Cognitive Change, Mild Cognitive Impairment
Conditions
Keywords
Behavioral intervention, Social engagement, Conversational engagement, Social network, Cognitive Reserve, Alzheimer's disease
Brief summary
Past epidemiological studies have demonstrated that larger social networks, or more frequent social interactions, could have potential protective effects on the incidence of Alzheimer's Disease (AD). However, in those studies, indicators of social interactions were often broad, and included distinct elements that affected cognition and overall health. This project will examine whether conversation-based cognitive stimulation has positive effects on domain-specific cognitive functions among the elderly. Face-to-face communication will be conducted through the use of personal computers, webcams, and user-friendly simple interactive Internet programs to allow participants to have social engagement while staying at their home and also for the cost effective execution of the study.
Detailed description
Participants are randomized into the control group (weekly 10 minutes phone check-in only) or experimental group (30 minutes daily video chat with standardized/trained conversational staff). User-friendly equipment and internet are provided.
Interventions
BEHAVIORALActive social engagement group
Engage in 30 minutes conversation daily using internet/webcam, 5 days per week for 6 weeks, tracking of daily conversational amount outside of the trial by using a digital recording device, lasting effects will be assessed at the 3rd and 6th month after completion of the intervention
BEHAVIORALControl group
No active intervention, weekly phone calls by interviewer to complete health/social engagement monitoring survey, tracking of daily conversational amount by using a digital recording device. Participants will be reassessed at the 3rd and 6th month after completion of the intervention.
Sponsors
National Institute on Aging (NIA)
Oregon Health and Science University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Masking description
Investigators and assessors are blind to the group assignment
Intervention model description
Experimental and control groups. The experimental group will have 30 minutes daily (5 times per week) video chat with standardized conversational staff for 6 weeks, while the control group will have phone check-in once per week for 10 minutes for increasing retention. Both groups will complete weekly web-based heath form using PC and internet.
Eligibility
Sex/Gender
ALL
Age
70 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Non-demented participants * Willing to participate in daily conversation using internet/webcam with interviewers for 6 weeks * Willing to monitor daily conversational amount using a digital recording device * Willing informant who has frequent contact with the participant
Exclusion criteria
* have major illness or disabilities which interfere with interacting using the audio/video technology * diagnosed as dementia * MMSE \< 24 at screening * Geriatric Depression Scale (15 items) \>4 at screening
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Global Cognitive Function Using Mini Mental State Examination Score (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | Mini Mental State Examination assess global cognitive function. Possible score ranges from 0 to 30. In this study, score ranges from 24 to 30 (those with MMSE \<24 at baseline were excluded according to the study exclusion criteria). Changes in test results among the experimental group are compared with changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) Higher values (post-pre) indicate that decline was less or test score improved more. |
| Changes in Category Fluency (Animals) Test Scores (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | Verbal fluency Animals test is a neuropsychological test. In the test, participants have to produce as many words as possible from a category of animals within 60 seconds. Total score ranges from 0 to 70. Changes in test results among the experimental group are compared with changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Higher values mean decline is less or score improve at post-study assessment. |
| Changes in Verbal Fluency Letter Test Scores (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | Verbal fluency letter test is a neuropsychological test. In the test, participants have to produce as many words as possible which start with a letter F, A and S (3 separate test for each letter) within 60 seconds. Each test score ranges from 0 to 40. Total of 3 tests scores (F, A and S) ranges from 0 to 120. Changes in test results among the experimental group are compared with changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) Higher values mean decline is less or test scores improved at post-study assessment. |
| Changes in the Consortium to Establish a Registry for Alzheimer's Disease Word List Immediate Recall (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | Consortium to Establish a Registry for Alzheimer's Disease Word List Immediate Recall (CERAD Word List Immediate Recall) total score counts number of words correctly recalled over 3 trials (with each trial having 10 words), and ranges from 0 to 30. Pre-post changes in test results among the experimental group were compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) |
| Changes in the Consortium to Establish a Registry for Alzheimer's Disease Word List Delayed Recall (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | Consortium to Establish a Registry for Alzheimer's Disease Word List Delayed Recall (CERAD Word List Delayed Recall) total score counts number of words correctly recalled in one trial (10 words) and it ranges from 0 to 10. Pre-post trial changes in test results among the experimental group was compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) |
