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Social FeatureMeasurementHypothesis
Do Other Frameworks offer this? (or pretend to?)
Feasibility
Available in Public SDK
Sampling Rate?Privacy Invasiveness
Privacy Considerations
Behavioral Noise Technical Noise
Technical Effort
API to usePrevious ResearchNotes
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Features describing social behavior, including activity related to phone calls, texting, social network size, and other people in the user’s context.Call duration (incoming or outgoing)-Call logThe social category had the lowest percentage of statistically
significant correlations, by vote counting, across studies (10/38,
26%). Social included features such as call duration and number
of conversations, which can be accessed on Android phones,
contrary to iPhones [77].
Ben-Zeev D, Schueller S, Begale M, Duffecy J, Kane J, Mohr D. Strategies for mHealth research: lessons from 3 mobile
intervention studies. Adm Policy Ment Health 2015 Mar;42(2):157-167 [FREE Full text] [doi: 10.1007/s10488-014-0556-2]
[Medline: 24824311]
YesNoall calls?Lowhttps://www.apple.com/ca/privacy/213https://dl.acm.org/doi/pdf/10.1145/1864349.1864394.
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Call frequency (incoming or outgoing)-Call logYesNoAll calls?Low213https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6200557
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Maximum call duration-Call logYesNoall calls?Low213https://mental.jmir.org/2018/3/e56/
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SMS text messages (sent or received)-SMS text message logYesNo
all texts? (group texts, sms, MMS, messaging apps?)
High112
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Characters in SMS text message (sent or received)-SMS text message logYes
Only as initiated by an app
all texts? (group texts, sms, MMS, messaging apps?)
High112
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SMS text messages received (characters)-SMS text message logYes
Only as initiated by an app
all texts? (group texts, sms, MMS, messaging apps?)
High112
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Physical Movement
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Features describing physical activity, including movement and step count.Activity (afternoon, day, evening, morning, night)-AccelerometerCompare Acc movement in x,y,z planes during daytime and nighttime
Pattern of lower daytime activity but higher nighttime activity
in depression
Burton C, McKinstry B, Szentagotai TA, Serrano-Blanco A, Pagliari C, Wolters M. Activity monitoring in patients with
depression: a systematic review. J Affect Disord 2013 Feb 15;145(1):21-28. [doi: 10.1016/j.jad.2012.07.001] [Medline:
22868056]
Yes
Apps can read their own usage and background usage if given permission
What are the cut offs for this and how many samples per hour?
Lowhttps://www.apple.com/legal/privacy/apple-health-studies/en-ww/122https://docs.expo.io/versions/v38.0.0/sdk/gyroscope/
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Autocorrelation-Accelerometer.
Autocorrelation is the average of the product of a data sample with a version of itself advanced by a lag. The autocorrelation plot can provide answers to the following questions: (1) Is an observation related to adjacent observation? (2) Is the observed time series white noise? (3) Is the observed time series autoregressive? The autocorrelation function is described by the equation below,
Lower autocorrelation = irregular movement patterns = more depression
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3859053/
YesYes
What are the cut offs for this and how many samples per hour?
Low321https://dl.acm.org/doi/abs/10.1145/3089341.3089342?casa_token=JuazzHXzK-8AAAAA:7KYsz2_vBzYHC9BgYtgj6Sd-LC1RkB72-dWHYmL29uuTLy9_0w9NHlN5YQ3_WOB_3s6vQ9FHC7hB6g
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Vigorous activity-AccelerometerIn order for physical activity to be classified as MVPA, mean acceleration in the 5s-epoch (ENMO) needed to be at or above 100 mgA majority of these features indicates that enhanced physical activity and more movement outside of the house are observed when participants score lower on the depression scale.YesYes
What are the cut offs for this and how many samples per hour?
Low321https://link.springer.com/article/10.1007%2Fs00779-011-0465-2
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Distance-Accelerometer, GPSAccelerometer x, y planes. Access iPhone health app (pedometer). Or GPS distance traveled
Abdullah S, Matthews M, Frank E, Doherty G, Gay G, Choudhury T. Automatic detection of social rhythms in bipolar
disorder. J Am Med Inform Assoc 2016 May;23(3):538-543. [doi: 10.1093/jamia/ocv200] [Medline: 26977102]
YesYes
What are the cut offs for this and how many samples per hour?
