Trial Outcomes & Findings for A Reader Study to Assess Accuracy and Reliability of Flortaucipir F 18 Positron Emission Tomography (PET) Scan Interpretation (NCT NCT03901092)

Last Updated: 2020-09-09

Results Overview

Sensitivity and specificity of 5 independent readers' interpretations of ante-mortem 18F-AV-1451 PET imaging for detection of a pattern of 18F-AV-1451 neocortical uptake that corresponds to neurofibrillary tangles (NFT) Score of B3 (Hyman et al., 2012; Montine et al., 2012). NFT B scores range from B0 (no NFTs in the brain) to B3 (widespread NFTs in the brain). Sensitivity and specificity are percentages that can range from 0 to 100%. The hypothesis tested was that, of the 5 independent imaging physicians, at least 3 will have the lower bounds of 2-sided 95% CIs ≥50%, for both sensitivity and specificity.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

242 participants

Primary outcome timeframe

baseline scan

Results posted on

2020-09-09

Participant Flow

Subjects were not recruited for this study. Study scans were selected from 2 previously completed imaging studies. Scans previously acquired from Study A16 (NCT02516046) and A05 (NCT02016560) were read by 5 independent, blinded to other study information.

Participant milestones

Participant milestones
Measure	All Autopsy Cases Cases that had a valid scan and came to autopsy in in study A16 and the A16 supplemental cohort	Non-Autopsy Cases Mild cognitive impairment (MCI) and AD cases from the A05 confirmatory cohort
Overall Study STARTED	83	159
Overall Study COMPLETED	83	159
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	All Cases n=242 Participants All eligible subject scans from contributing studies
Age, Continuous Study A16 Autopsy Cases	81.6 years STANDARD_DEVIATION 9.91 • n=83 Participants • Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Age, Continuous Study A05 Non-autopsy Cases	72.9 years STANDARD_DEVIATION 9.64 • n=159 Participants • Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Sex: Female, Male Study A16 Autopsy Cases · Female	41 Participants n=83 Participants • Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Sex: Female, Male Study A16 Autopsy Cases · Male	42 Participants n=83 Participants • Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Sex: Female, Male Study A05 Non-autopsy Cases · Female	74 Participants n=159 Participants • Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Sex: Female, Male Study A05 Non-autopsy Cases · Male	85 Participants n=159 Participants • Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Ethnicity (NIH/OMB) Study A16 Autopsy Cases · Hispanic or Latino	4 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Ethnicity (NIH/OMB) Study A16 Autopsy Cases · Not Hispanic or Latino	79 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Ethnicity (NIH/OMB) Study A16 Autopsy Cases · Unknown or Not Reported	0 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Ethnicity (NIH/OMB) Study A05 Non-autopsy Cases · Hispanic or Latino	9 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Ethnicity (NIH/OMB) Study A05 Non-autopsy Cases · Not Hispanic or Latino	150 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Ethnicity (NIH/OMB) Study A05 Non-autopsy Cases · Unknown or Not Reported	0 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A16 Autopsy Cases · American Indian or Alaska Native	0 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A16 Autopsy Cases · Asian	1 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A16 Autopsy Cases · Native Hawaiian or Other Pacific Islander	0 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A16 Autopsy Cases · Black or African American	1 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A16 Autopsy Cases · White	81 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A16 Autopsy Cases · More than one race	0 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A16 Autopsy Cases · Unknown or Not Reported	0 Participants n=83 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A05 Non-autopsy Cases · American Indian or Alaska Native	0 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A05 Non-autopsy Cases · Asian	2 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A05 Non-autopsy Cases · Native Hawaiian or Other Pacific Islander	0 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A05 Non-autopsy Cases · Black or African American	3 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A05 Non-autopsy Cases · White	154 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A05 Non-autopsy Cases · More than one race	0 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).
Race (NIH/OMB) Study A05 Non-autopsy Cases · Unknown or Not Reported	0 Participants n=159 Participants • Measure Analysis Population Description: Baseline analysis includes Study A16 autopsy cases (n=83) and Study A05 Non-autopsy cases (n=159).

PRIMARY outcome

Timeframe: baseline scan

Population: Analysis included all autopsy subjects with an evaluable flortaucipir PET scan interpretation (n=82). One autopsy subject scan was rated as unevaluable. n=47 were truth positive for NFTs. n=35 were truth negative for NFTs.

