Confidence Interval Of Mean Difference Research Articles

Absorption of calcium and magnesium in patients with intestinal resections treated with medium chain fatty acids

BACKGROUNDSteatorrhoea is associated with increased faecal loss of calcium and magnesium. Medium chain C8-C10 triglycerides (MCTs) improve fat absorption in patients with small bowel resections but the effects on intestinal...

Placement of the intubating laryngeal mask is easier than the laryngeal mask during manual in-line neck stabilization

We have compared in 25 patients ease of placement of the conventional and intubating laryngeal masks while the patient's head and neck were stabilized by a manual in-line method, in a randomized, crossover study. After induction of anaesthesia and neuromuscular block, the masks were placed in turn. Adequacy of ventilation and ease of placement (using a 10-cm visual analogue scale (VAS)) were assessed; time for placement between removal of the face mask and connection of the laryngeal mask to the breathing system was measured. Adequate ventilation was always obtained after placement of the intubating laryngeal mask, whereas ventilation was adequate in 22 of 25 patients after placement of the conventional laryngeal mask. Placement of the intubating laryngeal mask was significantly easier (P < 0.001; 95% confidence intervals (CI) for median difference 8-31 mm in VAS) and faster (P << 0.001; 95% CI for mean difference 3.2-6.2 s) than that of the conventional mask.

Periodontal repair in dogs: evaluation of the natural disease model

Animal models are frequently consulted for histometric analysis of periodontal reconstructive therapy. Such models include surgical, periodontitis-simulating and natural disease defects in canines or non-human primates. Our studies suggest that homogeneity in defect height is critical for sensitivity of surgical and periodontitis-simulating supraalevolar defect models in discriminating treatment effects. We herein evaluate this model aspect for natural disease defects. Buccal-lingual histologic sections from the 2nd, 3rd, and 4th mandibular premolar teeth (P2, P3, P4) from 6 aged beagle dogs with advanced natural periodontal disease were used. Defect heights from the reduced alveolar bone to the cemento-enamel junction were recorded in central step-serial sections at the buccal and lingual surfaces of the mesial and distal roots for the premolar teeth. Mean defect height, standard deviation and coefficient of variation were calculated for tooth types and jaw quadrants, separately, and for all teeth. Confidence intervals were calculated for teeth in left and right jaw quadrants. Mean defect height and standard deviation for left and right jaw quadrants was 3.6 +/- 0.9 and 3.3 +/- 0.6 mm for P2, 3.3 +/- 0.9 and 2.3 +/- 0.9 mm for P3, and 3.3 +/- 1.0 and 4.5 +/- 1.6 mm for P4, respectively. Coefficient of variation for defects for left and right jaw quadrants was 26 and 40%, respectively. Using confidence intervals for mean differences between jaw quadrants, it was determined that a mean treatment effect may be as large as 0.8, 1.1 and 1.9 mm for P2, P3 and P4, respectively, before being detected as statistically significant (p < or = 0.05; N = 6).(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence of hypercholesterolaemia and its relationship with albuminuria in insulin-dependent diabetic patients: an epidemiological study.

To assess the prevalence of hypercholesterolaemia and its relationship with metabolic control and urinary albumin excretion in Type 1 diabetic patients, all 1577 insulin-dependent patients attending the outpatient clinic at the Steno Memorial Hospital were studied. None had previously received lipid-lowering drugs. Hypercholesterolaemia, defined as plasma concentration of cholesterol above 6.4 mmol l-1 was found in 156 patients (10%) (95%) confidence intervals (CI) 8.4-11.5%) compared with 11% in the Danish background population. Compared with the normolipidaemic diabetic patients, the hyperlipidaemic patients were older (42 vs 37 years: p less than 0.001, 95% CI for difference in means 3-7 years), they had a higher glycosylated HbA1C (9.2 vs 8.6%, p less than 0.001, 95% CI for difference in means 0.4-1.3%) and their urinary albumin excretion was 32 vs 12 mg 24 h-1, p less than 0.001. Of the 1577 diabetic patients, 1084 patients (73%) had normal urinary albumin excretion (UAE less than 30 mg 24 h-1), 255 (17%) had microalbuminuria (UAE 30-300 mg 24 h-1) and 136 (9%) had overt clinical nephropathy (UAE greater than 300 mg 24 h-1). The plasma concentration of cholesterol rose significantly with increasing urinary albumin excretion; normoalbuminuric 4.78 mmol l-1 +/- 1.06 (mean +/- SD); microalbuminuric: 5.12 mmol l-1 +/- 1.23 and macroalbuminuric: 4.89 mmol l-1 +/- 1.38 (p less than 0.001). The influence of metabolic control on the plasma level of cholesterol was of only minor clinical importance.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced Erythrocyte Superoxide Dismutase Activity in Low Birth Weight Infants Given Iron Supplements

