Association between guideline adherence and clinical outcome for patients referred for diagnostic breast imaging.

OBJECTIVE: To assess the adherence to a guideline for additional breast ultrasonography in a cross-sectional survey among hospitals in The Netherlands. Furthermore, consequences of current practice non-adherence for the patient outcome of diagnostic breast imaging were studied. METHODS: Current practice was compared with a guideline made up of three recommendations for the use of ultrasonography after mammography and three recommendations for not using ultrasonography. All patients referred for mammography to the radiology departments of the participating hospitals during 2 months in 2004 were eligible for the study. No data on the gold standard for breast cancer were analysed, but clinical consequences were estimated by using a probability model based on the data of a former prospective clinical study. RESULTS: In total, 17 of the 66 hospitals approached were participating in the study. Of the 13,694 patients assessed for eligibility, 6457 were included. High adherence rates (81-97%, mean 94%) were observed for the recommendations, which indicate additional ultrasonography, whereas lower adherence rates (68-94%, mean 83%) were seen for the recommendations which do not advise additional ultrasonography. Overall, in all included hospitals, non-adherence would result in 27.2 false-positive and 1.1 false-negative imaging results. CONCLUSION: Current daily practice of diagnostic breast imaging in the hospitals in this survey corresponds to a great extent to the guideline proposed. Non-adherence in current practice results in a relatively small number of false-positive and false-negative imaging results.

Diagnostic performance of breast technologists in reading mammograms in a clinical patient population.

PURPOSE: In the setting of an increasing workload for radiologists, this study focuses on the feasibility of skill mixing in breast imaging in a hospital radiology department. METHODS: Two radiological technologists with more than 10 years of experience in performing mammograms were trained in prereading mammograms to select the cases that require further evaluation by a radiologist. Mammograms of consecutive patients were independently evaluated by the technologists, next to the standard clinical interpretation by the radiologist on duty. Mammographic findings were recorded and a BI-RADS classification was assigned for each breast. Different prereading scenarios were analysed using clinical decision rules. Two different cut-off points of BI-RADS classifications were applied to the data. Analysis was performed for the overall clinical patient population as well as for a subgroup of patients with no immediate indication for further work-up. RESULTS: Mammograms of 1994 patients were evaluated. In total, 93 breast cancers were found in 91 patients (prevalence 4.6%). Sensitivity and specificity in selecting mammographic findings (cut-off point between BI-RADS 1 and BI-RADS 0, 2-5 and the radiologist's diagnosis as reference standard) was 98% and 74% for technologist 1 and 98% and 78% for technologist 2. In distinguishing normal and benign mammograms from those with abnormalities that are probably benign, suspicious or highly suggestive for malignancy (cut-off point BI-RADS 1-2 and BI-RADS 0, 3-5 and pathology results as reference standard), sensitivity decreased to 89% and 91% respectively. Specificity increased to 82% for both technologists. In a subgroup of 1389 patients with no immediate indication for additional imaging with the involvement of a radiologist, technologists obtained a mean sensitivity and specificity of 98% and 77% in detecting mammographic findings, and a mean sensitivity and specificity of 78% and 88% in detecting suspicious abnormalities. CONCLUSIONS: The employment of technologists in prereading mammograms seems to be an effective working strategy in daily clinical practice. However, its position in clinical practice remains indistinct as a continuous availability of radiologists still needs to be guaranteed. Nevertheless, as a substantial proportion of mammograms could be evaluated without the attention of a radiologist, the employment of technologists in prereading mammograms seems a promising new working strategy.

Pre-reading mammograms by specialised breast technologists: legal implications for technologist and radiologist in The Netherlands.

This paper focuses on the legal implications in terms of duties and responsibilities for radiologists and radiologic technologists of independent pre-reading of mammograms by radiologic technologists, so patients could be discharged without being seen by a radiologist. Pre-reading could be effectuated when preconditions are met to perform reserved procedures by unauthorised professionals as stated in the Individual Health Care Professions (IHCP) Act. Furthermore, compliance with a protocol or code of conduct in combination with adequate training and supervision should be sufficient to disprove potential claims. For a wide implementation, pre-reading should be well-embedded in legal rules and should answer the professional standard of care.

Performance of radiographers in mammogram interpretation: a systematic review.

