The risks of venous thromboembolic disease among German women using oral contraceptives: a database study

Contraception. 1998 Feb;57(2):67-70. doi: 10.1016/s0010-7824(98)00002-x.

Abstract

This study investigated the risk of venous thromboembolic disease (VTE) between second and third generation combined oral contraceptives, using the German MediPlus database of patient records. Women studied included 42 patients between the ages of 18 and 49 years, with a diagnosis of VTE treated with an anticoagulant, who were exposed to an oral contraceptive (OC). Four controls per patient (168), matched by year of birth and exposure to an OC on the even day, were identified. More women were users of second generation than third generation OC, and none were using progestogen-only pills. There was no significant difference between patients and control subjects with respect to the type of OC used on the event day (unadjusted odds ratio for third versus second generation users was 0.77; 95% confidence interval [CI] 0.38-1.57). There was no significant age difference between second and third generation users among patients or control subjects. Between January 1 and the event date, there was no significant difference between the patients and control subjects in terms of the number of oral contraceptive prescriptions, number of consultations for psychotherapeutic complaints, or mixed physical and psychotherapeutic consultations; however, patients did demonstrate significantly more consultations for purely physical complaints compared with control subjects (p < 0.0001). There were no significant consultation differences between patients with pulmonary emboli (n = 6) and other VTE patients (n = 36). No significant differences with respect to VTE risk between users of second and third generation oral contraceptives were found in this study. Consultations (physical) for patients were higher than for control subjects before the VTE event. If consultation rate relates to the general health status of a person, this might indicate that VTE risk is higher among women of poorer health, but that this is not related to the type of progestogen in the oral contraceptive that they use.

PIP: The German MediPlus database of patient records from 451 practices was used to investigate the risk of venous thromboembolism (VTE) in users of second- and third-generation combined oral contraceptives (OCs). Cases included 42 women 18-49 years of age with a diagnosis in 1992-95 of a VTE treated with an anticoagulant and with a history of OC use. Also enrolled were 168 controls (4 per case), matched to cases by year of birth and exposure to an OC on the event day. 64.3% of cases and 53.0% of controls had used a second-generation OC; use of a third-generation OC was reported by 35.7% of cases and 38.1% of controls. No significant differences in terms of VTE risk factors were identified between users of second- and third-generation OCs. The odds ratio for VTE among users of third-generation compared to second-generation OCs was 0.77 (95% confidence interval, 0.38-1.57). There were no significant differences between cases and controls in terms of the type of OC used, age, the total number of OC prescriptions issued, number of consultations for psychotherapeutic complaints, and number of consultations for mixed psychotherapeutic and physical complaints. Although cases had more consultations for physical complaints before the VTE (presumed to be a proxy for poor general health), this was not related to the type of progestogen in the OC.

MeSH terms

  • Adolescent
  • Adult
  • Contraceptives, Oral / adverse effects*
  • Databases, Factual
  • Female
  • Germany
  • Heparin / therapeutic use
  • Humans
  • Middle Aged
  • Phlebitis / chemically induced
  • Pulmonary Embolism / chemically induced
  • Risk Factors
  • Thromboembolism / chemically induced*
  • Thrombophlebitis / chemically induced
  • Warfarin / therapeutic use

Substances

  • Contraceptives, Oral
  • Warfarin
  • Heparin