Erythrocyte superoxide dismutase (ESOD) activity reflects copper utilization and the risk of copper deficiency. To investigate the possible effects of inorganic iron on the metabolism of copper in low birth weight infants, we have measured ESOD activities in three groups of infants receiving different iron supplements. Fifty-five low birth weight infants were randomly assigned to receive daily from 28 d either 13.8 mg (HiFe), 7 mg (MidFe), or no elemental iron (NatFe) as iron edetate. At 27 d, 8, 12, and 20 wk postnatal age, infants were weighed and measured and hematologic indices, plasma ferritin, zinc, and copper concentrations, and ESOD activities were assayed. Anthropometrical and hematologic indices and plasma copper and zinc concentrations did not differ among treatment groups at any time, but at 20 wk, plasma ferritin concentrations [(micrograms/L) mean; SD] were lower in the NatFe group (17; 2.0) than in the HiFe group (32; 1.9: 95% confidence interval for mean difference 6.6 to 22.0, p less than 0.01). ESOD activities (U/g Hb) were similar in HiFe (1447; 263), MidFe (1552; 322), and NatFe (1538; 382) groups at 27 d, but by 20 wk activities in the HiFe group (1537; 211) were lower than in the MidFe (1789; 403: 95% confidence interval 38 to 466, p less than 0.05) and NatFe (1858; 304: 95% confidence interval 150 to 492, p less than 0.01) groups. The lower ESOD activities found in the HiFe group at 20 wk may reflect altered copper metabolism induced by the iron supplement, but the clinical importance of this observation is unknown.

Skeletal age assessment using the first, second, and third fingers of the hand

The purpose of this study was to determine whether skeletal age assessments using the first, second, and third fingers of the hand are as valid as those using the entire hand-wrist. Previous studies have demonstrated that treatment can be better oriented to the unique physiologic characteristics of the individual if skeletal age is used to assess maturational status. The sample was selected from the files of the Bolton-Brush Foundation and consisted of radiographs of 19 male and 20 female subjects whose yearly hand-wrist radiographs were available covering the age span of 10 to 16 years for girls and 12 to 18 years for male subjects. Two maturity indicators, the sesamoid and the epiphyseal-diaphyseal stages of ossification, were evaluated. Reliability of the method was tested by the t test for paired comparisons and the Pearson product-moment correlation. To determine the validity of the method, an analysis of variance (ANOVA) was used. In addition, the Pearson product-moment correlations between the two methods were performed and the 95% confidence intervals for mean differences for each sex and time were calculated. As indicated by the ANOVA, the two methods differed by a statistically significant amount, with the three-fingers assessments being slightly more advanced than the hand-wrist assessments. Although they differed, for the male subjects, the three-fingers method never deviated from that of the hand-wrist by more than 2.89 months with a minimum deviation of 0.32 months. For the female subjects, the maximum deviation was 4.45 months with a minimum of 1.55 months. The maximum deviations occurred during the time of epiphyseal-diaphyseal fusion when growth is nearing its completion and therefore they are of no clinical importance. The advantage of the use of the three-fingers method is that it can be incorporated in the lateral cephalometric radiograph, thus eliminating the need for additional radiographs.

Acute controlled hypotension and EEG in patients with hypertension and cerebrovascular disease.

Forty-seven patients with hypertension and/or cerebrovascular disease were examined by an acute controlled hypotension test. This was performed by intravenous administration of the ganglionic blocking agent pentholonium and head-up tilting on a pivoted table with observation of the clinical neurological state and simultaneous EEG recording. Blood pressure was reduced by approximately 55% and brought to the point where signs of general cerebral ischaemia developed. By tilting back to horizontal the blood pressure returned to near the normal level. No change in focal neurological symptoms or changes in the EEG were observed, and it is concluded that the majority of hypertensive patients with or without previous stroke do tolerate normalization of their blood pressure. Controlled hypotension with tilting seems a simple and valuable test for excluding those few subjects who might not tolerate a blood pressure reduction. Whether EEG monitoring during the test increases the value of the test has not been answered.