High321https://www.jmir.org/2015/7/e175/?ncid=txtlnkusaolp00000618
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Fourier analysis-Accelerometerhttps://www.npmjs.com/package/fourier-transform
Hauge ER, Berle J, Oedegaard KJ, Holsten F, Fasmer OB. Nonlinear analysis of motor activity shows differences between
schizophrenia and depression: a study using Fourier analysis and sample entropy. PLoS One 2011 Jan 28;6(1):e16291
[FREE Full text] [doi: 10.1371/journal.pone.0016291] [Medline: 21297977]
YesYes
What are the cut offs for this and how many samples per hour?
Low321https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6200557
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Inactivity duration-AccelerometerNo movement in x,y,z planes.
Faurholt-Jepsen M, Brage S, Vinberg M, Christensen EM, Knorr U, Jensen HM, et al. Differences in psychomotor activity
in patients suffering from unipolar and bipolar affective disorder in the remitted or mild/moderate
Yes
Apps can read their own usage and background usage if given permission
What are the cut offs for this and how many samples per hour?
Low321
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Sample Entropy-AccelerometerYes
Apps can read their own usage and background usage if given permission
What are the cut offs for this and how many samples per hour?
Low321
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Movement duration-GPSTime between start of movement and end of movementYes
Apps can read their own usage and background usage if given permission
If I read this in morning and once at night I'd get a distance travelled of 0, probably... so you have to sample throughout day
High321
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Movement speed-Accelerometer, GPSGPS: newLocation.speedYes
Apps can read their own usage and background usage if given permission
What are the cut offs for this and how many samples per hour?
High321
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Movement speed variance-GPSGPS: var(newLoc.speed)
(newLoc.speed - averageSpeed) ** 2 for every recorded speed
Yes
Apps can read their own usage and background usage if given permission
What are the cut offs for this and how many samples per hour?
Low321
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Steps-Accelerometer, PedometerTime-sampled total number of steps via pedometerYes
Apps can read their own usage and background usage if given permission
What are the cut offs for this and how many samples per hour?
Low321
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0
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Location
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Features describing mobility, including GPS tracking, clustering of location (eg, home stay), and transition time.Home stay-GPSWithin 100m around their specified address (or the location where they sleep at night)Longer durations of staying at home correlated with depressionYesYes
How to detect "at home"
Highhttps://www.apple.com/privacy/docs/Location_Services_White_Paper_Nov_2019.pdf111https://docs.expo.io/versions/v38.0.0/sdk/location/
Will need to have a way for user to define "home"
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Location clusters-GPS
Locations where person spends time
YesYesLow111https://psycnet.apa.org/doiLanding?doi=10.1037%2Fprj0000130Needs more definition
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Circadian rhythm-GPS/accNo more location changes on GPS + no more movement in x,y,z planes for 2 hours+More regular sleep/wake cycles in healthy participants. Sleeping late and waking up late or at random hours in depressionYesYesSleep cycles? Low321https://dl.acm.org/doi/abs/10.1145/2750858.2805845?casa_token=6DZx7khAVxUAAAAA:NYYCSZnWSVs7mSm4Rqch0VYI2BZkRiBt-uDiWWuryHeg1Kb0ho8wHM3ovpMKnNZ2vf4yviapazRuBQNeeds more definition
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Entropy-GPSTime spent at each location cluster Entropy is a measure that captures the distribution of time spent at the different location clusters registered. Thus, a high entropy would indicate that the participant spends time more uniformly across different location clusters. Because all studies consistently showed a negative correlation, this implies that a higher entropy correlates with a better mood.YesYesLow221https://dl.acm.org/doi/abs/10.1145/2462456.2464449?casa_token=8JttqeRVHkQAAAAA:mDJPjaDOme8drRFN9Ht1wU-rPj26T88Kj_5nOUCsVwpZ9znh-6Xy-T9L-wkMixMPkHxjM5jPiEcz-A
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Home to location cluster-GPSAverage distance between home GPS location and GPS locations where participant spends timeGeographical distance between home and other locations where the participant spends time. The hypothesis is that more depressed participants will remain in closer vicinity to their homes and thus have a smaller home to location cluster.YesYesLow221Needs more definition
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Maximum distance between clusters-GPSGPS coordinates of farthest two location clustersYesYesLow311
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Transition time-GPSTime traveling between locations.Transition time has been currently only investigated by the
research group of Saeb et al [7,39], who conducted a study to
replicate previous findings of the same features. The first study
showed a positive correlation (r=0.21, P=.40), while a second
study showed negative correlation (r=−0.32, nonsignificant).
