The quantitative validation of non-endoscopic disease activity indices in ulcerative colitis.

BACKGROUND: Ulcerative colitis disease activity indices have not been formally validated. AIM: To analise quantitatively the psychometric and performance validity of two non-endoscopic indices for ulcerative colitis, the Simple Clinical Colitis Activity Index and the Seo Index. METHODS: In 66 patients with ulcerative colitis, the measurement of disease activity was repeated with the two non-endoscopic indices, St Mark's Index, and the Inflammatory Bowel Disease Questionnaire. Psychometric validity was evaluated by measuring the content, construct, criterion-convergent and criterion-predictive validity on a 0-1 scale. Performance validity was evaluated by measuring the reproducibility and responsiveness on a 0-1 scale. RESULTS: The Simple Clinical Colitis Activity Index had good to excellent psychometric and performance validity, while the Seo Index had moderate to excellent psychometric validity and moderate to good performance validity. The Simple Clinical Colitis Activity Index had weaknesses in content validity and in responsiveness. The Seo Index had weaknesses in content validity, construct validity and responsiveness. CONCLUSIONS: These two non-endoscopic indices for ulcerative colitis have good psychometric and performance validity, and are now the most rigorously validated disease activity indices for ulcerative colitis. The Simple Clinical Colitis Activity Index appears to have better overall validity. Quantitative evaluation identifies weaknesses in disease activity indices, and can lead to better disease activity indices for ulcerative colitis.

Patient defined dichotomous end points for remission and clinical improvement in ulcerative colitis.

BACKGROUND AND AIMS: Ulcerative colitis disease activity indices offer good statistical power but small changes in these indices may not be clinically important. There are no validated definitions of remission or of significant improvement for these indices. The use of clinically important end points would strengthen the validity of study outcomes. Our aims were to identify objective end points in standard disease activity indices for remission and for improvement in ulcerative colitis. METHODS: Sixty six consecutive patients with ulcerative colitis provided information about remission status and their disease activity. At a return visit 1-14 months later, these patients provided information about the change in their disease activity, and non-invasive indices were measured. RESULTS: Specific objective end points for determining remission with four standard indices and a quality of life instrument were determined (St Mark's <3.5, ulcerative colitis disease activity index <2.5, simple clinical colitis activity index (SCCAI) <2.5, Seo <120, and inflammatory bowel disease quality of life index (IBDQ) >205). These cut offs also identified patients who met a regulatory definition of remission. Specific objective end points for clinical improvement in two non-invasive indices and a quality of life instrument were determined with good sensitivity and specificity (SCCAI decrease >1.5, Seo decrease >30, IBDQ increase >20). CONCLUSIONS: We found specific cut off values for disease activity indices that identify patients who have significantly improved or achieved remission in an objective, sensitive, and specific manner. These cut offs should help in the interpretation of the outcomes of clinical trials in ulcerative colitis.

Lack of dopamine receptor agonists effect on striatal dopamine transporter binding sites.

Depending on experimental conditions, chronic cocaine exposure can induce an increase in binding to the dopamine transporter (DAT). One possible mechanism for the cocaine-induced-upregulation in DAT binding sites is through stimulation of presynaptic D2 receptors by excess synaptic dopamine. To test this hypothesis, the present experiment examined in rats the effect of chronic quinpirole and apomorphine treatments on striatal DAT binding sites. Rats were chronically injected subcutaneously with either: quinpirole, 0.7 mg/kg body weight, apomorphine, 2.0 mg/kg body weight, or vehicle. Striatal DAT binding was then examined autoradiographically using the DAT-selective cocaine congeners [125I]RTI-121 and [3H]WIN 35428. Analysis of the results indicated that quinpirole and apomorphine administration did not alter DAT cocaine binding sites.