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T Beazoglou

Publications and source records attributed to T Beazoglou.

At least 19 recordsLinked to original sources
PubMed2001

Estimates for the sensitivity and false-positive rates for second trimester serum screening for Down syndrome and trisomy 18 with adjustment for cross-identification and double-positive results.

Second trimester screening for fetal Down syndrome and trisomy 18 is available through separate protocols that combine the maternal age-specific risk and the analysis of maternal serum markers. We have determined the extent to which additional Down syndrome affected pregnancies may be identified through trisomy 18 screening, and the extent to which additional cases of trisomy 18 may be screen-positive for Down syndrome. The combined false-positive rate, taking into consideration those pregnancies that are screen-positive by both protocols, has also been determined. Sensitivity and false-positive rates were determined by computer simulation of results that incorporated previously published statistical variables into the model. Using second trimester risk cut-offs of 1:270 for Down syndrome and 1:100 for trisomy 18, it was found that few additional cases of Down syndrome are identified through trisomy 18 screening. However, approximately 6-10% of trisomy 18 affected pregnancies will be screen-positive for Down syndrome but screen-negative for trisomy 18. For women aged 40 or more, the false-positive rate for trisomy 18 exceeds 1% and approximately half of these cases will also be screen-positive for Down syndrome. For a population with maternal ages equivalent to that in the United States in 1998, after adjusting for the cross-identification, the sensitivity for three-analyte trisomy 18 screening is 78%. If this testing is performed in conjunction with Down syndrome "triple" screening, the Down syndrome sensitivity is 75% and the combined false-positive rate is 8.5%. If the three-analyte trisomy 18 screening is performed with the Down syndrome "quad" screen, the trisomy 18 sensitivity remains at 78%, the Down syndrome sensitivity is 79%, and combined false-positive rate is 7.5%. Sensitivity and false-positive rates are also provided for other widely used Down syndrome and trisomy 18 risk cut-offs. Sensitivity and false-positive rates that take into consideration cross-identification and double-positives should be helpful for pre-test counseling and the evaluation of serum screening programs.

Adolescent↗
PubMed2000

Cost-benefit analysis of prenatal diagnosis for Down syndrome using the British or the American approach.

OBJECTIVE: To compare the cost and benefits of prenatal diagnosis for Down syndrome using the British and American approaches. METHODS: This cost-benefit analysis was based on a decision-analytic approach. The British strategy included screening by a first-trimester ultrasound at 10-14 weeks for nuchal translucency thickness, and the American strategy included only second-trimester screening by using maternal age and maternal serum screening. The key probabilities of the decision-tree analysis and all cost estimates were based on American standards. The best scenario of the British strategy assumed ultrasound nuchal translucency thickness sensitivity (for detecting Down syndrome) of 80% and a false-positive rate of 5% and the worst scenario assumed a sensitivity of 50% and a false-positive rate of 10%. The results were expressed in annual costs based on approximately 4 million births per year in the United States. RESULTS: As compared with do-nothing, the American strategy was found to allow savings of approximately $96 million per year and the best scenario for the British strategy was savings of approximately $5 million per year. The financial costs of the British and American strategies would be comparable only if the first-trimester ultrasound had a sensitivity of 80% and a false-positive rate of 5% in detecting Down syndrome. CONCLUSION: The British strategy does not appear to be economically beneficial in the United States even under the most ideal scenarios of ultrasound accuracy.

Cost-Benefit Analysis↗
PubMed2000

Routine second-trimester ultrasonography in the United States: a cost-benefit analysis.