Outcome measures

Outcome measures
Measure	Sensitivity of Flortaucipir vs Autopsy NFT Score n=47 Participants Subjects with a positive autopsy NFT score truth standard (NFT B3)	Specificity of Flortaucipir vs Autopsy NFT Score n=35 Participants Subjects with a negative autopsy NFT score truth standard (NFT B2 or lower)
Primary Objective 1 Analysis 1: Diagnostic Performance of Individual Readers (NFT Score) Reader 1	91.5 percentage of cases correctly identified Interval 80.07 to 96.64	77.1 percentage of cases correctly identified Interval 60.98 to 87.93
Primary Objective 1 Analysis 1: Diagnostic Performance of Individual Readers (NFT Score) Reader 2	89.4 percentage of cases correctly identified Interval 77.41 to 95.37	91.4 percentage of cases correctly identified Interval 77.62 to 97.04
Primary Objective 1 Analysis 1: Diagnostic Performance of Individual Readers (NFT Score) Reader 3	87.2 percentage of cases correctly identified Interval 74.83 to 94.02	85.7 percentage of cases correctly identified Interval 70.62 to 93.74
Primary Objective 1 Analysis 1: Diagnostic Performance of Individual Readers (NFT Score) Reader 4	93.6 percentage of cases correctly identified Interval 82.84 to 97.81	62.9 percentage of cases correctly identified Interval 46.34 to 76.83
Primary Objective 1 Analysis 1: Diagnostic Performance of Individual Readers (NFT Score) Reader 5	89.4 percentage of cases correctly identified Interval 77.41 to 95.37	77.1 percentage of cases correctly identified Interval 60.98 to 87.93

PRIMARY outcome

Timeframe: baseline scan

Population: Analysis included all autopsy subjects with an evaluable flortaucipir PET scan interpretation (n=82). One autopsy subject scan was rated as unevaluable. n=41 were truth positive. n=41 were truth negative.

Sensitivity and specificity of 5 independent readers' interpretations of ante-mortem 18F-AV-1451 PET imaging for detection of a pattern of 18F-AV-1451 neocortical uptake that corresponds to high levels of AD neuropathologic change (High ADNC) as defined by National Institute on Aging-Alzheimer's Association (NIA-AA) criteria (see Hyman et al. 2012). ADNC categories are None, Low, Intermediate and High, with High indicating the most severe level of AD-related pathology changes in the brain. The hypothesis tested was that, of the 5 independent imaging physicians, at least 3 will have the lower bounds of 2-sided 95% CIs ≥50%, for both sensitivity and specificity.

Outcome measures

Outcome measures
Measure	Sensitivity of Flortaucipir vs Autopsy NFT Score n=41 Participants Subjects with a positive autopsy NFT score truth standard (NFT B3)	Specificity of Flortaucipir vs Autopsy NFT Score n=41 Participants Subjects with a negative autopsy NFT score truth standard (NFT B2 or lower)
Primary Objective 1 Analysis 2: Diagnostic Performance of Individual Readers (NIA-AA Autopsy Diagnosis) Reader 5	95.1 percentage of cases correctly identified Interval 83.86 to 98.65	73.2 percentage of cases correctly identified Interval 58.07 to 84.31
Primary Objective 1 Analysis 2: Diagnostic Performance of Individual Readers (NIA-AA Autopsy Diagnosis) Reader 1	95.1 percentage of cases correctly identified Interval 83.86 to 98.65	70.7 percentage of cases correctly identified Interval 55.52 to 82.39
Primary Objective 1 Analysis 2: Diagnostic Performance of Individual Readers (NIA-AA Autopsy Diagnosis) Reader 2	95.1 percentage of cases correctly identified Interval 83.86 to 98.65	85.4 percentage of cases correctly identified Interval 71.56 to 93.12
Primary Objective 1 Analysis 2: Diagnostic Performance of Individual Readers (NIA-AA Autopsy Diagnosis) Reader 3	95.1 percentage of cases correctly identified Interval 83.86 to 98.65	82.9 percentage of cases correctly identified Interval 68.74 to 91.47
Primary Objective 1 Analysis 2: Diagnostic Performance of Individual Readers (NIA-AA Autopsy Diagnosis) Reader 4	97.6 percentage of cases correctly identified Interval 87.4 to 99.57	58.5 percentage of cases correctly identified Interval 43.37 to 72.24

PRIMARY outcome

Timeframe: baseline scan

Population: Analysis included all subjects who had a valid flortaucipir PET scan in the autopsy and non-autopsy groups (n=241)

As measured by Fleiss' Kappa across all scans read. Fleiss' kappa is a statistical measure for assessing the reliability of agreement between a fixed number of raters when assigning categorical ratings to a number of items or classifying items. Fleiss' kappa can range from 0 to 1 with 1 indicating perfect agreement between the readers. Scan results binarized as positive AD pattern versus negative AD pattern. Results are displayed as percentage of agreement for individual reader pairs, computed as follows: number of images for which reader had the same interpretation divided by the total number of images evaluated, multiplied by 100%.

