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Smartphone Passive Digital Phenotyping in Frontotemporal Lobar Degeneration
Paolillo, E. W.; Dhanam, S.; Taylor, J. C.; Sanderson-Cimino, M.; Fregly, R.; Saloner, R.; Casaletto, K. B.; Kramer et al.. medRxiv (preprint), 2026-09-21
Topic: Brain proteins, microglia and lab models
IntroductionFrontotemporal lobar degeneration (FTLD) is a devastating disease that commonly results in early onset dementia, yet its rarity and heterogeneity limit large-scale research and clinical trials. Remote monitoring via low-burden digital health tools may overcome these barriers. We evaluated clinical utility of passive smartphone monitoring in FTLD using a multi-domain mobile assessment platform. MethodsParticipants were 567 adults (53% clinically normal, 21% prodromal FTLD, 26% symptomatic FTLD) who completed an in-person study visit and downloaded the ALLFTD Mobile App on their personal smartphones. The app delivered unsupervised cognitive tests and passively collected continuous data on battery percentage (proxy for smartphone use) and step count. Longitudinal follow-up included smartphone monitoring and annual in-person study visits. Primary analyses examined associations between passive smartphone features and markers of disease severity at baseline and longitudinally, and tested whether passive features added incremental value beyond app-based cognitive testing. ResultsPassive smartphone features were feasible to collect and showed excellent reliability with 0.9). Features capturing smartphone use and movement demonstrated sensitivity to gold-standard clinical measures of disease severity both at baseline and longitudinally. A classification model combining passive features, the app-based cognitive composite score, and demographics detected longitudinal functional decline (AUC=0.89); passive features alone (AUC=0.84) performed comparably to a cognitive screener (AUC=0.85). DiscussionPassive smartphone monitoring is a valid, zero-burden measure of disease severity and progression in FTLD that adds modest incremental value beyond app-based cognitive testing. Findings support its use as a scalable digital endpoint in longitudinal FTLD research.
Key findings
- IntroductionFrontotemporal lobar degeneration (FTLD) is a devastating disease that commonly results in early onset dementia, yet its rarity and heterogeneity limit large-scale research and clinical trials.
- Features capturing smartphone use and movement demonstrated sensitivity to gold-standard clinical measures of disease severity both at baseline and longitudinally.
Why it matters
This study found that passive smartphone data, such as step count and battery use, was feasible to collect and reflected disease severity in people with frontotemporal lobar degeneration. It is early work on remote monitoring tools and does not test any treatment.
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Study details
- Study designlongitudinal study
- Participants567
- Effect sizeAUC=0.89; AUC=0.84; AUC=0.85
- Evidence strengthModerate
How this study scored 16/100
Preprint — not yet peer-reviewed. It scored 43 on the same rubric, but non-peer-reviewed sources are capped at 16, so it shows as 16. Scored zero for randomised / blinded because the record does not state it. We have no data on impact for its field and year, so that was left out: it earned 40 of the 94 points we could judge it on, which is 43 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 2 / 10 | Tier 4 — not a peer-reviewed journal (medRxiv (preprint)) |
| Journal's citation record | 0 / 4 | Not a journal article, so the journal's record does not count |
| Study design | 7 / 12 | A longitudinal study following the same people over time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 4 / 10 | Preprint — not yet peer-reviewed. Hosted on a preprint server. |
| How recent | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 2 / 4 | 567 participants |
| Effect reported | 3 / 3 | Effect reported with a statistic (interval, p-value, ratio or similar) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 0 / 7 | Cited 0 times (OpenAlex, 2026-10-10) |
| Citations per year | 0 / 5 | 0.0 citations a year over 2 year(s) since 2026 |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | 0 / 6 | No other study in this library cites it |
| Still being cited | 0 / 4 | Cited 0 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 2 / 4 | Last-listed author Adam M. Staffaroni: h-index 38 (OpenAlex, whole career) |
| Institution's track record | 3 / 3 | Harvard University: institution h-index 3,235 (OpenAlex) |
| Multi-centre collaboration | 3 / 3 | OpenAlex lists 21 institution(s) in 2 countries |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 2 / 2 | Free to read |
| Points | 40 / 94 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 40 of the 94 points we could judge it on is 43 out of 100. |
| Total | 43 / 100 | Capped to 16 because this is not a peer-reviewed article. |
What each of these 20 components measures, and what this score is not →
Read the original
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Paolillo, E. W., Dhanam, S., Taylor, J. C., Sanderson-Cimino, M., Fregly, R., Saloner, R., et al. (2026). Smartphone Passive Digital Phenotyping in Frontotemporal Lobar Degeneration. medRxiv (preprint). https://doi.org/10.64898/2026.09.18.26363439
Vancouver
Paolillo EW, Dhanam S, Taylor JC, Sanderson-Cimino M, Fregly R, Saloner R, et al. Smartphone Passive Digital Phenotyping in Frontotemporal Lobar Degeneration. medRxiv (preprint). 2026. doi:10.64898/2026.09.18.26363439.
BibTeX
@article{paolillo2026-7ef6cdb9,
author = {Paolillo, E. W. and Dhanam, S. and Taylor, J. C. and Sanderson-Cimino, M. and Fregly, R. and Saloner, R. and Casaletto, K. B. and Kramer and others},
title = {{Smartphone Passive Digital Phenotyping in Frontotemporal Lobar Degeneration}},
journal = {medRxiv (preprint)},
year = {2026},
doi = {10.64898/2026.09.18.26363439},
url = {https://doi.org/10.64898/2026.09.18.26363439}
}
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