PubMed Health⌕ Search

PubMed · 12940333

Position Development Conference.

Abstract

In a series of three published articles, the International Society for Clinical Densitometry has recorded the findings reached by an expert panel at the ISCD Position Development Conference held in July 2001. The key elements of those papers have been reviewed in this executive summary. It should be emphasized that the ISCD recommendations are not meant to serve as rigid guidelines or to replace clinical judgment. The recommendations will be reviewed and updated periodically as more data become available. A second Position Development Conference will be held in July 2003 in Cincinnati, OH. For information, visit the ISCD web site: http://www.iscd.org/.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Leon Lenchik, Edward S Leib, Ronald C Hamdy, Neil C Binkley, Paul D Miller, Nelson B Watts. 2003. Position Development Conference.. https://doi.org/10.1097/01.smj.0000074555.82339.40

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Quantifying the treatment effect explained by markers in the presence of measurement error.

Surrogate markers or intermediate markers are important in identifying subjects with high risk of a serious disease or for monitoring disease progression of a subject on treatment. Quantifying the proportion of treatment effect (PTE) explained by markers has been studied extensively. Due to reasons such as biological variation, limited machine precision, etc. markers are generally measured with error. The estimated PTE ignoring the measurement error could be biased, which may lead to incorrect conclusions. In this article, we adjust for the measurement error using regression calibration to construct a less biased estimator of excess relative odds, a quantity to measure the treatment effect explained by markers. The method is applied to data from a clinical study in osteoporosis.

Absorptiometry, Photon↗

Estimating the response rate in the presence of measurement error.

In clinical research, it is often of interest to estimate the response rate (i.e. the proportion of subjects who achieve a clinically meaningful threshold) for a particular variable. The standard estimator of the response rate is generally biased in the presence of measurement error. The estimation accounting for the measurement error utilizing fully nonparametric (NP) methods is complicated and may not be efficient. Therefore, we propose a model-based approach assuming a parametric model for the true value and only the first few moments for the measurement error. The estimator for the true response rate and the variance for the estimator are derived. An innovative method using bootstrap simulation is proposed to check the model assumption. Simulations show that the proposed estimator outperforms a fully NP estimator if the model assumption for X holds. This method is applied to address a commonly occurring question in osteoporosis regarding response to treatment in terms of longitudinal changes in bone mineral density (BMD). Bootstrap simulations showed that the model utilized is appropriate. The proposed method can also be applied in other fields of clinical research.

Absorptiometry, Photon↗

Quantitative bone mineral density assessment in malignant infantile osteopetrosis.

PURPOSE: To investigate the use of quantitative computed tomography (QCT) and dual energy absorptiometry (DXA) for assessing bone mineral density (BMD) in the evaluation of children with malignant infantile osteopetrosis (MIOP). METHODS AND PATIENTS: We retrospectively reviewed QCT- and DXA-determined BMD in six patients with infantile osteopetrosis and correlated BMD measured during the initial evaluation with patient characteristics. RESULTS: Five male and one female infant met the eligibility criteria. BMD was markedly elevated in all patients as determined by each modality, QCT or DXA. For QCT, in which age-specific normal values are known, the BMD was found to be 22.4-32.6 standard deviations above the mean. Using DXA, the estimated BMD of the lumbar spine ranged from 0.45 to 0.8 g/cm(2); children with similarly appearing bone radiographs had quite disparate BMD. While the qualitative trend of BMD among the patients was similar for both measures, the units and numerical values of BMD differed. We found no correlation between BMD results and hematopoiesis observed in the bone marrow or with visual evaluation of the radiographs. CONCLUSION: Both QCT and DXA are effective quantitative measures of BMD in children with MIOP. However, the same modality should be employed for longitudinal evaluation of a given patient. Each technique has unique advantages and disadvantages and may complement one another in the evaluation of MIOP or other bone disorders. Quantitative assessment of BMD in children with MIOP will likely serve to further characterize this disease.

Absorptiometry, Photon↗