CERTAS - Researcher Configurable Palm-Based Self-Monitoring System
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Researcher Configurable Palm-Based Self-Monitoring System


PICS has conducted a number of clinical trials substantiating the data integrity and reliability of the CERTAS system. Study trials have included protocols for self-reported alcohol consumption, smoking, dietary intake, and physical activity.


Riley WT, Carson SC, Martin N, Behar, A, Forman-Hoffman VL, & Jerome, A. Initial feasibility of a researcher configurable computerized self-monitoring system. Computers in Human Behavior. 2005;21:1005-1018.

Riley W, Carson SC, Forman V, & Obermayer J. The effects of PDA vs. paper-based monitoring on recording compliance and nicotine gum use among smokers attempting to quit. The Science of Real-Time Data Capture Conference, Charleston, SC 2003:

  • Background: This study sought to evaluate the difference between PDA-based vs. paper-based monitoring on both compliance to recording and on nicotine gum use.
  • Methods: Forty-nine smokers who desired to quit using nicotine gum were enrolled into the study and randomly assigned to either the pocket PC (PDA) or paper-based self monitoring (LOG) condition. All subjects were to quit smoking using nicotine gum and then record their gum and/or cigarette use for a 3 week period. The self-monitoring protocol consisted of three scheduled recording sessions each day in which the subject recorded for the prior 5-hr. period the number of cigarettes smoked, number of pieces of gum used, and ratings of cigarette craving or nicotine gum side effects.
  • Results: Significant differences were found between groups in recording compliance for all 3 weeks, particularly in the later 2 weeks of the trial (e.g. 69% vs. 39% in week 3). Participants in the PDA group reported chewing significantly more pieces of gum per assessment period than participants in the LOG group (3.5 vs. 2.4) but did not differ significantly on reports of concomitant gum and cigarette use during the same assessment period (14% PDA, 19% LOG).
  • Discussion: These results indicate that hand-held, computer-based recording improves self-monitoring compliance, especially over time and even in difficult recording contexts (i.e. relapsed smokers continuing to record gum and cigarette use). Computerized recording also appears to have an effect on nicotine gum use, although a variety of factors could contribute to these observed differences.