Consumer activity trackers are inexpensive, user friendly, and reasonably accurate, so it's not surprising that as their public profile has grown, so have the number of researchers using them in clinical trials. We did a search of ClinicalTrials.gov for "Fitbit" -- just one of the activity trackers out there, but one of the most popular and high profile -- and found a surprising number of in-progress trials. 

In some of these, the Fitbit device is the intervention being tested. In others, it's an outcome measure in use by both the intervention and control group. And the trials deal with a wide range of health conditions, including diabetes, cancer, cystic fibrosis and arthritis. Read on for our roundup of 21 ongoing clinical trials using Fitbit activity trackers.

Who? University Hospital Case Medical Center in Cleveland
What? Using Fitbits with obese pediatric patients
Expected completion? April 2016

This study aims to test the effect of the Fitbit as a component of an intensive weight management intervention. At University Hospital in Cleveland, researchers are giving 60 obese pediatric patients Fitbit Charge HR devices and enrolling them in a 12-week weight management class. Half of the children will receive their device at the start of the class and half will receive it at the end. During the 12-week period, participants in both groups will receive weekly check-in phone calls — but for the Fitbit group, they will have data to review during those calls. 

Patients will be evaluated for activity, heart rate, BMI, and other health metrics at the end of the class and at a 12-week followup.

Who? Lancaster General Hospital in Pennsylvania
What? Patients using Fitbits after weight loss surgery
Expected completion? April 2017

At Lancaster, researchers are testing to see if the Fitbit can improve weight loss, promote lifestyle improvements, and prevent comorbidity in patients that have had vertical sleeve gastrectomy, a weight loss surgery.

Estimated enrollment is 213, and the patients — split into a control and intervention group — will be evaluated for a year on their activity levels, their percent of excess weight loss, and whether they developed any other comorbid conditions. Both groups will also be compared to historical control data.

Who? Children’s Hospital Boston 
What? Using Fitbits to increase activity for young cystic fibrosis patients
Expected completion? December 2018

In this study, 80 young adult cystic fibrosis patients will receive either regular counseling and an exercise prescription, or those things plus an activity tracker. They’ll be evaluated based on use of the device, activity levels, and lung function at the end of a two-year study period.

“For patients with CF, young adulthood and adolescence is a significant time of vulnerability,” researchers wrote in the CT.gov posting. “In addition to normal behavioral challenges of adolescence and young adulthood (seeking independence/autonomy while also choosing rebellion), those with CF are often dealing with significant disease progression. Therefore, working in new innovative ways to improve adherence to regimens that improve lung function such as exercise are needed to continue to support patients during this vulnerable time.”

Who? University of California, San Francisco
What? Preventing diabetes in adolescents with Fitbit devices
Expected completion? December 2016

In this study of 60 teens, half were given an Omron pedometer and a food diary and half will be given a Fitbit Ultra, which sends data to their EHR as well as to a gamified mobile app. The app includes a number of features: tracking of physical activity and diet, goal setting and monitoring, tips on incorporating activity into every day life, and interactive games related to physical activity and healthy diet. Participants will be evaluated on BMI, activity, and blood pressure at the end of three months.

Who? Cedars-Sinai Medical Center in Los Angeles
What? Using Fitbits to evaluate cancer patients’ fitness for chemotherapy
Expected completion? September 2016

The study, which MobiHealthNews covered in January, is seeking to enroll 30 patients in advanced stages of cancer who are ambulatory, over 18, and have access to an internet-connected smartphone. The trial will mainly be a feasibility study, seeing how effective the Fitbit — as well as questionnaires — are at monitoring this population. Ultimately, researchers hope to use Fitbits to help evaluate which patients are good candidates for chemotherapy.

All 30 patients will be given Fitbit Charge HR devices and asked to wear them at all times, other than in the bath and other times the tracker would be submerged, for two weeks. They will fill out questionnaires at two oncologist visits during the trial period, and again at a six month follow-up. Researchers will also review mortality and hospitalization for the subjects, as well as whether they wore the device as directed.

