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Aliment Pharmacol Ther 2010; 32: 270–281 Background Many bodies advise that people with bowel symptoms undergo colonoscopy to detect colorectal cancer. Aim To determine which bowel symptoms predict cancer on colonoscopy. Methods Information was collected on symptoms, demographics and medical history from patients subsequently undergoing colonoscopy. Multiple logistic regression modelling was used to identify predictors of colorectal cancer. An ROC curve was estimated for each model, and the area under the curve ( AUC) was computed. Results Cancer was found in 159 patients and no cancer or adenoma in 7577 patients. Bowel symptoms that predicted cancer were rectal bleeding, change in bowel habit and rectal mucus. Prediction was the strongest in patients who had symptoms at least weekly and commencing within the previous 12 months; abdominal pain was predictive only in such patients. The odds ratios never exceeded 4.27. A model based on age, gender, and medical history was highly predictive ( AUC = 0.79). Adding symptoms to this model increased the AUC to 0.85. Conclusions This model predicts patients in whom colonoscopy will have the highest yield. Conversely, colonoscopy can be avoided in people at low risk: in our study, 95% of cancers could have been detected by doing only 60% of the colonoscopies. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To examine women's informed preference for the management of a mildly abnormal Pap smear and the impact of a decision aid. METHODS: Women (n=106) were given a choice of management supported by a decision aid and surveyed before, and after decision making to evaluate predictors of choice and decision aid impact. RESULTS: HPV triage was preferred by most women (65%) although a substantial minority selected repeat Pap testing (35%). Women who chose HPV triage were more likely to have had children, have had a previous abnormal Pap smear and were more distressed than women who chose a repeat Pap test. In total, 68% of women made an informed choice. Rapid timing of follow-up was important for women choosing HPV testing. The lower chance of colposcopy and greater opportunity for regression, were rated as important by women choosing Pap testing. Decisional conflict was lower among women who chose HPV triage. No other differences in short-term psychological outcomes were found. CONCLUSION: The decision aid supported informed choice among the majority of women. Women tailored their choice to their practical, health and psychological needs. PRACTICE IMPLICATIONS: Offering women an informed choice for a mildly abnormal Pap smear may enable women to select the management that best suits their circumstances. [ABSTRACT FROM AUTHOR]

Background: Cholesterol level monitoring is a common clinical activity, but the optimal monitoring interval is unknown and practice varies.Objective: To estimate, in patients receiving cholesterol-lowering medication, the variation in initial response to treatment, the long-term drift from initial response, and the detectability of long-term changes in on-treatment cholesterol level ("signal") given short-term, within-person variation ("noise").Design: Analysis of cholesterol measurement data in the LIPID (Long-Term Intervention with Pravastatin in Ischaemic Disease) study.Setting: Randomized, placebo-controlled trial in Australia and New Zealand (June 1990 to May 1997).Patients: 9014 patients with past coronary heart disease who were randomly assigned to receive pravastatin or placebo.Measurements: Serial cholesterol concentrations at randomization, 6 months, and 12 months, and then annually to 5 years.Results: Both the placebo and pravastatin groups showed small increases in within-person variability over time. The estimated within-person SD increased from 0.40 mmol/L (15 mg/dL) (coefficient of variation, 7%) to 0.60 mmol/L (23 mg/dL) (coefficient of variation, 11%), but it took almost 4 years for the long-term variation to exceed the short-term variation. This slow increase in variation and the modest increase in mean cholesterol level, about 2% per year, suggest that most of the variation in the study is due to short-term biological and analytic variability. Our calculations suggest that, for patients with levels that are 0.5 mmol/L or more (> or =19 mg/dL) under target, monitoring is likely to detect many more false-positive results than true-positive results for at least the first 3 years after treatment has commenced.Limitations: Patients may respond differently to agents other than pravastatin. Future values for nonadherent patients were imputed.Conclusion: The signal-noise ratio in cholesterol level monitoring is weak. The signal of a small increase in cholesterol level is difficult to detect against the background of a short-term variability of 7%. In annual rechecks in adherent patients, many apparent increases in cholesterol level may be false positive. Independent of the office visit schedule, the interval for monitoring patients who are receiving stable cholesterol-lowering treatment could be lengthened. [ABSTRACT FROM AUTHOR]

