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Using e-diaries to capture clinical trial data

The following story is part of an ongoing series celebrating Rare Disease Day 2022. For more information, click here.

Today, we take a look at how Takeda is rethinking the way clinical trial data is tracked by study subjects and their caregivers using e-diaries, specifically for Dravet syndrome and Lennox-Gastaut syndrome.

When participating in clinical trials, study subjects and/or their caregivers often have to physically take notes on symptoms observed, experience with treatments, lifestyle changes and more. These data are brought by the study subjects and caregivers to their care team at in-person doctor visits, at which point their data are manually entered into tracking systems to be analyzed.

Physical note taking is not always the most effective or efficient, as, first and foremost, written notes could be lost or damaged. It can also be especially cumbersome to caregivers, who regularly manage not only the tracking of seizure episodes but also treatment schedules, doctor’s visits, schooling, work and more. Study subjects and their caregivers need a simpler, less demanding, more seamless data-sharing solution.

This is where Takeda comes in. We are rethinking how study subjects and caregivers track and share their trial data, starting with our Phase 3 Dravet syndrome and Lennox-Gastaut syndrome clinical trials.

  • Dravet syndrome and Lennox-Gastaut syndrome are types of developmental and epileptic encephalopathies (DEEs), a heterogeneous group of rare epilepsy syndromes. These syndromes typically become apparent during infancy or early childhood and are highly resistant to many antiseizure medications.1-7 In the U.S., Dravet syndrome has a birth prevalence of approximately 1 in 15,700 people,8 while Lennox-Gastaut syndrome is estimated to affect approximately .26 people per 1,000 at age 10.9

In the Phase 3 clinical trials, we offer e-diaries to study subjects and caregivers to capture daily seizure data and other quality of life measures digitally. The electronic diary seamlessly records data in almost real-time via a smartphone app, also making it available to each study subject’s care team. This alleviates the need to manually enter the data and allows sites to flag potential compliance challenges. Moreover, it ensures that healthcare providers have the latest data in hand in advance of each study subject’s visit, allowing for more effective discussions with subjects about what they are experiencing at home. In addition to the e-diary, Takeda is implementing virtual site visits along with in-person visits. This has alleviated the study subject burden of having to travel frequently to study sites, as some people have mobility challenges or do not live near trial sites.

We look forward to using e-diary technology to advance how we think about Dravet syndrome and Lennox-Gastaut syndrome tracking and treatment, and to progress our understanding of how such a tool can be applied to other rare disease areas in need to support study subjects, caregivers and their healthcare providers in making more informed healthcare decisions based on real-life situations.

Read more of our Rare Disease Day 2022 stories here.


  1. Anwar A, et al. Dravet syndrome: an overview. Cureus. 2019;11(6):e5006. doi: 10.7759/cureus.5006.
  2. Dravet C. The core Dravet syndrome phenotype. Epilepsia. 2011;52 Suppl 2:3-9. doi: 10.1111/j.1528-1167.2011.02994.
  3. Asadi-Pooya AA. Lennox-Gastaut syndrome: a comprehensive review. Neurol Sci. 2018;39(3):403–14. doi: 10.1007/s10072-017-3188.
  4. Cooper MS, et al. Mortality in Dravet syndrome. Epilepsy Res. 2016;128:43–7. doi: 0.1016/j.eplepsyres.2016.10.006.
  5. Resnick T, et al. Early diagnosis and treatment of Lennox-Gastaut syndrome. J Child Neurol. 2017;32(11):947–55. doi: 10.1177/0883073817714394.
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  7. He N, et al. Few individuals with Lennox-Gastaut syndrome have autism spectrum disorder: a comparison with Dravet syndrome. J Neurodev Disord. 2018;10:10. doi: 10.1186/s11689-018-9229
  8. Wu YW, et al. Incidence of Dravet syndrome in a US population. Pediatrics. 2015;136(5):e1310-5. doi: 10.1542/peds.2015-1807
  9. Trevathan E, et al. Prevalence and descriptive epidemiology of Lennox-Gastaut syndrome among Atlanta children. Epilepsia. 1997;38(12):1283-8. doi: 10.1111/j.1528-1157.1997.tb00065.x