Compare Rates of Agreement Between Clinical Diagnosis and Visual Assessment of DaTscan™ Images in Non-Caucasian and Caucasian Subjects With Parkinson's Disease (PD) or Essential Tremor (ET)

Study Overview
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Brief Summary
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The primary objective of this study is to determine if the diagnostic performance of DaTscan™ single photon emission computed tomography (SPECT) imaging is different in non-Caucasian subjects compared with Caucasian subjects with movement disorders.

Official Title
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A Retrospective Clinical Study to Compare the Rates of Agreement Between Clinical Diagnosis and Visual Assessment of DaTscan™ Images in Non-Caucasian and Caucasian Subjects With Parkinson's Disease (PD) or Essential Tremor (ET)

Conditions
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Essential Tremor, Parkinson's Disease

Intervention / Treatment
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* Other: DaTscan™ - Non-Caucasian Participants
* Other: DaTscan™ - Caucasian Participants


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For Non-Caucasians: Non-Caucasian male and female adult participants (greater than or equal to 18 years of age) with an initial diagnosis of suspected PD or ET who underwent DaTscan SPECT imaging to assist with the participant's final clinical diagnosis of PD or ET. The participant had existing diagnostic-quality and interpretable DaTscan SPECT images of the brain. For Caucasians: Caucasian male and female adult participants (greater than or equal to 18 years of age) with an initial diagnosis of suspected PD or ET who underwent DaTscan SPECT imaging to assist with the participant's final clinical diagnosis of PD or ET. The participant had existing diagnostic-quality and interpretable DaTscan SPECT images of the brain. The participant was matched by final clinical diagnosis, sex and age (±5 years) with a non-Caucasian participant. Exclusion Criteria: Known/suspected structural abnormalities of the brain (e.g., hydrocephalus; brain tumor; stroke; etc.) that could grossly distort the DaTscan images. Participants whose race and ethnic information could not be determined from source document review.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| DaTscan™ - Non-Caucasian Participants<br>Non-Caucasian participants previously administered DaTscan™, with an initial diagnosis of suspected PD or ET who underwent DaTscan SPECT imaging to assist with the participant's final clinical diagnosis of PD or ET. | Other: DaTscan™ - Non-Caucasian Participants<br>* Participants who previously administered DaTscan™ and had undergone SPECT imaging of the brain per local practice at each institution.<br>|
| DaTscan™- Caucasian Participants<br>Caucasian participants previously administered DaTscan™, with an initial diagnosis of suspected PD or ET who underwent DaTscan SPECT imaging to assist with the participant's final clinical diagnosis of PD or ET. | Other: DaTscan™ - Caucasian Participants<br>* Participants who previously administered DaTscan™ and had undergone SPECT imaging of the brain per local practice at each institution.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Positive Percent Agreement of Blinded Visual Assessment of Each Participant's DaTscan Image - Intent-to-diagnose (ITD) Population | The majority blinded visual interpretation of each participant's image (3 blinded readers) was compared to his/her final clinical diagnosis, and the image interpretation was classified as true positive, false positive, true negative, or false negative. The counts of each classification type were used to determine the positive percent agreement (PPA, analogous to sensitivity) of the blinded visual image interpretations. The majority assessment was based on ≥ 2 of the 3 readers in agreement on the assessment. | Day 1 | 
| Positive Percent Agreement of Blinded Visual Assessment of Each Participant's DaTscan Image - Per Protocol (PP) Population | The majority blinded visual interpretation of each participant's image (3 blinded readers) was compared to his/her final clinical diagnosis, and the image interpretation was classified as true positive, false positive, true negative, or false negative. The counts of each classification type were used to determine the positive percent agreement (PPA, analogous to sensitivity) of the blinded visual image interpretations. The majority assessment was based on ≥ 2 of the 3 readers in agreement on the assessment. | Day 1 | 
| Negative Percent Agreement of Blinded Visual Assessment of Each Participant's DaTscan Image - Intent-to-diagnose (ITD) Population | The majority blinded visual interpretation of each participant's image (3 blinded readers) was compared to his/her final clinical diagnosis, and the image interpretation was classified as true positive, false positive, true negative, or false negative. The counts of each classification type were used to determine the negative percent agreement (NPA, analogous to specificity) of the blinded visual image interpretations. The majority assessment was based on ≥ 2 of the 3 readers in agreement on the assessment. | Day 1 | 
| Negative Percent Agreement of Blinded Visual Assessment of Each Participant's DaTscan Image - Per Protocol (PP) Population | The majority blinded visual interpretation of each participant's image (3 blinded readers) was compared to his/her final clinical diagnosis, and the image interpretation was classified as true positive, false positive, true negative, or false negative. The counts of each classification type were used to determine the negative percent agreement (NPA, analogous to specificity) of the blinded visual image interpretations. The majority assessment was based on ≥ 2 of the 3 readers in agreement on the assessment. | Day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall Percent Agreement of Blinded Visual Assessment of Each Participant's DaTscan Image - Intent-to-diagnose (ITD) Population | Overall percent agreement (OPA) regardless of image interpretation (analogous to accuracy; ratio of number of true results / number of all participants) for each racial group, was tested to determine if it was greater than 80% in both racial groups. The majority assessment was based on ≥2 of the 3 readers in agreement on the assessment. | Day 1 | 
| Overall Percent Agreement of Blinded Visual Assessment of Each Participant's DaTscan Image - Per Protocol (PP) Population | Overall percent agreement (OPA) regardless of image interpretation (analogous to accuracy; ratio of number of true results / number of all participants) for each racial group, was tested to determine if it was greater than 80% in both racial groups. The majority assessment was based on ≥2 of the 3 readers in agreement on the assessment. | Day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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DaTscan, Parkinson's Disease