Original Article Using technology to improve longitudinal studies: self-reporting with ChronoRecord in bipolar disorder Bipolar disorder is episodic, recurrent and hetero- geneous (1). Almost all patients have multiple episodes, with the relapse rate by 5 years estimated to be 90% (2). The course of bipolar disorder is associated with both interindividual variation and heterogeneity between patients (3–5). Over a life- time, a patient may experience mixed states, rapid cycling, psychosis, and depressive, manic or hypo- manic episodes. There is great variation between patients in the severity of symptoms, duration of episodes, number of episodes, degree of recovery from episodes, pattern of polarity of episodes and intervals between episodes. Furthermore, current Bauer M, Grof P, Gyulai L, Rasgon N, Glenn T, Whybrow PC. Using technology to improve longitudinal studies: self-reporting with ChronoRecord in bipolar disorder. Bipolar Disord 2004: 6: 67–74. ª Blackwell Munksgaard, 2004 Objectives: Longitudinal studies are an optimal approach to investigating the highly variable course and outcome associated with bipolar disorder, but are expensive and often have missing data. This study validates patient self-reported mood ratings using a home computer-based system (ChronoRecord) with clinician mood ratings on the Hamilton Depression Rating scale (HAMD) and Young Mania Rating scale (YMRS), and investigates the patient acceptance of the technology. Methods: After brief training, outpatients with bipolar disorder were given the software version of an established paper based self-reporting form (ChronoSheet) to install on a home computer. Every day for 3 months, patients entered mood, medications, sleep, life events, and menstrual data. Weight was entered weekly. Results: Eighty of 96 (83%) patients returned 8662 days of data. The mean days of data returned was 114.7 ± 32.3 SD The mean percentage of days missing for mood data was 6.1% ± 9.3 SD, equivalent to missing 7.3 day of the 114.7 days. Self-reported ratings were strongly correlated with clinician HAMD ratings ()0.683, p < 0.001). Conclusions: This study demonstrates concurrent validity between ChronoRecord and HAMD. Patients with bipolar disorder showed high acceptance of a computer-based system for self-reporting of daily data. Automation of data collection can reduce missing data and eliminate errors associated with data entry. This technology also enables on-going feedback for both patient and researcher during a long-term study. Michael Bauer a,b , Paul Grof c , Laszlo Gyulai d , Natalie Rasgon b,e , Tasha Glenn f and Peter C Whybrow b a Department of Psychiatry and Psychotherapy, Charite ´ -University Medicine Berlin, Berlin, Germany, b Neuropsychiatric Institute and Hospital, Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles (UCLA), Los Angeles, CA, USA, c Department of Psychiatry, University of Ottawa, Royal Ottawa Hospital, Ottawa, Canada, d Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, PA, USA, e Department of Psychiatry, Stanford School of Medicine, Palo Alto, CA, USA, f ChronoRecord Association, Inc., Fullerton, CA, USA Key words: bipolar disorder – ChronoRecord computer software – longitudinal studies – methodology – self-reporting – technology Received 10 March 2003, revised and accepted for publication 4 September 2003 Corresponding author: Michael Bauer, MD, PhD, Department of Psychiatry and Psychotherapy, Charite ´ -University Medicine Berlin, Campus Charite ´ -Mitte (CCM), Schumannstr. 20/21, 10117 Berlin, Germany. Fax: +49-30-450-51-79-62; e-mail: michael.bauer@charite.de In part presented at the American Psychiatric Association Annual Meeting, Philadelphia, PA, May 18–23, 2002; NCDEU June 10–13, 2002, Boca Raton, FL; the European Stanley Foundation Meeting, Freiburg, Germany, September 12–14, 2002; and the 16th Annual Meeting of the International Group for the Study of Lithium-Treated Patients (IGSLI), Prague, Czech Republic, September 26–29, 2002. The ChronoRecord Association is a non-profit organization that distributes ChronoRecord software at no charge to qualified clinicians (http://www.chronorecord.org). None of the authors have a financial interest in the ChronoRecord Association. Bipolar Disorders 2004: 6: 67–74 Copyright ª Blackwell Munksgaard 2004 BIPOLAR DISORDERS 67