OBJECTIVE: The objective of this study was to perform a cost-benefit analysis of routine second-trimester screening ultrasonography in the United States as compared with performing ultrasonography only in the presence of indications. STUDY DESIGN: It was assumed that 1 million pregnant women are available annually who otherwise would not have an indication for an ultrasonographic examination. Cost savings from early detection and therapeutic abortion were considered only for fetal conditions for which lifetime cost estimates are available, including spina bifida, major cardiac disease, cleft lip or palate, renal agenesis or dysgenesis, urinary obstruction, lower or upper limb reduction, omphalocele, gastroschisis, and diaphragmatic hernia. Two separate cost-benefit analyses were considered with the range of fetal anomaly detection rates before 24 weeks' gestation as reported by tertiary and non-tertiary centers in the Routine Antenatal Diagnostic Imaging with Ultrasound (RADIUS) trial. Potential cost savings from averting treatment for preterm labor and postdate gestations were also considered. RESULTS: The ratio of savings to cost was between 1.35 and 1.70 (savings of $1.35-$1.70 per $1 spent) if the ultrasonographic examinations were performed in tertiary care centers. The ratio of savings to cost was between 0.40 and 0.74 (loss of $0.26-$0.60 per $1 spent) if the examinations were performed in nontertiary centers. If the screening ultrasonography was performed in tertiary centers, the expected annual net benefits were estimated at $97 to 189 million. If ultrasonographic screening was performed in nontertiary centers, the expected annual net losses were estimated at $69 to 161 million. CONCLUSION: Routine second-trimester ultrasonographic screening appears to be associated with net benefits only if the ultrasonography is performed in tertiary care centers.

Congenital Abnormalities↗
PubMed2000

Selling your practice at retirement. Are there problems ahead?

BACKGROUND: The dental work force is maturing as fewer dentists enter practice. In this article, the authors considered two questions: "Will demographic trends in the numbers of dentists leaving and entering practice place additional downward pressure on the value of dental practices?" and "How important is the sale of practices for retirement income?" METHODS: To address the first question, the authors estimated the number of retirees using 62 years as retirement age, and they projected the number of graduates using current trends of first-year enrollments. To address the second question, the authors used the ADA's 1995 Survey of Current Issues in Dentistry, which addressed dentists' retirement savings. RESULTS: The annual rate of dentists' retiring is projected to be 2.1 percent compared with 1 percent among dentists projected to graduate during the period of 2001-2020. Although dental practice value is 40 percent or more of practitioners' reported retirement savings, the majority of dentists report that they do not depend on the sale of their practices to finance their retirement. CONCLUSIONS: In the next 20 years, the number of retirees will grow faster than the number of graduates, exerting a downward pressure on the value of dental practices. PRACTICE IMPLICATIONS: To successfully plan for retirement, dentists need to carefully assess their target levels of retirement savings, the time of their retirement and their dependence on the sales of their practices.

Adult↗
PubMed1999

Cost-benefit analysis of targeted ultrasonography for prenatal detection of spina bifida in patients with an elevated concentration of second-trimester maternal serum alpha-fetoprotein.

OBJECTIVE: The objectives of this study were to examine (1) the diagnostic accuracy requirements (from the cost-benefit point of view) of targeted ultrasonography versus genetic amniocentesis for prenatal detection of spina bifida in women with an elevated level of maternal serum alpha-fetoprotein, (2) the ultrasonographic accuracy of previously published studies from the cost-benefit point of view, and (3) the possible economic impact for the United States of offering targeted ultrasonography instead of routine amniocentesis to this group of patients. STUDY DESIGN: Our cost-benefit formula was based on the hypothesis that the cost of universal genetic amniocentesis in patients with an elevated concentration of maternal serum alpha-fetoprotein in the second trimester should be at least equal to the cost of universal targeted ultrasonography, with amniocentesis used only for those with abnormalities on a sonogram. The main components of the formula included the diagnostic accuracy of targeted ultrasonography (sensitivity and specificity for detecting spina bifida), the cost of the amniocentesis package, the cost of targeted ultrasonography, and the lifetime cost of spina bifida not detected by targeted ultrasonography. After appropriate manipulation of the formula, a graph was constructed to represent the balance between the sensitivity and false-positive rate of targeted ultrasonography and was used to examine the accuracy of previously published ultrasonographic studies from the cost-benefit point of view. Sensitivity analyses included a range of prevalences of spina bifida in women with elevated maternal serum alpha-fetoprotein from 1:50 to 1:200 and false-positive rates of targeted ultrasonography from 1% to 10%. RESULTS: Assuming overall prevalences of spina bifida of 1:50, 1:100, or 1:200 among women with elevated maternal serum alpha-fetoprotein, we found targeted ultrasonography to be beneficial only if the overall sensitivities for detecting fetal spina bifida were >88%, >76%, and >51%, respectively. All 17 studies published after the mid-1980s, which used the "cranial signs" for detecting spina bifida, had accuracies compatible with economic benefits (sensitivities, 92% to 100%; false-positive rates, 0% to 3%). CONCLUSION: The benefit of second-trimester targeted ultrasonography for fetal spina bifida depends on diagnostic accuracy (ie, sensitivity and false-positive rate). Currently achieved ultrasonographic accuracies are compatible with net benefits. Targeted ultrasonography in patients with an elevated level of second-trimester maternal serum alpha-fetoprotein in the United States has the potential for annual savings of approximately $36 million to $49 million and for avoiding 268 fetal deaths.

