| 1. |
- Aerts, Marc, et al.
(författare)
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Pooled individual patient data from five countries were used to derive a clinical prediction rule for coronary artery disease in primary care.
- 2017
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Ingår i: Journal of Clinical Epidemiology. - : Elsevier. - 0895-4356 .- 1878-5921. ; 81, s. 120-128
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To construct a clinical prediction rule for coronary artery disease (CAD) presenting with chest pain in primary care.STUDY DESIGN AND SETTING: Meta-Analysis using 3,099 patients from five studies. To identify candidate predictors, we used random forest trees, multiple imputation of missing values, and logistic regression within individual studies. To generate a prediction rule on the pooled data, we applied a regression model that took account of the differing standard data sets collected by the five studies.RESULTS: The most parsimonious rule included six equally weighted predictors: age ≥55 (males) or ≥65 (females) (+1); attending physician suspected a serious diagnosis (+1); history of CAD (+1); pain brought on by exertion (+1); pain feels like "pressure" (+1); pain reproducible by palpation (-1). CAD was considered absent if the prediction score is <2. The area under the ROC curve was 0.84. We applied this rule to a study setting with a CAD prevalence of 13.2% using a prediction score cutoff of <2 (i.e., -1, 0, or +1). When the score was <2, the probability of CAD was 2.1% (95% CI: 1.1-3.9%); when the score was ≥ 2, it was 43.0% (95% CI: 35.8-50.4%).CONCLUSIONS: Clinical prediction rules are a key strategy for individualizing care. Large data sets based on electronic health records from diverse sites create opportunities for improving their internal and external validity. Our patient-level meta-analysis from five primary care sites should improve external validity. Our strategy for addressing site-to-site systematic variation in missing data should improve internal validity. Using principles derived from decision theory, we also discuss the problem of setting the cutoff prediction score for taking action.
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| 2. |
- Arbyn, Marc, et al.
(författare)
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Triage of women with equivocal or low-grade cervical cytology results: a meta-analysis of the HPV test positivity rate
- 2009
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Ingår i: Journal of Cellular and Molecular Medicine. - : Wiley. - 1582-1838 .- 1582-4934. ; 13:4, s. 648-659
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Forskningsöversikt (refereegranskat)abstract
- Introduction Methods Results Discussion Conclusion Consistent evidence underlines the utility of human papillomavirus (HPV) DNA testing in the management of women with equivocal cervical cytological abnormalities, but not in case of low-grade lesions. We performed a meta-analysis including studies where the high-risk probe of the Hybrid Capture-II is used to triage these two cytological categories. The triage test-positivity rate reflects the colposcopy referral workload.Data were pooled on the HPV test positivity rate in women with atypical squamous cells of undetermined significance (ASCUS/ASC-US) or low-grade squamous intraepithelial lesions (LSIL), derived from different cytological classification systems. The meta-analysis was restricted to studies, published between 1991 and 2007. A random-effect model was applied for meta-analytical pooling and the influence of covariates on the HPV positivity rate was analyzed by meta-regression. The variation by age was assessed within individual studies since age strata were not defined uniformly. On an average, 43% (95% CI: 40-46%) of women with ASCUS/ASC-US were high-risk HPV positive (range 23-74%). In women with LSIL, the pooled positivity rate was 76% (95% CI: 71-81%; range 55-89%). In spite of considerable inter-study heterogeneity, the difference in HPV positivity between the two triage groups was large and highly significant: 32% (95% CI: 27-38%). HPV rates dropped tremendously as age and cutoffs of test positivity increased. Other factors (cytological classification system, country, continent, collection method and year of publication) had no statistically significant impact, except in LSIL triage where HPV positivity was significantly lower in European compared to American studies. Women with LSIL, especially younger women, have high HPV positivity rates suggesting limited utility of reflex HPV triaging these cases. Research is needed to identify more specific methods to triage women with low-grade squamous cervical lesions.
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| 3. |
- Goossens, Maria E., et al.
(författare)
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International pooled study on diet and bladder cancer : the bladder cancer, epidemiology and nutritional determinants (BLEND) study: design and baseline characteristics
- 2016
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Ingår i: Archives of Public Health. - : BMC. - 0778-7367 .- 2049-3258. ; 74
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Tidskriftsartikel (refereegranskat)abstract
- Background: In 2012, more than 400,000 urinary bladder cancer cases occurred worldwide, making it the 7th most common type of cancer. Although many previous studies focused on the relationship between diet and bladder cancer, the evidence related to specific food items or nutrients that could be involved in the development of bladder cancer remains inconclusive. Dietary components can either be, or be activated into, potential carcinogens through metabolism, or act to prevent carcinogen damage. Methods/design: The BLadder cancer, Epidemiology and Nutritional Determinants (BLEND) study was set up with the purpose of collecting individual patient data from observational studies on diet and bladder cancer. In total, data from 11,261 bladder cancer cases and 675,532 non-cases from 18 case-control and 6 cohort studies from all over the world were included with the aim to investigate the association between individual food items, nutrients and dietary patterns and risk of developing bladder cancer. Discussion: The substantial number of cases included in this study will enable us to provide evidence with large statistical power, for dietary recommendations on the prevention of bladder cancer.
