Table 3.
Key findings of the impact of amyloid disclosure on patient outcomes
| Outcome | Measure | Author (year) | Level of Cognitive Impairment | Study design | Timing of outcome | Analysis | Key Findings |
|---|---|---|---|---|---|---|---|
| Depression | Patient health questionnaire (PHQ-4) | Mattos (2019) | MCI | RCT | Each day, for 14 days after amyloid PET scan disclosure | Random coefficient modelling | No significant difference in depressive symptoms by scan result. Those with positive scans showed greater daily variability in depressive symptoms over the follow-up period compared to those with negative scans |
| Center for Epidemiological Studies Depression Scale (CESD) | Lingler (2020) | MCI | RCT | Before and 4, 24, and 52 weeks post-disclosure | Intention to treat using linear mixed modelling | No significant difference in depressive symptoms between those who received and amyloid scan and those who received psychoeducation | |
| Taswell (2017) | MCI & ADRD | Pre/Post | Before the scan and approximately 57 days after the scan | Paired-samples t-test | No significant difference before and after scan. No significant difference between amyloid positive and amyloid negative groups. No significant differences between participants with MCI and participants with ADRD. | ||
| Depression subscale of depression anxiety and stress scale (DASS) | Lim (2016) | SCD | Pre/Post | Before disclosure and 9 or 18 months post scan | Not reported | Amyloid positive participants showed little change in DASS scores | |
| Beck Depression Inventory (BDI-II) | Wake (2018) | SCD | Pre/Post | Before disclosure and 6 week follow-up | ANOVA | Depression scores did not change over time, nor were there any differences in depressive symptoms between amyloid positive and amyloid negative groups | |
| Geriatric Depression Scale (GDS) | Taswell (2017) | MCI & ADRD | Pre/Post | Before the scan and approximately 57 days after the scan | Paired-samples t-test | No significant difference before and after scan. No significant difference between amyloid positive and amyloid negative groups. No significant differences between participants with MCI and participants with ADRD. | |
| Hospital Anxiety and Depression Scales (HADS-D) | Taswell (2017) | MCI & ADRD | Pre/Post | Before the scan and approximately 57 days after the scan | Paired-samples t-test | No significant difference before and after scan. No significant difference between amyloid positive and amyloid negative groups. No significant differences between participants with MCI and participants with ADRD. | |
| Anxiety | Spielberger State Anxiety Inventory (STAI) | Lingler (2020) | MCI | RCT | Before and 4, 24, and 52 weeks post-disclosure | Intention to treat using linear mixed modelling | All participant’s symptoms of anxiety remained stable over the entire follow-up period |
| Wake (2018) | SCD | Pre/Post | Before disclosure and 6 week follow-up | ANOVA | Anxiety scores did not change over time, nor were there any differences in anxiety scores between amyloid positive and amyloid negative groups | ||
| Taswell (2017) | MCI & ADRD | Pre/Post | Before the scan and approximately 57 days after the scan | Paired-samples t-test | No significant difference before and after scan. No significant difference between amyloid positive and amyloid negative groups. No significant differences between participants with MCI and participants with ADRD. | ||
| Anxiety subscale of patient health questionnaire (PHQ-4) | Mattos (2019) | MCI | RCT | Each day, for 14 days after amyloid PET scan disclosure | Random coefficient modelling | No significant difference in anxious symptoms by scan result. Those with positive scans showed greater daily variability in anxious symptoms over the follow-up period compared to those with negative scans | |
| Hospital Anxiety and Depression Scales (HADS-A) | Taswell (2017) | MCI & ADRD | Pre/Post | Before the scan and approximately 57 days after the scan | Paired-samples t-test | No significant difference before and after scan. No significant difference between amyloid positive and amyloid negative groups. No significant differences between participants with MCI and participants with ADRD. | |