Background: Privacy laws have recently created restrictions on how researchers can approach study participants. Method: In a randomised trial of 152 patients, 50-74 years old, in a family practice, 60 were randomly selected to opt-out and 92 to opt-in methods. Patients were sent an introductory letter by their doctor in two phases, opt-out before and opt-in after introduction of the new Privacy Legislation in December 2001. Opt-out patients were contacted by researchers. Opt-in patients were contacted if patients responded by email, free telephone number or a reply-paid card. Results: Opt-in recruited fewer patients (47%; 43/92) after invitation compared with opt-out (67%; 40/60); (-20%; [-4% to 36%]). No proportional difference in recruitment was found between opt-in and opt-out groups varied by age, sex or socioeconomic status. The opt-in group had significantly more people in active decision-making roles (+30%; [10% to 50%]; p=0.003). Non-significant trends were observed towards opt-in being Jess likely to include people with lower education (-11.8%; [-30% to 6.4%]; p=0.13) and people who were not screened (-19.1%; [-40.1% to 1.9%]; p=0.08). Opt-in was more likely to recruit people with a family history of colorectal cancer (+12.7%; [-2.8%, 28.2%]; p = 0.12). Conclusions: The number of participants required to be approached was markedly increased in opt-in recruitment. Existing participants (eg, screening attendees) with a vested interest such as increased risk, and those preferring an active role in health decision making and with less education were likely to be recruited in opt-in. Research costs and generalisability are affected by implementing privacy legislation. [ABSTRACT FROM AUTHOR]

Interval breast cancers-those diagnosed after a negative mammographic screen and before the next scheduled screen-are an important indicator of the potential effectiveness of population screening for breast cancer. Although the incidence of interval cancers is usually monitored, radiological surveillance is not undertaken routinely in most screening programmes. Here, we describe radiological surveillance of interval breast cancers and discuss methodological difficulties in the radiological review process and in the categorisation of interval cancers as false-negative, true, or occult. Furthermore, we identify methods that affect whether an interval cancer is classified as a false-negative (missed) or a true interval cancer. For all radiological categories of interval cancers, we outline possible changes to screening programmes that might improve cancer detection. Standardised radiological surveillance of interval cancers might allow within-programme comparisons and has the potential to guide practice and improve quality. [ABSTRACT FROM AUTHOR]

Examines the meta-analysis of sentinel node imprint cytology in breast cancer. Performance of a systematic search of electronic databases; Use of the meta-regression analysis for predictor of sensitivity; Risk factors in single-variable meta-regression analysis.

Breast ultrasound is generally interpreted with knowledge of the mammographic examination. This study examined the influence of knowledge of mammography findings on the accuracy of ultrasound in women with breast symptoms. Subjects were sampled from all women 25-55 years of age consecutively attending a breast clinic. This included all 240 women shown to have breast cancer and 240 age-matched women shown not to have cancer. Ultrasound films were prospectively reviewed and reported by two radiologists independent of each other and in a blinded manner. A two-phase design was used. In the first phase, the radiologists provided an opinion on the ultrasound films. In the second phase, the ultrasound films were reread with consideration of the corresponding mammographic examination. The accuracy of reading the ultrasound with and without knowledge of the findings on mammography was compared using sensitivity and specificity, and receiver operating characteristics (ROC) curves. Reporting the ultrasound with knowledge of mammography (compared to without mammography) improved sensitivity and reduced specificity for both radiologists. For one reader, sensitivity increased from 77.5% to 86.7% (p = 0.0002) and specificity decreased from 89.7% to 85.4% (p = 0.04). For the other reader, sensitivity increased from 81.3% to 87.5% (p = 0.0023) and specificity decreased from 87.1% to 85.0% (p = 0.27). ROC curves for both radiologists showed that reporting ultrasound with knowledge of mammography resulted in small (about 3%), but significant improvement in the area under the ROC curve. Our study indicates that knowledge of the findings of mammography improves the interpretation of breast ultrasound in symptomatic women. [ABSTRACT FROM AUTHOR]

