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PubMed2005

How do smokers control their cigarette expenditures?

When faced with high cigarette prices, smokers can potentially control cigarette expenditures by limiting consumption or seeking cheaper cigarettes. The present study examined both these options and whether the use of price-minimizing strategies (the second option) could counteract a further price increase without smokers having to reduce consumption. Data for 5,109 smokers who purchased manufactured cigarettes were from the 2002 cross-sectional, population-based, random-digit-dialed California Tobacco Survey. We used logistic regression to examine which smokers used consumption-limiting or price-minimizing strategies, and multiple linear regression to determine how much price-minimizing strategies reduced the average price paid per pack. Overall, 32.3% of California smokers said they limited consumption and 74.1% used at least one of the five price-minimizing strategies identified: choosing cheaper retail outlets (61.1%), using promotional offers (35.2%), choosing cheaper brands (28.7%), purchasing by the carton (27.7%), and using low-tax or nontaxed sources (6.3%). Different groups of smokers used different strategies. Except for the use of promotional offers, all price-minimizing strategies significantly reduced the price paid per pack. Carton purchasers saved 1.01 US dollars/pack, and those buying from low-tax or nontaxed sources saved 1.23 US dollars/pack. However, pack buyers were reluctant to purchase cartons, mostly because they thought they might smoke too much, or because they considered the upfront cost unaffordable. The average California smoker could potentially save 0.33-0.66 US dollars/pack or 6.00-12.00 US dollars/month by using other price-minimizing strategies. Reducing consumption by 3 cigarettes/day could save a smoker 18.00 US dollars/month. Whereas price-minimizing strategies appeared to save money, cutting consumption could save even more. Thus further substantial tax increases would likely have the desired effect.

Adult↗

PubMed1997

The soluble interleukin-2 receptor predicts mortality in older hospitalized men.

BACKGROUND: There is an inverse relationship between the soluble interleukin-2 receptor (sIL-2R) and serum albumin, cholesterol, transferrin, prealbumin, and hemoglobin. Inasmuch as low serum albumin and cholesterol have been associated with excess mortality, we hypothesized that elevated sIL-2R would predict mortality in older adults. OBJECTIVE: To determine if elevated sIL-2R predicts mortality in patients on a geriatric rehabilitation unit. DESIGN: Prospective cohort. SETTING: University-affiliated VA medical center. PARTICIPANTS: Seventy-two male patients aged greater than 60 years admitted to a geriatric rehabilitation unit. Patients with severe hepatic or renal disease were excluded. MEASUREMENTS: We measured serum albumin, prealbumin, cholesterol, transferrin, hemoglobin, body mass index (BMI), C-reactive protein (CRP), and sIL-2R upon admission. Subjects were followed for 1 year. RESULTS: Low serum albumin, prealbumin, and hemoglobin and high sIL-2R and CRP predicted 1-year mortality on univariate analysis. When these predictors were included as covariates in a Cox regression model, only sIL-2R was a significant independent predictor of mortality (P = .043). Multiple linear regression with the above covariates revealed that only sIL-2R predicted time to death at (P = .003). CONCLUSIONS: High sIL-2R and CRP and low albumin, prealbumin, and hemoglobin predicted mortality using univariate analysis on a rehabilitation unit. However, with multivariate analysis, sIL-2R was the sole predictor of mortality.

Aged↗

PubMed1992

Assessment of glucose tolerance test criteria for diagnosis of diabetes in Chinese subjects.