Who? Sheffield Teaching Hospitals in England
What? Feasibility study of Fitbits used in conjunction with a COPD app
Expected completion? December 2017

Investigators in Sheffield are testing a COPD app they developed among 30 patients. Data collection with a Fitbit Charge is part of the functionality of the app. Both the control group and the experiment group will wear the device for the 15-week study, but the control group will be blinded to the data the device is producing, which allows the Fitbit data to be one of the outcome measures of the study. 

Who? University of Minnesota
What? Using Fitbits to evaluate exercise interventions for smoking cessation
Expected completion? August 2016

This study of 60 patients is using the Fitbit Flex to evaluate how two different programs of exercise — high intensity and moderate intensity interval training — affect physical activity in young adult smokers. The study is called “EASY-A” or Exercise, Activity, and Smoking in Young Adults.

Who? Duke-NUS Graduate Medical School in Singapore
What? Promoting physical activity in children and their parents with Fitbits and cash incentives
Expected completion? February 2017

In this Singaporean study, investigators will actually pay children to exercise in order to promote public health. The Fitbit Zip will be used to measure activity, along with a website for participants. Children will be able to earn up to $5 a week (7 Singapore dollars) by meeting a step goal, but only if their parents also meet that step goal. 

“This proposal is an extension of a prior study where the investigators showed that modest financial incentives can increase physical activity levels among children,” investigators wrote. “The investigators now propose to conduct a follow-on trial where the reward is tied not only to the child's own steps, but to that of a parent. Rewards will be based on step activity measured through a state-of-the-art wireless step counter worn on the wrist or hip. Just as children were motivated to increase their own activity levels in efforts to achieve the incentive, the investigators hypothesize that they will also be effective advocates for increasing the activity levels of their parents.”

A similar trial by Duke-NUS uses Fitbits to test the effect of financial incentives on diabetes self-management.

Who? University of Minnesota
What? Using the Fitbit to evaluate the quality of life for brain tumor patients
Expected completion? September 2018

In this study, researchers will evaluate the quality of life of 75 patients with brain tumors based on a combination of a quality of life survey, a sleep survey, and the data from Fitbit Flex devices that all participants will wear to monitor sleep and activity.

Who? Arkansas Children's Hospital 
What? Using the Fitbit to find connections between sleep, physical activity, and asthma
Expected completion? July 2016

In this study, the Fitbit Charge HR is more of a data collection device than part of the intervention. Researchers are seeking to learn more about the connection between sleep, physical activity, and asthma in adolescent patients (14 to 17 years old). In this proof-of-concept/feasibility study, they’ll collect data on 20 patients for eight weeks.

Who? Butler Hospital in Providence, Rhode Island with the National Institute on Alcohol Abuse and Alcoholism (NIAAA)
What? Developing a Fitbit-based intervention for women recovering from alcoholism
Expected completion? July 2016

The team at Butler is developing a physical activity-based intervention for women recovering from alcoholism that uses the Fitbit as a motivational and accountability tool. They’ll enroll 20 women in a small open pilot and another 50 women in a randomized control trial. 

“The Lifestyle Physical Activity+Fitbit intervention proposed in this application is simple, low-cost, and easily transportable to the varied clinical settings women with alcohol use disorders receive treatment,” investigators wrote. "If women with AUDs find the LPA+Fitbit intervention feasible, acceptable, and helpful during early recovery, they could be afforded with a much needed alternate coping strategy that would reduce relapse risk and decrease the overall negative impact of alcohol use on their health and well-being.”

Who? Duke University
What? Using Fitbit data in a tailored text message campaign to increase physical activity for cancer survivors
Expected completion? December 2017

In this intervention, 15 current and 15 recent cancer patients will be issued a Fitbit device and enrolled in a 12-week daily text message program. The messages they receive will be tailored to the activity level reported via the Fitbit devices. Physical activity is especially important for cancer survivors as it reduces the risk of side effects from treatment, investigators write.

