Videoconferencing for Preclinical Alzheimer Cognitive Composite Score is Accurate, Accessible

February 4, 2021
Victoria Johnson
Victoria Johnson

Victoria Johnson, Assistant Editor for NeurologyLive, joined the MJH Life Sciences team in October 2020. Follow her on Twitter @_vic_j or email her at

Researchers found that time between assessments was the only predictor of PACC score differences.

A recent study has found that Preclinical Alzheimer Cognitive Composite (PACC) scores assessed over videoconferencing were accurate and strongly correlated with PACC scores traditionally assessed in person.

The PACC scores assessed over videoconferencing were strongly correlated with PACC scores assessed in person, with a Pearson correlation coefficient of 0.82 (95%CI, 0.66-0.98). Multiple linear regression revealed time between assessments predicted a decrease in PACC difference by −0.004 points (β = −0.004; 95% CI, –0.007 to −0.00008) with increasing time between assessments (in days), signifying that each additional day between assessments increased differences in PACC score by 0.004.

Senior author Valentina Gallo, MBBS, senior lecturer in epidemiology, Queen Mary University of London, and colleagues wrote that “the PACC is designed to be administered in person, by a trained research psychologist or nurse. However, in epidemiological studies, in-person assessments are costly, often require extensive traveling, and are difficult in the current pandemic situation. Assessing cognitive function in older adults may be possible via videoconferencing, but there have been calls for further validation studies.”

Gallo and colleagues re-assessed 28 participants via videoconferencing from the ongoing HEalth and Ageing Data IN the Game of football (HEADING) study that aims to assess the relationship between concussions and repetitive sub-concussive head injuries in retired football players, and cognitive function as measured with the PACC score. The participants were a median age of 60 years old (interquartile range [IQR], 16). They had previously been assessed in person and 80% of the remote assessments were conducted over Skype or Zoom.

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PACC scores consisted of averaged z-scores from the Mini Mental State Examination, Face-Name Associative Memory Test, the delayed recall score on the logical memory 2a subtest from the Weschler Memory Scale, and the Digit Symbol Substitution Test score from the Weschler Adult Intelligence Scale Revised.

The median duration between in-person and videoconference assessments was 236.5 days (IQR, 62.5; range, 103-293). Five (17%) participants had less than 149 days between assessments, 3 (10%) had between 150 and 199 days, 12 (40%) had between 200 and 249 days and 10 (13%) had over 250 days between assessments.

Gallo and colleagues determined the Pearson correlation coefficient of 0.82 (95% CI, 0.66-0.98) that showed a strong correlation between in-person and remote assessments. The multiple linear regression considered age, education, internet speed, in-person and remote assessors, and time between assessments. The regression produced a constant value of −0.17 (95% CI, −0.54 to 0.19), meaning that the ‘average’ person in the study had a remote PACC score 0.17 lower than assessed in-person.

The authors found that time between assessments predicted differences and that each added day increased score differences by 0.004 (β = −0.004; 95% CI, −0.007 to −0.00008). Marginal analysis showed that when the two assessments were performed relatively closer in time, the remote test performed better, but with increasing time difference, the in-person assessment performed better.

Gallo and colleagues also surveyed participants and found that 22 (78%) felt extremely comfortable performing the remote assessment, and 3 participants (10.7%) felt more comfortable in person. Despite technological problems associated with remote assessment, participants felt that assessments were equal in quality.

“This feasibility study showed how the use of videoconferencing software that are all freely available to download, are easy to use by study participants and fit for the scope. This is an advantage in epidemiological studies, as it can reduce cost and time involved with in-person assessments as well as adapt to uncertain circumstances when face-to-face assessments are not possible. To further understand whether remote testing can replace in-person assessments, a larger sample size and more adequate study design, will need to be used,” Gallo and colleagues concluded.

Seghezzo G, Van Hoecke Y, James L, et al. Feasibility study of assessing the Preclinical Alzheimer Cognitive Composite (PACC) score via videoconferencing. J Neurol. Published online January 26, 2021. doi: 10.1007/s00415-021-10403-1