OBJECTIVE: To examine and compare WHO diagnostic criteria for diabetes mellitus. RESEARCH DESIGN AND METHOD: The relationship between FPG and 2-h glucose are examined in 680 OGTTs with a quadratic regression model and ROC analysis. Simultaneous measurements of HbA1 and fructosamine are also compared with multiple linear regression. RESULTS: Two hundred eighteen subjects (32%) had 2-h glucose greater than or equal to 11.1 mM, of which only 86 had FPG greater than or equal to 7.8 mM. Only 2 subjects had FPG greater than 7.8 mM and 2-h glucose less than 7.8 mM. Of subjects with 2-h glucose less than 7.8 mM (n = 332), only 9 had FPG greater than 6.0 mM. From the quadratic model, the predicted FPG corresponding to 2-h glucose = 11.1 mM was 5.7 mM, whereas the predicted 2-h glucose corresponding to FPG = 7.8 mM was 15.2 mM. ROC analysis showed that, with 2-h glucose greater than or equal to 11.1 mM as indicating diabetes, an FPG of 5.6 mM gave an intersect for sensitivity and specificity of 87%. HbA1 and fructosamine correlated more closely with 2-h glucose and area under the OGTT curve than with FPG. CONCLUSIONS: Given that a 2-h glucose cutoff of 11.1 mM can be justified from other studies, our results suggest that the FPG cutoff of 7.8 mM when used for screening purposes should be reduced. At a suggested value of 7.0 mM, specificity remains 98.5%, whereas sensitivity increases to 57%.

China↗

PubMed2005

Milk fluoridation: a comparison of dental health in two school communities in England.

OBJECTIVE: To compare levels of caries experience in children attending schools in Wirral that have a fluoridated milk programme with children in a similar community which does not have a fluoridated milk programme. STUDY DESIGN: A cross sectional study measuring caries experience in first permanent molars. Children were examined on an 'intention to treat' basis and the effect of clustering of children within schools was taken into account. PARTICIPANTS: 690 children in Wirral (test group) and 1,835 children in Sefton (comparison group) were examined for caries experience (DMFT/DT/DFS) in 2003. The mean ages of the children examined in the test and comparison groups were 10.79 and 10.83 years respectively. RESULTS: Mean DMFT/DT/DFS values were 1.01/0.59/1.20 respectively in the test group and 1.46/1.02/1.89 respectively in the comparison group. Multiple linear regression analysis taking clustering of children within schools into account and with the Index of Multiple Deprivation 2000 as an explanatory variable gave the coefficients and p-values for DMFT/DT/DFS of 0.49 (p < 0.001)/0.43 (p < 0.001)/0.74 (p < 0.001) respectively. CONCLUSION: A difference in children with caries experience of 13% and a difference in children with active decay of 16% was found when a district with a community fluoridated milk programme was compared with a district without a fluoridated milk programme.

Animals↗

PubMed1993

Erythropoietin in human fetuses with immune hemolytic anemia and hydrops fetalis.

OBJECTIVE: To determine whether plasma erythropoietin is increased in fetuses with anemia due to Rh isoimmunization. METHODS: Hemoglobin and erythropoietin were measured in samples obtained by funipuncture from 15 fetuses with Rh isoimmunization (gestational age 26.2 +/- 5.0 weeks, mean +/- standard deviation) and from 13 control fetuses (23.1 +/- 6.7 weeks). Hemoglobin and erythropoietin also were determined in umbilical cord blood collected at birth from 20 term fetuses delivered by elective cesarean. RESULTS: Fetuses with Rh isoimmunization had lower hemoglobin and higher plasma erythropoietin measurements than mid-gestation controls (6.1 +/- 3.9 versus 10.7 +/- 1.5 g/dL and 105.5 +/- 168.1 versus 12.5 +/- 3.1 mU/mL, P < .05, respectively). Hemoglobin and plasma erythropoietin increased with gestational age in control fetuses. There was an inverse association between hemoglobin and plasma erythropoietin in control and Rh-isoimmunized fetuses (r = -0.56, P < .005). Using multiple linear regression, hemoglobin and gestational age were associated independently with plasma erythropoietin (overall F2,25 = 12.3, multiple r2 = 0.49, P < .001). Despite marked decreases in hemoglobin, fetuses below 24 weeks' gestation had minimal increases in plasma erythropoietin compared to fetuses above that gestational age. Mildly anemic Rh-isoimmunized fetuses (hemoglobin 11.6 +/- 2.0 g/dL) delivered vaginally had significantly higher erythropoietin levels in umbilical cord plasma than Rh-isoimmunized fetuses with comparable hemoglobin (10.9 +/- 3.5 g/dL) delivered by elective cesarean without labor (1246 +/- 856 versus 106 +/- 66 mU/mL, respectively, P < .05). CONCLUSION: Fetuses with anemia at mid to late gestation respond with increases in plasma erythropoietin, but these changes are substantially attenuated before 24 weeks' gestation.

