Contrast effects in judgments of health hazards

Anchoring in Destination-Therapy Left Ventricular Assist Device Decision Making: A Mechanical Turk Survey

BACKGROUND

People with end-stage heart failure may have to decide about destination-therapy left ventricular assist device (DT-LVAD). Individuals facing difficult decisions often rely on heuristics, such as anchoring, which predictably bias decision outcomes. We aimed to investigate whether showing a larger historical Heartmate XVE creates an anchoring effect, making the smaller Heartmate II (HMII) appear more favorable.

METHODS

With the use of Amazon Mechanical Turk, participants watched videos asking them to imagine themselves dying of end-stage heart failure, then were presented the option of LVAD as potentially life-prolonging therapy. Participants were randomized to a control group who were only shown the HMII device, and the intervention group who saw the XVE device before the HMII. Participants then completed surveys.

RESULTS

A total of 487 participants completed the survey (control = 252; intervention = 235); 79% were <40 years of age, 84% were white, and 55% were male. The intervention group was not more likely to accept the LVAD therapy (68% vs 61%; P = .37). However, participants in the intervention group were more likely (51% vs 17%; P < .01) to agree or strongly agree with the statement that the HMII was "smaller than expected." Participants in the intervention group were also more likely to rate the size of the device as "important" or "very important" in their decision (61% vs 46%; P < .01).

CONCLUSIONS

Although the XVE anchor did not affect likelihood of accepting the LVAD, it did affect device perception. This article highlights an important point with clinical implications: factors such as anchoring have the potential to inappropriately influence perceptions and decisions and should be carefully considered in research and practice.

Clinician Misperceptions about the Importance of Adolescent HPV Vaccination

Introduction

Adolescent HPV vaccination rates remain suboptimal. The purpose of the study was to investigate attitudes about HPV vaccine relative to other adolescent vaccines among clinical staff from primary care offices and school based clinics.

Methods

We interviewed clinicians in primary care offices and school-based clinics regarding their attitudes about HPV vaccine relative to Tdap and MCV4.

Results

Respondents (n = 36) included clinical staff in family medicine (47%), pediatrics (25%), obstetrics/gynecology (19%) and school-based health clinics (8%). Only 3% strongly agreed and 17% agreed that completion of HPV vaccine was more important than completion of pertussis vaccine (Tdap), while 6% strongly agreed and 33% agreed that completion of HPV vaccine was more important than completion of meningitis vaccine (MCV4).

Discussion

Providing clinicians with additional information about the cancer prevention benefits of the HPV vaccine and the greater risk for HPV infection/disease relative to other vaccine preventable adolescent diseases may help to increase HPV vaccination rates among adolescents.

Physician communication about adolescent vaccination: How is human papillomavirus vaccine different?

BACKGROUND

Low human papillomavirus (HPV) vaccination coverage stands in stark contrast to our success in delivering other adolescent vaccines. To identify opportunities for improving physicians' recommendations for HPV vaccination, we sought to understand how the communication context surrounding adolescent vaccination varies by vaccine type.

METHODS

A national sample of 776 U.S. physicians (53% pediatricians, 47% family medicine physicians) completed our online survey in 2014. We assessed physicians' perceptions and communication practices related to recommending adolescent vaccines for 11- and 12-year-old patients.

RESULTS

About three-quarters of physicians (73%) reported recommending HPV vaccine as highly important for patients, ages 11-12. More physicians recommended tetanus, diphtheria, and acellular pertussis (Tdap) (95%) and meningococcal vaccines (87%, both p<0.001) as highly important for this age group. Only 13% of physicians perceived HPV vaccine as being highly important to parents, which was far fewer than perceived parental support for Tdap (74%) and meningococcal vaccines (62%, both p<0.001). Physicians reported that discussing HPV vaccine took almost twice as long as discussing Tdap. Among physicians with a preferred order for discussing adolescent vaccines, most (70%) discussed HPV vaccine last.

CONCLUSIONS

Our findings suggest that primary care physicians perceived HPV vaccine discussions to be burdensome, requiring more time and engendering less parental support than other adolescent vaccines. Perhaps for this reason, physicians in our national study recommended HPV vaccine less strongly than other adolescent vaccines, and often chose to discuss it last. Communication strategies are needed to support physicians in recommending HPV vaccine with greater confidence and efficiency.

'You're certainly relatively competent': assessor bias due to recent experiences

CONTEXT

A recent study has suggested that assessors judge performance comparatively rather than against fixed standards. Ratings assigned to borderline trainees were found to be biased by previously seen candidates' performances. We extended that programme of investigation by examining these effects across a range of performance levels. Furthermore, we investigated whether confidence in the rating assigned predicts susceptibility to manipulation and whether prompting consideration of typical performance lessens the influence of recent experience.

METHODS

Consultant doctors were randomised to groups within an internet experiment. The descending performance group judged videos of Foundation Year 1 (F1; postgraduate Year 1) doctors in descending order of proficiency; the ascending performance group judged the same videos in ascending order. For all videos, participants rated: (i) trainee competence; (ii) rater confidence and (iii) percentage better (the percentage of other F1 doctors who would perform better on the same task).

RESULTS

Overall, the descending performance group assigned lower scores than the ascending performance group (2.97 [95% confidence interval 2.73-3.20] versus 3.50 [95% confidence interval 3.25-3.74]; F(1,47) = 9.80, p = 0.003, d = 0.52). Pairwise comparisons showed differences were significant for good and borderline performances. The percentage better ratings showed a similar pattern (descending performance mean = 57.4 [95% confidence interval 52.5-62.3], ascending performance mean = 43.4 [95% confidence interval 38.4-48.5]; F(1, 46) = 16.0, p < 0.001, d = 0.67). Confidence ratings did not vary by level of performance and showed no relationship with the effect of group.

DISCUSSION

Assessors' judgements showed contrast effects at both good and borderline performance levels. Findings suggest that assessors use normative rather than criterion-referenced decision making while judging, and that the norms referenced are weakly represented in memory and easily influenced. Confidence ratings suggested a lack of insight into this phenomenon. Raters' judgements could be importantly influenced in ways that are unfair to candidates.

Associations between risk perceptions and worry about common diseases: a between- and within-subjects examination

The relationships between worry and perceptions of likelihood and severity were evaluated across eight common diseases. Individual and disease variability in worry and perceptions were examined. 294 participants were recruited through the Multiplex Initiative, in which a genetic susceptibility test for eight common diseases was offered to healthy adults. Participants completed a baseline telephone survey and web-based surveys without a commitment to be tested, and then made a choice on testing. Between- and within-subjects analyses yielded the following main findings: (1) worry is more closely related to likelihood perceptions than to severity perceptions; (2) severity perceptions add significantly to explained worry variances above and beyond likelihood perceptions; (3) risk perceptions and worries form two clusters: cancer diseases and cardiovascular-metabolic diseases; and (4) variance in risk perception and worry is explained by a combination of between- and within-subjects variances. Risk perception research should attend to severity perceptions, within-subjects variability and inter-disease differences, and to strategies for grouping conditions.