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| 4. |
- Haasenritter, Joerg, et al.
(författare)
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Coronary heart disease in primary care: accuracy of medical history and physical findings in patients with chest pain - a study protocol for a systematic review with individual patient data
- 2012
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Ingår i: BMC Family Practice. - : BioMed Central. - 1471-2296. ; 13:81
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Forskningsöversikt (refereegranskat)abstract
- Background: Chest pain is a common complaint in primary care, with coronary heart disease (CHD) being the most concerning of many potential causes. Systematic reviews on the sensitivity and specificity of symptoms and signs summarize the evidence about which of them are most useful in making a diagnosis. Previous meta-analyses are dominated by studies of patients referred to specialists. Moreover, as the analysis is typically based on study-level data, the statistical analyses in these reviews are limited while meta-analyses based on individual patient data can provide additional information. Our patient-level meta-analysis has three unique aims. First, we strive to determine the diagnostic accuracy of symptoms and signs for myocardial ischemia in primary care. Second, we investigate associations between study-or patient-level characteristics and measures of diagnostic accuracy. Third, we aim to validate existing clinical prediction rules for diagnosing myocardial ischemia in primary care. This article describes the methods of our study and six prospective studies of primary care patients with chest pain. Later articles will describe the main results. less thanbrgreater than less thanbrgreater thanMethods/Design: We will conduct a systematic review and IPD meta-analysis of studies evaluating the diagnostic accuracy of symptoms and signs for diagnosing coronary heart disease in primary care. We will perform bivariate analyses to determine the sensitivity, specificity and likelihood ratios of individual symptoms and signs and multivariate analyses to explore the diagnostic value of an optimal combination of all symptoms and signs based on all data of all studies. We will validate existing clinical prediction rules from each of the included studies by calculating measures of diagnostic accuracy separately by study. less thanbrgreater than less thanbrgreater thanDiscussion: Our study will face several methodological challenges. First, the number of studies will be limited. Second, the investigators of original studies defined some outcomes and predictors differently. Third, the studies did not collect the same standard clinical data set. Fourth, missing data, varying from partly missing to fully missing, will have to be dealt with. Despite these limitations, we aim to summarize the available evidence regarding the diagnostic accuracy of symptoms and signs for diagnosing CHD in patients presenting with chest pain in primary care. less thanbrgreater than less thanbrgreater thanReview registration: Centre for Reviews and Dissemination (University of York): CRD42011001170
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| 5. |
- Holtedahl, Knut, et al.
(författare)
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Abdominal symptoms and cancer in the Abdomen : Prospective cohort study in European primary care
- 2018
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Ingår i: British Journal of General Practice. - : ROYAL COLL GENERAL PRACTITIONERS. - 0960-1643 .- 1478-5242. ; 68:670, s. 301-310
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Forskningsöversikt (refereegranskat)abstract
- Background: Different abdominal symptoms may signal cancer, but their role is unclear. Aim: To examine associations between abdominal symptoms and subsequent cancer diagnosed in the abdominal region. Design and setting: Prospective cohort study comprising 493 GPs from surgeries in Norway, Denmark, Sweden, Scotland, Belgium, and the Netherlands. Method: Over a 10-day period, the GPs recorded consecutive consultations and noted: patients who presented with abdominal symptoms pre-specified on the registration form; additional data on non-specific symptoms; and features of the consultation. Eight months later, data on all cancer diagnoses among all study patients in the participating general practices were requested from the GPs. Results: Consultations with 61 802 patients were recorded and abdominal symptoms were documented in 6264 (10.1%) patients. Malignancy, both abdominal and non-abdominal, was subsequently diagnosed in 511 patients (0.8%). Among patients with a new cancer in the abdomen (n = 251), 175 (69.7%) were diagnosed within 180 days after consultation. In a multivariate model, the highest sex- and age-adjusted hazard ratio (HR) was for the single symptom of rectal bleeding (HR 19.1, 95% confidence interval = 8.7 to 41.7). Positive predictive values of >3% were found for macroscopic haematuria, rectal bleeding, and involuntary weight loss, with variations according to age and sex. The three symptoms relating to irregular bleeding had particularly high specificity in terms of colorectal, uterine, and bladder cancer. Conclusions: A patient with undiagnosed cancer may present with symptoms or no symptoms. Irregular bleeding must always be explained. Abdominal pain occurs with all types of abdominal cancer and several symptoms may signal colorectal cancer. The findings are important as they influence how GPs think and act, and how they can contribute to an earlier diagnosis of cancer.
