility criterion, higher 72-hour average SIRI was independently associated with in-hospital mortality. As a time-averaged measure, SIRI should be interpreted as a dynamic marker integrating the initial inflammatory state and the early clinical course rather than as a purely baseline prognostic factor. Although adding SIRI to the base model modestly improved discrimination and risk reclassification, it should be considered a candidate prognostic marker requiring external validation before clinical application.

Humans↗

PubMed2005

Application of two chemometric methods for the determination of imipramine, amitriptyline and perphenazine in content uniformity and drug dissolution studies.

Double-divisor spectra derivative and partial least squares methods were developed for content uniformity and dissolution tests in binary or ternary mixtures. The simultaneous determinations of perphenazine (PER) combined with amitriptyline hydrochloride (AMI) and/or imipramine hydrochloride (IMI) have been accomplished using the information of the absorption spectra of appropriate solutions. The double-divisor method is based on the use of the first derivative of the ratio spectrum obtained by dividing the absorption spectrum of the ternary mixture PER-AMI-IMI by a standard spectrum resulted from the addition of two of the three analytes in equal concentrations. The concentration of each component is then determined from their respective calibration graphs established by measuring the ratio derivative analytical signal at a specific wavelength. In this method, the linear determination ranges were of 3.65-18.24 microg/mL for PER, 4.32-21.60 microg/mL for AMI, and 4.83-24.19 microg/mL for IMI. The results were compared with those obtained by partial least squares multivariate calibration (PLS) method pre-treated by a wavelet compression-orthogonal signal correction (W-OSC) filter in zero-order derivative spectra. The calibration model was evaluated by internal validation (cross-validation) and by external validation over synthetic mixtures, content uniformity and dissolution tests. According to the dissolution profile test more than 95% of the three substances were dissolved within 10 min. The results from both techniques were statistically compared with each other and can be satisfactorily used for quantitative analysis and dissolution tests of multicomponent tablets.

Amitriptyline↗

PubMed2026

Exploring precision risk in pediatric vesicoureteral reflux: Innate immune gene variations and reflux outcomes in the RIVUR cohort.

INTRODUCTION: Children with vesicoureteral reflux (VUR) are at increased risk for morbidity from recurrent urinary tract infections (UTIs), yet the factors influencing spontaneous VUR resolution remain poorly defined. This study evaluates whether genetic variations in key urinary innate immune effectors (DEFA1A3, DMBT1, and RNASE7) influences VUR resolution and interacts with prophylaxis to alter clinical response. METHODS: We conducted a secondary analysis of 303 RIVUR participants with available DEFA1A3 and DMBT1 copy number variation (CNV) data and RNASE7 rs1263872 genotype. Primary outcomes were (1) VUR improvement (decrease in grade) and (2) VUR resolution at study exit. Multivariable logistic regression models included genotype, treatment, and their interactions, adjusting for age, sex, baseline grade (high vs low), laterality, bowel/bladder dysfunction, and any UTI. Internal validation used 2000-sample bootstrap with bias-corrected and accelerated confidence intervals and influence diagnostics. RESULTS: Clinical covariates did not significantly predict VUR improvement. Children with DEFA1A3 CNV >5 had higher odds of improvement (OR 2.36, 95% CI 1.12-4.96, p = 0.023), an effect that remained significant in bootstrap analyses. High-grade VUR was associated with lower odds of resolution (OR 0.34, 95% CI 0.12-0.94, p = 0.038). A significant interaction was observed between prophylaxis and high DMBT1 copy number for VUR resolution (interaction OR 2.99, 95% CI 1.11-8.04, p = 0.031); no interaction was seen for improvement. RNASE7 rs1263872 was not associated with either outcome. CONCLUSION: Innate immune gene variation may contribute to heterogeneity in VUR outcomes. High DEFA1A3 copy number was associated with reflux improvement and a DMBT1-prophylaxis interaction was associated with reflux resolution. The results of this study is hypothesis-generating and prompt further evaluation to assess whether a subset of children may experience structural benefit from prophylaxis or have a more favorable natural history based on their innate immune genotype.

Humans↗

PubMed2026

Factors associated with additional intervention requirement following ESWL in pediatric patients with urolithiasis.

