Identification of premature ovarian failure patients with underlying autoimmunity

Although known causes of premature ovarian failure (POF) include X chromosome deletions, radiation and chemotherapy, and genetic defects of the gonadotropin hormones or receptors, at least one third to one half of cases remain idiopathic. A significant proportion of patients with apparently idiopathic POF have some evidence for an autoimmune etiology. However, the only gold standard for detecting autoimmune causes of immune ovarian destruction has been invasive ovarian biopsy. Serum antibodies to ovarian and other self-tissue have been described in up to one third of women with POF, but the tests are not well standardized, not well correlated with ovarian histology, and highly variable. Recently, specific defects of expression of cell surface markers on peripheral blood lymphocytes have been shown to identify, in population-based studies, individuals destined to develop autoimmune pancreatic destruction and type I diabetes mellitus, even before any other evidence of autoimmunity. We, therefore, sought to test the ability of cell surface marker expression in women with POF to identify autoimmune defects. Seventeen women with POF, 11 of whom had positive antibody titers to ovary, thyroid, or antinuclear antibody, were studied on at least two occasions and compared in blinded fashion with normal controls and patients with autoimmune type I diabetes mellitus. The most useful marker for identifying autoimmunity was the surface density of conformationally correct HLA class I molecules on macrophages, a structure essential for T cell education. Using this marker, 7 of the 9 patients with autoantibodies and 3 of the 8 patients without autoantibodies were identified as having evidence of a defect in self-antigen presentation similar to that of type I diabetics (chi-square, p = 0.03). Subsequent testing identified antismooth muscle antibodies in 1 of the women with a defect of HLA class I molecules but no previously identified autoimmunity. In addition, there were increased numbers of CD8 T cells in both autoimmune POF and insulin-dependent diabetes mellitus (IDDM) patients. Exclusive to POF patients was a statistically significant increase in CD8 density on T cells. This was most prominent in POF patients with an underlying autoimmune etiology. These data further support a role for autoimmunity in POF patients and suggest that the further development of cell surface markers in combination with other diagnostic tests could result in diagnosis before the development of complete ovarian failure. The possibility for disease-specific therapy to prevent further autoimmune ovarian damage in selected POF patients is also envisioned.

Utilization and cost analysis of bedside capillary glucose testing in a large teaching hospital: implications for managing point of care testing

PURPOSE

To study the use and cost of bedside capillary glucose testing in a large teaching hospital.

PATIENTS AND METHODS

In a prospective study of 40 inpatient units and 10 outpatient units at Massachusetts General Hospital, records were maintained by each unit of the date, time, operator, and results of patient and quality control tests. Cost analysis was performed using data from time studies, test tallies in logbooks, and hospital administration records.

RESULTS

The number of glucose meters in the hospital increased from 10 to 54 over a 2-year period. In 1992, 67,596 tests were performed by the bedside method, representing 30.7% of all glucose measurements performed in the institution. The majority of tests (94.7%) were performed on inpatients, and 10.2% of all hospital admissions underwent bedside glucose testing. The impact on the number of glucose tests performed in the clinical laboratories was minimal, indicating that bedside glucose testing was added as an extra test rather than as a substitute for laboratory-based glucose measurements. The cost of bedside glucose testing was $4.19 per test compared with $3.84 in the clinical laboratory. The cost varied from one unit to another (median $5.52, range $3.08 to $48.16), an effect largely attributed to the difference in the volume of tests performed by different units. In seven high-volume units the cost per test was lower than the corresponding value in the laboratory. The cost of bedside glucose testing included labor (80.2%) and supplies (19.8%). The percent of costs attributed directly to patient testing was 57.7%, whereas the costs for all other related activities (training, quality control, and quality assurance) was 42.3%.

CONCLUSIONS

Bedside capillary glucose testing is a rapidly expanding technology and is performed on a significant percentage of hospital admissions. Bedside glucose testing is not inherently more expensive than centralized laboratory measurements but implementation on inefficient care units with low utilization can add substantially to the cost. Much of the excess cost of the bedside method can be attributed to the high costs of quality control and quality assurance, training, and documentation.

Implementation of capillary blood glucose monitoring in a teaching hospital and determination of program requirements to maintain quality testing

PURPOSE

To study the implementation of bedside capillary glucose monitoring using a hospital-wide quality control (QC) program.

