Challenges in systematic reviews of diagnostic technologies.

Diagnostic tests are critical components of effective health care. They help determine treatments that are most beneficial for a given patient. Their assessment is a complex process that includes such challenges as a dearth of studies that evaluate clinical outcomes and lack of data on use of the test in realistic clinical settings. The methodologic quality of studies of diagnostic tests also lags behind the quality of studies of therapeutic interventions. Statistical methods to combine diagnostic accuracy data are more complex and not as well developed, leading to difficulties in the interpretation of results. The Agency for Healthcare Research and Quality Technology Assessment Program has adopted a 6-level framework for evaluating diagnostic technologies. The model emphasizes the need for systematic reviews of diagnostic test studies to go beyond the assessment of technical feasibility and accuracy to examine the impact of the test on health outcomes. In this paper, we use examples from 3 Evidence-based Practice Center reports to illustrate 3 challenges reviewers may face when reviewing diagnostic test literature: finding relevant studies, assessing methodologic quality of diagnostic accuracy studies, and synthesizing studies that evaluate tests in different patient populations or use different outcomes.

Should FDG PET be used to decide whether a patient with an abnormal mammogram or breast finding at physical examination should undergo biopsy?

RATIONALE AND OBJECTIVES: The purpose of this systematic review was to assess the performance of fluorodeoxyglucose positron emission tomography (PET) in the differential diagnosis of benign from malignant lesions among patients with abnormal mammograms or a palpable breast mass and to examine the effects of PET findings on patient care and health outcomes. MATERIALS AND METHODS: A search of the MEDLINE and CancerLit databases covered articles entered between January 1966 and March 2001. Thirteen articles met the selection criteria. Each article was assessed for study quality characteristics. Meta-analysis was performed with a random effects model and a summary receiver operating characteristic curve. RESULTS: A point on the summary receiver operating characteristic curve was selected that reflected average performance, with an estimated sensitivity of 89% and a specificity of 80%. When the prevalence of malignancy is 50%, 40% of all patients would benefit by avoiding the harm of a biopsy with negative biopsy results. The risk of a false-negative result, leading to delayed diagnosis and treatment, is 5.5%. The negative predictive value is 87.9%; thus, the false-negative risk is 12.1%. For a patient with a negative PET scan, a 12% chance of missed or delayed diagnosis of breast cancer is probably too high to make it worth the 88% chance of avoiding biopsy of a benign lesion. CONCLUSION: The evidence does not favor the use of fluorodeoxyglucose PET to help decide whether to perform biopsy. Available studies omit a critical segment of the biopsy population with indeterminate mammograms or nonpalpable masses, for which no conclusions can be reached.

Report on the ASCO 2010 Provider-Payer Initiative Meeting.

The ASCO Provider-Payer Initiative meeting was convened to explore ways in which providers and payers could work together to improve patient care.

The Blue Cross Blue Shield Association Technology Evaluation Center: how we evaluate radiology technologies.

Evidence-based technology assessment can help answer critical questions concerning the safety, effectiveness, and appropriate uses of medical technologies. This practice can be used to avoid the promotion of ineffective technologies and the premature diffusion of technologies that have not been demonstrated to improve patient-oriented health outcomes, both of which draw resources from effective and appropriate medical care. This article describes the process of such evaluation as undertaken by the Blue Cross Blue Shield Association Technology Evaluation Center. The key components of the assessment process are described, including the problem formulation and evaluation of study quality, as well as the process by which the available evidence is judged against the five Technology Evaluation Center criteria.

Technology Evaluation Center assessment synopsis: use of magnetic resonance imaging to avoid a biopsy in women with suspicious primary breast lesions.

Imaging technologies (e.g., magnetic resonance imaging [MRI]) have been proposed as noninvasive alternatives to surgical biopsy techniques in the follow-up of women with suspicious primary breast lesions. This article is a synopsis of a systematic review by the Blue Cross and Blue Shield Association Technology Evaluation Center. According to the best available evidence, the sensitivity and specificity of MRI ranged from 91% to 99% and from 31% to 91%, respectively. Predictive values were calculated by using three likely scenarios of diagnostic performance and disease prevalence. The potential harm of failing to diagnose or delaying diagnosis of breast cancer in patients with false-negative MRI results is of significant concern. We conclude that the potential benefit of sparing some patients from unnecessary biopsy by using noninvasive imaging does not outweigh the potential harm of a missed or delayed diagnosis of breast cancer.

Wireless capsule endoscopy in patients with obscure small-intestinal bleeding.

Wireless capsule endoscopy is proposed in the management of patients with obscure gastrointestinal (GI) bleeding, defined as persistent or recurrent GI bleeding without a cause identified on routine endoscopy. Obscure GI bleeding often originates from a small-intestinal abnormality, which presents diagnostic and therapeutic challenges because the small intestine is not easily visualized on conventional workup. This is a synopsis of a systematic review by the Blue Cross Blue Shield Association Technology Evaluation Center. Limited evidence shows that capsule endoscopy identified small-bowel lesions generally beyond the reach of push enteroscopy in 25% to 50% of patients and revealed additional diagnostic findings in 25% of patients compared with small-bowel barium radiographic studies. The authors conclude that in some cases, the information provided by capsule endoscopy in this specific patient population with obscure GI bleeding not diagnosed via conventional workup can lead to changes in management that would improve net health outcome.