OBJECTIVE: To identify predictors of additional intervention following extracorporeal shock wave lithotripsy (ESWL) in pediatric patients and to develop a clinically applicable predictive model. MATERIALS AND METHODS: This retrospective cohort study included 647 pediatric patients who underwent ESWL between 2015 and 2025. Demographic, clinical, and radiological variables were analyzed. Univariable and multivariable logistic regression analyses were performed to identify independent predictors of additional intervention. Model performance was evaluated using receiver operating characteristic curve analysis. RESULTS: Additional intervention was required in 65 patients (10.0%). On multivariable analysis, stone size 10-20 mm (OR: 3.04, p = 0.003), moderate (OR: 2.16, p = 0.049) and severe hydronephrosis (OR: 6.05, p < 0.001), and multiple stones (OR: 3.52, p = 0.030) were identified as independent risk factors. Increasing age (OR: 0.84, p = 0.026), history of urolithiasis (OR: 0.41, p = 0.006), and lower calyx location (OR: 0.14, p = 0.034) were associated with a reduced risk. The model demonstrated good discriminative performance (AUC: 0.794), with a sensitivity of 72% and specificity of 75%. Internal validation using bootstrap resampling demonstrated stable model performance, yielding a corrected AUC of 0.732. CONCLUSION: Stone burden, hydronephrosis severity, and stone multiplicity are key determinants of additional intervention after ESWL in pediatric patients. The proposed model shows good predictive performance and may support individualized risk stratification and clinical decision-making.

Humans↗

PubMed2006

Nomogram for predicting disease recurrence after radical cystectomy for transitional cell carcinoma of the bladder.

PURPOSE: American Joint Committee on Cancer staging represents the gold standard for prediction of recurrence after radical cystectomy in patients with invasive bladder cancer. We tested the hypothesis that American Joint Committee on Cancer stage based predictions may be improved when pathological tumor and node stage information is combined with additional clinical and pathological variables within a prognostic nomogram. MATERIALS AND METHODS: We used Cox proportional hazards regression analysis to model variables of 728 patients with transitional cell carcinoma of the bladder treated with radical cystectomy and bilateral pelvic lymphadenectomy at 1 of 3 participating institutions. Standard predictors, pT and pN, were complemented by age, gender, tumor grade at cystectomy, presence of lymphovascular invasion, presence of carcinoma in situ in the cystectomy specimen, neoadjuvant chemotherapy, adjuvant chemotherapy and adjuvant radiotherapy. The concordance index was used to quantify the accuracy of regression coefficient based nomograms. A total of 200 bootstrap resamples were used to reduce overfit bias and for internal validation. Calibration plots were used to graphically explore the performance characteristics of the multivariate nomogram. RESULTS: Followup ranged from 0.1 to 183.4 months (median 24.9, mean 36.4). Recurrence was recorded in 249 (34.2%) patients with a median time to recurrence of 108 months (range 0.8 to 131.9). Actuarial recurrence-free probabilities were 69.6% (95% CI 65.8%-73.0%), 60.2% (55.8%-64.3%) and 52.9% (47.3%-58.1%) at 2, 5 and 8 years after cystectomy, respectively. Two-hundred bootstrap corrected predictive accuracy of American Joint Committee on Cancer stage based predictions was 0.748. Accuracy increased by 3.2% (0.780) when age, lymphovascular invasion, carcinoma in situ, neoadjuvant chemotherapy, adjuvant chemotherapy and adjuvant radiotherapy were added to pathological stage information and used within a nomogram. CONCLUSIONS: A nomogram predicting bladder cancer recurrence after cystectomy is 3.2% more accurate than American Joint Committee on Cancer stage based predictions. Moreover, a nomogram approach combines several advantages such as easy and precise estimation of individual recurrence probability at key points after cystectomy, which all patients deserve to know and all treating physicians need to know.

Adult↗

PubMed2026

Automated CEAP Classification of Venous Duplex Reports Using Multimodal Artificial Intelligence.