We systematically reviewed the literature on the accuracy of new technologies proposed for breast cancer screening. Four potential tests were identified (ultrasound, magnetic resonance imaging (MRI), full-field digital mammography (FFDM), and computer-aided detection (CAD)) for which primary studies met quality and applicability criteria and provided adequate data on test accuracy. These technologies have been assessed in cross-sectional studies of test accuracy where the new test is compared to mammography. Ultrasound, used as an adjunct to mammography in women with radiologically dense breasts, detects additional cancers and causes additional false positives. Magnetic resonance imaging may have a better sensitivity (but lower specificity) than mammography in selected high-risk women, but studies of this technology included small number of cancers. Computer-aided detection may enhance the sensitivity of mammography and warrants further evaluation in large prospective trials. One study of FFDM suggests that it may identify some cancers not identified on conventional mammography and may result in a lower recall rate. The evidence is currently insufficient to support the use of any of these new technologies in population screening, but would support further evaluation.British Journal of Cancer (2004) 90, 2118-2122. doi:10.1038/sj.bjc.6601836 www.bjcancer.com Published online 27 April 2004 [ABSTRACT FROM AUTHOR]

Exfoliative cytology is only occasionally used in clinical practice to diagnose basal cell carcinoma (BCC). To systematically review the literature examining exfoliative cytology as a diagnostic tool for BCC and to meta-analytically summarize the accuracy of this test. Diagnostic test meta-analysis. A computerized database search was made of MEDLINE (1966–2000) and EMBASE (1950–2000) using appropriately indexed terms. Hand searches of relevant journals were made. Bibliographies of relevant articles were further explored. Histopathology was used as the reference standard. A summary receiver–operating characteristic curve analysis was performed using the statistical package Meta-Test version 0·6 (J. Lau, New England Medical Center, Boston, MA, U.S.A., 1997). Eight primary studies (seven English language and one Italian language) fulfilled the inclusion criteria. The pooled sample included 1261 BCCs. These studies varied greatly in methodological quality and were, in general, poor. A meta-analysis showed the pooled sensitivity to be high at 97%[95% confidence interval (CI) 94–99]. Consequently, only 3% of BCCs included were misdiagnosed as non-BCC by cytology. The corresponding pooled specificity was 86% (95% CI 80–91). Exfoliative cytology probably has a high diagnostic accuracy for BCC. However, large, better designed and better reported studies are needed to ascertain the true accuracy of this technique. In the interim, this test should be considered in specific subgroups of patients in whom even a 2-mm punch biopsy may be considered inappropriate, e.g. a cosmetically sensitive site in a young person. Similarly, it should be considered when a BCC is to be treated without a diagnostic biopsy being taken, e.g. with cryotherapy. [ABSTRACT FROM AUTHOR]

SummaryAims Screening for asymptomatic Type 2 diabetes mellitus has been advocated on the grounds that diabetes is a common condition associated with increased morbidity and mortality, but uncertainty remains about the impact of early treatment. This study aimed to determine whether the potential benefits of screening are likely to outweigh the potential harm and to explore which variables significantly influence the balance of benefit and harm resulting from screening. Methods A decision analysis comparing the relative impact of using a single fasting blood glucose screening test, between the ages of 45 and 60 years, with the impact of not screening. The model weighs the increase in quality adjusted life years (QALYs) from reduction in microvascular and cardiovascular complications against the potential decrease in QALYs associated with earlier diagnosis and treatment in an asymptomatic population. Results The baseline model suggests a saving of 10 QALYs for every 10 000 individuals screened: a gain of four from postponed microvascular complications and 17 from avoided cardiovascular complications, as opposed to a loss of 11 as a result of earlier diagnosis in screening detected cases. The balance of benefit and harm is sensitive to baseline cardiovascular risk, the effectiveness of cardiovascular interventions and the relative disutility assigned to early diagnosis and treatment for an individual without symptoms. Conclusions The immediate disutility of earlier diagnosis and additional treatment may be greater than the potential long-term benefit from postponing microvascular complications. Screening decisions should therefore be based largely on consideration of cardiovascular risk and the availability of evidence based interventions to reduce cardiovascular risk. [ABSTRACT FROM AUTHOR]