Cost-Benefit Analysis↗
PubMed1999

Maternal serum screening for fetal trisomy 18: a comparison of fixed cutoff and patient-specific risk protocols.

OBJECTIVE: To compare the effectiveness of two widely used protocols for second-trimester screening for fetal trisomy 18. METHODS: Second-trimester screening results for 41,565 women were reviewed to determine whether pregnancies could be considered to be at high risk for trisomy 18. The screening test was considered positive if either maternal serum concentrations of alpha-fetoprotein (MSAFP), hCG, and unconjugated estriol (E3) fell below defined levels, or the second-trimester patient-specific risk (based on maternal age and serum analytes) was greater than 1:100. Detection rates, false-positive rates, and pregnancy outcomes for the two protocols were compared. RESULTS: The fixed-cutoff method showed a 23% detection rate and a 0.19% false-positive rate for trisomy 18. These low rates were in close agreement with a theoretical expectation for fixed-cutoff trisomy 18 screening. The risk-based approach resulted in a 69% detection rate and a 0.45% false-positive rate. Both methods identified pregnancies with other fetal anomalies. CONCLUSION: Overall, the risk-based method is more effective than the fixed-cutoff approach to trisomy 18 screening.

Abnormalities, Multiple↗
PubMed1999

Cost-effectiveness of estimating gestational age by ultrasonography in Down syndrome screening.

OBJECTIVE: To quantify the financial benefits of using ultrasound estimation of gestational age in maternal serum screening for Down syndrome. METHODS: Maternal age-specific sensitivity and false-positive rates for Down syndrome were derived for the triple test (alpha-fetoprotein, hCG, and unconjugated estriol) using gestational age based on ultrasound dating and also time from the last menstrual period (LMP). These rates were entered into a formula to determine the societal financial net benefit of Down syndrome screening. The average per-case net benefits of ultrasound- and LMP-dated pregnancies were then compared. Average net benefits were also calculated separately with ultrasound versus LMP dating for triple tests referred to our laboratory, and the additional costs associated with any post-test ultrasound scans, repeat testing, or recalculations were estimated. RESULTS: The use of ultrasound dating resulted in higher detection rates for Down syndrome and lower false-positive rates, which translated into an average per-case savings to society of $33.54. For women referred to our program with LMP dating, there was an average reduction of $31.60 in net benefits, plus added costs of $14.39 attributable to extra ultrasound, repeat testing, and recalculation. CONCLUSION: When ultrasound dating is available before serum screening, it should be used preferentially to establish Down syndrome risk. Routine first-trimester ultrasound examination can be justified for women with a known LMP if the cost of the ultrasound examination is less than $46.

Adolescent↗
PubMed1998

Economic evaluation of prenatal screening for Down syndrome in the U.S.A.

