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PubMed2005

Universal bone densitometry screening combined with alendronate therapy for those diagnosed with osteoporosis is highly cost-effective for elderly women.

OBJECTIVES: To investigate the cost-effectiveness of universal bone densitometry in women aged 65 and older combined with alendronate treatment for those diagnosed with osteoporosis (femoral neck T-score < or = -2.5). DESIGN: A Markov model with a lifetime time horizon and eight health states (no fracture, distal forearm fracture, radiographic (but clinically inapparent) vertebral fracture, clinical vertebral fracture, hip fracture, hip and vertebral fracture, and other fractures), using the societal perspective. SETTING: Women living independently and those in nursing homes. PARTICIPANTS: Caucasian women aged 65, 75, 85, or 95. INTERVENTION: Bone densitometry of the hip, with 5 years of alendronate therapy for those found to have osteoporosis versus no intervention (densitometry or drug therapy). MEASUREMENTS: Lifetime accumulated quality adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios. RESULTS: The cost per QALY gained for the screen-and-treat strategy was 43,000 dollars per QALY gained for 65-year-old women and 5,600 dollars per QALY gained for 75-year-old women. For 85- and 95-year-old women, the screen-and-treat strategy was cost saving. Sensitivity analyses showed that the screen-and-treat strategy was cost-effective even under assumptions of reduced adherence to drug therapy, reduced fracture reduction benefit from alendronate therapy, or reduced QALYs saved by preventing fracture. CONCLUSION: Universal bone densitometry combined with alendronate therapy for those found to have osteoporosis is highly cost-effective for women aged 65 and older and may be cost saving for ambulatory women aged 85 and older (whether independently living or residing in nursing homes).

Absorptiometry, Photon↗
PubMed2006

[Proportion of individuals with indication criteria for bone densitometry and frequency of factors of risk of low osseous mass in primary care consultations].

OBJECTIVE: To find the number of individuals with indication for Bone Densitometry in Primary Care, according to the criteria of the WHO, the Agency for Evaluating Medical Technology of Catalonia (AETM) and the International Committee on Clinical Guides to Osteoporosis (CIGCO), and the frequency of factors of risk of low osseous mass. DESIGN: Multi-centre, prospective, transversal study. SETTING: Primary care consultations. PARTICIPANTS: Patients over 18 (307 women and 139 men) with mean age of 54.3+/-16.8, who attended for consultation with an appointment. MAIN MEASUREMENTS: Presence or absence of factors relating to each of the indication criteria for bone densitometry. RESULTS: A 36.3% of individuals had indication of densitometry under the AETM criteria, 76.7% with the WHO criteria, and 50.5% with the CIGCO criteria (applicable only to women). Percentages increased with age and were higher for women. Concordance between the various criteria was under 37%. CONCLUSIONS: The percentage of individuals with indication for bone densitometry was highly variable under different criteria. It was greater in women and increased with age. Concordance between different criteria was low.

Absorptiometry, Photon↗
PubMed2004

Position statement: introduction, methods, and participants. The Writing Group for the International Society for Clinical Densitometry (ISCD) Position Development Conference.

Following publication of the proceedings from the first Position Development Conference (PDC) of the International Society for Clinical Densitometry (ISCD), members of the ISCD Scientific Advisory Committee (SAC) addressed additional topics of interest in the field of bone densitometry. These topics were addressed at a subsequent PDC, which was held in Cincinnati, Ohio, July 25-27, 2003. Five topics were chosen for discussion: (1) the diagnosis of osteoporosis in men, premenopausal women, and children; (2) technical standardization for dual-energy X-ray absorptiometry (DXA); (3) indications for bone densitometry; (4) reporting of bone density results; and (5) nomenclature and decimal places for bone densitometry. This report describes the methodology used for the development, presentation, and finalization of PDC positions. These positions are discussed in the following papers.

Absorptiometry, Photon↗
PubMed1994

Clinical value of bone densitometry.

