Abstract
OBJECTIVE: To study the association between knowledge about levonorgestrel emergency contraception (LNG-EC) and the risk of ectopic pregnancy (EP) following LNG-EC failure. METHODS: This study included 600 women who had visited the hospital with LNG-EC failure. Of these, 300 with EP and 300 with intrauterine pregnancy (IUP) were recruited to the EP group and IUP group respectively. The participants were interviewed face-to-face using a standardized questionnaire. MAIN OUTCOME MEASURES: Pearson's chi-square tests and t-test were used to compare the sociodemographic characteristics, reproductive and gynecological history, surgical history, previous contraceptive experience, and answers to 10 questions concerning the knowledge about LNG-EC. RESULTS: Those who gave incorrect answers to the question regarding the basic mechanism and specific method of levonorgestrel emergency contraceptive pills (LNG-ECPs) were at a higher risk of EP after LNG-EC failure. Women who did not strictly follow instructions or advice from healthcare professionals were more likely to subsequently experience EP (p < 10(-4) ). Women with LNG-EC failure reported friends/peers, TV, and Internet as the main sources of information. No difference was observed with regard to the sources of knowledge on LNG-EC (p = 0.07). CONCLUSIONS: The results illustrate the importance of strictly following the doctor's guidance or drug instructions when using LNG-ECPs. The media should be used to disseminate information about responsible EC, and pharmacy staff should receive regular educational training sessions in this regard. © 2016 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.