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| 6. |
- Holtedahl, Knut, et al.
(författare)
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Symptoms and signs of urogenital cancer in primary care
- 2023
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Ingår i: BMC primary care. - : BMC. - 2731-4553. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Urogenital cancers are common, accounting for approximately 20% of cancer incidence globally. Cancers belonging to the same organ system often present with similar symptoms, making initial management challenging. In this study, 511 cases of cancer were recorded after the date of consultation among 61,802 randomly selected patients presenting in primary care in six European countries: a subgroup analysis of urogenital cancers was carried out in order to study variation in symptom presentation. METHODS: Initial data capture was by completion of standardised forms containing closed questions about symptoms recorded during the consultation. The general practitioner (GP) provided follow-up data after diagnosis, based on medical record data made after the consultation. GPs also provided free text comments about the diagnostic procedure for individual patients. RESULTS: The most common symptoms were mainly associated with one or two specific types of cancer: 'Macroscopic haematuria' with bladder or renal cancer (combined sensitivity 28.3%), 'Increased urinary frequency' with bladder (sensitivity 13.3%) or prostatic (sensitivity 32.1%) cancer, or to uterine body (sensitivity 14.3%) cancer, 'Unexpected genital bleeding' with uterine cancer (cervix, sensitivity 20.0%, uterine body, sensitivity 71.4%). 'Distended abdomen, bloating' had sensitivity 62.5% (based on eight cases of ovarian cancer). In ovarian cancer, increased abdominal circumference and a palpable tumour also were important diagnostic elements. Specificity for 'Macroscopic haematuria' was 99.8% (99.7-99.8). PPV>3% was noted for 'Macroscopic haematuria' and bladder or renal cancer combined, for bladder cancer in male patients. In males aged 55-74, PPV=7.1% for 'Macroscopic haematuria' and bladder cancer. Abdominal pain was an infrequent symptom in urogenital cancers. CONCLUSIONS: Most types of urogenital cancer present with rather specific symptoms. If the GP considers ovarian cancer, increased abdominal circumference should be actively determined. Several cases were clarified through the GP's clinical examination, or laboratory investigations.
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| 7. |
- Kellen, Eliane, et al.
(författare)
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Pooled analysis and meta-analysis of the glutathione S-transferase P1 lle 105Val polymorphism and bladder cancer: A HuGE-GSEC review
- 2007
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 165:11, s. 1221-1230
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Forskningsöversikt (refereegranskat)abstract
- The glutathione S-transferase P1 genotype (GSTP1) is involved in the inactivation of cigarette smoke carcinogens, and sequence variation in the gene may alter bladder cancer susceptibility. To examine the association between GSTP1lle 105Val and bladder cancer, the authors undertook a meta- and pooled analysis. Summary crude and adjusted odds ratios and corresponding 95% confidence intervals were pooled by using a random-effects model. In the meta-analysis (16 studies, 4,273 cases and 5,081 controls), the unadjusted summary odds ratios for GSTP1 lle/Val and Val/Val compared with GSTP1 lle/lle were 1.54 (95% confidence interval: 1.21,1.99; p < 0.001) and 2.17 (95% confidence interval: 1.27, 3.71; p = 0.005). The association appeared to be the strongest in Asian countries. When the analysis was limited to European descendents (nine studies), the summary odds ratio decreased (odds ratio = 1.24, 95% confidence interval: 1.00, 1.52) (Q = 17.50; p = 0.02). All relevant data previously contributed to the International Study on Genetic Susceptibility to Environmental Carcinogens were pooled (eight studies, 1,305 cases and 1,558 controls). The summary odds ratios were similar to the ones from the meta-analysis. Case-only analyses did not detect an interaction between the GSTP1 genotype and smoking status (never/ever). GSTP1 lle 105Val appears to be associated with a modest increase in the risk of bladder cancer.
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| 8. |
- Kiemeney, Lambertus A, et al.
(författare)
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A sequence variant at 4p16.3 confers susceptibility to urinary bladder cancer.