The purpose of this article is to provide insight into the long-standing controversy over the clinical value of noninvasive measurement of bone mass. Results of recent studies have increasingly supported the judicious use of bone densitometry as a clinical tool [1]. These reports contradict editorials on the limitations of bone densitometry that have appeared in a variety of subspecialty publications [2,3]. The importance of bone mass measurement is underscored by the lack of success in predicting bone density from various combinations of anthropometric and historical variables. Growing evidence suggests that densitometry is a useful tool for determining which women near menopause are at risk for osteoporosis and, therefore, are candidates for estrogen-replacement therapy. This article summarizes current concepts on the subject and attempts to prove that bone densitometry is a beneficial and indicated procedure for selected patients.

Absorptiometry, Photon↗
PubMed2004

[The influencing factors of the compliance level with therapeutic regimen after the bone mineral densitometry].

PURPOSE: This study was to identify the influencing factors of the compliance level to a therapeutic regimen after a bone mineral densitometry test. METHOD: The sample for the study was 95 people who took the bone mineral densitometry test from March, 2002 to July, 2002. Data was collected by mail using a self reporting questionnaire on the selected variables such as the compliance level, self efficacy, health locus of control, susceptibility, severity, usefulness, barrier, and self esteem. RESULT: The average compliance level was 63.93. Through multiple regression, three independent variables including chance health locus of control on personality, the result of bone mineral density and self-efficacy were entered in the model as the significant determinants of the compliance level after a bone mineral densitometry test. The coefficients of determination of each variable were 10.9%, 8.3% and 8.1% respectively. CONCLUSION: The identification of the determinants of the compliance level to the therapeutic regimen after bone mineral densitometry is expected to contribute to the development of an intervention program to improve the compliance level to the therapeutic regimen in osteoporosis patients.

Aged↗
PubMedDate not supplied

Bone densitometry as a screening tool for osteoporosis in postmenopausal women.

This report provides general information about osteoporosis and describes the use of bone densitometry as a tool to screen for, diagnose and manage osteoporosis in white postmenopausal women. Discussion is limited to white women because of lack of research on osteoporosis in men, and in women of different racial and ethnic groups. The report does not evaluate the safety and efficacy of all bone densitometry devices, but focuses on the two diffusing most rapidly in Minnesota--dual x-ray absorptiometry (DXA or DEXA) and quantitative computed tomography (QCT). Osteoporosis is a degenerative bone disease that affects approximately 24 million Americans. Of that number 33 percent are post-menopausal women who have decreased bone density due to lowered estrogen levels. Because the estimated cost of osteoporosis-related fractures in the United States is between $8 and $10 billion each year, there is great interest in the diagnosis, prevention and treatment of the disease. Of all related fractures, hip fractures pose the most serious health problem. The incidence of this fracture appears to be increasing, with 250,000 to 300,000 occurring each year Treatment options are limited, if a person's bone mass or density has deteriorated to the point where fractures may occur. Preventive measures should therefore be undertaken by all women early in life to decrease their risk of osteoporosis. Based on available evidence, the HTAC concludes that state-of-the-art bone densitometry is safe and indicated as a diagnostic and treatment aid for postmenopausal women at risk for the disease. However, bone densitometry is not indicated as a broad screening tool for all postmenopausal women, regardless of whether they are at risk for the disease.

Absorptiometry, Photon↗
PubMed2000

Biochemical markers and bone densitometry in inflammatory bowel disease.