Who? University of British Columbia in Vancouver
What? Increasing physical activity in patients with arthritis using Fitbits
Expected completion? October 2017

In this study of 60 patients with knee osteoarthritis, researchers will investigate the value of a three-part intervention including a Fitbit Flex, a group education session, and remote coaching by a physical therapist. At the end of six months, they’ll evaluate participants’ levels of moderate to vigorous physical activity and sedentary behavior. As a secondary outcome measure, they’ll also evaluate the intervention’s effect on cognitive function. They’ll also do in-depth interviews with study participants. UBC is also conducting two other similar studies on different arthritis patient populations.

Who? Duke University with Verizon
What? Mobile health study in patients with Peripheral Artery Disease
Expected completion? August 2016

This study of 45 to 55 patients is evaluating not only a Fitbit, but also an iHealth glucometer and a Withings blood pressure cuff. Patients who are being evaluated for leg pain at Duke’s Peripheral Artery Disease lab will be split into two groups, one of which will be monitored with the whole suite of mobile health tools. At 12 and 24 weeks they’ll be evaluated based on health metrics, and at 28 weeks they will take a patient satisfaction survey.

Who? Wake Forest University 
What? Using the Fitbit to identify patients at risk for surgical complications
Expected completion? March 2016

In this feasibility study, 38 patients wore a Fitbit Zip activity tracker both before and after abdominal cancer surgery. The objective was to find out whether patients would use the devices and whether the activity data could be used to predict patients who were more likely to have complications from the surgery. The National Cancer Institute helped fund the study.

Who? Joslin Diabetes Center
What? Testing a digital diabetes education and management platform in patients with Type 2 diabetes
Expected completion? March 2017

Once again, the Fitbit is just one part of the intervention being studied in this research, which involves a cohort of Latinos with type-2 diabetes. For nine months, patients will have weekly video conferences and phone calls with a diabetes educator and will track both their activity (with a Fitbit) and their blood glucose level with a Glooko-connected glucometer. Joslin hopes to see a reduction in hemoglobin A1c levels after 9 months.

Who? University of Wisconsin, Madison
What? Using a Fitbit to promote physical activity for breast cancer survivors
Expected completion? February 2017

The University of Wisconsin is running a randomized trial of 100 breast cancer patients, half of whom will be given a care plan that involves educational materials, a quality of life assessment, and a Fitbit and half of whom will get just the educational materials and the quality of life assessment. This is a pilot for a larger trial, so the primary outcome is feasibility of recruitment. The secondary outcome is physical activity, as measured by an ActiGraph device.

Who? Duke University
What? Testing Vida, a mobile health coaching application
Expected completion? August 2016

In this 40 patient trial, Duke is testing the mobile health coaching application Vida, in which a patient is matched with a live health coach. Patients in the Vida group will also get Fitbit activity trackers they can use to monitor their physical activity. At the end of the 12-week study, patients’ BMI, fitness level, and activity levels will be evaluated.

Who? Rutgers University
What? Using Fitbits and SparkPeople to help breast cancer survivors maintain weight  
Expected completion? May 2017

At Rutgers, 70 patients — African American women who are in remission from breast cancer — will receive Fitbit devices, but half of them will be enrolled in the online health social community SparkPeople as well. The study is primarily aimed at feasibility: seeing whether participants used SparkPeople and whether it increased their uptake of the Fitbit device. But they’ll also evaluate participants’ weight loss, caloric intake, fitness, and quality of life. This study is also NCI-supported.

Who? University of Minnesota
What? Using Fitbits to evaluate the effect of an exercise program on children with cancer
Expected completion? January 2018

The Fitbit is a fairly minor part of this study, which is evaluating the effect of the “Kids are Moving” exercise education program on children in treatment for cancer. The 40-participant trial has a historical control, wherein the study participants will be compared to measurements from children who received usual care before the exercise program began. The Fitbit Flex is being used to measure children’s activity levels.

Who? Nationwide Children’s Hospital in Columbus, Ohio
What? Promoting physical activity for new mothers with Fitbits
Expected completion? April 2017

This three-arm, 30-patient study of postpartum moms will evaluate the Fitbit, the Fitbit plus ankle weights, and a control group. Patients will enter the study two to six months after giving birth and will be evaluated 12 months afterward. Researchers will collect data on participants’ physical activity, body composition, and their feelings and feedback about the interventions and study design.