Anemia, Hemolytic, Autoimmune↗

PubMed2003

Comparative assessment of neural networks and regression models for forecasting summertime ozone in Athens.

A comparison study has been performed with neural networks (NNs) and multiple linear regression models to forecast the next day's maximum hourly ozone concentration in the Athens basin at four representative monitoring stations that show very different behavior. All models use 11 predictors (eight meteorological and three persistence variables) and are developed and validated between April and October from 1992 to 1999. Performance results based on a wide set of forecast quality measures indicate that the NNs provide better estimates of ozone concentrations at the monitoring sites, whilst the more often used linear models are less efficient at accurately forecasting high ozone concentrations. The violation of the European information threshold of 180 microg/m(3) is successfully predicted by the NN in 72% of the cases on average. Results at all stations are consistent with similar ozone forecast studies using NNs in other European cities.

Journal Article↗

PubMed2006

A comparison of the effects of C2-cyclosporine and C0-tacrolimus on renal function and cardiovascular risk factors in kidney transplant recipients.

BACKGROUND: There are few data directly comparing the effects of two-hour postingestion monitored cyclosporine (C2-CsA) vs. trough-monitored tacrolimus (C0-Tac) on renal function and cardiovascular risk factors. METHODS: We studied 378 (202 C2-CsA vs. 176 C0-Tac) incident kidney transplant recipients in Toronto, Canada, from August 1, 2000 and December 31, 2003. Outcomes included changes in estimated glomerular filtration rate (eGFR at 1 and 6 months by modification of diet in renal disease four-variable equation), mean arterial pressure (MAP), total cholesterol (TC), and new-onset diabetes mellitus (NODM) at six months posttransplant. The independent effect of treatment/monitoring strategies on continuous outcomes and time-to-NODM was modeled using linear and Cox regression, respectively. RESULTS: Mean eGFR was 59.5 vs. 62.9 ml/min at one month and 50.6 vs. 61.2 ml/min at six months for C2-CsA vs. C0-Tac, respectively. Multiple linear regression revealed the slope of eGFR to be 0.93 ml/min/month lower in C2-CsA patients. This was equivalent to an adjusted average eGFR difference of 4.64 ml/min between months one and six posttransplant. There was no significant difference in average MAP and TC. In a stepwise multivariable Cox model and a propensity score analysis, there was no significant association between the type of treatment/monitoring strategy and time-to-NODM. CONCLUSIONS: There was a greater decline in eGFR for patients on C2-CsA (vs. C0-Tac) between one and six months posttransplant. However, MAP, TC, and the risk of NODM were comparable in both treatment/monitoring groups. The long-term impact of short-term reductions in eGFR as a function of the type of treatment/monitoring strategy requires further study.

Adolescent↗

PubMed1996

Insulin resistance in relatives of NIDDM patients: the role of physical fitness and muscle metabolism.