Outcome measures

Outcome measures
Measure	Sensitivity of Flortaucipir vs Autopsy NFT Score n=241 Participants Subjects with a positive autopsy NFT score truth standard (NFT B3)	Specificity of Flortaucipir vs Autopsy NFT Score Subjects with a negative autopsy NFT score truth standard (NFT B2 or lower)
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 1 v Reader 2	95.0 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 1 v Reader 3	93.4 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 1 v Reader 4	94.6 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 1 v Reader 5	97.1 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 2 v Reader 3	97.1 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 2 v Reader 4	91.3 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 2 v Reader 5	94.6 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 3 v Reader 4	91.3 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 3 v Reader 5	93.8 percentage agreement of cases	—
Primary Objective 2: Inter-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 4 v Reader 5	95.0 percentage agreement of cases	—

SECONDARY outcome

Timeframe: baseline scan

Flortaucipir F 18 PET imaging will be classified by each reader as either neocortical uptake not consistent with AD (τAD-), neocortical uptake consistent with AD (τAD+), or neocortical uptake consistent with AD with uptake beyond the temporal/occipital regions (τAD++). NFT scoring is according to Hyman, et al 2012. Truth positive is a NFT B3 score. Truth negative is NFT \<B3 score.

Outcome measures

Outcome measures
Measure	Sensitivity of Flortaucipir vs Autopsy NFT Score n=47 Participants Subjects with a positive autopsy NFT score truth standard (NFT B3)	Specificity of Flortaucipir vs Autopsy NFT Score n=35 Participants Subjects with a negative autopsy NFT score truth standard (NFT B2 or lower)
Secondary Objective 1 Analysis 1: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect B3 NFTs Reader 1	87.2 percentage cases correctly identified Interval 74.83 to 94.02	88.6 percentage cases correctly identified Interval 74.05 to 95.46
Secondary Objective 1 Analysis 1: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect B3 NFTs Reader 2	80.9 percentage cases correctly identified Interval 67.46 to 89.58	100.0 percentage cases correctly identified Interval 90.11 to 100.0
Secondary Objective 1 Analysis 1: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect B3 NFTs Reader 3	76.6 percentage cases correctly identified Interval 62.78 to 86.4	94.3 percentage cases correctly identified Interval 81.39 to 98.42
Secondary Objective 1 Analysis 1: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect B3 NFTs Reader 4	89.4 percentage cases correctly identified Interval 77.41 to 95.37	82.9 percentage cases correctly identified Interval 67.32 to 91.9
Secondary Objective 1 Analysis 1: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect B3 NFTs Reader 5	83.0 percentage cases correctly identified Interval 69.86 to 91.11	94.3 percentage cases correctly identified Interval 81.39 to 98.42

SECONDARY outcome

Timeframe: baseline scan

Outcome measures

Outcome measures
Measure	Sensitivity of Flortaucipir vs Autopsy NFT Score n=41 Participants Subjects with a positive autopsy NFT score truth standard (NFT B3)	Specificity of Flortaucipir vs Autopsy NFT Score n=41 Participants Subjects with a negative autopsy NFT score truth standard (NFT B2 or lower)
Secondary Objective 1 Analysis 2: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect High ADNC Reader 1	92.7 percentage of cases correctly identified Interval 80.57 to 97.48	82.9 percentage of cases correctly identified Interval 68.74 to 91.47
Secondary Objective 1 Analysis 2: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect High ADNC Reader 2	85.4 percentage of cases correctly identified Interval 71.56 to 93.12	92.7 percentage of cases correctly identified Interval 80.57 to 97.48
Secondary Objective 1 Analysis 2: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect High ADNC Reader 3	85.4 percentage of cases correctly identified Interval 71.56 to 93.12	92.7 percentage of cases correctly identified Interval 80.57 to 97.48
Secondary Objective 1 Analysis 2: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect High ADNC Reader 4	92.7 percentage of cases correctly identified Interval 80.57 to 97.48	75.6 percentage of cases correctly identified Interval 60.66 to 86.17
Secondary Objective 1 Analysis 2: Diagnostic Performance of τAD++ Flortaucipir PET Images to Detect High ADNC Reader 5	87.8 percentage of cases correctly identified Interval 74.46 to 94.68	87.8 percentage of cases correctly identified Interval 74.46 to 94.68

