Using meta-analysis to answer clinical questions.
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Clinical Trials as Topic↗
Biomedical subjects
R J Laheij
Publications and source records attributed to R J Laheij.
Magnetic resonance imaging and mammography in women with a hereditary risk of breast cancer.
BACKGROUND: Although breast cancer screening is recommended to start at a younger age for women with a hereditary risk of breast cancer, the sensitivity of mammography for these women is reduced. We compared magnetic resonance imaging (MRI) with mammography to determine which is more sensitive and whether MRI could play a role in the early detection of breast cancer for these women. METHODS: We constructed a retrospective cohort of all breast MRI and mammography surveillance reports made in our department from November 1994 to February 2001. All of the 179 women in the cohort had received biannual palpation in addition to annual imaging by MRI, mammography, or both. The 258 MRI images and the 262 mammograms were classified with the use of the BI-RADS (i.e., Breast Imaging Reporting and Data System) scoring system, which has five categories to indicate the level of suspicion of a lesion. Receiver operator characteristic curves were generated for MRI and mammography, and the area under each curve (AUC) was assessed for the entire cohort of 179 women and for a subset of 75 women who had received both an MRI and a mammographic examination within a 4-month period. All statistical tests were two-sided. RESULTS: In the cohort of 179 women, we detected 13 breast cancers. Seven cancers were not revealed by mammography, but all were detected by MRI. For the entire cohort, the AUC for mammography was 0.74 (95% confidence interval [CI] = 0.68 to 0.79), and the AUC for MRI was 0.99 (95% CI = 0.98 to 1.0). For the subset of women who had both examinations, the AUC for mammography was 0.70 (95% CI = 0.60 to 0.80), and the AUC for MRI was 0.98 (95% CI = 0.95 to 1.0). CONCLUSION: MRI was more accurate than mammography in annual breast cancer surveillance of women with a hereditary risk of breast cancer. Larger prospective studies to examine the role of MRI in screening programs are justified.
Adult↗
Empirical treatment or prompt endoscopy.
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Cost-Benefit Analysis↗
Efficient diagnostic test sequence: applications of the probability-modifying plot.
Excessive diagnostic testing rarely leads to complete certainty of the disease status of a patient. Because of constraints of health care budgets, physicians should be aware of the diminishing marginal gain of each subsequent test in a testing strategy related to costs. We developed the probability-modifying plot to determine economically efficient sequence of testing without losing clinical effectiveness. Two applications of the model are presented: diagnosis of Helicobacter pylori and diagnosis of benign prostatic hyperplasia. The probability-modifying plots are drawn to visualize and calculate the economic efficiency of all possible test sequences, meaning that although the different test sequences are equally accurate, some have even lower costs than others.
Decision Support Techniques↗
Helicobacter pylori infection as a risk factor for gastrointestinal symptoms in patients using aspirin to prevent ischaemic heart disease.
BACKGROUND: Aspirin use in the secondary prevention of ischaemic heart disease may provoke gastrointestinal discomfort. OBJECTIVE: To register gastrointestinal symptoms and complications in patients with cardiovascular disease using aspirin and to relate these symptoms to infection with H. pylori. METHODS: Blood samples were obtained from 398 consecutive patients in the Coronary-Care Unit, University Hospital Nijmegen and analysed for serum antibody levels to H. pylori infection. Questionnaires were sent 2 weeks after discharge to assess gastrointestinal symptoms. RESULTS: Questionnaires were returned by 314 patients (79%). A total of 183 out of 314 patients (46%) reported gastrointestinal symptoms. Of 238 patients using 80-100 mg aspirin daily, 145 (61%) recorded gastrointestinal symptoms. Besides aspirin, the use of calcium antagonists was correlated with gastrointestinal symptoms. Of the 128 patients using calcium antagonists, 84 (66%) reported gastrointestinal symptoms. The prevalence of gastrointestinal symptoms in H. pylori-positive and -negative patients using aspirin was 48% and 52%, respectively. CONCLUSIONS: Two weeks after discharge almost 50% of the patients with cardiovascular disease experienced gastrointestinal symptoms, especially patients using aspirin or calcium antagonists. Patients seropositive for H. pylori and using aspirin or calcium antagonists did not have more gastrointestinal discomfort compared to non-infected patients.