AIMS: Bone mineral density is reduced in patients with inflammatory bowel disease. The possible causes of this situation are delayed puberty, malabsorption, and corticosteroid use, among others. No published data exist regarding the use of biochemical markers and bone densitometry to assess osteopenia in these patients in Spain. METHODS: We studied 54 patients (24 men and 30 women), 22 with Crohn's disease and 32 with ulcerative colitis. Age, type of disease and average daily dose of prednisone-equivalent corticosteroids were evaluated. Lumbar bone mineral density was assessed quantitative digital radiography densitometry. The bone resorption marker urine D-pyridinoline and the bone formation marker serum osteocalcin were also assessed. RESULTS: Mean age was 36.61 +/- 13.37 years. Daily corticosteroid dose was correlated with D-pyridinoline (r = 0.413; p < 0.01), and D-pyridinoline was inversely correlated with osteocalcin (r = -0.304; p < 0.01). There was a negative correlation between bone mineral density and corticosteroid dose. There was no relationship between biochemical markers and bone densitometry findings in these patients. There were no differences in terms of bone densitometry findings or biochemical markers between the two types of inflammatory bowel disease. CONCLUSIONS: D-pyridinoline correlated inversely with osteocalcin. Daily corticosteroid dose correlated directly with D-pyridinoline, and inversely with bone mineral density.

Adrenal Cortex Hormones↗
PubMed2001

Influence of bone densitometry results on the treatment of osteoporosis.

BACKGROUND: Measurement of bone mineral density is widely used to diagnose osteoporosis. The objectives of this study are to determine how bone densitometry affects subsequent treatment of osteopenia and osteoporosis with either hormone replacement therapy or bisphosphonates and to examine clinical factors associated with starting either therapy after bone densitometry. METHODS: We conducted a prospective study involving women over 50 years of age who were referred to a tertiary care hospital for the first time to undergo bone density measurement using dual-energy x-ray absorptiometry (DXA). Baseline clinical data were collected through face-to-face interviews before the test. Subsequently, the scans were reviewed and categorized as showing no bone loss, osteopenia or osteoporosis, based on World Health Organization criteria. Three months after DXA, subjects were contacted by telephone to determine their understanding of the test results and any new treatments started or recommended since the scan. RESULTS: Of 383 women recruited at the time of their DXA, 335 (87.5%) completed the 3-month follow-up. Among those reached at follow-up, DXA results showed no bone loss in 119 (35.5%), osteopenia in 137 (40.9%) and osteoporosis in 79 (23.6%). The proportion of subjects with osteoporosis receiving either hormone replacement therapy or bisphosphonate therapy was 15.2% before the test, increasing to 63.3% after the scan. The following factors were independently associated with the initiation of either therapy: actual DXA result showing osteoporosis (odds ratio [OR] 7.2; 95% confidence interval [CI] 1.7-30.3), compared with a normal scan; subjects' perception that their scan showed bone loss (osteopenia, or osteoporosis) (OR 13.5; 95% CI 4.0-45.5) or that they were unclear about the results (OR 5.4; 95% CI 1.6-18.8), compared with the perception that the results were normal; and discussion of the DXA results with a physician (OR 5.5; 95% CI 1.9-16.0). INTERPRETATION: The proportion of women with osteoporosis receiving hormone replacement therapy or bisphosphonate therapy increases after diagnosis with densitometry. However, communication by physicians so that patients understand their test results is a critical component in the initiation of therapy after bone densitometry.

Absorptiometry, Photon↗
PubMed1998

Bone densitometry as an adjunct to GnRH agonist therapy.