OBJECTIVE: To develop and internally validate a prototype multimodal artificial intelligence system for automated CEAP (Clinical, Etiological, Anatomical and Pathophysiological) classification of venous duplex ultrasound (VDUS) reports, integrating natural language processing of free-text components with computer vision analysis of hand-drawn anatomical diagrams. METHODS: Single centre retrospective observational study using routinely collected clinical data. One thousand consecutive venous duplex ultrasound reports from Cambridge University Hospitals NHS Foundation Trust, UK (July 2024 - May 2025) were labelled according to the CEAP classification, excluding the Etiological component, which could not be reliably determined from duplex reports alone. Transfer learning was applied using ClinicalBERT for text and MobileNetV3 for diagrammatic data. Clinical classes were predicted from request line text. Text- and image-based pathophysiological models were developed for four anatomical territories (Great Saphenous Vein, Small Saphenous Vein, Deep system, Perforators), combined using late fusion with probability averaging. RESULTS: The clinical CEAP model achieved accuracy of 0.91, macro-F1 of 0.82, and macro-AUC of 0.98. Pathophysiological prediction varied, with text models broadly outperforming image models. Fusion yielded heterogeneous benefits, improving SSV performance but reducing Deep system accuracy. The performance of the final pathophysiological CEAP fusion models varied across anatomical territories: accuracy ranged from 0.70-0.92 and macro-AUC from 0.80-0.92. CONCLUSION: This study demonstrates the feasibility of automated CEAP classification from VDUS reports. Despite class imbalance affecting minority class predictions, the strong discriminatory performance validates this multimodal ML model for extracting clinically meaningful information from real-world data. This approach offers potential, pending external validation, to streamline vascular services through automated triage and guideline-compliant decision making.

Artificial intelligence↗

PubMed2005

Inter-examiner reliability of passive assessment of intervertebral motion in the cervical and lumbar spine: a systematic review.

A systematic review was conducted to determine inter-examiner reliability of passive assessment of segmental intervertebral motion in the cervical and lumbar spine as well as to explore sources of heterogeneity. Passive assessment of motion is used to decide on treatments for neck and low-back pain patients. Inter-examiner reliability has been a matter of debate, resulting in questions about professional credibility and accountability. A structured search for relevant studies in MEDLINE and CINAHL was followed by extensive reference tracing and hand searching. Studies presenting estimates of reliability for individual motion segments were included. No language restrictions were imposed. Study quality was assessed using criteria derived from the Standards for Reporting of Diagnostic Accuracy (STARD) statement and a quality assessment tool for studies of diagnostic accuracy included in systematic reviews (QUADAS). Study selection, quality assessment, and data extraction were performed by two reviewers independently. Qualitative analyses and additional subgroup analyses were conducted. Nineteen studies were included. Two studies satisfied criteria for external and internal validity, of which one found fair to moderate reliability. Assessment of motion segments C1-C2 and C2-C3 almost consistently reached at least fair reliability. Overall, inter-examiner reliability was poor to fair. However, most studies were found to be of poor methodological quality. We propose explicit recommendations for the conduct and reporting of future research.

Cervical Vertebrae↗

PubMed2005

Large-scale randomised trials--a misguided approach to clinical research.

Large-scale randomised trials influence the clinical management of millions of patients throughout the world and are believed to be the most reliable source of evidence on which to base therapeutic decisions. But do they really deserve the accolades bestowed upon them? The decision to perform these studies implies that the treatment difference is expected to be small and, thus, that large numbers of patients are required to achieve statistical significance. This small treatment difference is a direct consequence of limited knowledge of the subject matter which precludes the formation of homogeneous classes of patients with respect to the outcome. In fact, the majority of patients recruited are redundant in the sense that they would not develop the outcome regardless of treatment and, hence, could not participate in testing the efficacy of the drug in question. The conventional view is that randomisation satisfactorily addresses the issues resulting from heterogeneous study populations. However, the statistical approach to causation--which ignores the fundamental features of causal inference characteristic of both everyday discourse and the scientific method--that is used in large-scale randomised trials fails to deliver reliable generalisations even if the many potential obstacles to internal validity are set aside. Moreover, the results of large-scale randomised trials are not open to independent verification. Given the enormous profits to be made from the long-term treatment of common chronic diseases, the absence of any satisfactory method to detect research fraud is of some concern. Fewer than 5% of patients given treatment on the basis of large-scale randomised trials derive any benefit whatsoever. Arguments based on the benefits of such treatment to the wider community of patients are weakened by the dubious external validity of these studies but, in any case, cannot be used to promote the treatment of individual patients. Interestingly, when patients are provided with detailed information about the size of the benefits, most decline treatment. This is hardly surprising as it is debatable whether or not such meagre treatment effects could have any meaning to an individual patient. Large-scale randomised trials continue to be regarded as the gold standard of clinical research. This, of course, merely reflects the ability of powerful vested interests--in particular the pharmaceutical industry--to defy the sound arguments which demonstrate that the methodology of these studies is deeply flawed. Sooner or later, though, common sense must prevail.