Radiologists may be relieved from work that could be performed by radiographers. This systematic literature review focuses on the performance of radiographers (also referring to technologists and physician assistants) compared with radiologists in the interpretation of mammograms; the effect of training; and the question whether there are any studies evaluating the effects of involving radiographers in the interpretation of diagnostic mammograms in daily clinical practice on the sensitivity and specificity of cancer detection in breast imaging. Six studies met the inclusion criteria (primary aim of the study has to be the evaluation of the performance of radiographers, sensitivity and specificity have to be reported or calculable and there has to be a sufficient gold standard). The results showed that, in a screening setting, radiographers scored higher false positive rates with a similar sensitivity in the detection of malignancies, compared with radiologists. Furthermore, results suggested that training could improve their performance. No studies were reported assessing the performance of radiographers interpreting diagnostic mammograms in a consecutive patient population in a daily clinical setting. This indicates a need for a well-designed diagnostic study using an adequate gold standard, in order to evaluate the feasibility of deploying radiographers in the interpretation of diagnostic mammograms in a clinical setting.

[Peripheral artery disease: clinical and cost comparison between duplex ultrasonography and contrast-enhanced magnetic resonance angiography--a multicenter randomized trial]. / De kosten en de effecten van magnetischeresonantieangiografie en duplexechografie bij patiënten met perifeer arterieel vaatlijden: een multicentrische gerandomiseerde studie.

OBJECTIVE: To determine the clinical and economic consequences of replacing duplex ultrasonography (DUS) by contrast-enhanced magnetic resonance angiography (CE-MRA) for the initial diagnostic work-up of patients with peripheral artery disease (PAD). DESIGN: Randomised multicentre study. METHOD: In the period from January 2002 to August 2003, consecutive patients with PAD were randomly assigned to CE-MRA or DUS. The primary outcome measure was the costs. Secondary outcome measures included the confidence with which the specialist could take a therapeutic decision on the basis of the imaging study, the change in disease severity, and the change in quality of life (QOL) assessed during 6 months of follow-up. In addition, all costs of imaging, therapeutic interventions and outpatient visits were calculated. RESULTS: After 6 months of follow-up the data on 352 patients were analysed. Use of CE-MRA reduced the number of additional vascular-imaging procedures by 42% ((69-40)/69) and the specialists felt more confident about their therapeutic decisions. The diagnostic costs of all imaging studies taken together were Euro 167,- higher, on average, in the CE-MRA group (p < 0.001). However, after 6 months of follow-up, no statistically significant differences were found between the two groups with regard to the change in disease severity, the QOL, or the total costs (p > 0.05). CONCLUSION: Based on these findings, a specialist that replaces DUS by CE-MRA will feel more confident about taking a therapeutic decision and will feel less need for additional imaging. However, the diagnostic costs were higher with CE-MRA.

Renovascular disease in patients with hypertension: detection with duplex ultrasound.

The aim of this study was to evaluate the accuracy of duplex ultrasound for the diagnosis of renovascular disease in a cohort of hypertensive patients. In 78 patients suspected of renovascular hypertension on clinical grounds duplex ultrasound examination of the renal arteries was performed. Renal angiography was used as the standard of reference. Duplex ultrasound was inconclusive in 11 kidneys (7%). None of the supernumerary renal arteries was detected with duplex ultrasound. The overall prevalence of significant renovascular disease (> or =50% stenosis) was 20%. Based on the combination of parameters at thresholds commonly applied in current literature: ie PSV(max) >180 cm/sec and RAR >3.5 the overall sensitivity of duplex ultrasound for detection of haemodynamically significant renovascular disease was 50.0% with a specificity of 91.3% (PPV: 87.9%; NPV: 59.1). Lowering the thresholds for both parameters improved the test results at the cost of a significant increase of false positive examinations. In a population of hypertensive patients clinically suspected of renovascular hypertension, only limited results for duplex ultrasound could be acquired in the detection of renovascular disease. This result, in combination with the wide range of sensitivities and specificities published in international literature and the relatively large number of incomplete examinations does not support the general application of duplex ultrasound as a screening procedure for detection and assessment of renovascular disease.

The role of ultrasonography as an adjunct to mammography in the detection of breast cancer. a systematic review.

