Exemplar: Determining the Best Practices for EMA Studies
Condition: Ecological Momentary Assessment Best Practices
Study type: Interventional

Summary: 
      Ecological momentary assessment (EMA) is a measurement methodology that utilizes the repeated
      collection of real-time data on participants' behavior and experience in their natural
      environment. While EMA allows researchers to gain valuable insights into dynamic behavioral
      processes, the need for frequent self-report can be burdensome and disruptive to
      participants. Compliance with EMA protocols is important for accurate, unbiased sampling, yet
      there is no "gold standard" for EMA study design. In the present study, the investigators aim
      to use a factorial design to identify the optimal components, or combinations of components,
      for achieving the highest compliance rates for smartphone-based ecological momentary
      assessments (EMAs). Participants will be randomized into 1 of 32 conditions in a 2x2x2x2x2
      design (i.e., number of questions per EMA survey [15 vs. 25] x number of EMAs per day [2 vs.
      4] x EMA prompting schedule [random vs. fixed times]) x payment type [per EMA vs. based on
      percentage of EMAs completed] x order of EMA item question types [i.e., slider type first 2
      weeks vs. Likert-type questions first 2 weeks]). All participants will complete EMAs for 4
      weeks. The effect of each factor on EMA compliance will be examined, as well as the effects
      of interactions on EMA compliance. The investigators will also examine within and
      between-subjects factors that influence response rates, and 2) contextual features such as
      environment and mood that may be associated with better compliance and participant
      engagement. The results of this study will have broad applications for developing best
      practices guidelines for future studies utilizing EMA methodologies.
    

Detailed description: 
      Ecological momentary assessment (EMA) is a measurement methodology that utilizes the repeated
      collection of real-time data on participants' behavior and experience in their natural
      environment. EMA has been used in behavioral science for years, including research examining
      the environmental and psychological antecedents of cigarette smoking, substance use
      disorders, anxiety, eating, and sleep. EMA sampling strategies are typically time-based or
      event-based. Time-based sampling is solicited based on a schedule; for example, a daily diary
      prompted every day at the same time, or at random intervals (e.g., every 3-4 hours) each day.
      In contrast, event- based sampling is centered around a pre-defined event and is typically
      initiated by the participant. For example, a participant may be asked to initiate an
      assessment every time the participant smokes a cigarette.

      Several studies have examined the impact of EMA study design features on participant
      compliance. In a recent meta-analysis of compliance with EMA protocols among substance users,
      there was no evidence that compliance rates were associated with prompt frequency, length of
      assessment period, or reimbursement. Another study using a pooled dataset of 10 EMA studies
      found that compliance declined across days, and varied significantly depending on the time of
      day. In a meta-analysis of EMA studies in mental health research, a higher number of EMAs per
      day were associated with lower compliance, however the number of days was not. While these
      studies provide preliminary guidance regarding EMA study design, their results are
      unfortunately inconsistent, and the varied reporting across studies with respect to the
      definition of compliance, study design elements, and study populations make it difficult to
      clearly derive best practice guidelines for EMA design.

      In the present study, the investigators use a factorial design to identify the optimal
      components, or combinations of components, for achieving the highest compliance rates for
      smartphone-based ecological momentary assessments (EMAs). In addition, the investigators will
      explore the association between EMA design features and participant compliance/response
      rates. A factorial design is ideal for exploring these research questions because it is
      statistically more efficient, as this type of design needs fewer participants to answer
      questions about each experimental factor of interest.6 In this study, participants will be
      randomized into 1 of 32 conditions (i.e., number of questions per EMA survey x number of EMAs
      per day x EMA prompting schedule x EMA item type x payment type) to explore:

        1. both within and between-subjects factors that influence response rates, and

        2. contextual features such as environment and mood that may be associated with better
           compliance and participant engagement. The results of this study will have broad
           applications for developing best practice guidelines for future studies utilizing EMA
           methodologies.
    

Intervention name(s): Ecologial Momentary Assessment settings
Intervention type(s): Behavioral
Intervention description(s): Various settings for ecological momentary assessments
Allocation: Randomized
Intervention model: Factorial Assignment
Intervention model description: Participants will be randomized into 1 of 32 conditions in a 2x2x2x2x2 design (i.e., number of questions per EMA survey [15 vs. 25] x number of EMAs per day [2 vs. 4] x EMA prompting schedule [random vs. fixed times]) x payment type [per EMA vs. based on percentage of EMAs completed] x order of EMA item question types [i.e., slider type first 2 weeks vs. Likert-type questions first 2 weeks]).
Masking: None (Open Label)
Primary purpose: Other
Keywords: Ecological Momentary Assessment; Health Behavior; Smartphone Application