Measured versus self-reported compliance with doxycycline therapy for chlamydia-associated syndromes: high therapeutic success rates despite poor compliance

Sex Transm Dis. 1999 May;26(5):272-8. doi: 10.1097/00007435-199905000-00006.


Objective: To compare self-reported doxycycline compliance in men and women attending an STD clinic with indications for Chlamydia trachomatis treatment to compliance measured using microprocessor-containing medication vials to count each time and date medication vials were opened. A secondary objective was to correlate outcomes of therapy, as measured by symptom resolution and persistence of chlamydial nucleic acids, with measured doxycycline compliance.

Methods: Between September 1995 and July 1997, Medication Event Monitoring System (MEMS) caps were used to measure compliance with recommended doxycycline therapy (14 doses over 7 days) in patients treated for presumed C. trachomatis infections. Polymerase chain reaction (PCR) assays for C. trachomatis were performed on urine specimens collected at the time of follow-up evaluation.

Results: Of 221 evaluable participants, although 90% reported taking their medication as directed, only 33 (16%) managed this level of compliance according to data obtained from the MEMS cap. Although 144 (65%) patients took more than 11 of 14 doses over 8 days, 147 (67%) participants had at least one interval of 24 hours or longer between doses in an 8-day period. Of 81 participants with positive C. trachomatis cultures at enrollment, follow-up urine PCR for C. trachomatis was positive in 5 (6%). Medication Event Monitoring System data for four of the five patients with positive PCR tests as follow-up showed each had two or more 24-hour intervals when their medication vials were not opened and three of four had opened their vials less than 11 times.

Conclusions: This study suggests that few patients take medications as prescribed and that self-report substantially underestimates medication noncompliance. Despite poor compliance, there were few treatment failures.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Bacterial Agents / adverse effects
  • Anti-Bacterial Agents / therapeutic use*
  • Chlamydia Infections / drug therapy*
  • Chlamydia Infections / microbiology
  • Chlamydia trachomatis* / genetics
  • Chlamydia trachomatis* / isolation & purification
  • Doxycycline / adverse effects
  • Doxycycline / therapeutic use*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Patient Compliance*
  • Self Administration
  • Treatment Outcome


  • Anti-Bacterial Agents
  • Doxycycline