| Changes in Trail Making Test A Scores (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | In Trail Making test A, the subject is instructed to connect a set of 25 dots as quickly as possible while still maintaining accuracy within 150 seconds. Time to complete is used here. Pre-post trial changes in test results among the experimental group are compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Larger changes mean subjects got slower to complete the test at the post-trial assessment. Negative changes indicates subjects completed the test faster at the post-trial assessment. |
| Changes in Trail Making Test B Scores (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | In Trail Making test B, the subject is instructed to connect a set of 25 dots as quickly as possible while still maintaining accuracy within 300 seconds. In Test B, the circles include both numbers (1 - 13) and letters (A - L). Time to complete is used here. Pre-post trial changes in test results among the experimental group are compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Larger changes mean subjects got slower to complete the test at the post-trial assessment. Negative changes indicates subjects completed the test faster at the post-trial assessment. |
| Changes in the Stroop Color and Word Test (Stroop Test C) Scores (Post-study Test Scores - Baseline Test Scores) | 6 weeks (primary endpoint) from baseline | In the Stroop test, subjects are required to read three different pages of stimuli in a designated time as quickly as possible. First, the individual is asked to name a series of colored squares (Color Naming task, Stroop Test A). Second, the individual is asked to read color words (Word Reading task, Stroop Test B). The final task is the Color-Word Naming task (Stroop Test C) on which the individual is shown the names of colors printed in conflicting ink colors (e.g., the word red in blue ink) and is asked to name the color of the ink rather than the word. Each test (A, B, C) is administered for 45 seconds. The number of words correctly named for the Stroop Test C was used here. The maximum score of this test is 100 (range: 0 - 100). The higher score indicates better functions. The changes (post-study - baseline test scores) among the experimental group are compared with those among the control group. The higher change scores mean improved function. |
| Changes in Cogstate Computerized Test: Detection Test (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | In detection test, the on-screen instructions ask: Has the card turned over?. A playing card is presented face down in the center of the screen. The card flips over so it is face up. As soon as the card flips over the participant must press Yes. The participant is encouraged to work as quickly as they can and be as accurate as possible.Speed of performance (mean of the log10 transformed reaction times for correct responses) is used here. Pre-post trial changes in test results among the experimental group were compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Larger changes mean subjects got slower in reaction at the post-trial assessment. Negative changes indicates subjects got faster in reaction at the post-trial assessment. |
| Changes in Cogstate One Back Accuracy (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | In this test, the on-screen instructions ask: Is the previous card the same?. A playing card is presented face up in the center of the screen. The participant must decide whether the card is the same as the previous card. If the card is the same the participant should press Yes, and if it is not the same the participant should press No. The participant is encouraged to work as quickly as they can and be as accurate as possible. Accuracy of performance (arcsine transformation of the square root of the proportion of correct responses) is reported here. Pre-post trial changes in test results among the experimental group will be compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Larger changes mean the score improved at the post trial assessment. |
| Changes in Cogstate Two Back Accuracy (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | In this test, the on-screen instructions ask: Is the card the same as that shown two cards ago?. A playing card is presented face up in the center of the screen. The participant must decide whether the card is the same as the card shown two cards previously. If the card is the same the participant should press Yes, and if it is not the same the participant should press No. The participant is encouraged to work as quickly as they can and be as accurate as possible. Accuracy of performance (arcsine transformation of the square root of the proportion of correct responses) is reported here. Pre-post trial changes in test results among the experimental group will be compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) |
| Changes in CAMCI Total Score (Post-study Test Score - Baseline Test Score) | 6 weeks (primary endpoint) from baseline | Computer Assessment of Mild Cognitive Assessment (CAMCI) is a battery of computerized tasks to assess cognitive performance, developed by the Psychology Software Tools. The software provides standardized score (z-score) based on subject's age, sex and education.\* The Z-score indicates the number of standard deviations away from the mean. A Z-score of 0 is equal to the mean. Higher Z-score means better cognitive function. A positive change in Z-scores here indicates a favorable outcome. Total score (global cognitive function measure) is used here. Pre-post trial changes in test results among the experimental group are compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) \*: Saxton J, Morrow L, Eschman A, Archer G, Luther J, Zuccolotto A. Computer assessment of mild cognitive impairment. Postgrad Med. 2009;121(2):177-85. |
Countries
United States
Participant flow
Recruitment details
From November 2011 to August 2012, we distributed 2000 surveys targeting those living in retirement communities and senior centers located in the Portland, metropolitan area, within an approximately 1-hour commute from Oregon Health & Science University (Portland, OR).
