Coagulation and bleeding problems are associated with substantial morbidity and mortality, and inappropriate testing practices may lead to bleeding or thrombotic complications.
To evaluate practices reported by hospital coagulation laboratories in the United States and to determine if the number of beds in a hospital was associated with different practices.
From a sampling frame of institutions listed in the 1999 directory of the American Hospital Association, stratified into hospitals with 200 or more beds ("large hospitals") and those with fewer than 200 beds ("small hospitals"), we randomly selected 425 large hospitals (sampling rate, 25.6%) and 375 small hospitals (sampling rate, 8.8%) and sent a survey to them between June and October 2001. Of these, 321 large hospitals (75.5%) and 311 small hospitals (82.9%) responded.
An estimated 97.1% of respondents reported performing some coagulation laboratory tests. Of these, 71.6% reported using 3.2% sodium citrate as the specimen anticoagulant to determine prothrombin time (81.3% of large vs 67.7% of small hospitals, P < .001). Of the same respondents, 45.3% reported selecting thromboplastins insensitive to heparin in the therapeutic range when measuring prothrombin time (59.4% of large vs 39.8% of small hospitals, P < .001), and 58.8% reported having a therapeutic range for heparin (72.9% of large vs 53.2% of small hospitals, P < .001). An estimated 96.3% of respondents assayed specimens for activated partial thromboplastin time within 4 hours after phlebotomy, and 89.4% of respondents centrifuged specimens within 1 hour of collection. An estimated 12.1% reported monitoring low-molecular-weight heparin therapy, and to do so, 79% used an assay for activated partial thromboplastin time (58% of large vs 96% of small hospitals, P = .001), whereas 38% used an antifactor Xa assay (65% of large vs 18% of small hospitals, P = .001).
Substantial variability in certain laboratory practices was evident. Where significant differences existed between the hospital groups, usually large hospitals adhered to accepted practice guidelines to a greater extent. Some reported practices are not consistent with current recommendations, showing a need to understand the reasons for noncompliance so that better adherence to accepted standards of laboratory practice can be promoted.