title: Testing self-regulation interventions to increase walking using factorial randomized N-of-1 trials.
abstract: OBJECTIVE
  To investigate the suitability of N-of-1 randomized controlled trials (RCTs) as a means of testing the effectiveness of behavior change techniques based on self-regulation theory (goal setting and self-monitoring) for promoting walking in healthy adult volunteers.
  
  
  METHODS
  A series of N-of-1 RCTs in 10 normal and overweight adults ages 19-67 (M = 36.9 years). We randomly allocated 60 days within each individual to text message-prompted daily goal-setting and/or self-monitoring interventions in accordance with a 2 (step-count goal prompt vs. alternative goal prompt) × 2 (self-monitoring: open vs. blinded Omron-HJ-113-E pedometer) factorial design. Aggregated data were analyzed using random intercept multilevel models. Single cases were analyzed individually. The primary outcome was daily pedometer step counts over 60 days.
  
  
  RESULTS
  Single-case analyses showed that 4 participants significantly increased walking: 2 on self-monitoring days and 2 on goal-setting days, compared with control days. Six participants did not benefit from the interventions. In aggregated analyses, mean step counts were higher on goal-setting days (8,499.9 vs. 7,956.3) and on self-monitoring days (8,630.3 vs. 7,825.9). Multilevel analyses showed a significant effect of the self-monitoring condition (p = .01), the goal-setting condition approached significance (p = .08), and there was a small linear increase in walking over time (p = .03).
  
  
  CONCLUSIONS
  N-of-1 randomized trials are a suitable means to test behavioral interventions in individual participants.
authors.affiliation: Institute of Health and Society, Newcastle University, Newcastle, England. falko.sniehotta@ncl.ac.uk
authors.forename: Falko F
authors.initials: FF
authors.lastname: Sniehotta
authors.forename: Justin
authors.initials: J
authors.lastname: Presseau
authors.forename: Nicola
authors.initials: N
authors.lastname: Hobbs
authors.forename: Vera
authors.initials: V
authors.lastname: Araújo-Soares
mesh_terms: D000328:Adult; D000368:Aged; D005240:Feasibility Studies; D005260:Female; D006040:Goals; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011582:Psychological Theory; D012107:Research Design; D012927:Social Control, Informal; D060145:Text Messaging; D016138:Walking / Q000523:psychology* / Q000706:statistics & numerical data*