OBJECTIVE: To outline the optimal use of bone densitometry in women receiving gonadotropin releasing hormone (GnRH) agonist therapy. STUDY DESIGN: The use of bone densitometry during clinical trials of the use of GnRH agonists in endometriosis has resulted in a number of publications with varying conclusions about the effects of these agents on the skeleton. A review of this literature, taking into account known concepts of bone physiology and the varying quantities measured by different bone densitometry devices, was done to place these results into a common framework. Within this context, a proposal is made for when and how to use various bone densitometry methods in individual patients and how to interpret the results properly. RESULTS: Bone density in young women being treated for endometriosis is usually within the normal range, with even those 2 SD below normal not at significant risk of osteoporotic fracture. However, the clinical results show that most, if not all, women treated with GnRH agonists experience an increase in bone turnover due to estrogen deficiency during treatment, and this can result in a transient decrease in bone density. Even though the bone is regained after treatment is stopped, it may take years to recover fully. For those women who had low bone density to start, they may lose sufficient bone to increase their risk of osteoporotic fracture, and it is important to identify those individuals before treatment and to monitor them carefully. If the result of a peripheral bone density measurement (hand, forearm, heel) or central measurement (spine or hip) before treatment is higher than about 1 SD below a young normal mean, then even if a woman loses some bone, she will not have a significant increase in the risk of fracture. However, if a measurement is low (> 1 SD below the mean, putting her in the lower 15%), then it is advisable to have a spinal measurement by quantitative computed tomography or dual energy x-ray absorptiometry before and after therapy to determine what the bone changes are and to follow-up after the end of treatment. This is especially true if she decides to become pregnant, needs retreatment with a GnRH agonist or will be going through natural menopause in the near future; all can cause further bone loss. CONCLUSION: Different bone density methods give different information and must be interpreted properly when used in evaluating patients on GnRH agonist therapy. Any bone measurement may be used to assess skeletal status before treatment, but if a peripheral bone measurement is low, it should be followed with a spinal measurement by quantitative computed tomography or dual energy x-ray absorptiometry so that the effect of the treatment can be monitored. Bone loss is transient with GnRH treatment, but only spinal measurements have sufficient sensitivity to follow patients and evaluate the skeletal changes in a meaningful way.

Absorptiometry, Photon↗
PubMed1990

Comparison of flow cytometry with static densitometry in papillary thyroid carcinoma.

The prognostic accuracy of flow cytometric and static densitometric DNA analysis was compared in 31 patients who had undergone surgery for papillary thyroid carcinoma between 1959 and 1978 (median follow-up 18 years). There were five deaths from papillary thyroid carcinoma. Three of six patients with DNA aneuploid tumours on flow cytometry died (P greater than 0.05, Fisher's exact test) compared with four of eight patients whose tumours were found to be aneuploid by static densitometry (P less than 0.02). When quantitative analysis was applied to the static densitometry data, all five patients who died from papillary carcinoma were distinguished, with no false positives (P less than 0.002). The prognostic accuracy of flow cytometric DNA analysis is less than that of static densitometry in which morphological selection of malignant cells permits quantitative measurements. DNA analysis may add refinement to existing scoring systems in predicting the risk of death from papillary thyroid carcinoma. Such information could provide the basis for controlled prospective evaluation of bilateral resection as opposed to lobectomy in defined high risk patients. At present there is insufficient evidence upon which aneuploidy should be used as a determinant of the extent of operation for papillary thyroid carcinoma.

Adult↗
PubMed2006

Quality and performance measures in bone densitometry. Part 2: fracture risk.

INTRODUCTION: This is part 2 of a core chapter of the forthcoming Report on Bone Densitometry commissioned by the International Commission on Radiation Units (ICRU). It is written with the aim to review definitions of quantities and units used in bone densitometry research and to describe parameters and methods that can be used to compare and standardize densitometric equipment and measurements. Part 2 of this chapter contains the section on fracture risk. PERFORMANCE MEASURES IN THE ASSESSMENT OF FRACTURE RISK: Building on concepts of risk assessment, including risk ratios and odds ratios, we review statistical concepts commonly used in cross-sectional and prospective fracture studies. Performance measures are defined that allow a comparison of the ability of densitometry techniques to assess fracture risk. DISCUSSION: The methods of discriminant analysis, logistic regression, Poisson regression models, and the Cox proportional hazard model are presented and compared. In addition, statistical concepts to characterize risk for the individual patient are reviewed.

Aged↗
PubMed1986

Foveal densitometry as a diagnostic technique in Stargardt's disease.

