Quantitative ultrasound of the calcaneus as a screening tool to detect osteoporosis: different reference ranges for caucasian women, african american women, and caucasian men.

The interpretation of results measured by quantitative ultrasound (QUS) of the heel depends on the population studied. We measured estimated bone mineral density (BMD) of the heel using the Hologic Sahara sonometer. People were studied at county fairs, health fairs, and churches. Subjects were not on treatments that would affect bone density, other than calcium supplementation. This included 823 Caucasian women, 131 African American women, and 301 Caucasian men. In contrast to women, for Caucasian men the squared term for age was not significant, and a straight line of decline was the best fit for estimated BMD. African American women had a standard deviation larger than that reported by Hologic for Caucasian women. We compared a history of self-reported fractures with a subject's estimated BMD. An estimated BMD of 0.57 gm/cm2 included 75% of all fractures. This cutoff point was associated with increased fracture prevalence in subjects over age 50, relative risk of 1.4. This result corresponds to the Hologic data T-score of -0.2. When used as a screening tool for osteoporosis fracture risk, an estimated BMD of 0.57 gm/cm2 seems reasonable in those subjects over age 50.

Guidelines for Monitoring of NSAIDS: Who Listened?

The side effects of nonsteroidal anti-inflammatory drugs (NSAID) include problems involving peptic ulceration, renal function, and liver disease. Publications have stressed the need to monitor patients for these problems and the rheumatology community across the country has echoed these concerns in continuing education activities to physicians over the years. The American College of Rheumatology (ACR) disseminated recommendations for nonsteroidal anti-inflammatory drugs (NSAID) monitoring in rheumatoid arthritis (RA) patients. We used this as an example of expert opinion for monitoring of NSAID and compared it with the frequency of monitoring by primary care physicians using NSAID for various diseases. We asked whether the rheumatology community's efforts were successful over time to enhance NSAID monitoring by primary care physicians. Physicians across the United States, using a computerized medical record, allowed data to be extracted from their medical practices. Dates of NSAID prescriptions and laboratory test monitoring for any diagnosis were analyzed. Those tests included a CBC, hepatic panel, and renal tests. The frequency of baseline tests performed within 3 months before starting a NSAID by internists was 30% compared with 6% by family practitioners in private practice and 1% in academic family practice centers before publication of the ACR guideline. After dissemination of the guidelines in 1996, the frequency of baseline testing by these groups was lower. Follow-up monitoring within 3 months of starting a NSAID was also low (24, 3, and 2% respectively) and did not improve after ACR guideline publication. Publication and dissemination of the ACR guidelines, and other efforts, did not improve rates of monitoring. The rheumatology community needs to re-evaluate the effectiveness of programs that teach safe use of rheumatologic medications by primary care physicians.

Regression with covariates and outcome calculated from a common set of variables measured with error: estimation using the SIMEX method.

In medical research, a situation commonly arises where new variables are calculated from a common set of directly measured variables. When the directly measured variables each contain an error component, the relationship between the observed calculated variables can often be distorted. A source of this distortion is the presence of common measurement error in the observed calculated variables. Often known as coupled error, it is still possible to estimate the relationship between the calculated variables when measurement error is present. This paper presents two general methodologies that account for the presence of correlated measurement error when working with calculated variables. The equivalence of the methods will be established for one case, while the general advantage of the simulation extrapolation technique will be shown for more complicated situations. The performance of the estimators will be examined with examples arising from the medical literature.

Calcium, phosphorus, and alkaline phosphatase values of elderly subjects.

OBJECTIVE: To determine if significant gender differences existed between subjects 65 years of age and older, with regard to calcium, phosphorus, and alkaline phosphatase levels. DESIGN: A retrospective chart review of laboratory procedures performed in six different physician practices. The data consisted of 178 subjects representing 92 males and 86 females over the age of 65. DATA SOURCES: Patient data were obtained from the charts housed in a cardiac care center. Subjects, with charts preceding them, were referred by a physician to the cardiac center. The laboratory procedures had been performed previously in the laboratories of the referring physicians. MAIN OUTCOME MEASURES: After accounting for variation between laboratories, mean values of calcium, phosphorus, and alkaline phosphatase were examined to establish if a gender difference existed in patients over the age of 65. A blocked analysis of variance (ANOVA) was conducted at the 0.05 significance level. RESULTS: ANOVA analysis yielded significant gender differences for calcium, phosphorus, and alkaline phosphatase (p < 0.05). Females over the age of 65 consistently showed higher levels than males over the age of 65 for all three variables in five of the six laboratories studied. CONCLUSION: A statistically significant difference was found between the mean levels of men and women 65 years of age and older for calcium, inorganic phosphorus, and alkaline phosphatase. Gender and age are important variables to consider when analyzing and interpreting calcium, phosphorus, and acid phosphatase levels.