Evaluation of the diabetes health plan to improve diabetes care and prevention.

Investigators from the University of California, Los Angeles (UCLA), and members of the leadership and data analysis teams at UnitedHealthcare (UHC) are partnering to evaluate the Diabetes Health Plan (DHP), an innovative disease-specific insurance product designed by UHC specifically for patients with prediabetes or diabetes. The DHP provides improved access to care management, telephone coaching, and enhanced Internet-based communication with enrollees. The evaluation will use a quasi-experimental design, comparing patients from employer groups that offer the DHP with patients from groups that do not, to determine the effect of the DHP on incidence of diabetes, adherence to metformin, and costs of care among patients with prediabetes. Other factors studied will be cardiovascular risk factor control, adherence to preventive services, health care use, and costs of care among patients with existing diabetes.

Urinary interleukin-8 with asymptomatic bacteriuria in pregnancy.

OBJECTIVE: To evaluate urinary interleukin-8 (IL-8), an inflammatory cytokine, as a screening method for detecting asymptomatic bacteriuria in pregnancy. METHODS: Clean-catch urine samples from 200 pregnant women undergoing screening for asymptomatic bacteriuria were evaluated by urine culture, urine dipstick analysis, and measurement of IL-8. Interleukin-8 levels were measured by a chemiluminescent immunoassay (Immulite IL-8, Diagnostic Products Corp., Los Angeles, CA), and a receiver operating characteristic curve was used to determine the optimal cutoff point. Asymptomatic bacteriuria was defined as at least 100,000 colony-forming units of a single organism per mL. Dipstick testing included nitrite assessment as positive or negative and leukocyte esterase as negative, trace, 1+, 2+, or 3+. Dipstick testing was considered positive if nitrite was positive or leukocyte esterase was trace or greater. Sensitivities, specificities, positive and negative predictive values were determined for urinary leukocyte esterase and nitrite and compared with those of IL-8. chi(2) and Mann-Whitney U tests were used for statistical analyses. RESULTS: Twenty women were identified with asymptomatic bacteriuria by urine culture. The median urinary IL-8 levels for women with and without asymptomatic bacteriuria were 356 pg/mL and 125 pg/mL, respectively (P <.01, Mann-Whitney U test). Using an optimal cutoff point of 264 pg/mL, IL-8 had a sensitivity, specificity, positive and negative predictive value of 70%, 67%, 19%, and 95% for predicting asymptomatic bacteriuria. Urine dipstick analysis with either a positive leukocyte esterase or nitrite had a sensitivity, specificity, positive and negative predictive value of 45%, 62%, 12%, and 91%, respectively, for detecting asymptomatic bacteriuria. The differences between these testing methods were not statistically significant. CONCLUSION: Urinary interleukin-8 is not an acceptable screening method for asymptomatic bacteriuria in pregnancy because it fails to detect 30% of women with this condition.

Effects of storage temperature and time before centrifugation on ionized calcium in blood collected in plain vacutainer tubes and silicone-separator (SST) tubes.

We studied the stability of ionized calcium and pH in samples stored at either room temperature or 4 degrees C, in centrifuged and uncentrifuged blood-collection tubes and in centrifuged tubes containing a silicone-separator gel (SST tubes). At room temperature, in uncentrifuged blood from healthy individuals, mean ionized calcium usually increased no more than 10 mumol/L per hour; at 4 degrees C it did not change detectably for 70 h. This stability was fortuitous, however: the concentrations of both hydrogen and lactate ions in these samples increased, apparently with offsetting effects on the concentration of ionized calcium. Blood stored for 70 h at 4 degrees C in centrifuged SST tubes, although showing a slightly greater change in ionized calcium, had less change of pH and no change in the ionized calcium corrected to pH 7.4. In 11 heparinized whole-blood samples from eight patients in intensive care, the mean change per hour in ionized calcium and pH after storage at room temperature was +10 mumol/L and -0.04 units, respectively.

Spectrophotometric micro method for measurement of dialyzable calcium by use of cresolphthalein complexone and continuous-flow analysis.

We adapted a method for dialyzable calcium from fluorometric detection by use of calcein to a more specific spectrophotometric determination with cresolphthalein complexone. The reagents are available commercially and perform satisfactorily with respect to noise level, drift, stability, and sensitivity. Construction of the continuous-flow manifold with commercially available components (injection blocks, coils, and dialyzer) and the use of a 9-mm pathlength flow cell in an AutoAnalyzer I colorimeter have permitted a sampling rate of 70/h, and decreased the volume of serum required to 130 microL. A comparison of 71 sera analyzed by the present and the calcein method gave means of 1.39 (SD 0.14) and 1.39 (SD 0.13) mmol/L, respectively. The regression equation was: present method = 1.016 calcein--0.022 mmol/L (r = 0.97). The CV for the new method, as determined from 46 randomized duplicate analyses, was < 1%. The reference interval, as evaluated from results for 93 different individuals, was 1.26-1.43 mmol/L. We conclude that our methods is an improvement with respect to noise level, drift, specificity, detectability, and more general availability of instrumentation. Moreover, the smaller sample volume required makes possible the routine measurement of dialyzable calcium in pediatric samples.