Aspirin↗
Risk factors for endoleak and the evidence for stent-graft oversizing in patients undergoing endovascular aneurysm repair.
OBJECTIVES: the aim of this study was to assess the relationship between patient factors, the anatomy of the proximal aneurysm neck; the type of endovascular graft; and the consequences of graft/neck size mismatch and the occurrence of proximal endoleak. Design multicentre clinical study. MATERIALS: of a total of 2194 patients, 2146 underwent successful endovascular repair of infra-renal abdominal aortic aneurysms (AAA). METHODS: endoleaks were identified by radiological imaging immediately after completion of the procedure as per study protocols. Clinical and anatomical features of AAA in patients with endoleak were compared to patients without endoleak and data were analysed using the Chi-square test. A multivariate logistic regression model was constructed by selecting variables found to be significantly associated with complications in a univariate analysis. RESULTS: intra-operative endoleak was observed in 16.7% overall, and 3.3% were noted to have proximal endoleak. Aneurysm size larger than 60 mm (p =0.004), ex-smokers ( p =0.005) and age over 75 years ( p =0.01) were independently associated with endoleak of all types. Univariate and multivariate analysis revealed correlation between proximal endoleak and (i) diameter of the aneurysm neck-proximal (D2a), middle (D2b), distal (D2c), at all levels (p <0.005); (ii) proximal aortic neck length ( p =0.0001); (iii) aortic device diameter ( p =0.0024). No correlation was identified for angulation and form of the aortic neck. A model of the frequency of proximal endoleak, in relation to the ratio of the aortic device diameter to the distal aortic neck diameter, revealed that endoleak decreased when the aortic device diameter became oversized by more than 10% and confidence intervals remained tight for up to and over 20% oversize.
Adult↗
The association between co-morbidity and mortality after abdominal aortic aneurysm endografting in patients ineligible for elective open surgery.
OBJECTIVE: To investigate whether co-morbidity affects mortality after endovascular stenting in patients who are fit and unfit for open surgery. METHODS: Data were obtained from the EUROSTAR registry. The association between co-morbidity and mortality was examined by Cox proportional hazards models. RESULTS: Between 1994 and July 2000, 2862 patients underwent aneurysm stenting; 381 were unfit for open surgery. The early/late mortality rates for patients fit for surgery, patients unfit for surgery and patients unfit for anaesthesia were 2.7/5.2%, 5.1/11.4% (p=0.035/p<0.0001) and 3.7/11.0% (NS/p=0.016), respectively. The survival curves among patients with poor medical condition were significantly worse than in those patients with a good medical condition (p=0.001). The presence or absence of co-existing diseases did not affect the mortality rate in patients unfit for open surgery. The age-adjusted mortality risks of patients fit for open surgery and pulmonary disease or diabetes mellitus were 1.41 (1.02-1.95) and 1.75 (1.12-2.74), respectively. CONCLUSIONS: Patients with co-morbidity had a significantly higher mortality after aortic endografting compared with patients fit for open surgery. Co-morbidity did not increase mortality after endovascular abdominal repair in patients unfit for open surgery. Endovascular repair of abdominal aortic aneurysm seems to have a limited benefit in patients unfit for open surgery.
Adult↗
The evolving technique of endovascular stenting of abdominal aortic aneurysm; time for reappraisal.
PURPOSE: to investigate the occurrence of intra-operative device-related complications during stent-grafting for abdominal aortic aneurysm. MATERIALS AND METHODS: data on patient characteristics, vascular morphology, operative technical details, procedural and device-related complications were obtained from the European collaborators on stent-graft techniques for abdominal aortic aneurysm repair (EUROSTAR) registry. Only intra-operative device-related complications were taken into account. Potential risk factors for device-related complications were examined by logistic regression analysis. The association between these complications and conversion to open surgery and death were determined. RESULTS: between January 1994 and July 2000, 2862 patients in 90 participating hospitals underwent endovascular abdominal aortic aneurysm repair. Device-related complications occurred in 238 (8.3%) patients. Complications were associated with the age of the patient (p=0.002), gender (p=0.05), smoking habit (p=0.001), pre-operative aneurysm diameter (p=0.005), type of device implanted (p=0.0001), fitness of the patient for open surgery (p=0.002), and year of operation (p=0.001). Adjusted for risk factors, the occurrence of complications decreased between 1994 to 2000 from 21.7% to 7.3%, respectively. Patients with device-related complications were 13.6 times (95% CI; 9.2-20.1) more likely to have conversion to an open procedure and 2.4 times (95% CI; 1.4-4.0) more likely to die within 30 days of the operation. CONCLUSIONS: intra-operative device-related complications were common, although appear to be decreasing in frequency, and were significantly related to conversion and post-operative death.