Foveal densitometry was performed in eight patients with Stargardt's disease. Their visual acuities were between 20/200 and 20/16. All eight had low two-way densities, ranging from 0.07 to less than or equal to 0.01 (mean value for a control group, 0.32 +/- 0.03). Two patients had poor visual acuities combined with ophthalmoscopically normal maculas. Because two-way densities were very low in these patients, ranging between 0.04 and less than or equal to 0.01, foveal densitometry may be a useful diagnostic technique in the diagnosis of Stargardt's disease. Foveal densitometry was also performed in two patients with fundus flavimaculatus and good visual acuities for the sake of comparison. Two-way densities were between 0.09 and 0.24. One patient with cone dystrophy and poor visual acuity had low two-way densities (0.02 bilaterally). Three patients with vitelliform dystrophy and vitelliform cysts on ophthalmoscopy had two-way densities between 0.07 and 0.14 and increased half-times of regeneration (between 90 and 126 seconds). One patient with a vitelliform cyst in one eye showed only fine pigmentations in the other eye, which had a normal two-way density (0.32).

Adolescent↗
PubMed1988

Quantitative evaluation by computer-based video densitometry of film response to different isotopes and fluorographic treatments.

Previous investigations of fluorographic methods have generally reported the minimum level of radioactivity that can be detected for a given length of exposure or the amount of radioactivity needed to reach a given optical density value. Even when the full characteristic curve is given, comparisons with other published values are difficult or, if different lengths of exposures are used, impossible. Computer-based video densitometry was used to evaluate different fluorographic methods. Sections of polyacrylamide gels with uniform distributions of either 35S or 125I radioactivity were embedded with different fluors and used to expose X-ray film for various lengths of time. Due to its compatibility with algorithms used in densitometry, the effectiveness of various treatments was evaluated by fitting relevant parameters to a modified Hill-type equation. The two parameters that were affected by treatments were the amount of radioactivity needed to half-saturate the film (ED50, or the midpoint) and the slope at the midpoint. The relationship between length of exposure and film density was investigated. Since the ED50 values for both 35S and 125I were found to vary in a linear fashion with respect to 1/time, one can determine the ED50 for lengths of exposure not reported. A unique feature of this method of evaluating effectiveness of different treatments, therefore, is that it is possible to compare films that were exposed for different lengths of time. The method of presenting data used here overcomes many of the difficulties in comparing different fluorographic and film treatments, is compatible with the needs of computer-based densitometry, and is suggested as a useful way in which to present the relationship among isotopes, fluors, and films.

Autoradiography↗
PubMed1992

Assessment of neutrophil chemotaxis by laser and video densitometry.

A laser densitometer and a video densitometer were used to evaluate neutrophil chemotaxis slides which were also assessed by the standard microscopic technique. A linear relationship was observed between cell number per high power field (HPF) and peak height by laser densitometry (r2 = 0.66) or peak area by video densitometry (r2 = 0.81). For wells containing more than 20 cells/HPF the least variability was observed with video densitometry. Quantitative results from neutrophil chemotaxis assays performed in 48-well microchambers can be obtained rapidly and conveniently by the use of commercially available video densitometers.

Chemotaxis, Leukocyte↗
PubMed1991

Assay and purity control of metacycline by thin-layer chromatography combined with UV and fluorescence densitometry--a comparison with liquid chromatography.

A thin-layer chromatographic (TLC) method involving UV and fluorescence densitometry is described for the assay and purity control of metacycline. With a mobile phase dichloromethane-methanol-water (58:35:7, v/v/v) and a silica gel thin-layer, previously sprayed with 10% sodium edetate solution adjusted to pH 9.0, all the potential impurities of metacycline were well separated from the main component and from each other. Results obtained with UV densitometry (TLC-UV) and fluorescence densitometry (TLC-F) were compared with those obtained by a liquid chromatography (LC) method using a poly(styrene-divinylbenzene) stationary phase. The correlation coefficients (r) for TLC-UV and LC or TLC-F and LC were better than 0.9999. For TLC-UV the relative standard deviation (RSD) for the assay of the main component was less than 2%, for TLC-F less than 3.0% and for LC less than 1.0%.

