You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Outcome", "Participant", "Intervention"].

Please return the output as a JSON object of the format: {"Participant" : ["patients with COPD", ...], "Intervention" : ["Atenolol", ...], "Outcome" : ["blood pressure", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

[ Prophylactic use of low molecular weight heparin in combination with graduated compression stockings in post-operative patients with gynecologic cancer ] . OBJECTIVE The aim of this study was to compare the efficacy of low molecular weight heparin ( LMWH ) combined with graduated compression stockings ( GCS ) with GCS alone as prophylactic measures for venous thromboembolism ( VTE ) in post-operative patients with gynecologic cancer . METHODS Patients diagnosed with gynecologic cancer undergoing primary major surgery between 2010 and 2011 in our institute were randomized to receive LMWH+GCS or GCS as VTE prophylaxis post-operatively . RESULTS Altogether 247 patients were enrolled . The incidence of VTE in patients treated with LMWH + GCS was significantly lower than that in patients using GCS alone ( 0.8 % Vs. 8.1 % , P = 0.01 ) . There were no severe bleeding complications in the patients with prophylactic use of LMWH and the occurrence rate of wound dehiscence was comparable between the two groups ( P > 0.05 ) . Multivariable logistic regression analysis revealed that age over 60 years ( P = 0.015 ) , duration of operation over 3 hours ( P = 0.04 ) and without prophylactic use of LMWH ( P = 0.02 ) were independent risk factors for VTE . CONCLUSIONS Dual prophylaxis with LMWH and GCS should be recommended for gynecologic cancer patients undergoing major surgery for its better efficacy than GCS . Prophylactic use of LMWH is safe and convenient . Patients with older age and prolonged operation time are at highest risk of developing VTE post-operatively .
{"Intervention": ["GCS", "low molecular weight heparin", "GCS .", "graduated compression stockings", "GCS alone", "low molecular weight heparin ( LMWH )", "LMWH+GCS", "graduated compression stockings ( GCS )", "LMWH"], "Outcome": ["incidence of VTE", "efficacy", "VTE post-operatively .", "prophylactic measures for venous thromboembolism ( VTE )", "severe bleeding complications", "occurrence rate of wound dehiscence"], "Participant": ["post-operative patients with gynecologic cancer ]", "247", "post-operative patients with gynecologic cancer", "gynecologic cancer"]}