Durable effects of implementation intentions: reduced rates of confirmed pregnancy at 2 years

Health Psychol. 2011 May;30(3):368-73. doi: 10.1037/a0022739.


Objective: To assess the long-term impact of implementation intention formation in reducing consultations for emergency contraception and pregnancy testing among teenage women.

Design: Teenage women visiting a family planning clinic were randomly assigned to implementation intention versus control conditions.

Main outcome measures: Objective measures of consultation outcomes were obtained from clinic records at 2-year follow-up (N = 227).

Results: Rates of consultation for emergency contraception and pregnancy testing in the implementation intentions condition were 19% and 33% lower, respectively, compared to the rates observed in the control condition. Pregnancy rates were 43% lower. Intervention participants who consulted for emergency contraception and pregnancy testing at baseline were more than twice as likely to change to consulting for contraceptive supplies over the follow-up period compared to equivalent control participants (19% vs. 9%).

Conclusion: The impact of implementation intention formation on reducing pregnancy risk among teenagers is durable over 2 years. Implementation intentions were successful in changing behavior among precisely those participants who were at greatest risk of becoming pregnant.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Condoms / statistics & numerical data
  • Contraception / methods
  • Contraception / psychology
  • Contraception Behavior / psychology*
  • Female
  • Health Promotion / methods*
  • Humans
  • Intention
  • Pregnancy / statistics & numerical data
  • Surveys and Questionnaires