Predictive Utility of Marketed Volumetric Software Tools in Subjects at Risk for Alzheimer Disease: Do Regions Outside the Hippocampus Matter?

BACKGROUND AND PURPOSE

Alzheimer disease is a prevalent neurodegenerative disease. Computer assessment of brain atrophy patterns can help predict conversion to Alzheimer disease. Our aim was to assess the prognostic efficacy of individual-versus-combined regional volumetrics in 2 commercially available brain volumetric software packages for predicting conversion of patients with mild cognitive impairment to Alzheimer disease.

MATERIALS AND METHODS

Data were obtained through the Alzheimer's Disease Neuroimaging Initiative. One hundred ninety-two subjects (mean age, 74.8 years; 39% female) diagnosed with mild cognitive impairment at baseline were studied. All had T1-weighted MR imaging sequences at baseline and 3-year clinical follow-up. Analysis was performed with NeuroQuant and Neuroreader. Receiver operating characteristic curves assessing the prognostic efficacy of each software package were generated by using a univariable approach using individual regional brain volumes and 2 multivariable approaches (multiple regression and random forest), combining multiple volumes.

RESULTS

On univariable analysis of 11 NeuroQuant and 11 Neuroreader regional volumes, hippocampal volume had the highest area under the curve for both software packages (0.69, NeuroQuant; 0.68, Neuroreader) and was not significantly different (P > .05) between packages. Multivariable analysis did not increase the area under the curve for either package (0.63, logistic regression; 0.60, random forest NeuroQuant; 0.65, logistic regression; 0.62, random forest Neuroreader).

CONCLUSIONS

Of the multiple regional volume measures available in FDA-cleared brain volumetric software packages, hippocampal volume remains the best single predictor of conversion of mild cognitive impairment to Alzheimer disease at 3-year follow-up. Combining volumetrics did not add additional prognostic efficacy. Therefore, future prognostic studies in mild cognitive impairment, combining such tools with demographic and other biomarker measures, are justified in using hippocampal volume as the only volumetric biomarker.

Effectiveness of strategies to recruit underrepresented populations into cancer clinical trials

Background Certain populations, including racial and ethnic minorities and older persons, have had a history of low participation in cancer-related trials, yet there has been little information reported on recruitment strategies tailored to improve their enrollment.

Methods We conducted a systematic literature review to examine the methods used to study recruitment of underrepresented populations into cancer prevention and treatment trials and examined the studies that compared the efficacy and/or effectiveness of different recruitment strategies. We performed an electronic search through multiple databases including PubMed and a hand search of 34 journals. Potential studies were pulled and underwent title, abstract, and article review by at least two investigators.

Results Fourteen articles examined recruitment of underrepresented populations into cancer trials and, of these, five compared efficacy or effectiveness of different strategies for recruitment of underrepresented populations into randomized or concurrent controlled trials. These five studies used various strategies but only three reported that specific recruitment strategies, such as media campaigns and churchbased project sessions, resulted in improvement in accrual to cancer trials.

Conclusion There is limited evidence for efficacious or effective strategies to recruit underrepresented populations in cancer-related trials. The available evidence cannot be generalized to these heterogeneous groups. Further study is needed on efficacious strategies for recruitment of underrepresented populations into cancerrelated trials.

Imaging Signs in Spontaneous Intracranial Hypotension: Prevalence and Relationship to CSF Pressure

BACKGROUND AND PURPOSE

Patients with spontaneous intracranial hypotension often exhibit low CSF pressure and changes on brain MR imaging and/or evidence of CSF leak on myelography. We investigated whether individual imaging signs of spontaneous intracranial hypotension correlate with measured CSF pressure and how frequently these 2 markers of spontaneous intracranial hypotension were concordant.

MATERIALS AND METHODS

We performed a retrospective, cross-sectional study of 99 subjects with spontaneous intracranial hypotension. Prevalence of brain and myelographic imaging signs of spontaneous intracranial hypotension was recorded. CSF pressure among subjects with or without individual imaging signs was compared by using a 2-tailed t test and ANOVA. Concordance between low CSF pressure (≤6 cm H2O) and imaging was defined as the presence of the sign in a subject with low CSF pressure or absence of the sign when pressure was not low.

RESULTS

Dural enhancement, brain sagging, and venous distension sign were present in 83%, 61%, and 75% of subjects, respectively, and myelographic evidence of CSF leak was seen in 55%. Marginal correlations between CSF pressure and brain sagging (P = .046) and the venous distension sign (P = .047) were found. Dural enhancement and myelographic evidence of leak were not significantly correlated with CSF pressure. Rates of concordance between imaging signs and low CSF pressure were generally low, ranging from 39% to 55%.

CONCLUSIONS

Brain and myelographic signs of spontaneous intracranial hypotension correlate poorly with CSF pressure. These findings reinforce the need to base the diagnosis of spontaneous intracranial hypotension on multiple diagnostic criteria and suggest the presence of patient-specific variables that influence CSF pressure in these individuals.

Applying justice in clinical trials for diverse populations

Background Considerable attention has focused on increasing clinical trial participation for members of “underrepresented groups”. However, doing so involves clarifying how to meet the demands of justice, or fairness, which provides the ethical mandate to enhance broad trial representation.

Purpose To examine the ethical principle of justice as it applies to recruiting diverse populations to clinical trials representation.

Methods In this paper, we analyse the conceptual and practical challenges in applying the principle of justice to clinical trials representation.

Results Different facets of justice include demands for both fair outcomes and fair processes. Including both of these facets in clinical trials policy should not only promote access to trials, but also help to provide a framework to improve fairness in representation in clinical trials. Efforts to evaluate recruitment of representation should include outcome and process measures.