METHODS

A prospective study of QC performance in 7 outpatient and 39 inpatient treatment units was performed in a large teaching hospital over a 2-year period. Approximately 800 nurses were trained to perform bedside capillary glucose monitoring (Accu-Chek II, Boehringer-Mannheim, Indianapolis, IN). An eight-point QC program was instituted including proficiency testing, instrument maintenance, performance of daily controls, storage of reagent strips and supplies, instrument calibration, and documentation procedures.

RESULTS

Comparison of laboratory and bedside test results (split-sample proficiency testing) revealed Y = 1.004X + 7.26, r = 0.95, with a mean percent difference of -4.2% (p < 0.001). Less than 7% of results fell outside +/- 20% of the laboratory results. QC scores (0 = worst to 4 = best), based on adherence to the QC program, improved from 0 on the first inspection to 3.7 +/- 0.17 by the 11th inspection. The most common QC deficiencies were failure to perform split-sample testing (41.4%) and failure to perform instrument maintenance (30.2%). Significant differences were noted in the QC performance of different types of medical services. During the 2-year study period, the total number of glucose assays performed in the clinical laboratories decreased by 22.2% concurrent with initiation of bedside testing. The number of instruments in the hospital increased from 10 to 46.

CONCLUSIONS

Bedside capillary glucose assays can be widely implemented in large hospitals with an acceptable degree of accuracy. QC programs with frequent inspections are necessary to identify units that function inadequately, and a formal disciplinary policy is required to ensure compliance with the program.

The limited clinical value of home urine testing by diabetic patients

To investigate the value of home urine glucose testing in assessing chronic diabetic glucose control, the authors compared patients' glycosuria patterns with their mean blood glucose (MBG) levels calculated from glycosylated hemoglobin (Hb Alc). One hundred and twenty-one patients who regularly checked their urines reported on the frequencies of glycosuria over the preceding ten weeks. There was substantial overlap in the glycosuria patterns of patients at different levels of MBG. Glycosuria was not detectable in only 44% of patients with good control (MBG less than or equal to 150 mg/dl). The probability of such good control given no glycosuria was only 26%. Similarly, frequent glycosuria was reported by only 27% of patients with poor control (MGB greater than 250 mg/dl). The probability of such poor control given frequent glycosuria was only 34%. Because home urine testing cannot reliably identify good or poor control, it has a very limited role in assessing patients' chronic glucose control.

Bedside capillary glucose measurement by staff nurses in a general hospital

The accuracy of capillary blood glucose monitoring has been well demonstrated when applied by patients in the outpatient setting or by specially trained nurses on inpatient diabetes units. In order to determine the applicability of this technique in the more general hospital setting, a program was initiated for instructing general staff nurses in the use of Chemstrips bG strips and the Accu-Chek bG meter. As a pilot study, nurses on four general medical and surgical hospital floors performed capillary glucose determinations within 15 minutes of the drawing of venous blood samples for determination of plasma glucose in the hospital's Chemistry Laboratory. Two hundred ten paired measurements were made by 31 nurses. Linear regression analysis yielded a Pearson correlation coefficient of 0.96 between bedside and laboratory glucose measurements. The mean percent deviation between the two values was 7.9 percent. Acceptance by both nurses and patients was high. Properly supervised capillary glucose monitoring can provide a valuable adjunct to the care of hospitalized patients with diabetes.

The preparation of an acceptable placebo for NPH insulin

A suitable placebo for NPH insulin has not previously been available for clinical investigation. A series of organic and inorganic compounds were formulated as insulin placebos and analyzed according to the following criteria: (1) degree of visual similarity to insulin, (2) stability, (3) absence of local side effects, and (4) clinical safety. Dilute suspensions of cortisone acetate (1.25-2.5 mg/ml) were found to fulfill the criteria as acceptable insulin placebos. Placebo-controlled studies with NPH insulin can now be performed.

The clinical information value of the glycosylated hemoglobin assay

We evaluated the clinical information value of the glycosylated hemoglobin assay by comparing it with practitioners' estimates of glucose control over the preceding 10 weeks in 216 patients with diabetes. Twenty-four per cent of the practitioners' estimates, which were based on historical and laboratory data collected during a routine office visit, differed by more than +/- 75 mg per deciliter from the actual mean blood glucose levels calculated with the glycosylated hemoglobin assay. One third of the mean blood glucose concentration fell outside the confidence intervals physicians used to bound their estimates. When examined individually or in the aggregate, historical information, such as polyuria, nocturia, or home urine testing for glucose, and laboratory information, such as fasting or random blood glucose levels, were weak predictors of the actual mean concentration of blood glucose. We conclude that the glycosylated hemoglobin assay provides information about the degree of long-term glucose control that is not otherwise obtainable in the usual clinical setting.