Maternal serum screening for Down syndrome involves biochemical tests such as alpha-fetoprotein (alpha FP), human chorionic gonadotrophin (hCG) and unconjugated oestriol (uE3), either alone or in combination, that have variable detection and false-positive rates. Choosing a screening protocol requires a trade-off between a desired detection rate and an acceptable false-positive rate. Selecting a screening protocol that maximizes the net benefit to society provides one approach. We have developed a general formula for calculating the per case net social benefit of a screening test and have applied it to United States data. The maximum net benefit associated with each of the various screening options currently available is estimated and the model is further applied to determine the conditions under which the addition of a new marker to an existing protocol can be justified. For each test, or combination of tests, optimal net benefits occur at different detection and false-positive rates. Net benefits are strongly and positively dependent on maternal age; high net benefits are associated with older patients and low, or even negative, net benefits with younger patients. Also, net benefits are affected by the term risk cut-off rate. For triple testing, the 1:351 Down syndrome term risk cut-off appears to provide a higher net benefit than that obtained with 1:250 or 1:300. The optimization of societal net benefit provides a powerful approach to evaluating screening strategies, but the policies used must also consider individuals' freedom in decision making at each step of the prenatal diagnosis pathway.

Adult↗
PubMed1998

An economic evaluation of second-trimester genetic ultrasonography for prenatal detection of down syndrome.

OBJECTIVE: The objective of this study was to perform an economic evaluation of second-trimester genetic ultrasonography for prenatal detection of Down syndrome. More specifically, we sought to determine the following: (1) the diagnostic accuracy requirements (from the cost-benefit point of view) of genetic ultrasonography versus genetic amniocentesis for women at increased risk for fetal Down syndrome and (2) the possible economic impact of second-trimester genetic ultrasonography for the US population on the basis of the ultrasonographic accuracies reported in previously published studies. STUDY DESIGN: A cost-benefit equation was developed from the hypothesis that the cost of universal genetic amniocentesis of patients at increased risk for carrying a fetus with Down syndrome should be at least equal to the cost of universal genetic ultrasonography with amniocentesis used only for those with abnormal ultrasonographic results. The main components of the equation included the diagnostic accuracy of genetic ultrasonography (sensitivity and specificity for detecting Down syndrome), the costs of the amniocentesis package and genetic ultrasonography, and the lifetime cost of Down syndrome cases not detected by the genetic ultrasonography. After appropriate manipulation of the equation a graph was constructed, representing the balance between sensitivity and false-positive rate of genetic ultrasonography; this was used to examine the accuracy of previously published studies from the cost-benefit point of view. Sensitivity analyses included individual risks for Down syndrome ranging from 1:261 (risk of a 35-year-old at 18 weeks' gestation) to 1:44 (risk of a 44-year-old at 18 weeks' gestation). This economic evaluation was conducted from the societal perspective. RESULTS: Genetic ultrasonography was found to be economically beneficial only if the overall sensitivity for detecting Down syndrome was >74%. Even then, the cost-benefit ratio depended on the corresponding false-positive rate. Of the 7 published studies that used multiple ultrasonographic markers for genetic ultrasonography, 6 had accuracies compatible with benefits. The required ultrasonographic accuracy (sensitivity and false-positive rate) varied according to the prevalence of Down syndrome in the population tested. CONCLUSIONS: The cost-benefit ratio of second-trimester genetic ultrasonography depends on its diagnostic accuracy, and it is beneficial only when its overall sensitivity for Down syndrome is >74%.

Adult↗
PubMed1998

An economic evaluation of prenatal strategies for detection of trisomy 18.

