BACKGROUND The clinical utility of genotype-guided (pharmacogenetically based) dosing of warfarin has been tested only in small clinical trials or observational studies, with equivocal results. METHODS We randomly assigned 1015 patients to receive doses of warfarin during the first 5 days of therapy that were determined according to a dosing algorithm that included both clinical variables and genotype data or to one that included clinical variables only. All patients and clinicians were unaware of the dose of warfarin during the first 4 weeks of therapy. The primary outcome was the percentage of time that the international normalized ratio (INR) was in the therapeutic range from day 4 or 5 through day 28 of therapy. RESULTS At 4 weeks, the mean percentage of time in the therapeutic range was 45.2% in the genotype-guided group and 45.4% in the clinically guided group (adjusted mean difference, [genotype-guided group minus clinically guided group], −0.2; 95% confidence interval, −3.4 to 3.1; P=0.91). There also was no significant between-group difference among patients with a predicted dose difference between the two algorithms of 1 mg per day or more. There was, however, a significant interaction between dosing strategy and race (P=0.003). Among black patients, the mean percentage of time in the therapeutic range was less in the genotype-guided group than in the clinically guided group. The rates of the combined outcome of any INR of 4 or more, major bleeding, or thromboembolism did not differ significantly according to dosing strategy. CONCLUSIONS Genotype-guided dosing of warfarin did not improve anticoagulation control during the first 4 weeks of therapy. (Funded by the National Heart, Lung, and Blood Institute and others; COAG ClinicalTrials.gov number, NCT00839657.)

Background-The Mayo score and a non-invasive 9-point partial Mayo score are used as outcome measures for clinical trials assessing therapy for ulcerative colitis. There are limited data assessing what defines a clinically relevant change in these indices. We sought to assess what constitutes a clinically meaningful change in these indices using data from a recently completed placebo-controlled clinical trial.

The similarity in concordance overall indicates that genetic factors do not play a major role in causing typical PD. No genetic component is evident when the disease begins after age 50 years. However, genetic factors appear to be important when disease begins at or before age 50 years.

In a prospective study of 1,805 hospitalized patients in the Stroke Data Bank of the National Institute of Neurological and Communicative Disorders and Stroke, the 1,273 with infarction were classified into diagnostic subtypes. Diagnosis was based on the clinical history, examination, and laboratory tests including computed tomography, noninvasive vascular imaging, and where safe and relevant, angiography. Five hundred and eight cases (fully 40%) were labeled as infarcts of undetermined cause (IUC), of which 138 (27%) were evaluated with both computed tomography and angiography. The clinical syndrome and computed tomographic and angiographic findings in 91 (65.9%) of these 138 IUC cases were clearly not attributable to large-artery thrombosis and could permit reclassification of the infarct as due to some form of embolism. Failure to define a source of embolus kept them in the category of IUC. Thirty-one cases (22.5%) could be reclassified as due to stenosis or thrombosis of a large artery, and 16 (11.6%) as lacunar infarction. To determine if those selected for angiography among the IUC patients differed from those with other final diagnoses, a stepwise multiple logistic model was used. The most important characteristics were young age, presence of a superficial infarct, prior transient ischemic attack, low weakness score, and presentation with a nonlacunar syndrome. The results of the model suggest that angiography use was determined by clinical characteristics uniformly across centers and not by final diagnosis. Continued use of the category IUC may help clarify risk factors and stroke subtypes, allow new mechanisms of ischemic stroke to be uncovered, and prevent classification categories of stroke used in clinical trials from becoming too broad.

We examined the frequency of development of afebrile seizures in 1706 children who had experienced at least one febrile seizure and were followed to the age of seven years. Epilepsy developed by seven years of age in 20 per 1000 (2 per cent), and another 10 per 1000 had at least one afebrile seizure that did not meet our definition of epilepsy. In children whose neurologic or developmental status was suspect or abnormal before any seizure and whose first seizure was complex (longer than 15 minutes, multiple or focal) epilepsy developed at a rate 18 times higher than in children with no febrile seizures (92 vs. 5 per 1000; P less than 0.001). In the largest group with febrile seizures, those previously normal with noncomplex first febrile seizures, epilepsy developed in 11 per 1000; this rate, although moderate, was greater than that for children with no febrile seizures (P = 0.027). Prior neurologic and developmental status and characteristics of the first febrile seizure are important predictors of epilepsy after febrile seizures.