Association of Malignancy Prevalence With Test Properties and Performance of the Gene Expression Classifier in Indeterminate Thyroid Nodules.

Importance: It is crucial for clinicians to know the malignancy prevalence within each indeterminate cytologic category to estimate the performance of the gene expression classifier (GEC). Objective: To examine the variability in the performance of the GEC. Design, Setting, and Participants: This retrospective cohort study of patients with Bethesda category III and IV thyroid nodules used single-institution data from January 1, 2013, through February 29, 2016. Expected negative predictive value (NPV) was calculated by adopting published sensitivity and specificity. Observed NPV was calculated based on the true-negative rate. Outcomes were compared with pooled data from 11 studies published January 1, 2010, to January 31, 2016. Results: A total of 145 patients with 154 thyroid nodules were included in the study (mean [SD] age, 56.0 [16.2] years; 106 females [73.1%]). Malignancy prevalence was 45%. On the basis of this prevalence, the expected NPV is 85% and the observed NPV is 69%. If the prevalence is assumed to be 25%, the expected NPV would be 94%, whereas the observed NPV would be 85%. Pooled data analysis of 11 studies comprising 1303 participants revealed a malignancy prevalence of 31% (95% CI, 29%-34%) and a pooled NPV of 92% (95% CI, 87%-96%). Conclusions and Relevance: In this study, variability in the performance of the GEC was not solely a function of malignancy prevalence and may have been attributable to intrinsic variability of the test sensitivity and specificity. The utility of the GEC in practice is elusive because of this variability. A better definition of the GEC's intrinsic properties is needed.

Consequences of delayed pump infusion line change in patients with type 1 diabetes mellitus treated with continuous subcutaneous insulin infusion.

OBJECTIVE: To systematically investigate the effect of lack of adherence to the recommended change in insulin pump infusion line use beyond 48 h and determine whether the type of insulin made a difference. RESEARCH DESIGN AND METHODS: This was a double-blind, randomized, crossover trial with 20 patients with diabetes mellitus I using insulins aspart and lispro without a line change for up to 100 h. Using retrospective continuous glucose monitoring, we analyzed the average glucose over the day. Changes in serum 1,5-anhydroglucitol, carboxymethyllysine, and free 15-F(2t) isoprostane were also studied. RESULTS: From Day 2 to Day 5 of the pump line use, the daily average glucose level increased from 122.7 to 163.9 mg/dl (P<.05), fasting glucose from 120.3 to 154.5 mg/dl (P<.05), postprandial glucose from 114.6 to 172.1 mg/dl (P<.05), and the daily maximum glucose from 207.7 to 242.8 dl (P<.05 for the trend). Time period that the glucose was >180 mg/dl increased from 14.5% to 38.3% (P<.05). Loss of control occurred despite increase in total daily insulin dose from 48.5+/-11.8 to 55.3+/-17.9 U (P=.05). There was no difference in loss of control between insulin types, and biomarkers measured did not change significantly. CONCLUSIONS: The insulin pump infusion should be changed every 48 h in patients using continuous subcutaneous insulin infusion (CSII), to avoid loss of glycemic control. In the short-term, this loss of glycemic control has no impact on oxidative stress and glycation.