A double-blind, placebo-controlled, randomized, factorial study using a daily oral administration of 30 mg beta-carotene and/or 500 mg vitamin C was conducted in 141 women with colposcopically and histologically confirmed minor squamous atypia or cervical intra-epithelial neoplasia (CIN) I. Over approximately 2 years of follow-up, 43 lesions regressed to normal and 13 progressed to CIN II. The regression rate was slightly higher, but not significantly so, in those randomized to beta-carotene compared to no beta-carotene (hazard ratio = 1.58, 95% CI: 0.86-2.93,P = 0.14) and slightly lower, but not statistically significant, for those randomized to vitamin C compared to no vitamin C (hazard ratio = 0.65, 95% CI: 0.35-1.21,P = 0.17). In a model with no interaction, the progression rate was slightly higher in those randomized to beta-carotene (hazard ratio = 1.75, 95% CI: 0.57-5.36,P = 0.32) and also in those randomized to vitamin C (hazard ratio = 2.40, 95% CI: 0.74-7.80,P = 0.13). Neither of these were statistically significant. However, there was some evidence of an interaction effect of the two compounds on the progression rate (P = 0.052), with seven of the progressed lesions occurring in those randomized to both vitamins compared to a total of six in the three other groups. The currently available evidence from this and other trials suggests that high doses of these compounds are unlikely to increase the regression or decrease the progression of minor atypia and CIN I. [ABSTRACT FROM AUTHOR]

An individual's blood cholesterol measurement may differ from the true level because of short-term biological and technical measurement variability. Using data on the within-individual and population variance of serum cholesterol, we addressed the following clinical concerns: Given a cholesterol measurement, what is the individual's likely true level? The confidence interval for the true level is wide and asymmetrical around extreme measurements because of regression to the mean. Of particular concern is the misclassification of people with a screening measurement below 5.2 mmol/L who may be advised that their cholesterol level is "desirable" when their true level warrants further action To what extent does blood cholesterol change in response to an intervention? In general, confidence intervals are too wide to allow decision making and patient feedback about an individual's cholesterol response to a dietary intervention, even with multiple measurements. If no change is observed in an individual's cholesterol value based on three measurements before and three after dietary intervention, the 80% confidence interval ranges from a true increase of 4% to a true decrease of 9%. [ABSTRACT FROM AUTHOR]

Provides information on a flow diagram to illustrate the structure for making decisions about health care and research. How should a decision about heath care be formed; Reference made to policy-making in the health sector; Suggestion that decision-makers need reliable evidence to assess alternative strategies for preventing, treating and researching problems identified in health care; Importance of the flow diagram.