Participants by arm
| Arm | Count |
|---|---|
| Active Soocial Engagement Group Active Social Engagement: Engage in 30 minutes conversation daily with interviewers using internet/webcam for 6 weeks
Active social engagement group: Engage in 30 minutes conversation daily using internet/webcam, 5 days per week for 6 weeks, tracking of daily conversational amount outside of the trial by using a digital recording device, lasting effects will be assessed at the 3rd and 6th month after completion of the intervention | 41 |
| Control Group No daily conversational sessions with interviewers using webcam/internet. Weekly web-based heath form must be submitted using internet/PC. If not, subjects receive prompts from study personnel.
Control group: No active intervention, weekly phone calls by interviewer to complete health/social engagement monitoring survey, tracking of daily conversational amount by using a digital recording device | 42 |
| Total | 83 |
Baseline characteristics
| Characteristic | Active Soocial Engagement Group | Control Group | Total |
|---|---|---|---|
| Age, Continuous | 80.9 years STANDARD_DEVIATION 7.2 | 80.2 years STANDARD_DEVIATION 6.6 | 80.5 years STANDARD_DEVIATION 6.8 |
| Cognitive Status: Clinical Dementia Rating (CDR) Scale score of 0.5 (%) | 17 Participants | 17 Participants | 34 Participants |
| Education: High school completed or greater | 40 Participants | 40 Participants | 80 Participants |
| Experience using personal computer (PC) | 6 Participants | 6 Participants | 12 Participants |
| Global cognitive Status: Mini-Mental State Examination score | 28.2 units on a scale STANDARD_DEVIATION 1.7 | 28.3 units on a scale STANDARD_DEVIATION 1.8 | 28.3 units on a scale STANDARD_DEVIATION 1.8 |
| Levels of Education: The Wide Range Achievement Test--Revised (WRAT-R) | 72.0 units on a scale STANDARD_DEVIATION 12.9 | 72.0 units on a scale STANDARD_DEVIATION 11.5 | 72.0 units on a scale STANDARD_DEVIATION 12.1 |
| Marital Status: Married (%) | 18 Participants | 20 Participants | 38 Participants |
| Region of Enrollment United States | 41 participants | 42 participants | 83 participants |
| Sex: Female, Male Female | 32 Participants | 31 Participants | 63 Participants |
| Sex: Female, Male Male | 9 Participants | 11 Participants | 20 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 42 | 0 / 41 |
| other Total, other adverse events | 0 / 42 | 0 / 41 |
| serious Total, serious adverse events | 0 / 42 | 0 / 41 |
Outcome results
Primary
Changes in CAMCI Total Score (Post-study Test Score - Baseline Test Score)
Computer Assessment of Mild Cognitive Assessment (CAMCI) is a battery of computerized tasks to assess cognitive performance, developed by the Psychology Software Tools. The software provides standardized score (z-score) based on subject's age, sex and education.\* The Z-score indicates the number of standard deviations away from the mean. A Z-score of 0 is equal to the mean. Higher Z-score means better cognitive function. A positive change in Z-scores here indicates a favorable outcome. Total score (global cognitive function measure) is used here. Pre-post trial changes in test results among the experimental group are compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) \*: Saxton J, Morrow L, Eschman A, Archer G, Luther J, Zuccolotto A. Computer assessment of mild cognitive impairment. Postgrad Med. 2009;121(2):177-85.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in CAMCI Total Score (Post-study Test Score - Baseline Test Score) | 0.098 z-score (standardized score) | Standard Error 0.394 |
| Control Group | Changes in CAMCI Total Score (Post-study Test Score - Baseline Test Score) | 0.182 z-score (standardized score) | Standard Error 0.36 |
p-value: 0.3Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.75Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.12Regression, Linear
Primary
Changes in Category Fluency (Animals) Test Scores (Post-study Test Score - Baseline Test Score)
Verbal fluency Animals test is a neuropsychological test. In the test, participants have to produce as many words as possible from a category of animals within 60 seconds. Total score ranges from 0 to 70. Changes in test results among the experimental group are compared with changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Higher values mean decline is less or score improve at post-study assessment.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in Category Fluency (Animals) Test Scores (Post-study Test Score - Baseline Test Score) | 1.75 Number of words | Standard Deviation 4.21 |