Aged↗
Cardiac response and complications during endovascular repair of abdominal aortic aneurysms: a concurrent comparison with open surgery.
PURPOSE: The purpose of this study was to assess and to compare perioperative changes in left ventricular function and the incidence of adverse cardiac events in two groups of patients with abdominal aortic aneurysms, one during endovascular aneurysm repair (EAR) and the other during open aneurysm repair (OAR). METHODS: One hundred twenty consecutive patients who underwent EAR (49 patients) or OAR (71 patients) were prospectively studied. During the operation, the left ventricular function was assessed by the recording of the left ventricle stroke work index (SWI) and the cardiac index (CI) with a pulmonary artery catheter. Measurements were performed before, during, and after stent-graft deployment or aortic cross-clamping. Both maneuvers were defined as aortic occlusion (AO). Transesophageal echocardiography was performed to identify signs of wall motion abnormalities of the left ventricular wall, which indicated myocardial ischemia. Six-lead electrocardiograph monitoring was maintained until discharge from the intensive care unit. Postoperative cardiac complications were diagnosed by clinical observation, 12-lead ECG analysis at 1, 3, and 7 days after the operation, transthoracic echocardiography at 1 month, and measurement of cardiac enzymes. RESULTS: The two study groups were comparable with regard to most clinical aspects. The baseline myocardial performance was worse in patients who underwent EAR compared with patients who underwent OAR, as indicated by a reduced SWI (33.1 and 37.4, respectively; P =.03). During AO there was a comparable increase of the CI in both groups. However, after AO the rise in CI was higher in patients who underwent OAR compared with patients who underwent EAR (0.7 and 0.2, respectively; P <.01), representing a more pronounced hyperdynamic state. In addition, the SWI demonstrated a decrease in patients who underwent OAR compared with an increase in patients who underwent EAR during AO (-1.4 and +1.9, respectively; P =.04) and after AO (-0.9 and +2.6, respectively; P =.01). These findings represent more severe myocardial stress in patients who underwent OAR. The incidence of postoperative clinical cardiac adverse events was comparable in the two study groups. However, myocardial ischemia, as indicated by electrocardiography and transesophageal echocardiography, had a higher incidence in patients who underwent open surgery as compared with patients whose condition was managed endovascularly (57% and 33%, respectively; P =.01). CONCLUSION: Hemodynamic alterations during endovascular repair were not as severe as those in patients with open surgery and indicated less myocardial stress in the former category. These findings may explain a lower incidence of myocardial ischemia that was observed during endovascular repair. A lower frequency of clinical perioperative cardiac events in patients undergoing endovascular treatment may ultimately be expected.
Aorta↗
Tuberculous meningitis: is a 6-month treatment regimen sufficient?
SETTING: The British Thoracic Society and the American Thoracic Society advise 12 months treatment for tuberculous meningitis, with at least isoniazid (H), rifampicin (R) and pyrazinamide (Z). OBJECTIVE: To establish whether a 6-month treatment regimen for tuberculous meningitis is equally as effective as longer treatment. METHOD: Medline search for papers published between 1978 and 1999. INCLUSION CRITERIA: study populations of patients with tuberculous meningitis in whom the diagnosis was confirmed with clinical, cerebrospinal fluid and epidemiological findings; a treatment regimen with at least HRZ and at least 12 months of follow-up after the completion of treatment. OUTCOME MEASURE: the number of relapses. RESULTS: There were four 6-month treatment regimens (G6) and seven longer treatment regimens (G>6); 160/197 (81%) patients completed the 6-month treatment regimens, while 577/675 (85%) completed the longer-term regimens. The clinical stage of patients in the G6 group was poorer than in the G>6 group. Relapse occurred in two out of 131 (1.5%) G6 and in 0 out of 591 G>6 patients. CONCLUSION: Although no studies have compared 6-month treatment regimens with longer treatment, it can be concluded on the basis of this literature review that 6-month treatment is sufficient for tuberculous meningitis with fully susceptible mycobacteria.