Anti-Bacterial Agents↗
PubMed1995

Assay and purity control of minocycline by thin-layer chromatography using UV and fluorescence densitometry--a comparison with liquid chromatography.

A thin-layer chromatography (TLC) method using UV and fluoresecence densitometry is described for the assay and purity control of minocycline (MC). With a mobile phase dichloromethane-methanol-water (57:35:8, v/v/v) and a silica gel thin-layer, previously sprayed with 10% m/v sodium edetate adjusted to pH 9.0, 4-epiminocycline and 7-didemethylminocycline were well separated from MC and from each other, 7-monodemethylminocycline and 6-deoxy-6-demethyltetracycline (6-DODMTC) were not separated from each other and were only partially separated from minocycline. 6-DODMTC was selectively determined by fluorescence densitometry, while quantification of other impurities and the assay of MC were performed by UV densitometry. Results obtained with qualitative TLC were compared with those obtained by a liquid chromatography (LC) method using a poly(styrene-divinylbenzene) copolymer stationary phase. The correlation coefficient for TLC and LC results was > 0.999. For TLC the relative standard deviation for the assay of MC at 1.25 mg ml-1 was < 3.0% (n = 4), while for LC it was < 1.0% (n = 4).

Anti-Bacterial Agents↗
PubMed1994

Serial foveal densitometry and visual function after retinal detachment surgery with macular involvement.

PURPOSE: Fundus reflection densitometry was used as an objective means for monitoring the recovery of foveal cone photopigments in nine patients who underwent anatomically successful surgery of a rhegmatogenous retinal detachment with macular involvement. METHODS: Postoperative assessment of foveal densitometry, visual acuity, color matching, and the Amsler grid were performed at repeated intervals for up to 14 months. RESULTS: Gradual recovery of foveal cone photopigments was found in all patients 1 to 14 months after surgery, with considerable interindividual variation. Maximal recovery to values equalling those in the fellow eye was found in only one patient with a macular detachment duration of 5 days. All other patients had final photopigment densities below those of the fellow eye. The length of the preoperative detachment period was inversely related to the recovery of photopigment. The recovery of photopigment seems to increase further in the second year after surgery. Visual acuity increased rapidly in all patients during the first 6 months after surgery, to levels ranging between 20/67 and 20/25; thereafter, visual acuity did not change. A return to normal color matching after an episode of pseudoprotanomaly was found in four of nine patients, whereas pseudoprotanomaly remained in five patients. Complete resolution of metamorphopsia after surgery was seen only in the patient who had the shortest detachment duration. Metamorphopsia was consistent with decreased foveal cone photopigment densities. CONCLUSION: Foveal densitometry shows a slow recovery of the cone photopigments after reattachment, probably because of regrowth and realignment of the cone photoreceptor outer segments and metabolic recovery of the retinal pigment epithelium-cone photoreceptor complex. Recovery of photopigment, color matching, and metamorphosia follow a slower time course than recovery of visual acuity.

Adult↗
PubMedDate not supplied

Estimates of fat-free mass (FFM) by densitometry, dual energy X-ray absorptiometry (DXA), and bioimpedance spectroscopy (BIS) in caucasian and Chinese-American women.

Estimates of fat-free mass (FFM) from dual energy X-ray absorptiometry and bioelectrical impedance spectroscopy (BIS) were compared to results obtained by densitometry in a group of Caucasian and Chinese-American women. Each group included 38 women between the ages of 18 and 24 years. The Chinese-American women were significantly shorter in stature, had lower body weights, and lower values for FFM compared to the Caucasian women. DXA estimates of FFM were consistently lower than those obtained from densitometry; BIS estimates were similar to densitometry results.

Absorptiometry, Photon↗