Background: Bowel symptoms are considered indicators of the presence of colorectal cancer and other bowel diseases. Self administered questionnaires that elicit information about lower bowel symptoms have not been assessed for reliability, although this has been done for upper bowel symptoms. Our aim was to develop a self administered questionnaire for eliciting the presence, nature and severity of lower bowel symptoms potentially related to colorectal cancer, and assess its reliability.Methods: Immediately before consulting a gastroenterologist or colorectal surgeon, 263 patients likely to have a colonoscopy completed the questionnaire. Reliability was assessed in two ways: by assessing agreement between patient responses and (a) responses given by the doctor at the consultation; and (b) responses given by patients two weeks later.Results: There was more than 75% agreement for 78% of the questions for the patient-doctor comparison and for 92% of the questions for the patient-patient comparison. Agreement for the length of time a symptom was present, its severity, duration, frequency of occurrence and whether or not medical consultation had been sought, all had agreement of greater than 70%. Over all questions, the chance corrected agreement for the patient-doctor comparison had a median kappa of 65% (which represents substantial agreement), interquartile range 57-72%. The patient-patient comparison also showed substantial agreement with a median kappa of 75%, interquartile range 68-81%.Conclusion: This self administered questionnaire about lower bowel symptoms is a useful way of eliciting details of bowel symptoms. It is a reliable instrument that is acceptable to patients and easily completed. Its use could guide the clinical consultation, allowing a more efficient, comprehensive and useful interaction, ensuring that all symptoms are assessed. It will also be a useful tool in research studies on bowel symptoms and their predictive value for colorectal cancer and other diseases. Studies assessing whether bowel symptoms predict the presence of colorectal cancer should provide estimates of the reliability of the symptom elicitation. [ABSTRACT FROM AUTHOR]

Douglass Hanly Moir is a large Australian laboratory which has recently introduced the ThinPrep Imaging System (TPI) for reading ThinPrep slides, which is still performed using a split-sample technique. The Imager is a computerized system which identifies 22 fields for the cytologist to review using automated light microscopy. We compared the accuracy of TPI and conventional cytology (CC) during normal laboratory operation. The ThinPrep sample was prepared after taking a conventional Pap smear. TPI and CC reading was done without knowledge of the result of the other reading. The final cytology report issued to the referring doctor reflected the more severe of these two results. Histology results for all cases in which TPI and CC cytology results showed more than minimal disagreement were sought from the NSW Pap Test Register. Of 55 164 split sample pairs, 3.1% of CC of slides and 1.8% of TPI slides were unsatisfactory. There were 1758 women for whom there was more than minimal discrepancy between TPI and CC cytology results. TPI gave the more severe result in 1193 of the 1758 cases. In cases where only one of each pair of discrepant cytology results was CIN1 or higher grade, TPI detected 133 cases of high-grade histology among 380 biopsies (35%), whereas CC detected 62 cases among 210 biopsies (29.5%). A repeat analysis based on reading of histology by one pathologist blinded to initial Pap smear result showed a similar result. Reading times were measured over 5 months for both TPI and CC for twenty cytologists who read both types of smears. On average, they read 13.3 TPI slides per hour and 6.1 CC slides per hour. This study provides evidence that cervical cytology read using the TPI detects more histological high-grade disease than does CC. Further evidence shows that reading times are significantly reduced for cytologists using the TPI. [ABSTRACT FROM AUTHOR]

Background:Magnetic resonance imaging (MRI) has been proposed to guide breast cancer surgery by measuring residual tumour after neoadjuvant chemotherapy. This study-level meta-analysis examines MRI's agreement with pathology, compares MRI with alternative tests and investigates consistency between different measures of agreement.Methods:A systematic literature search was undertaken. Mean differences (MDs) in tumour size between MRI or comparator tests and pathology were pooled by assuming a fixed effect. Limits of agreement (LOA) were estimated from a pooled variance by assuming equal variance of the differences across studies.Results:Data were extracted from 19 studies (958 patients). The pooled MD between MRI and pathology from six studies was 0.1 cm (95% LOA: −4.2 to 4.4 cm). Similar overestimation for MRI (MD: 0.1 cm) and ultrasound (US) (MD: 0.1 cm) was observed, with comparable LOA (two studies). Overestimation was lower for MRI (MD: 0.1 cm) than mammography (MD: 0.4 cm; two studies). Overestimation by MRI (MD: 0.1 cm) was smaller than underestimation by clinical examination (MD: −0.3 cm). The LOA for mammography and clinical examination were wider than that for MRI. Percentage agreement between MRI and pathology was greater than that of comparator tests (six studies). The range of Pearson's/Spearman's correlations was wide (0.21-0.92; 16 studies). Inconsistencies between MDs, percentage agreement and correlations were common.Conclusion:Magnetic resonance imaging appears to slightly overestimate pathologic size, but measurement errors may be large enough to be clinically significant. Comparable performance by US was observed, but agreement with pathology was poorer for mammography and clinical examination. Percentage agreement can provide supplementary information to MDs and LOA, but Pearson's/Spearman's correlation does not provide evidence of agreement and should be avoided. Further comparisons of MRI and other tests using the recommended methods are warranted. [ABSTRACT FROM AUTHOR]