Limitations The suggestions offered based on this conceptual analysis need to be tested empirically.

Conclusions Those involved in the design, conduct and oversight of clinical trials should consider all of the facets of justice when assessing representation in clinical trials and attempt to balance fair access to trials with a fair process that may require protection from being unduly pressured to participate. Clinical Trials 2007; 4: 264—269; http://ctj.sagepub.com

Radiology reports for incidental thyroid nodules on CT and MRI: high variability across subspecialties

BACKGROUND AND PURPOSE

Variability in radiologists' reporting styles and recommendations for incidental thyroid nodules can lead to confusion among clinicians and may contribute to inconsistent patient care. Our aim was to describe reporting practices of radiologists for incidental thyroid nodules seen on CT and MR imaging and to determine factors that influence reporting styles.

MATERIALS AND METHODS

This is a retrospective study of patients with incidental thyroid nodules reported on CT and MR imaging between January and December 2011, identified by text search for "thyroid nodule" in all CT and MR imaging reports. The studies included CT and MR imaging scans of the neck, spine, and chest. Radiology reports were divided into those that mentioned the incidental thyroid nodules only in the "Findings" section versus those that reported the incidental thyroid nodules in the "Impression" section as well, because this latter reporting style gives more emphasis to the finding. Univariate and multivariate analyses were performed to identify radiologist, patient, and nodule characteristics that influenced reporting styles.

RESULTS

Three hundred seventy-five patients met the criterion of having incidental thyroid nodules. One hundred thirty-eight (37%) patients had incidental thyroid nodules reported in the "Impression" section. On multivariate analysis, only radiologists' divisions and nodule size were associated with reporting in "Impression." Chest radiologists and neuroradiologists were more likely to report incidental thyroid nodules in the "Impression" section than their abdominal imaging colleagues, and larger incidental thyroid nodules were more likely to be reported in "Impression" (P ≤ .03). Seventy-three percent of patients with incidental thyroid nodules of ≥20 mm were reported in the "Impression" section, but higher variability in reporting was seen for incidental thyroid nodules measuring 10-14 mm and 15-19 mm, which were reported in "Impression" for 61% and 50% of patients, respectively.

CONCLUSIONS

Reporting practices for incidental thyroid nodules detected on CT and MR imaging are predominantly influenced by nodule size and the radiologist's subspecialty. Reporting was highly variable for nodules measuring 10-19 mm; this finding can be partially attributed to different reporting styles among radiology subspecialty divisions. The variability demonstrated in this study further underscores the need to develop CT and MR imaging practice guidelines with the goal of standardizing reporting of incidental thyroid nodules and thereby potentially improving the consistency and quality of patient care.

Barriers to recruiting underrepresented populations to cancer clinical trials: a systematic review

Racial and ethnic minorities, older adults, rural residents, and individuals of low socioeconomic status are underrepresented among participants in cancer-related trials. The authors conducted a systematic review to determine the barriers to participation of underrepresented populations in cancer-related trials. Their search included English-language publications that reported original data on the recruitment of underrepresented groups to cancer treatment or prevention trials between 1966 and December 2005 in multiple electronic databases. They also hand-searched titles in 34 journals from January 2003 to December 2005 and they examined reference lists for eligible articles. Titles and abstracts were reviewed to identify relevant studies. Data on barriers to participation were synthesized both qualitatively and based on statistically significant associations with trial enrollment. Of 5257 studies that were cited, 65 studies were eligible for inclusion in the current analysis, including 46 studies on recruitment into cancer therapeutic trials, 15 studies on recruitment into prevention trials, and 4 studies on recruitment into both prevention and treatment trials. Numerous factors were reported as barriers to participation in cancer-related trials. However, only 20 of the studies reported statistically significant associations between hypothesized barriers and enrollment. The available evidence had limitations in quality regarding representativeness, justification of study methods, the reliability and validity of data-collection methods, potential for bias, and data analysis. The results indicated that underrepresented populations face numerous barriers to participation in cancer-related trials. The current systematic review highlighting the literature on recruitment of underrepresented populations to cancer trials and may be used as the evidence base toward developing an agenda for etiologic and intervention research to reduce the disparities in participation in cancer-related trials.

Provider roles in the recruitment of underrepresented populations to cancer clinical trials

BACKGROUND

Providers play a vital role in the successful recruitment of underrepresented patients to cancer clinical trials because they often introduce the opportunity of clinical trials. The purpose of the current systematic review was to describe provider-related factors influencing recruitment of underrepresented populations to cancer clinical trials.

METHODS

To find original studies on the recruitment of underrepresented populations to cancer clinical trials, electronic databases from January 1966 to December 2005 were searched; hand-searched titles in 34 journals from January 2003 to January 2006; and reference lists were examined of eligible articles. Title and abstract reviews were conducted to identify relevant studies. Potential articles were then abstracted using a structured instrument and a serial review process by 2 investigators.

RESULTS

Eighteen studies were eligible for review: 13 targeted healthcare providers, 3 targeted patients/participants, and 2 targeted both providers and patients. The study designs included randomized controlled trial, concurrent controlled trial, case-control, descriptive, and qualitative. A lack of available protocols and/or a lack of provider awareness about clinical trials prevented providers from discussing the opportunity of clinical trials in 2 studies. In 14 studies, patient accrual was affected by provider attitudinal barriers relating to patient adherence to the study protocol, patient mistrust of research, patient costs, data collection costs, and/or patient eligibility. Providers' communication methods were barriers in 5 studies and promoters in 1 study.

CONCLUSIONS

A heterogeneous body of evidence suggests that several provider-related factors influence recruitment of underrepresented groups to clinical trials. Future recruitment efforts should address these factors.