First degree relatives of patients with non-insulin-dependent diabetes mellitus (NIDDM) are often reported to be insulin resistant. To examine the possible role of reduced physical fitness in this condition 21 first degree relatives of NIDDM patients and 22 control subjects without any history of diabetes were examined employing a 150-min hyperinsulinaemic (0.6 mU insulin. kg-1.min-1) euglycaemic clamp combined with the isotope dilution technique (3-(3)H-glucose, Hot GINF), the forearm technique and indirect calorimetry. During hyperinsulinaemia glucose disposal (Rd) and forearm glucose extraction were significantly diminished in the relatives (p < 0.01 and p < 0.05), but glucose oxidation and the suppressive effect on hepatic glucose production were normal. Arteriovenous differences across the forearm of the gluconeogenic precursors lactate, alanine and glycerol as well as the increments in forearm blood flow during hyperinsulinaemia were similar in the two groups. Maximal oxygen uptake (VO2 max) was lower in the relatives than in the control subjects (36.8 +/- 1.9 vs 42.1 +/- 2.0 ml.kg-1.min-1; p = 0.03). There was a highly significant correlation between Rd and VO2 max in both relatives and control subjects (r = 0.68 and 0.66, respectively; both p < 0.001). Comparison of the linear regression analyses of insulin-stimulated Rd on VO2 max in the two groups showed no significant differences between the slopes (0.10 +/- 0.03 vs 0.09 +/- 0.02) or the intercepts. In stepwise multiple linear regression analyses with insulin-stimulated Rd as the dependent variable VO2 max significantly determined the level of Rd (p < 0.01), whereas forearm blood flow and anthropometric data did not. In conclusion, the insulin resistance in healthy first degree relatives of patients with NIDDM is associated with a diminished physical work capacity. Whether, this finding is ascribable to environmental or genetic factors (e.g. differences in muscle fibre types, capillary density etc) remains to be determined.

Adult↗

PubMed2000

Close relationship of abnormal glucose tolerance with endothelial dysfunction in hypertension.

Hypertension is frequently accompanied by left ventricular hypertrophy, endothelial dysfunction, and abnormal glucose metabolism. However, no study has examined the relative pathological significance of left ventricular hypertrophy and abnormal glucose metabolism on endothelial dysfunction in hypertension. This study was conducted to evaluate whether abnormal glucose tolerance assessed by 75-g oral glucose tolerance test or left ventricular hypertrophy is more closely associated with endothelial dysfunction in never-treated hypertensive patients without elevated fasting blood glucose. We studied 107 unmedicated hypertensive patients (mean age, 54+/-10 years) whose fasting blood glucose was <7.0 mmol/L. Endothelial function was assessed by change in brachial artery diameter in response to reactive hyperemia, and left ventricular mass index was determined by ultrasonography. Simple linear regression analysis demonstrated that endothelial function significantly correlated with left ventricular mass index and 2-hour blood glucose in 75-g oral glucose tolerance test, but not with fasting blood glucose. Multiple linear regression analysis revealed that endothelial function significantly correlated with 2-hour blood glucose (beta=-2.68, P<0.05) after we controlled for other clinical variables. Patients were divided into 3 groups according to 2-hour blood glucose levels. Endothelial function was more impaired in patients with diabetes (n=12; 4.7+/-1.8%) and in those with impaired glucose tolerance (n=31; 6.3+/-2.9%) than in those with normal glucose tolerance (n=64; 8.4+/-4.5%) (P<0.05), but left ventricular mass index was similar in these 3 groups. Abnormal glucose tolerance assessed by 75-g oral glucose tolerance test, rather than left ventricular hypertrophy, may have direct pathophysiological relevance to endothelial dysfunction in borderline to moderate hypertensive patients.

Adult↗

PubMed1985

Energy intake, norepinephrine excretion, and oxygen consumption in low birthweight infants.

Eleven healthy, appropriately grown low birthweight infants, ages 3-15 days and 28-33 weeks gestation, were the subjects of this study. Energy intake, urinary norepinephrine excretion, and metabolic rate as reflected in VO2 were examined concurrently. Energy intakes were recorded. Simultaneous collection of a timed urine for norepinephrine excretion and measurement of VO2 using indirect calorimetry were performed. A servo control device was used to maintain an abdominal skin temperature of 36.5 degrees C. The results demonstrated increases in energy intake, urinary norepinephrine, and VO2 with advancing postnatal age. Simple linear regression analysis revealed significant positive correlations between energy intake and VO2 (p less than 0.003), norepinephrine excretion and VO2 (p less than 0.003), postnatal age and VO2 (p less than 0.01), and postnatal age and energy intake (p less than 0.001). Multiple regression analysis revealed a strong positive correlation between urinary norepinephrine excretion and VO2, and energy intake and VO2. When postnatal age was added to the multiple linear regression analysis as a variable, energy intake was no longer strongly correlated with VO2. This implies postnatal age and energy intake are closely linked in this study, and further studies are needed to better define these relationships.