Background: Pathologists sometimes disagree over the histopathologic diagnosis of melanoma. 'Over‐calling' and 'under‐calling' of melanoma may harm individuals and healthcare systems. Objectives: To estimate the extent of 'over‐calling' and 'under‐calling' of melanoma for a population undergoing one excision per person and to model the impact of potential solutions. Methods: In this epidemiological modelling study, we undertook simulations using published data on the prevalence and diagnostic accuracy of melanocytic histopathology in the U.S. population. We simulated results for 10 000 patients each undergoing excision of one melanocytic lesion, interpreted by one community pathologist. We repeated the simulation using a hypothetical intervention that improves diagnostic agreement between community pathologist and a specialist dermatopathologist. We then evaluated four scenarios for how melanocytic lesions judged to be neither clearly benign (post‐test probability of melanoma < 5%), nor clearly malignant (post‐test probability of melanoma > 90%) might be handled, before sending for expert dermatopathologist review to decide the final diagnosis. These were (1) no intervention before expert review, (2) formal second community pathologist review, (3) intervention to increase diagnostic agreement and (4) both the intervention and formal second community pathologist review. The main outcomes were the probability of 'over‐calling' and 'under‐calling' melanoma, and number of lesions requiring expert referral for each scenario. Results: For 10 000 individuals undergoing excision of one melanocytic lesion, interpreted by a community pathologist, a hypothetical intervention to improve histopathology agreement reduced the number of benign lesions 'over‐called' as melanoma from 308 to 164 and the number of melanomas 'under‐called' from 289 to 240. If all uncertain diagnoses were sent for expert review, the number of referrals would decrease from 1500 to 737 cases if formal second community pathologist review was used, and to 701 cases if the hypothetical intervention was additionally used. Conclusions: Interventions to improve histopathology agreement may reduce melanoma 'over‐calling' and 'under‐calling'. [ABSTRACT FROM AUTHOR]

The treatments under comparison in a randomised trial should ideally have equal value and acceptability - a position of equipoise - to study participants. However, it is unlikely that true equipoise exists in practice, because at least some participants may have preferences for one treatment or the other, for a variety of reasons. These preferences may be related to study outcomes, and hence affect the estimation of the treatment effect. Furthermore, the effects of preferences can sometimes be substantial, and may even be larger than the direct effect of treatment. Preference effects are of interest in their own right, but they cannot be assessed in the standard parallel group design for a randomised trial. In this paper, we describe a model to represent the impact of preferences on trial outcomes, in addition to the usual treatment effect. In particular, we describe how outcomes might differ between participants who would choose one treatment or the other, if they were free to do so. Additionally, we investigate the difference in outcomes depending on whether or not a participant receives his or her preferred treatment, which we characterise through a so-called preference effect. We then discuss several study designs that have been proposed to measure and exploit data on preferences, and which constitute alternatives to the conventional parallel group design. Based on the model framework, we determine which of the various preference effects can or cannot be estimated with each design. We also illustrate these ideas with some examples of preference designs from the literature. [ABSTRACT FROM AUTHOR]