- 2010
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 42:5, s. 415-9
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Tidskriftsartikel (refereegranskat)abstract
- Previously, we reported germline DNA variants associated with risk of urinary bladder cancer (UBC) in Dutch and Icelandic subjects. Here we expanded the Icelandic sample set and tested the top 20 markers from the combined analysis in several European case-control sample sets, with a total of 4,739 cases and 45,549 controls. The T allele of rs798766 on 4p16.3 was found to associate with UBC (odds ratio = 1.24, P = 9.9 x 10(-12)). rs798766 is located in an intron of TACC3, 70 kb from FGFR3, which often harbors activating somatic mutations in low-grade, noninvasive UBC. Notably, rs798766[T] shows stronger association with low-grade and low-stage UBC than with more aggressive forms of the disease and is associated with higher risk of recurrence in low-grade stage Ta tumors. The frequency of rs798766[T] is higher in Ta tumors that carry an activating mutation in FGFR3 than in Ta tumors with wild-type FGFR3. Our results show a link between germline variants, somatic mutations of FGFR3 and risk of UBC.
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| 9. |
- Rafnar, Thorunn, et al.
(författare)
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European genome-wide association study identifies SLC14A1 as a new urinary bladder cancer susceptibility gene.
- 2011
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Ingår i: Human molecular genetics. - : Oxford University Press (OUP). - 1460-2083 .- 0964-6906. ; 20:21, s. 4268-81
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Tidskriftsartikel (refereegranskat)abstract
- Three genome-wide association studies in Europe and the USA have reported eight urinary bladder cancer (UBC) susceptibility loci. Using extended case and control series and 1000 Genomes imputations of 5 340 737 single-nucleotide polymorphisms (SNPs), we searched for additional loci in the European GWAS. The discovery sample set consisted of 1631 cases and 3822 controls from the Netherlands and 603 cases and 37 781 controls from Iceland. For follow-up, we used 3790 cases and 7507 controls from 13 sample sets of European and Iranian ancestry. Based on the discovery analysis, we followed up signals in the urea transporter (UT) gene SLC14A. The strongest signal at this locus was represented by a SNP in intron 3, rs17674580, that reached genome-wide significance in the overall analysis of the discovery and follow-up groups: odds ratio = 1.17, P = 7.6 × 10(-11). SLC14A1 codes for UTs that define the Kidd blood group and are crucial for the maintenance of a constant urea concentration gradient in the renal medulla and, through this, the kidney's ability to concentrate urine. It is speculated that rs17674580, or other sequence variants in LD with it, indirectly modifies UBC risk by affecting urine production. If confirmed, this would support the 'urogenous contact hypothesis' that urine production and voiding frequency modify the risk of UBC.
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| 10. |
- Truyers, Carla, et al.
(författare)
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The use of human tissue in epidemiological research : ethical and legal considerations in two biobanks in Belgium
- 2010
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Ingår i: Medicine, Health care and Philosophy. - : Springer Science and Business Media LLC. - 1386-7423 .- 1572-8633. ; 13:2, s. 169-175
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses the legal implications of setting up two new biobanks in Belgium. The first is hospital-based and will archive tissue from patients with haematologic cancer, whereas the second is linked to a general practice based morbidity registry and will involve storage of blood samples. To date, Belgium has no specific legislation that regulates storage of human tissue and related databases. Several issues concerning the protection of individuals with regard to the processing of personal medical data are discussed from the existing privacy legislation. We will address the principle of consent (broad versus specific) and the type of data recorded (anonymous, encoded and identifiable) for both biobanks.
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| 11. |
- Wu, Xifeng, et al.
(författare)
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Genetic variation in the prostate stem cell antigen gene PSCA confers susceptibility to urinary bladder cancer.
- 2009
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 41:9, s. 991-5
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Tidskriftsartikel (refereegranskat)abstract
- We conducted a genome-wide association study on 969 bladder cancer cases and 957 controls from Texas. For fast-track validation, we evaluated 60 SNPs in three additional US populations and validated the top SNP in nine European populations. A missense variant (rs2294008) in the PSCA gene showed consistent association with bladder cancer in US and European populations. Combining all subjects (6,667 cases, 39,590 controls), the overall P-value was 2.14 x 10(-10) and the allelic odds ratio was 1.15 (95% confidence interval 1.10-1.20). rs2294008 alters the start codon and is predicted to cause truncation of nine amino acids from the N-terminal signal sequence of the primary PSCA translation product. In vitro reporter gene assay showed that the variant allele significantly reduced promoter activity. Resequencing of the PSCA genomic region showed that rs2294008 is the only common missense SNP in PSCA. Our data identify rs2294008 as a new bladder cancer susceptibility locus.
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