Birth Weight↗

PubMed1976

Constant returns to scale for prescription dispensing in U.S. community pharmacy.

By using data from a sample of 1767 community pharmacies, a total cost function was estimated by a polynomial regression of total cost on output. The Cobb-Douglas production function was estimated by a multiple linear regression of natural logarithmic transformations of output on natural logarithmic transformation of labor and capital. No economies of scale were found in prescription departments. Cost data led to a conclusion of constant marginal costs.

Costs and Cost Analysis↗

PubMed2004

Evaluating factors that influence microbial phenanthrene biodegradation rates by regression with categorical variables.

To advance the accuracy of bioremediation measurements, it is useful before specific experiments to attribute or estimate the influence of both experimental as well as field conditions on the expected magnitudes of microbial degradation rate coefficients. This paper analyzes the numerical contribution, or influence, of categories of conditions, such as bacterial adaptive state, electron acceptor type, mixing, generalized sorption conditions, and biodegradation temperature, on published phenanthrene biodegradation rates as an example of our regression approach. A fundamental microbial degradation rate equation is transformed to an additive model, then using multiple linear regression on published data, coefficients (of categorical variables) and a linear model are presented that estimate first-order biodegradation rate coefficients to within a factor of 3. Numerical estimates of how much bacterial adaptive state and presence of a sorption phase, the two most statistically significant factors, alter the phenanthrene biodegradation rate are presented. The influence of some measurement or field conditions, for example, the influence of oxygen reduction versus optimal nitrate reduction, cannot be distinguished statistically given the available data and range. The regression model is tested using conditions from newly published papers to estimate a priori the expected rate, which compares very favorably to measurements reported in the papers. Due to limited published data and range for extreme cases, the current coefficients do not apply to degradation of very aged phenanthrene nor very low concentrations of electron acceptors. As estimating tools, however, the coefficients themselves and the regression approach have very beneficial roles in design of experiments for both laboratory and field settings. Our method can be applied to other PAHs as sufficient data become available.

Adsorption↗

PubMed2003

Factors associated with improvement in breathing capacity during exercise in patients with chronic obstructive pulmonary disease.

OBJECTIVES: The aim of this study was to explore the relationship between resting pulmonary function indices and the ratio of minute ventilation at peak exercise to the maximal voluntary ventilation (VEmax/MVV) and to determine whether an improvement in breathing capacity during exercise (i.e. VEmax/MVV > 1) is associated with greater exercise capacity in patients with COPD. METHODOLOGY: The results of pulmonary function tests and incremental, symptom-limited cardiopulmonary exercise testing in 84 patients with predominantly moderate to severe COPD were reviewed. Multiple linear regression analysis was applied to determine the relationship of VEmax/MVV with selected independent variables at rest. Multiple logistic regression was used to determine significant predictors of VEmax/MVV </= or > 1. RESULTS: FEV1/FVC and inspiratory capacity (IC) were the only variables among resting pulmonary function indices that were significant independent determinants of VEmax/MVV and the stepwise analysis generated the following equation: VEmax/MVV = (-1.05E-02 x FEV1/FVC) + (0.15 x IC) + 1.28; r= 0.701, P < 0.001. Using multiple logistic regression with VEmax/MVV </= or > 1 as a dependent categorical variable, FEV1/FVC was the only significant predictor among resting pulmonary indices of a VEmax/MVV ratio of > 1 (Odds ratio 0.93, 95%CI 0.89, 0.97). There was a significant association between VEmax/MVV and peak oxygen uptake (VO2max) after adjusting for FEV1 (r = 0.66, P < 0.001). If the categorical variable of VEmax/MVV (</= or > 1) was used instead of a continuous variable, a significant association with VO2max remained after adjusting for FEV1 (r = 0.60, P < 0.001). CONCLUSIONS: Among resting pulmonary function indices, the FEV1/FVC ratio is the best determinant of an improvement in breathing capacity during exercise in COPD patients. After adjusting for FEV1, an improvement in breathing capacity during exercise is associated with significantly higher exercise capacity.