The feature then yields a low negative wD due to the latter
including more participants and placed more centrally due to
the contradictive results.
YesYesLow221
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Location variance-GPS
GPS mobility independent of location
Saeb, S., Zhang, M., Karr, C. J., Schueller, S. M., Corden, M. E., Kording, K. P., & Mohr, D. C. (2015). Mobile phone sensor correlates of depressive symptom severity in daily-life behavior: an exploratory study. Journal of medical Internet research, 17(7), e175.
YesYesLow221
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Device
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Features describing device (mobile phone or wearable) usage, including app usage, lock or unlock events, and classification of app usage.Communication or social app usageThe low variability with device-based features could indicate that there is a general tendency for participants to use their phones more, but at the same time, withdraw from the social context by lowering the communication app usage.
Mestry M, Mehta J, Mishra A, Gawande K. Identifying associations between smartphone usage and mental health during
depression, anxiety and stress. 2015 Presented at: Proceedings - 2015 International Conference on Communication,
Information and Computing Technology, ICCICT 2015; January 16-17, 2015; Mumbai, India. [doi:
10.1109/ICCICT.2015.7045656]
YesNoHighhttps://www.apple.com/privacy/control/333
manually screenshotting their screen time screen every day
https://www.annualreviews.org/doi/pdf/10.1146/annurev-clinpsy-032816-044949
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Duration of app usageYesYesHigh322
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Browser app usageYesNoHigh
https://www.apple.com/safari/docs/Safari_White_Paper_Nov_2019.pdf
332
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Images taken-CameraYesYesHigh
https://www.apple.com/ios/photos/pdf/Photos_Tech_Brief_Sept_2019.pdf
111
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Number of running appsYesNoLow
https://www.apple.com/privacy/control/
323
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Response time for NotificationsYes
App Can Measure this for its own
Low
https://developer.apple.com/library/archive/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/APNSOverview.html#//apple_ref/doc/uid/TP40008194-CH8-SW1
333
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Screen active duration
Thomée S, Härenstam A, Hagberg M. Mobile phone use and stress, sleep disturbances, and symptoms of depression among
young adults--a prospective cohort study. BMC Public Health 2011 Jan 31;11:66 [FREE Full text] [doi:
10.1186/1471-2458-11-66] [Medline: 21281471]
YesNoHighhttps://www.apple.com/privacy/control/222
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Screen Active FrequencyYesNoHigh222
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Screen clicksYesYes, via MicHigh333https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6076371/
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Data transmitted via Wi-FiYes
App Can Measure this for its own
High212
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Deviation of F0-Microphone
Muaremi A, Gravenhorst F, Grünerbl A, Arnrich B, Tröster G. Assessing bipolar episodes using speech cues derived from
phone calls. In: Lect Notes Inst Comput Sci Soc Telecommun Eng LNICST. 2014 Presented at: MindCare: Pervasive
Computing Paradigms for Mental Health; May 8-9, 2014; Tokyo, Japan p. 103-114. [doi: 10.1007/978-3-319-11564-1_11]
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Fundamental frequency-Microphone
• Harmonics-to-noise ratio-Microphone
• Pauses in recording-Microphone
• Short turns during conversation-Microphone
• Sleep (duration, efficiency, onset latency)-Accelerometer
• SD pitch frequency-Microphone
• Laying down-Camera • SD sleep-Accelerometer
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