Attitudes of Research Participants and the General Public Regarding Disclosure of Alzheimer Disease Research Results.

IMPORTANCE: Results of Alzheimer disease (AD) research assessments typically are not disclosed to participants. Recent research has suggested interest in disclosure, but, to our knowledge, few studies have accounted for awareness of potential benefits and limitations of disclosure. OBJECTIVE: To determine the attitudes of cognitively normal research participants and members of the general public regarding disclosure of AD research results. DESIGN, SETTING, AND PARTICIPANTS: Participants in a longitudinal aging study (Alzheimer Disease Research Center [ADRC]) were given preintervention and postintervention surveys about disclosure attitudes. In a general public sample (The American Panel Survey), participants responded to a similar survey about disclosure attitudes. INTERVENTIONS: Participants in the ADRC sample were randomly assigned to a group (n = 119) that read an education intervention about the usefulness of AD biomarkers or to a placebo group (n = 100) that read as its intervention general information about the ADRC. Participants in the general public sample read a brief vignette describing participation in a longitudinal AD study. MAIN OUTCOME AND MEASURE: Interest in disclosure of AD research results. RESULTS: Cognitively normal ADRC participants (n = 219) were 60.7% (n = 133) female, 83.6% (n = 183) of white race, and reported a mean of 15.91 years of education. Twenty-nine individuals refused participation. The American Panel Survey participants (n = 1418) indicated they did not have AD and were 50.5% (n = 716) female, 76.7% (n = 1087) of white race, and reported a mean of 13.85 years of education. Overall, 77.6% of eligible participants (1583 of 2041) completed the survey in July 2014. Interest in disclosure was high among the ADRC participants (55.1% [119 of 216] were "extremely interested"). Viewing the education intervention predicted lower interest in disclosure (odds ratio, 2.01; 95% CI, 1.15-3.53; P = .02). High subjective risk of AD, a family history of AD, and minimal attendance at research meetings were associated with high interest after the intervention. In the general public, interest was lower overall (12.5% [174 of 1389] were "extremely interested"), but the subset of participants most likely to join an AD research study reported higher interest (43.5% [40 of 92] were extremely interested). CONCLUSIONS AND RELEVANCE: Experience with AD appears to increase interest in disclosure of AD research results. Learning about potential limitations of disclosure somewhat tempered interest. These findings should inform the development of disclosure policies for asymptomatic individuals in AD studies.

A social choice approach to expert consensus panels.

This study uses recent theoretical work about group decision-making to assess the quality of decision-making by expert consensus panels. We specifically examine (1) when individual members of panels will divulge their private judgments about the decision to the panel, and (2) when the group judgment is superior to the judgment of individual panelists and will lead to better treatment for patients. We conclude that to maximize the chance of an accurate decision, panels should be made as large as possible, adopt the smallest supermajority rule, and attract members with the highest individual competencies. Furthermore, interdependence among panelists and the goal of reaching consensus can reduce the efficacy of these panels.

Temporoparietal hypometabolism in frontotemporal lobar degeneration and associated imaging diagnostic errors.

OBJECTIVE: To evaluate the cause of diagnostic errors in the visual interpretation of positron emission tomographic scans with fludeoxyglucose F 18 (FDG-PET) in patients with frontotemporal lobar degeneration (FTLD) and patients with Alzheimer disease (AD). DESIGN: Twelve trained raters unaware of clinical and autopsy information independently reviewed FDG-PET scans and provided their diagnostic impression and confidence of either FTLD or AD. Six of these raters also recorded whether metabolism appeared normal or abnormal in 5 predefined brain regions in each hemisphere-frontal cortex, anterior cingulate cortex, anterior temporal cortex, temporoparietal cortex, and posterior cingulate cortex. Results were compared with neuropathological diagnoses. SETTING: Academic medical centers. PATIENTS: Forty-five patients with pathologically confirmed FTLD (n=14) or AD (n=31). RESULTS: Raters had a high degree of diagnostic accuracy in the interpretation of FDG-PET scans; however, raters consistently found some scans more difficult to interpret than others. Unanimity of diagnosis among the raters was more frequent in patients with AD (27 of 31 patients [87%]) than in patients with FTLD (7 of 14 patients [50%]) (P=.02). Disagreements in interpretation of scans in patients with FTLD largely occurred when there was temporoparietal hypometabolism, which was present in 7 of the 14 FTLD scans and 6 of the 7 scans lacking unanimity. Hypometabolism of anterior cingulate and anterior temporal regions had higher specificities and positive likelihood ratios for FTLD than temporoparietal hypometabolism had for AD. CONCLUSIONS: Temporoparietal hypometabolism in FTLD is common and may cause inaccurate interpretation of FDG-PET scans. An interpretation paradigm that focuses on the absence of hypometabolism in regions typically affected in AD before considering FTLD is likely to misclassify a significant portion of FTLD scans. Anterior cingulate and/or anterior temporal hypometabolism indicates a high likelihood of FTLD, even when temporoparietal hypometabolism is present. Ultimately, the accurate interpretation of FDG-PET scans in patients with dementia cannot rest on the presence or absence of a single region of hypometabolism but rather must take into account the relative hypometabolism of all brain regions.

Validation of consensus panel diagnosis in dementia.

BACKGROUND: The clinical diagnosis of dementing diseases largely depends on the subjective interpretation of patient symptoms. Consensus panels are frequently used in research to determine diagnoses when definitive pathologic findings are unavailable. Nevertheless, research on group decision making indicates that many factors can adversely affect panel performance. OBJECTIVE: To determine conditions that improve consensus panel diagnosis. DESIGN: Comparison of neuropathologic diagnoses with individual and consensus panel diagnoses based on clinical scenarios only, fludeoxyglucose F 18 positron emission tomography images only, and scenarios plus images. SETTING: Expert and trainee individual and consensus panel deliberations using a modified Delphi method in a pilot research study of the diagnostic utility of fludeoxyglucose F 18 positron emission tomography. PATIENTS: Forty-five patients with pathologically confirmed Alzheimer disease or frontotemporal dementia. MAIN OUTCOME MEASURES: Statistical measures of diagnostic accuracy, agreement, and confidence for individual raters and panelists before and after consensus deliberations. RESULTS: The consensus protocol using trainees and experts surpassed the accuracy of individual expert diagnoses when clinical information elicited diverse judgments. In these situations, consensus was 3.5 times more likely to produce positive rather than negative changes in the accuracy and diagnostic certainty of individual panelists. A rule that forced group consensus was at least as accurate as majority and unanimity rules. CONCLUSIONS: Using a modified Delphi protocol to arrive at a consensus diagnosis is a reasonable substitute for pathologic information. This protocol improves diagnostic accuracy and certainty when panelist judgments differ and is easily adapted to other research and clinical settings while avoiding the potential pitfalls of group decision making.