| Control Group | Changes in Category Fluency (Animals) Test Scores (Post-study Test Score - Baseline Test Score) | -0.38 Number of words | Standard Deviation 4.08 |
p-value: 0.02Regression, Linear
Comparison: Analysis 2: AMONG CDR=0 group (N=49)p-value: 0.003Regression, Linear
Comparison: Analyses 3: CDR=0.5 (Mild Cognitive Impairment) group, N=34p-value: 0.65Regression, Linear
Primary
Changes in Cogstate Computerized Test: Detection Test (Post-study Test Score - Baseline Test Score)
In detection test, the on-screen instructions ask: Has the card turned over?. A playing card is presented face down in the center of the screen. The card flips over so it is face up. As soon as the card flips over the participant must press Yes. The participant is encouraged to work as quickly as they can and be as accurate as possible.Speed of performance (mean of the log10 transformed reaction times for correct responses) is used here. Pre-post trial changes in test results among the experimental group were compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Larger changes mean subjects got slower in reaction at the post-trial assessment. Negative changes indicates subjects got faster in reaction at the post-trial assessment.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in Cogstate Computerized Test: Detection Test (Post-study Test Score - Baseline Test Score) | 0.016 log 10 milliseconds | Standard Error 0.091 |
| Control Group | Changes in Cogstate Computerized Test: Detection Test (Post-study Test Score - Baseline Test Score) | 0.065 log 10 milliseconds | Standard Error 0.113 |
p-value: 0.03Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.24Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.04Regression, Linear
Primary
Changes in Cogstate One Back Accuracy (Post-study Test Score - Baseline Test Score)
In this test, the on-screen instructions ask: Is the previous card the same?. A playing card is presented face up in the center of the screen. The participant must decide whether the card is the same as the previous card. If the card is the same the participant should press Yes, and if it is not the same the participant should press No. The participant is encouraged to work as quickly as they can and be as accurate as possible. Accuracy of performance (arcsine transformation of the square root of the proportion of correct responses) is reported here. Pre-post trial changes in test results among the experimental group will be compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Larger changes mean the score improved at the post trial assessment.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in Cogstate One Back Accuracy (Post-study Test Score - Baseline Test Score) | 0.049 arcsine transformed values (see above) | Standard Error 0.246 |
| Control Group | Changes in Cogstate One Back Accuracy (Post-study Test Score - Baseline Test Score) | 0.062 arcsine transformed values (see above) | Standard Error 0.168 |
p-value: 0.65Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.64Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.42Regression, Linear
Primary
Changes in Cogstate Two Back Accuracy (Post-study Test Score - Baseline Test Score)
In this test, the on-screen instructions ask: Is the card the same as that shown two cards ago?. A playing card is presented face up in the center of the screen. The participant must decide whether the card is the same as the card shown two cards previously. If the card is the same the participant should press Yes, and if it is not the same the participant should press No. The participant is encouraged to work as quickly as they can and be as accurate as possible. Accuracy of performance (arcsine transformation of the square root of the proportion of correct responses) is reported here. Pre-post trial changes in test results among the experimental group will be compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM)
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in Cogstate Two Back Accuracy (Post-study Test Score - Baseline Test Score) | 0.020 arcsine transformed values (see above) | Standard Error 0.151 |
| Control Group | Changes in Cogstate Two Back Accuracy (Post-study Test Score - Baseline Test Score) | 0.048 arcsine transformed values (see above) | Standard Error 0.209 |
p-value: 0.45Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.93Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.4Regression, Linear