SECONDARY outcome

Timeframe: baseline scan

Population: Analysis included all subjects who had a valid flortaucipir PET scan in the autopsy and non-autopsy groups (n=241)

Overall reader agreement as measured by Fleiss' Kappa statistic. Scan results binarized as τAD++ versus τAD+/τAD-. Results are displayed as percentage of agreement for individual reader pairs, computed as follows: number of images for which reader had the same interpretation divided by the total number of images evaluated, multiplied by 100%.

Outcome measures

Outcome measures
Measure	Sensitivity of Flortaucipir vs Autopsy NFT Score n=241 Participants Subjects with a positive autopsy NFT score truth standard (NFT B3)	Specificity of Flortaucipir vs Autopsy NFT Score Subjects with a negative autopsy NFT score truth standard (NFT B2 or lower)
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 1 v Reader 2	92.5 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 1 v Reader 3	90.0 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 1 v Reader 4	91.3 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 1 v Reader 5	95.0 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 2 v Reader 3	91.7 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 2 v Reader 4	90.5 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 2 v Reader 5	94.2 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 3 v Reader 4	88.8 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 3 v Reader 5	92.5 percentage agreement of cases	—
Secondary Objective 2: Inter-reader Reliability of Reader Interpretation of τAD++ Flortaucipir PET Images Reader 4 v Reader 5	92.9 percentage agreement of cases	—

SECONDARY outcome

Timeframe: baseline scan

Population: Non-autopsy cases from Study A05

Reader agreement measured by Fleiss' Kappa across scans from non-autopsy cases from Study A05. Scan results binarized as positive for AD pattern versus negative for AD pattern. Results are displayed as percentage of agreement for individual reader pairs, computed as follows: number of images for which reader had the same interpretation divided by the total number of images evaluated, multiplied by 100%.

Outcome measures

Outcome measures
Measure	Sensitivity of Flortaucipir vs Autopsy NFT Score n=159 Participants Subjects with a positive autopsy NFT score truth standard (NFT B3)	Specificity of Flortaucipir vs Autopsy NFT Score Subjects with a negative autopsy NFT score truth standard (NFT B2 or lower)
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 1 v Reader 2	97.5 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 1 v Reader 3	93.1 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 1 v Reader 4	95.6 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 1 v Reader 5	97.5 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 2 v Reader 3	93.1 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 2 v Reader 4	94.3 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 2 v Reader 5	96.2 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 3 v Reader 4	93.7 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 3 v Reader 5	93.1 percentage agreement of cases	—
Secondary Objective 3: Inter-reader Reliability of Flortaucipir PET Scan Interpretation in the Population of Intended Use Reader 4 v Reader 5	96.9 percentage agreement of cases	—

SECONDARY outcome

Timeframe: baseline scan

Population: 20 scans read twice to assess the intra-reader reliability

Cohen's Kappa will be calculated for each of 5 readers to assess the intra-reader reliability of flortaucipir F 18 PET scan visual interpretation. The statistic takes into account the possibility of the agreement occurring by chance. Cohen's kappa values range from 0 to 1 with 1 representing perfect agreement. Results are displayed as percentage of agreement within a reader, computed as follows: number of images for which reader had the same interpretation at initial and second read divided by the total number of images evaluated twice by a reader, multiplied by 100%.

Outcome measures

Outcome measures
Measure	Sensitivity of Flortaucipir vs Autopsy NFT Score n=20 Participants Subjects with a positive autopsy NFT score truth standard (NFT B3)	Specificity of Flortaucipir vs Autopsy NFT Score Subjects with a negative autopsy NFT score truth standard (NFT B2 or lower)
Secondary Objective 4: Intra-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 1	95.0 percentage agreement of cases	—
Secondary Objective 4: Intra-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 2	85.0 percentage agreement of cases	—
Secondary Objective 4: Intra-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 3	80.0 percentage agreement of cases	—
Secondary Objective 4: Intra-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 4	95.0 percentage agreement of cases	—
Secondary Objective 4: Intra-reader Reliability of Reader Interpretation of Flortaucipir-PET Imaging Reader 5	90.0 percentage agreement of cases	—

Adverse Events

All Cases

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Medical Director

Avid Radiopharmaceuticals, Inc.

Phone: 215-298-0700

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Restriction type: LTE60