Is opium addiction a risk factor for deep vein thrombosis? A case-control study.

The objective of the present study was to investigate the association between opioid addiction and deep vein thrombosis (DVT) and whether opioid addiction is a risk factor of DVT. This case-control study was conducted in Kerman, Iran in 2008. The cases were selected among the patients hospitalized because of DVT. The controls were recruited from the same hospital from internal wards. Opioid addiction was investigated by physician's interview based on Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) criteria. Logistic regression modeling was carried out for statistical analysis. The crude odds ratio (OR) of opioid addiction for DVT was 4.25 (95% confidence interval = 2.6-6.9). However, multivariate logistic regression analysis revealed that opioid addiction was not an independent risk factor for DVT, OR 0.56 (0.1-3). The method of opioid usage--oral or inhaled and injected--OR 6.3 (1.41-28.3) and previous surgery in the last 3 months before the study, OR 3.1 (1.36-7), were significant independent risk factors for incidence of DVT. Opioid addiction per se was not a risk factor for DVT, whereas the method of its use especially injection was found to be independent risk factor for DVT. Our results suggested the prophylactic treatment of anticoagulant for intravenous drug abuser is considerable.