Bias↗

PubMed2006

Real-time PCR for the detection of Salmonella spp. in food: An alternative approach to a conventional PCR system suggested by the FOOD-PCR project.

A real-time PCR assay using non-patented primers and a TaqMan probe for the detection and quantification of Salmonella spp. is presented. The assay is based on an internationally validated conventional PCR system, which was suggested as a standard method for the detection of Salmonella spp. in the FOOD-PCR project. The assay was sensitive and specific. Consistent detection of 9.5 genome equivalents per PCR reaction was achieved, whereas samples containing an average of 0.95 genome equivalents per reaction were inconsistently positive. The assay performed equally well as a commercially available real-time PCR assay and allowed sensitive detection of Salmonella spp. in artificially contaminated food. After enrichment for 16 h in buffered peptone water (BPW) or universal pre-enrichment broth (UPB) 2.5 CFU/25 g salmon and minced meat, and 5 CFU/25 g chicken meat and 25 ml raw milk were detected. Enrichment in BPW yielded higher numbers of CFU/ml than UPB for all matrices tested. However, the productivity of UPB was sufficient, as all samples were positive with both real-time PCR methods, including those containing less than 300 CFU/ml enrichment broth (enrichment of 5 CFU/25 ml raw milk in UPB).

Animals↗

PubMed2005

Nurse administered telephone intervention for blood pressure control: a patient-tailored multifactorial intervention.

OBJECTIVES: A randomized controlled trial involving a nurse administered patient-tailored intervention is being conducted to improve blood pressure (BP) control. METHODS: Veterans with hypertension from an outpatient primary care clinic completed a baseline assessment and were randomly allocated to either a nurse administered intervention or to usual care. In this ongoing study, intervention patients receive the tailored intervention bi-monthly for 2 years via telephone; the goal of the intervention is to promote adherence with medication and improve health behaviors. Patient factors targeted for intervention include perceived risk of hypertension, memory, literacy, social support, patients' relationship with their health care provider, side effects of therapy, pill refill, missed appointments, and health behaviors. RESULTS: The sample randomized to the nurse intervention consisted of 294 veterans with hypertension (average age = 63 years; 41% African-American). A comparable sample of veterans was assigned to usual care (n = 294). We have maintained a 97% retention rate for the first 12 months of the study. The average phone call has lasted 3.7 min ranging from less than 1 to 40 min. At 6-month post-enrollment, individuals receiving the nurse intervention had a greater increase in confidence with following hypertension treatment (P < 0.007) than the usual care group. DISCUSSION: The intervention is easily implemented and is designed to enhance adherence with prescribed hypertension regimen. The study includes both general and patient-tailored information based upon need assessment. The study design ensures internal validity as well as the ability to generalize study findings to the clinic settings.

Attitude to Health↗

PubMed2004

Simulated hazards of loosing infection-free status in a Dutch BHV1 model.

A compulsory eradication programme for bovine herpesvirus 1 (BHV1) was implemented in the Netherlands in 1998. At the start of the programme, about 25% of the dairy herds were certified BHV1-free. Simulation models have played an important role in the decision-making process associated with BHV1 eradication. Our objective in this study was to improve understanding of model behaviour (as part of internal validation) regarding loss by herds of the BHV1-free certificate. Using a Cox proportional hazards model, the association between farm characteristics and the risk of certificate loss during simulation was quantified. The overall fraction of herds experiencing certificate loss amongst initially certified during simulation was 3.0% in 6.5 years. Factors that increased risk for earlier certificate loss in the final multivariable Cox model were higher 'yearly number of cattle purchased', 'farm density within a 1 km radius' and 'cattle density within a 1 km radius'. Qualitative behaviour of risk factors we found agreed with observations in field studies.

Animal Husbandry↗