OBJECTIVE: The objective of this study was to perform an economic evaluation of prenatal diagnostic strategies for women who are at increased risk for fetal trisomy 18 caused by either fetal choroid plexus cysts discovered in a conventional sonogram or an abnormal triple screen. STUDY DESIGN: The prevalence of trisomy 18 in the presence of second-trimester fetal choroid plexus cysts and also in the presence of abnormal triple screen were made on the basis of previously reported studies. A cost/benefit analysis and cost-effectiveness determination of 3 strategies were performed: (1) no prenatal diagnostic workup of at-risk patients, (2) universal genetic amniocentesis of all at-risk patients, and (3) universal second-trimester targeted genetic ultrasonography of all at-risk patients with amniocentesis (for fetal karyotyping) reserved only for those with abnormal ultrasonography results. RESULTS: The strategy of no prenatal diagnostic workup was the least expensive approach, costing $1,650,000 annually in the United States. The more costly approach was the strategy of universal amniocentesis for detecting fetal trisomy 18 in the presence of either second-trimester choroid plexus cysts or abnormal maternal serum screening, generating an annual cost of approximately $12 million and 40 fetal losses as a result of amniocenteses. The strategy of targeted genetic ultrasonography generated an annual cost of only $5 million and 8 fetal losses as a result of amniocenteses. CONCLUSIONS: Routine second-trimester amniocentesis in patients at increased risk for fetal trisomy 18 caused by either the presence of fetal choroid plexus cysts or abnormal triple screening is not justified from the cost/benefit point of view.

Amniocentesis↗
PubMed1998

A cost-effectiveness analysis of prenatal carrier screening for cystic fibrosis.

OBJECTIVE: To examine the cost-effectiveness of prenatal carrier screening for cystic fibrosis. METHODS: A cost-benefit equation was developed that was based on the hypothesis that the cost of prenatal diagnosis required to diagnose and prevent one case of cystic fibrosis should be equal to or less than the lifetime cost generated from the birth of a neonate with cystic fibrosis. The formula was adjusted because a woman's positive or negative carrier status remains unchanged, thus eliminating the need for testing in subsequent pregnancies. The formula was manipulated to identify the optimal cost per screening test, as well as the net cost savings per prenatally diagnosed case of cystic fibrosis for various racial or ethnic groups. Sensitivity analyses included some key assumptions regarding the cost per screening test ($50-150), patient screening acceptance rates (25-100%), and therapeutic abortion rates (50-100%). RESULTS: Assuming therapeutic abortion rates of 50-100%, the net savings per prenatally diagnosed case of cystic fibrosis are $58,369-$382,369 among whites. Given the previously reported patient screening acceptance rates of 50-78%, the overall annual cost savings in the United States for whites are $161-251 million. However, the screening program was not found to be cost-effective for blacks, Asians, or Hispanics. CONCLUSION: Under most assumptions and sensitivity analyses, a prenatal cystic fibrosis-carrier screening program appears to be cost-effective.

Cost Savings↗
PubMed1998

An economic evaluation of first-trimester genetic sonography for prenatal detection of Down syndrome.

OBJECTIVE: To determine 1) the diagnostic accuracy requirements of first-trimester genetic sonography from the cost-benefit point of view and 2) the economic impact of first-trimester genetic sonography for the United States on the basis of the accuracy of previously published studies. METHODS: A cost-benefit equation was developed on the basis of the hypothesis that the cost of chorionic villus sampling (CVS) in pregnant women with advanced maternal age (at least 35 years old) should be at least equal to the cost of genetic sonography with CVS used only for those with abnormal ultrasound results. The components of the equation included the diagnostic accuracy of genetic ultrasound (sensitivity and specificity for detecting Down syndrome), the costs of the CVS package and genetic ultrasound, and the lifetime cost of Down syndrome cases. RESULTS: First-trimester genetic sonography was found to be beneficial if the overall sensitivity for detecting Down syndrome was greater than 70%, and even then, the cost-benefit ratio depended on the corresponding false-positive rate. The required minimum ultrasound sensitivity varied according to the maternal age-specific prevalence of Down syndrome and ranged between 40% (for women 35 years old) to 96% (for women 44 years old). Of eight published cohorts using nuchal translucency thickness for genetic sonography, five had accuracies of genetic ultrasound compatible with net benefits. CONCLUSION: The benefits of first-trimester genetic sonography depend on its diagnostic accuracy. First-trimester genetic sonography has the potential for annual savings of 22 million dollars in the United States.

