A French study led by Dr Herve Decousus of St Etienne University Hospital analysed 844 people with leg superficial venous thrombosis (SVT) who had been referred to vascular specialists.
The researchers performed ultrasound scans of all participants' leg veins to determine whether they were also affected by DVT.
The team found that 25 per cent of patient assessed also had DVT.
At a three-month follow-up assessment, about one in 10 patients still had surface clots or presented new deep clots, despite 60 per cent having received anticoagulants and all having been given elastic stockings.
Risk factors for development of DVT at three months included male sex, PE and a diagnosis of cancer, as well as a history of DVT and absence of varicose veins, the study findings suggested.
The authors of the paper, published in the Annals of Internal Medicine, believe that this link between SVT and DVT may be more serious than is commonly recognised.
Dr Decousus and co-authors propose that compression ultrasonography might be considered for patients presenting with SVT so that potential DVT can be investigated.
They also suggested clinical trials should be undertaken to investigate the benefits and risks of anticoagulant therapy for the treatment of SVT and prevention of DVT.
A recent Austrian study of 46 patients with SVT also showed DVT in 24 per cent of cases. The researchers behind that study suggested patients diagnosed with SVT should be screened for DVT as a preventive measure.