Primary
Changes in Global Cognitive Function Using Mini Mental State Examination Score (Post-study Test Score - Baseline Test Score)
Mini Mental State Examination assess global cognitive function. Possible score ranges from 0 to 30. In this study, score ranges from 24 to 30 (those with MMSE \<24 at baseline were excluded according to the study exclusion criteria). Changes in test results among the experimental group are compared with changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) Higher values (post-pre) indicate that decline was less or test score improved more.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in Global Cognitive Function Using Mini Mental State Examination Score (Post-study Test Score - Baseline Test Score) | -0.51 score on a scale | Standard Deviation 1.51 |
| Control Group | Changes in Global Cognitive Function Using Mini Mental State Examination Score (Post-study Test Score - Baseline Test Score) | -0.07 score on a scale | Standard Deviation 1.65 |
p-value: 0.25Regression, Linear
Comparison: Analysis 2: AMONG CDR=0 group (N=49)p-value: 0.25Regression, Linear
Comparison: Analyses 3: AMONG CDR=0.5 (Mild Cognitive Impairment) group, N=34 .p-value: 0.85Regression, Linear
Primary
Changes in the Consortium to Establish a Registry for Alzheimer's Disease Word List Delayed Recall (Post-study Test Score - Baseline Test Score)
Consortium to Establish a Registry for Alzheimer's Disease Word List Delayed Recall (CERAD Word List Delayed Recall) total score counts number of words correctly recalled in one trial (10 words) and it ranges from 0 to 10. Pre-post trial changes in test results among the experimental group was compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM)
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in the Consortium to Establish a Registry for Alzheimer's Disease Word List Delayed Recall (Post-study Test Score - Baseline Test Score) | -0.20 Number of words | Standard Deviation 1.72 |
| Control Group | Changes in the Consortium to Establish a Registry for Alzheimer's Disease Word List Delayed Recall (Post-study Test Score - Baseline Test Score) | -0.19 Number of words | Standard Deviation 2.12 |
p-value: 0.92Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.92Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.94Regression, Linear
Primary
Changes in the Consortium to Establish a Registry for Alzheimer's Disease Word List Immediate Recall (Post-study Test Score - Baseline Test Score)
Consortium to Establish a Registry for Alzheimer's Disease Word List Immediate Recall (CERAD Word List Immediate Recall) total score counts number of words correctly recalled over 3 trials (with each trial having 10 words), and ranges from 0 to 30. Pre-post changes in test results among the experimental group were compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM)
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in the Consortium to Establish a Registry for Alzheimer's Disease Word List Immediate Recall (Post-study Test Score - Baseline Test Score) | 0.30 Number of words | Standard Deviation 2.69 |
| Control Group | Changes in the Consortium to Establish a Registry for Alzheimer's Disease Word List Immediate Recall (Post-study Test Score - Baseline Test Score) | 0.53 Number of words | Standard Deviation 3.03 |
p-value: 0.68Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.69Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.86Regression, Linear
Primary
Changes in the Stroop Color and Word Test (Stroop Test C) Scores (Post-study Test Scores - Baseline Test Scores)
In the Stroop test, subjects are required to read three different pages of stimuli in a designated time as quickly as possible. First, the individual is asked to name a series of colored squares (Color Naming task, Stroop Test A). Second, the individual is asked to read color words (Word Reading task, Stroop Test B). The final task is the Color-Word Naming task (Stroop Test C) on which the individual is shown the names of colors printed in conflicting ink colors (e.g., the word red in blue ink) and is asked to name the color of the ink rather than the word. Each test (A, B, C) is administered for 45 seconds. The number of words correctly named for the Stroop Test C was used here. The maximum score of this test is 100 (range: 0 - 100). The higher score indicates better functions. The changes (post-study - baseline test scores) among the experimental group are compared with those among the control group. The higher change scores mean improved function.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in the Stroop Color and Word Test (Stroop Test C) Scores (Post-study Test Scores - Baseline Test Scores) | 0.34 Number of words correctly named | Standard Deviation 3.88 |