Adult↗
Endovascular stenting of abdominal aortic aneurysm in patients unfit for elective open surgery. Eurostar group. EUROpean collaborators registry on Stent-graft Techniques for abdominal aortic Aneurysm Repair.
Endovascular aneurysm repair is useful for patients who are judged unfit for surgery. We investigated the outcome of endovascular repair of abdominal aortic aneurysm in patients fit and unfit for surgery. The 1-year cumulative survival for patients unfit for surgery and patients unfit for general anaesthesia was 20% and 23%, respectively. The overall health status of patients was an important predictor of survival after endovascular repair. The risks of endovascular aneurysm repair might, therefore, exceed that of non-operative management. Caution should be used when advising these patients about endovascular repair.
Adult↗
Rapid heroin detoxification under general anesthesia.
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Anesthesia, General↗
Precision and accuracy in measuring absence from work as a basis for calculating productivity costs in The Netherlands.
The impact of disease on the ability of a person to perform work should be part of an economic evaluation when a societal viewpoint is used for the analysis. This impact is reflected by calculating productivity costs. Measurement of these costs is often performed retrospectively. The purpose of our study was to study precision and accuracy of a retrospective self-administered questionnaire on sick leave. Employees of a company were asked to indicate the number of days absent from work due to illness during the past 2 weeks, 4 weeks, 2 months, 6 months, and the past 12 months. The percentage of respondents with an absolute difference of a maximum of respectively 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 or more days between reported, and company-registered absence due to illness was determined. Besides this, the proportional difference was calculated. A systematic difference was tested with a signed rank test. Of the reported data, 95% matched the registered data perfectly when the recall period was limited to 2 and 4 weeks. This percentage decreased to 87%, 57%, and 51% for 2 months, 6 months, and 12 months. The weighted mean proportional differences for the recall periods were respectively 32.9, 35.2, 45.3, 34.9, and 113.6%. No systematic positive or negative difference was found between registered and reported sick leave. The results suggest that the recall period for retrospective measurement of sick leave is limited according to the precision level, which seems to be appropriate for the subject and the purpose of the study. We recommend using a recall period of no more than 2 months.
Costs and Cost Analysis↗
Early complications and endoleaks after endovascular abdominal aortic aneurysm repair: report of a multicenter study.
OBJECTIVE: The aim of this study was the identification of risk factors for adverse events and the assessment of the early success rate in 1554 patients with abdominal aortic aneurysms (AAAs) who underwent treatment with endovascular technique between January 1994 and March 1999. For this purpose, the clinical and procedural data were correlated with observed complications and endoleaks. METHODS: The data were collected from 56 European centers and submitted to a central registry. Patient characteristics, aortoiliac anatomic features, operative technical details, types of devices used, and experience of the teams of physicians were correlated with the occurrence of complications and endoleaks. The technical success rate was assessed according to the Society for Vascular Surgery/International Society for Cardiovascular Surgery, North American Chapter, guidelines. For the assessment of correlations between risk factors and adverse events, a multivariate logistic regression analysis was used. RESULTS: The operative complications were grouped into three categories: failure to complete the procedure (39 patients, of which 27 underwent a conversion to an open AAA repair; 2.5%); device-related or procedure-related complications (149 patients; 10%); and arterial complications (51 patients; 3%). The most important risk factors for failure to complete the procedure included an aneurysm diameter of 60 mm or more and the need for adjuvant procedures. The factors that predicted device-related and arterial complications were the experience of the team with endovascular AAA treatment and the need for adjuvant procedures. Forty patients (2.6%) died within 30 days after operation. American Society of Anesthesiologists III and IV operative risk classification results predicted higher mortality rates than did American Society of Anesthesiologists operative risk classification I and II results. The patients who underwent operation in 1994, the first year documented in this registry, and those who required adjuvant procedures also had an increased risk of perioperative death. The incidence rate of systemic complications within the first 30 days (279 patients; 18%) was higher in patients aged 75 years or more, in patients with an impaired cardiac status, and in patients considered unfit for an open procedure. An endoleak was detected at the completion of the procedure in 16% of the cases and was still present after 1 month in 9%. The risk factors for primary endoleaks were female gender and age of 75 years and older. The observed technical success rate in this patient series was 72%. CONCLUSION: The learning curve of the doctors and the need for adjuvant procedures were independent risk factors of operative device-related and arterial complications. The importance of proper instruction during an institution's initial phase with this treatment is emphasized by these observations. Although the endovascular management of AAAs is less stressful than open surgery, systemic complications were still the most common adverse events during the first postoperative month. These complications were associated with several patient-related factors, including advanced age, impaired cardiac status, and poor general medical condition. These observations may be a guide for improved patient selection for endovascular AAA repair.