Aged↗

PubMed2002

Is obesity associated with early sexual maturation? A comparison of the association in American boys versus girls.

BACKGROUND: Increasing evidence suggests a close association between early sexual maturation (SM) and obesity in girls and female adults. Earlier maturing girls are more likely to be obese than nonearly maturers. However, limited research has been conducted in boys. OBJECTIVE: To examine the influence of early SM on fatness in boys and compare it with girls, and to test the hypothesis that the associations differ by gender because of the differences in growth and SM patterns in boys and girls. STUDY DESIGN: Cross-sectional study. SUBJECTS: One thousand five hundred one girls and 1520 boys (aged 8-14 years) who participated in the Third National Health and Nutrition Examination Survey survey (1988-1994) and had complete anthropometry (weight, height, skinfold thickness) and SM data. METHODS: Based on each individual's age and SM status (Tanner stages: genitalia stages for boys and breast stages for girls), the subjects were classified as: 1) early maturers (those who reached a certain Tanner stage earlier than the median age for that stage), and 2) the others (average and later maturers). Overweight was defined as a body mass index (BMI) > or =85th percentile, and obesity > or =95th percentile. Logistic regression analysis was to test how early maturation affected the risks for overweight and obese. Using multiple linear regression models, the associations between fatness (BMI and skinfold thickness) and SM were systematically examined. Covariates including age, ethnicity, residence, family income, energy intake, and physical activity were adjusted. RESULTS: Early SM was positively associated with overweight and obesity in girls, but the associations were reverse for boys. The prevalence of overweight in early maturers versus the others was 22.6% versus 31.6% in boys and 34.4% versus 23.2% in girls; the figures for obesity were 6.7% versus 14.8% and 15.6% versus 8.1%, respectively. Odd ratios and 95% confidence intervals for obesity were 0.4 (0.2, 0.8) for boys and 2.0 (1.1, 3.5) for girls, and covariates were adjusted. Most significant differences in overweight and obesity among ethnic groups disappeared after controlling for SM. Fatness (BMI and skinfold thickness) was associated with SM stages and with early maturation in boys and girls, but the associations were in opposite directions. Compared with their counterparts, early maturing boys were thinner, whereas early maturing girls were fatter. CONCLUSIONS: Obesity is associated with sexual maturation in both boys and girls, but the association differs. There is positive association in girls, but a negative one in boys. Maturation status should be taken into consideration when assessing child and adolescent obesity.

Adipose Tissue↗

PubMed1991

Median nerve somatosensory evoked potentials: studies on latency variability as a function of subject height, limb length and nerve conduction velocity.

Report on the results of regression analysis studies concerning median nerve somatosensory evoked potentials (SEPs) latencies, as dependent variables, and subject height, limb length and nerve conduction velocity (NCV), as independent variables. The tests were performed on 23 normal volunteers. Absolute SEP latencies could be predicted by a linear regression model when the independent variable was arm length; when it was subject height, however, both exponential and polynomial models proved better, the latter showing the best coefficients of determination, R 2. Multiple linear regression with two independent variables (arm length and NCV) was found to be better than simple linear regression for predicting P/N13 latency. The regression line for EP-P/N13 latency on height was found to be a polynomial curve; although the regression was found to be significant by the "F" test (alpha = 1%), the model had a low R 2 value (0.41). The same applies to the P/N13-N19 interpeak latency regression curve, but the regression was significant for alpha = 5% in that case. Although interwave latencies are the most useful parameters for clinical interpretation of median SEPs, absolute latencies may occasionally be important, and should be corrected for body size. In unusually tall subjects, it might be useful to double-check EP-P/N13 interwave latency prolongation by estimating the maximum expected P/N13 latency, using a model that takes into account both limb length and NCV.