The aim of this review was to summarise the diagnostic performance of ultrasonography as an adjunct to mammography in the detection of breast cancer and to identify clinical indications. A systematic review was performed of all publications in MEDLINE and EMBASE between 1990 and 2000 on the role of ultrasonography as an adjunct to mammography. 22 studies were included, showing a large variety of indications for ultrasonography and variations in the diagnostic performance of mammography and ultrasonography. There were six studies comparing a combined diagnosis of mammography and ultrasonography together with mammography alone, of which three studies had an increased sensitivity at the cost of a lower specificity. The methods of selecting the study population and interpretation of ultrasonography significantly influenced the diagnostic performance of mammography and ultrasonography relative to each other (P=0.003, P=0.03, respectively). Based on the studies reviewed, little evidence-based support was found to confirm the well recognised value of ultrasonography as an adjunct to mammography in the detection of breast cancer in clinical practice. Furthermore, no clinical indications for additional ultrasonography could be defined. The heterogeneity in the diagnostic performance in these studies may be explained by the methods of patient selection and ultrasonography interpretation, as well as by their poor quality.

Diagnostic value of radiological breast imaging in a non-screening population.

The aim of this study was to assess the diagnostic performance of breast imaging in the diagnosis of breast cancer in a non-screening population. In a consecutive set of patients referred for mammography in one year, the results of palpation and radiological breast imaging were scored on a 5-point grading scale and linked to pathology as gold standard after a follow up period of one year. The diagnostic performance was studied by logistic regression analysis and ROC-curves. There were 1,944 breast examinations in 1,890 patients and 3,816 breasts. Pathology results reported 118 malignancies in 115 women. With a cut-off point between benign and uncertain benign a sensitivity of 89% and a specificity of 98% was found for radiological imaging. ROC-curves showed a significant increase in diagnostic performance when radiology was added to results of palpation and age (p = 0.007). Radiological imaging tests have a large diagnostic value in the detection of breast cancer in addition to palpation and age. A sensitivity close to 100% could be reached.

The pharmacy screening project--an evaluation of pharmacy-based screening programmes.

OBJECTIVES: The purpose of this study was to establish the proportion of pharmacies providing screening tests in the areas of Pretoria, Potchefstroom and Klerksdorp, the types of tests used and their cost to patients, the criteria employed to select high-prevalence groups, the attitudes of pharmacists towards screening, and their knowledge of test characteristics. SETTING: In Pretoria, 155 pharmacies were randomly selected and all 43 pharmacies in Potchefstroom and Klerksdorp were included. METHODS: The pharmacies included in the study sample were first contacted by telephone to identify those providing screening tests. Pharmacies that provided screening tests and agreed to participate in this study were then visited and a questionnaire was administered. RESULTS: 57% of the pharmacies provided at least one type of screening test. Blood pressure measurement, serum cholesterol, capillary glucose and pregnancy testing were the most common screening tests available. With the exception of blood pressure measurement, the screening tests were conducted less than 5 times per week. All respondents referred clients with abnormal results to general practitioners but only 35% of pharmacies kept records of the patients tested and the test results. The knowledge of pharmacists concerning the important features of screening tests, such as false-positive and false-negative rates, was poor. No quality control procedures for the screening tests were employed. CONCLUSIONS: Providing pharmacists with specific training in the application and interpretation of screening procedures, and implementing quality control measures will reduce the number of false referrals or non-referrals, and will improve the quality of the service. If pharmacies are to play a meaningful role in screening for disease, coverage of the population will need to be increased substantially.

Pathophysiologic and prognostic role of cytokines in dengue hemorrhagic fever.

Dengue shock syndrome is a severe complication of dengue hemorrhagic fever (DHF), characterized by a massive increase in vascular permeability. Plasma cytokine concentrations were prospectively studied in 443 Vietnamese children with DHF, of whom 6 died. Shock was present in 188 children on admission to hospital, and in 71 children it developed later. Contrary to expectations, certain inflammatory markers (interleukin-6 and soluble intercellular adhesion molecule-1) were lower in the group with shock, and this may reflect the general loss of protein from the circulation due to capillary leakage. Only soluble tumor necrosis factor receptor (TNFR) levels showed a consistent positive relationship with disease severity. In patients with suspected DHF without shock, admission levels of sTNFR-75 in excess of 55 pg/mL predicted the subsequent development of shock, with a relative risk of 5.5 (95% confidence interval, 2.3-13.2). Large-scale release of soluble TNFR may be an early and specific marker of the endothelial changes that cause dengue shock syndrome.