Age Factors↗
Diagnostic performance of biopsy-based methods for determination of Helicobacter pylori infection without a reference standard.
Endoscopic biopsy-based tests are considered to be the reference method for diagnosing Helicobacter pylori infection and monitoring antibiotic treatment, but unbiased data on their diagnostic performance is lacking. In this study we evaluated the diagnostic performance of culture, histology and rapid urease testing of antral biopsies separately and in combination. Antral biopsies were taken from consecutive patients undergoing upper gastrointestinal endoscopies at a single center between January 1995 and May 1997. The biopsies were examined for culture, histology, and CLOtest. The diagnostic performance, i.e., the sensitivity and specificity of the tests was estimated with 7 non-linear equations in 7 unknowns. To determine sources of heterogeneity that may have biased the results, data were stratified for age, gender, and whether they were taken before or after anti-Helicobacter antibiotic treatment. During the study period 631 patients underwent 869 upper gastrointestinal endoscopies. In 122 (14%) of the antral specimens the test results of culture, histology and CLOtest differed. Based on the nonlinear regression techniques we estimated that in 347 tests (40%) H. pylori infection was present. Overall sensitivity, specificity, positive and negative predictive value for each test were as follows: culture 91.4%, 96.3%, 94.2%, 94.4%, respectively; histology 90.3%, 97.8%, 96.4%, 93.8%, respectively; CLOtest 94.9%, 96.7%, 95.0%, 96.6%, respectively. In combination, the three tests provided the definitive diagnosis, either non-infected or infected, in 862 out of the 869 tests. Sensitivity of gastric antral histology was 64.9% (95% CI: 38-86) in females who did and 84.5% (95% CI: 77-90) in females who did not have had recent antibiotic therapy to cure the infection. Approximately 5-10% of H. pylori infected patients, were mis-diagnosed with a single biopsy-based test taken from the gastric antrum. Only a combination of bacterial culture, histological examination and the CLOtest represents an appropriate reference standard for research purposes to identify infected patients.
Adult↗
Need for secondary interventions after endovascular repair of abdominal aortic aneurysms. Intermediate-term follow-up results of a European collaborative registry (EUROSTAR).
BACKGROUND: The frequency of secondary interventions after endovascular repair of abdominal aortic aneurysms (AAAs) was assessed and correlated with findings at clinical and imaging examination during follow-up. METHODS: Data were studied from 1023 patients with a follow-up of 12 months or longer, collected by 56 institutions in a multicentre data registry (EUROSTAR). Surveillance data were provided by the centres between September 1996 and November 1999. RESULTS: Overall, 186 patients (18 per cent) had a secondary intervention occurring a mean of 14 months after the initial endograft procedure. Twelve per cent of the interventions were transabdominal, 11 per cent consisted of an extra-anatomic bypass and 76 per cent involved a transfemoral procedure. The rates of freedom from intervention at 1, 3 and 4 years were 89, 67 and 62 per cent respectively. Migration (relative risk (RR) 8.9) and rupture (RR 22.6) were the most frequent causes of secondary transabdominal interventions. Graft limb thrombosis was the principal indication for extra-anatomic bypass (RR 37.5 for clinical evidence of graft limb thrombosis). Endoleak, graft kinking, stenosis or thrombosis and device migration were significant causes for secondary transfemoral interventions (RR 2.5-6.9). CONCLUSION: The high incidence of late secondary interventions is a cause for concern with regard to broad application of endovascular AAA repair, and emphasizes the need for lifelong surveillance.
Adult↗
Which factors increase the risk of conversion to open surgery following endovascular abdominal aortic aneurysm repair? The EUROSTAR collaborators.