| Test related distress | Impact of Event Scale (IES) | Lingler (2020) | MCI | RCT | 4, 24, and 52 weeks post-disclosure | Intention to treat using linear mixed modelling | Amyloid positive participants scored higher on the IES compared to amyloid negative. Although IES scores declined for amyloid positive patients over the study period, scores remained greater than for amyloid negative participants |
| Lim (2016) | SCD | Pre/Post | 9 or 18 months post scan | Not reported | Learning the PET scan results had low impact on participants IES scores | ||
| Wake (2018) | SCD | Pre/Post | At 6 week follow-up | ANOVA | IES scores were below the cut off for determining high levels of distress. There were no significant differences between IES scores between amyloid positive and amyloid negative participants | ||
| Distress and Positive Impact subscales of the Impact of Genetic Testing-Alzheimer’s Disease (IGT-AD) | Lingler (2020) | MCI | RCT | 4, 24, and 52 weeks post-disclosure | Intention to treat using linear mixed modelling | Amyloid Positive participants scored higher on the IGT-AD than amyloid positive patients 4 weeks after disclosure and remained stable over time. However, scores for amyloid negative gradually increased at each follow-up time point. | |
| Quality of Life | Quality of Life- Alzheimer’s Disease (QOL-AD) | van der Doelen (2022) | ADRD | Pre/Post | Before disclosure and at 3 month follow-up | Multivariate regression models | Change in diagnosis was associated with quality of life, when adjusting for other variables |
| EuroQoL EQ-5D | van der Doelen (2022) | ADRD | Pre/Post | Before disclosure and at 3 month follow-up | Multivariate regression models | Change in clinician confidence in diagnosis was associated with a small change in quality of life, when adjusting for other variables | |
| Self efficacy for coping | Self efficacy for coping scale (CSE) | Lingler (2020) | MCI | RCT | Before and 4, 24, and 52 weeks post-disclosure | Intention to treat using linear mixed modelling | There were no significant differences in self efficacy between participants who received an amyloid scan and those who received psychoeducation. There was no significant difference in scores over time |
| Understanding of scan result or diagnosis | Accurate reporting of scan result | James (2020) | MCI & ADRD | Cross-sectional | Approximately 4.5 months following disclosure | Chi-squared test | 83% of participants correctly reported the result of the amyloid PET scan. Participants with dementia were more likely to correctly recall the scan result than participants with MCI. |
| MCI/AD Knowledge Assessment | Lingler (2020) | MCI | RCT | Before and 4, 24, and 52 weeks post-disclosure | Intention to treat using linear mixed modelling | No significant difference in knowledge scores between time points or between those who received an amyloid PET scan and those who received psychoeducation. | |
| Illness coherences subscale of the revised illness perception questionnaire (IPQ-R) | Lingler (2020) | MCI | RCT | Before and 4, 24, and 52 weeks post-disclosure | Intention to treat using linear mixed modelling | No significant difference in understanding of MCI between amyloid PET scan and psychoeducational group. However, sub-group analyses showed increased perceived ambiguity amongst amyloid positive participants compared with amyloid negative. | |
| Willingness to accept risky treatment | The following question: Suppose there is a new technology that can return your memory to normal but has a risk of death. What is the highest risk of death, if any, that you would be willing to accept for this treatment? The number you give can be anywhere between 0% and 100% | Jutkowitz (2020) | MCI & ADRD | Cross-sectional | Approximately 4.5 months following disclosure | Marginal effects estimated through logistic and linear regression models | Patients on average were willing to accept a treatment that carried a 27.94% risk of death. Receiving a positive scan result was associated with an increased risk taking willingness to accept risky treatments. Scan recipients with a positive result were willing to accept 5.62 percentage points of a risk of death than those with a negative scan result. |
Note: SCD = subjective cognitive decline; MCI = Mild cognitive Impairment; ADRD = Alzheimer’s disease and related dementias; RCT = randomized controlled trial; PET = Positron Emission Tomography.