Outcomes in clinical trials may be affected by the choice of treatment that participants might make, if they were indeed allowed to choose (a so-called selection effect), and by whether they actually receive their preferred treatment (a preference effect). Selection and preference effects can be important, but they cannot be estimated in the conventional trial design. An alternative approach is the two-stage randomised trial, in which participants are first randomly divided into two subgroups. In one subgroup, participants are randomly assigned to treatments, while in the other, participants are allowed to choose their own treatment. This approach yields estimates of the direct treatment effect, and of the preference and selection effects. The latter two provide insight that goes considerably beyond what is possible in the standard randomised trial. In this paper, we determine the optimal proportion of participants who should be allocated to the choice subgroup. The precision of the estimated selection, preference and treatment effects are functions of: the total sample size; the proportion of participants allocated to choose their treatment; the variances of the outcome; the proportions of participants who select each treatment in the choice group; and the selection, preference and treatment effects themselves. We develop general expressions for the optimum proportion of participants in the choice group, depending on which effects are of primary interest. We illustrate the results with trial data comparing alternative clinical management strategies for women with abnormal results on cervical screening. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

When no gold standard is available to evaluate a diagnostic or screening test, as is often the case, an imperfect reference standard test must be used instead. Furthermore, the errors of the test and its reference standard may not be independent. Some authors have opined that positively dependent errors will lead to overestimation of test performance. Although positive dependence does increase agreement between the test and the reference standard, it is not clear if test accuracy will necessarily be overestimated in this situation, and the case of negatively associated test errors is even less clear. To examine this issue in more detail, we derive the apparent sensitivity, specificity, and overall accuracy of a test relative to an imperfect reference standard and the bias in these parameters. We demonstrate that either positive or negative bias can occur if the reference standard is imperfect. The type and magnitude of bias depend on several components: the disease prevalence, the true test sensitivity and specificity, the covariance between the false-negative test errors among the true disease cases, and the covariance between the false-positive test errors among the true noncases. If, for example, sensitivity and specificity are 0.8 for both the test and reference standard and the errors have a moderate positive dependence, test sensitivity is then underestimated at low prevalence but overestimated at high prevalence, while the opposite occurs for specificity. We illustrate these ideas through general numerical calculations and an empirical example of screening for breast cancer with magnetic resonance imaging and mammography. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article presents a study which explores the importance of identifying the accuracy of diagnostic tests in clinical studies. It states that diagnostic test accuracy studies evaluates the presence or absence of a disease which is expressed as test sensitivity and specificity. According to the authors, a clinically relevant disease must be used as a target condition for test accuracy studies. It is inferred that the definition of a disease as the target condition must be based on evidence from prognostic studies. INSET: Example of interpretation of test sensitivity and specificity....

Presents a letter to the editor commenting on dual-vision method to analyse agreement data of clinical diagnositic sensitivity and specificity published in November 2003 issue of the journal "Health Sciences."

Objectives: To introduce guidelines for the conduct, reporting, and critical appraisal of meta-analyses evaluating diagnostic tests and to apply these guidelines to recently published meta-analyses of diagnostic tests.Data Sources: Based on current concepts of how to assess diagnostic tests and conduct meta-analyses. They are applied to all meta-analyses evaluating diagnostic tests published in English-language journals from January 1990 through December 1991, identified through MEDLINE searching and by experts in the field.Study Selection: Meta-analyses were included if at least two of three independent readers regarded their main purpose as the evaluation of diagnostic tests against a concurrent reference standard.Data Extraction: By three independent readers on the extent to which meta-analyses fulfilled each guideline, with consensus defined as agreement by at least two readers.Data Synthesis: The guidelines are concerned with determining the objective of the meta-analysis, identifying the relevant literature and extracting the data, estimating diagnostic accuracy, and identifying the extent to which variability is explained by study design characteristics and characteristics of the patients and diagnostic test. In general, the guidelines were only partially fulfilled.Conclusion: Meta-analysis is potentially important in the assessment of diagnostic tests. Those reading meta-analyses evaluating diagnostic tests should critically appraise them; those doing meta-analyses should apply recently developed methods. The conduct and reporting of primary studies on which meta-analyses are based require improvement. [ABSTRACT FROM AUTHOR]