| Control Group | Changes in the Stroop Color and Word Test (Stroop Test C) Scores (Post-study Test Scores - Baseline Test Scores) | 1.14 Number of words correctly named | Standard Deviation 4.29 |
p-value: 0.38Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.39Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.59Regression, Linear
Primary
Changes in Trail Making Test A Scores (Post-study Test Score - Baseline Test Score)
In Trail Making test A, the subject is instructed to connect a set of 25 dots as quickly as possible while still maintaining accuracy within 150 seconds. Time to complete is used here. Pre-post trial changes in test results among the experimental group are compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Larger changes mean subjects got slower to complete the test at the post-trial assessment. Negative changes indicates subjects completed the test faster at the post-trial assessment.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in Trail Making Test A Scores (Post-study Test Score - Baseline Test Score) | -2.80 Seconds | Standard Deviation 15.25 |
| Control Group | Changes in Trail Making Test A Scores (Post-study Test Score - Baseline Test Score) | -0.85 Seconds | Standard Deviation 9.51 |
p-value: 0.46Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.61Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.8Regression, Linear
Primary
Changes in Trail Making Test B Scores (Post-study Test Score - Baseline Test Score)
In Trail Making test B, the subject is instructed to connect a set of 25 dots as quickly as possible while still maintaining accuracy within 300 seconds. In Test B, the circles include both numbers (1 - 13) and letters (A - L). Time to complete is used here. Pre-post trial changes in test results among the experimental group are compared with pre-post changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM). Larger changes mean subjects got slower to complete the test at the post-trial assessment. Negative changes indicates subjects completed the test faster at the post-trial assessment.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in Trail Making Test B Scores (Post-study Test Score - Baseline Test Score) | -10.18 Seconds | Standard Deviation 29.32 |
| Control Group | Changes in Trail Making Test B Scores (Post-study Test Score - Baseline Test Score) | -14.65 Seconds | Standard Deviation 46.85 |
p-value: 0.72Regression, Linear
Comparison: Analysis 2: CDR 0 (n=49)p-value: 0.84Regression, Linear
Comparison: Analysis 3: CDR 0.5 (n=34)p-value: 0.4Regression, Linear
Primary
Changes in Verbal Fluency Letter Test Scores (Post-study Test Score - Baseline Test Score)
Verbal fluency letter test is a neuropsychological test. In the test, participants have to produce as many words as possible which start with a letter F, A and S (3 separate test for each letter) within 60 seconds. Each test score ranges from 0 to 40. Total of 3 tests scores (F, A and S) ranges from 0 to 120. Changes in test results among the experimental group are compared with changes among the control group using linear regression models. (no drop out reported and therefore no need to use mixed effects models or MMRM) Higher values mean decline is less or test scores improved at post-study assessment.
Time frame: 6 weeks (primary endpoint) from baseline
Population: Sampling frame consists of retirement communities and Layton Aging Alzheimer's Disease research center volunteer lists. The survey asking whether they would like to participate in the study was distributed among 2000 subjects.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Active Social Engagement Group | Changes in Verbal Fluency Letter Test Scores (Post-study Test Score - Baseline Test Score) | 1.14 Number of words | Standard Deviation 6.45 |
| Control Group | Changes in Verbal Fluency Letter Test Scores (Post-study Test Score - Baseline Test Score) | 1.26 Number of words | Standard Deviation 5.59 |
p-value: 0.98Regression, Linear
Comparison: Analysis 2: Among CDR 0 (n=49)p-value: 0.96Regression, Linear
Comparison: Analysis 3: Among CDR 0.5 (n=34)p-value: 0.83Regression, Linear