Sleep and Physical Activity Validation Sub-study Fact Sheet

Study Title: Sleep and Physical Activity Validation Sub-study 

Principal Investigator: Dr. Jorge Chavarro

Contact information:

Purpose of this research

The purpose of this research is to understand the performance of sleep and physical activity measurement tools, including a Fitbit device and a smartphone application, Beiwe. 

The long-term goals of the research are to produce findings to facilitate the integration of mobile health measures of behavior in large cohort studies, by comparing how these measurement tools perform compared to research-grade accelerometers (Actisleeps).

Sponsor of this research

The study is funded  by the National Heart, Lung, and Blood Institute.

Who takes part in this research and why

About 50 participants will take part in this research study. All subjects are also participants in the Nurses’ Health Study 3. Many participants take part in this research because they believe sleep and physical activity are important topics of research. We couldn’t do this research without our participants.

Confidentiality and data security

Your privacy is important to us. Location data do not tell us what you are doing, who you are with, and generally does not track your specific location when you are inside a building. Data usage of the smartphone application is minimal (~10 MB per day) if you do not ever connect your phone to Wi-Fi, and it has been designed to have a minimal impact on your phone’s battery life. We also recommend connecting to Wi-Fi at least once a day to minimize data usage. There is also a potential–but unlikely–risk of loss of confidentiality associated with this study. We have never had a breach of confidentiality in Nurses’ Health Studies. We will protect your privacy by labeling your information with only a code and keeping the key to the code in a password protected database that is only accessible to study staff. 

Any risks associated with participation

The only foreseeable risk associated with this study is the unlikely and minimal risk of a breach of confidentiality. Protections are in place as described above. 


Your participation is voluntary, and you can stop at any time. As always, not participating in a sub-study does not affect your status as a valuable member of the NHS3 main study. If you receive care at Mass General Brigham, deciding not to participate won’t affect medical care you receive at Mass General Brigham now or in the future, or any benefits you receive now or have a right to receive.

Participation involves:

  • Completing a short online questionnaire on your sleep habits.
  • Wearing an NHS3-provided Fitbit device and Actisleep watch on the same wrist for 14 consecutive days, including while you sleep. 
  • Sharing Fitbit data via Fitabase, an online platform that delivers your sleep data to our research team. 
  • Answering a 5-minute sleep questionnaire each morning via the Beiwe app.

The Fitbit is yours to keep at the conclusion of the study.

Contact information for questions

If you have questions about this sub-study, please contact us at

IRB contact information

If you would like to speak to someone not involved in this research about your rights as a research subject, or any concerns or complaints you may have about the research, contact the Mass General Brigham Human Research Committee at (857) 282-1900.

Privacy of Health Information

We are required by the Health Insurance Portability and Accountability Act (HIPAA) to protect the privacy of health information obtained for research. This is an abbreviated notice and does not describe all details of this requirement. During this study, identifiable information about you or your health will be collected and shared with the researchers conducting the research. In general, under federal law, identifiable health information is private. However, there are exceptions to this rule. In some cases, others may see your identifiable health information for purposes of research oversight, quality control, public health and safety, or law enforcement. We share your health information only when we must, and we ask anyone who receives it from us to protect your privacy.