Medical history screening for thrombophilic risk: is this adequate?

Objective To evaluate the reliability of medical history taken before hormonal medication administration to identify women with an increased risk for thromboembolic events detected by laboratory screening. Design Prospective study. Setting Outpatient endocrine clinic of a university-based hospital. Patient(s) Four hundred forty-three consecutive women (median age 49 years) who presented with endocrine disorders. Intervention(s) None. Main Outcome Measure(s) Parallel screening, on first visit, with a complete medical history, and same-day laboratory screening for thromboembolic risk. Laboratory examination in a two-step procedure with a standard assay and confirmation by genotyping on the second visit. Result(s) A total of 13.8% (61/443) patients with an abnormal activated protein C (APC) resistance test were identified. Second blood samples revealed a prevalence of factor V (Leiden) heterozygosity in 10.9% (homozygosity in 0.2%). There was a significantly higher prevalence of thrombotic events in a first degree relative of patients with APC resistance (in 18.3%) compared with women with a normal test outcome (in 7.8%). However, medical history (personal and family history) was negative concerning hints for thromboembolic events in more than 80% of patients with a laboratory risk profile for thromboembolic morbidity. No association of APC and factor V testing with the patients’ gynecological/obstetric history (e.g., live birth rate, miscarriages) was observed. Conclusion(s) Medical history alone may be inadequate to identify all patients at risk for thromboembolic complications with hormonal treatment.