Adult↗
PubMed1993

Dental care utilization over time.

Between 1950 and 1978, per capita real dental expenditures in the U.S. grew at an average annual rate of 3.33%. Between 1978 and 1989 there was virtually no net growth in this measure of dental care utilization. This sharp curtailment of utilization growth has promoted debate about the sources of this change. Possible explanations include, among others, a reduction in dental disease due to increased exposure to fluoridation, the substitution of noncaloric sweeteners for refined sugar, preventive dentistry, , improved oral health habits, an increase in the net price of dental services, and the cost-containment efforts of insurers and employers. Changes have occurred in all of these variables, but little has done to isolate and quantify the individual effects. This decomposition is difficult, in part, because of the lack of an established model for time-series analysis of dental care utilization. A model of dental care demand, incorporating economic factors (out-of-pocket or net dental prices, per capita income, and nondental prices) as well as dietary factors (refined sugar consumption, noncaloric sweeteners, and exposure to fluoridated water), is combined with a simple model of dental care supply within an equilibrium framework. A two-stage estimation procedure is applied, using U.S. aggregate time-series data for the period 1950-89. Results show that economic and dietary factors are significantly related to changes in utilization. Net price and income elasticities of demand exhibit the expected signs and are compatible with estimates from cross-sectional studies. Decreases in cane and beet sugar consumption, facilitated by the increase in the use of noncaloric sweeteners, are associated with reductions in utilization. Fluoridation appears to be weakly but positively related to utilization. There also appears to have been a significant structural shift in demand since 1978. Overall goodness-of-fit is strong and the model accurately tracks the 1978-89 flattening of per capita real dental expenditures. Analysis of the relative contribution of each independent variable suggests that economic, dietary, and structural shift factors have contributed to this curtailment of growth.

Dental Care↗
PubMed1983

Approach-avoidance conflicts regarding participation in professional activity studies.

The intrapersonal conflict hypothesis was used to explain participation and nonparticipation by health professionals in a demonstration program in quality assurance and continuing education. Two variables, "perceived benefits" and "social barriers," predict participation (p less than .024, less than .005, respectively). A discriminant analysis suggests that "benefits" has a greater impact than "barriers." The model has practical value in enhancing participation in important professional activities.

Attitude of Health Personnel↗
PubMed1979

Sharing arrangements in the nonprofit hospital industry.

The major task of this paper is to develop hypotheses about voluntary sharing arrangements (SAs) from a plausible economic analysis of the hospital industry. The second task of the paper is to review some emerging evidence about SAs. Our research suggests that some SAs could or actually do reduce hospital costs to the community. However, there are reasons which indicate that cost reduction is neither a necessary nor a sufficient result for the success of many SAs.

Cost-Benefit Analysis↗
PubMedDate not supplied

Economic evaluation of prenatal carrier screening for fragile X syndrome.

OBJECTIVE: The objective of this study was to conduct an economic evaluation of routine prenatal carrier testing for fragile X syndrome. METHODS: This economic analysis was conducted from the societal perspective. A cost-benefit equation was developed based on the premise that the cost of routinely offering prenatal carrier testing for fragile X syndrome should be at least equal to, or less than, the cost of the current practice of not offering such testing. Sensitivity analyses included key assumptions regarding therapeutic abortion rates (50-100%) and patient screening acceptance rates (50-80%). RESULTS: A policy of routinely offering prenatal carrier testing for fragile X syndrome may be beneficial only if the cost per screening test is less than $120 during the first year of the screening program, or less than $240 when the program reaches its full maturity. Given the current cost per screening test of $250, prenatal screening for carrier status for fragile X syndrome carries the potential for annual losses of approximately $10 to $195 million in the United States. In addition, approximately 46-115 fetal lives may be lost due to invasive genetic procedures. CONCLUSIONS: Prenatal screening for fragile X syndrome may be economically beneficial only if the cost of the prenatal screening test for carrier identification is considerably less than the current cost.

Abortion, Therapeutic↗