OBJECTIVE: to identify factors that increase the risk of conversion to open surgery following endovascular repair of abdominal aortic aneurysms (AAAs) and to assess their outcome. Design analysis of 1871 patients enrolled in the EUROSTAR collaborators registry. MATERIALS AND METHODS: patient characteristics, anatomic features of the aneurysm, type of endovascular device, institutional experience and the year in which the procedure was performed were related to risk of conversion. RESULTS: forty-nine patients (2.6%) required conversion. In 38 patients conversion was performed during the first postoperative month (primary conversions) and in 11 patients during follow-up (secondary conversions). Primary conversion was mostly due to access problems and device migration. Secondary conversions were performed for rupture in six and for a persistent endoleak, with or without aneurysmal growth, in five patients. Patients who were converted were significantly older, had a lower body weight, and had a higher prevalence of chronic obstructive pulmonary disease. Conversion was associated with shorter, wider infrarenal necks and larger aneurysms. The conversion rate was lower when a team had performed more than 30 procedures, and in procedures performed during the last two years of the study period. The conversion rate was higher with EVT or Talent devices. Patients who required primary conversion had an 18% mortality rate, compared to 2.5% mortality in patients without conversion (p<0.01). Secondary conversion was associated with a perioperative mortality of 27%, and when performed for rupture 50%. CONCLUSION: both primary conversion and secondary conversion for rupture carry a high operative mortality. Awareness of the risk factors may reduce conversion rate as well as early and medium term mortality.
Age Factors↗
Incidence and risk factors of late rupture, conversion, and death after endovascular repair of infrarenal aortic aneurysms: the EUROSTAR experience. European Collaborators on Stent/graft techniques for aortic aneurysm repair.
OBJECTIVE: The EUROSTAR (European Collaborators on Stent/graft techniques for aortic aneurysm repair) Registry was established in 1996 to collect data on the outcome of treatment of patients with infrarenal aortic aneurysms with endovascular repair. To date, 88 European centers of vascular surgery have contributed. The purpose of the study was to evaluate the results of this treatment in the medium term (up to 4 years) according to the analysis of "hard" or primary end points of rupture, late conversion, and death. PATIENTS AND METHODS: Patients with aortic aneurysms suitable for endovascular aneurysm repair were notified to the EUROSTAR Data Registry Centre before treatment to eliminate bias due to selective reporting. The following information was collected on all patients: (1) demographic details and the anatomic characteristics of their aneurysms, (2) details of the endovascular device used, (3) complications encountered during the procedure and the immediate outcome, (4) results of contrast enhanced computed tomographic imaging at 3, 6, 12, and 18 months after operation and at yearly intervals thereafter, and (5) all adverse events. Life table analysis was performed to determine the cumulative rates of (1) death from all causes, (2) rupture, and (3) late conversion to open repair. Risk factors for rupture and late conversion were identified through regression analysis. RESULTS: By March 2000, 2464 patients had been registered, and their mean duration of follow-up was 12.19 months (SD, 12.3 months). There were 14 patients with confirmed rupture of their aneurysms. The cumulative rate (risk) of rupture was approximately 1% per year. Emergency surgery was undertaken in 12 (86%) patients, of whom five (41.6%) survived. Two patients who were not treated surgically also died, which resulted in an overall death rate of 64.5% (9/14) of the patients. Significant risk factors for rupture were proximal type I endoleak (P =.001), midgraft (type III) endoleak (P =.001), graft migration (P =.001), and postoperative kinking of the endograft (P =.001). Forty-one patients underwent late conversion to open repair with a perioperative mortality rate of 24.4% (10/41). The cumulative rate (risk) of late conversion was approximately 2.1% per year. Risk factors (indications) for late conversion were proximal type I endoleak (P =. 001), midgraft (type III) endoleak (P =.001), type II endoleak (P =. 003), graft migration (P =.001), graft kinking (P =.001), and distal type I endoleak (P =.001). CONCLUSIONS: Endovascular repair of infrarenal aortic aneurysms with the first- and second-generation devices that predominated in this study was associated with a risk of late failure, according to an analysis of observed hard end points of 3% per year. Action taken to address the risk factors identified by the study may improve results in the future.
Aortic Aneurysm, Abdominal↗