Body Constitution↗

PubMed1997

Maternal employment and breast-feeding: findings from the 1988 National Maternal and Infant Health Survey.

OBJECTIVES: This analysis uses nationally representative data from the 1988 National Maternal and Infant Health Survey to explore the factors, including employment, associated with breast-feeding initiation and duration. METHODS: Multiple logistic regression was used to model the determinants of breast-feeding initiation among 9087 US women. Multiple linear regression was used to model the duration of breast-feeding among women who breast-fed. RESULTS: Fifty-three percent of mothers initiated breast-feeding in 1988, and the decision to breast-feed was not associated with maternal employment. However, among breast-feeders, returning to work within a year of delivery was associated with a shorter duration of breast-feeding when other factors were controlled. Among employed mothers, the duration of maternity leave was positively associated with the duration of breast-feeding. CONCLUSIONS: The low rates of breast-feeding initiation in the United States are not attributable to maternal participation in the labor force. However, returning to work is associated with earlier weaning among women who breast-feed.

Adult↗

PubMed2003

Comparison of endocrine tests with respect to their predictive value on the outcome of ovarian hyperstimulation in IVF treatment: results of a prospective randomized study.

BACKGROUND: This study was designed to compare endocrine tests [clomiphene citrate challenge test (CCT), exogenous FSH ovarian reserve test (EFORT) and basal FSH, basal estradiol (E(2)) and basal inhibin B as an integral part of all CCT and EFORT], with respect to their ability to estimate the stimulable cohort of follicles in the ovaries (ovarian capacity) and to analyse which test or combination of tests would give the best prediction of ovarian capacity. METHODS: A total of 110 regularly menstruating patients, aged 18-39 years, participated in this prospective study, randomized by a computer-designed 4-block system study into two groups. Fifty-six patients underwent a CCT, and 54 patients underwent an EFORT. In all patients, the test was followed by an IVF treatment. The result of ovarian hyperstimulation during IVF treatment, expressed by the total number of follicles, was used as gold standard. RESULTS: Univariate linear regression analysis showed that the best correlation with the number of follicles after ovarian hyperstimulation (Y) is found by the inhibin B increment (InhB incr.) in the EFORT (Y = 3.957 + 0.081 x InhB incr. (95% CI 0.061-0.101); r = 0.751; P < 0.001). Multiple linear regression analysis showed a significant contributing value of the variables basal FSH, E(2) increment of the EFORT and inhibin B increment to the basic model with the variable age. The best prediction of ovarian capacity (Y) was seen when E(2) increment and inhibin B increment were used simultaneously in a stepforward multiple regression prediction model [Y = 2.659 + 0.052 x InhB incr. (0.026-0.078) + 0.027 x E(2) incr. (95% CI 0.012-0.054); r = 0.796; P < 0.001]. The CCT could not be used in a prediction model. CONCLUSIONS: The EFORT is the endocrine test which gives the best prediction of ovarian capacity.

Adolescent↗

PubMed2003

The influence of gender on factors associated with HIV transmission risk among young Russian injection drug users.

HIV infection rates are dramatically increasing in the Russian Federation. Epidemiological studies indicate that the greatest rise of HIV incidence has been among injection drug users (IDU). Young adults (N = 188) who reported injecting drug use completed surveys and interviews that assessed injection drug use behavior, sexual behavior, and HIV-related knowledge. The average age of participants was 21.3 years. Multiple linear regression analysis found male gender and younger age at sexual debut was positively and significantly associated with having multiple sexual partners. Gender moderated the effects of sexual debut and number of times injected drugs were used in the past month. Males who initiate sex at a younger age were more likely to report multiple sex partners and females who reported higher frequency of drug use were more likely to report multiple sex partners. Gender is an important factor, as well as moderator of risk behavior among Russian injection drug users. Delaying sexual debut, particularly for males, may be an effective strategy to reduce subsequent risk behavior. Prevention efforts among IDUs need to address sexual risk behavior in conjunction with injection risk behavior.

Adolescent↗