Transthyretin cardiac amyloidosis in continental Western Europe: an insight through the Transthyretin Amyloidosis Outcomes Survey (THAOS).

AIMS: Transthyretin amyloidosis (ATTR amyloidosis) is a heterogeneous disorder with cardiac, neurologic, and mixed phenotypes. We describe the phenotypic and genotypic profiles of this disease in continental Western Europe as it appears from the Transthyretin Amyloidosis Survey (THAOS). METHODS AND RESULTS: THAOS is an ongoing, worldwide, longitudinal, observational survey established to study differences in presentation, diagnosis, and natural history in ATTR amyloidosis subjects. At data cut-off, 1411 symptomatic subjects from nine continental Western European countries were enrolled in THAOS [1286 hereditary (ATTRm) amyloidosis; 125 wild-type ATTR (ATTRwt) amyloidosis]. Genotypes and phenotypes varied notably by country. Four mutations (Val122Ile, Leu111Met, Thr60Ala, and Ile68Leu), and ATTRwt, were associated with a mainly cardiac phenotype showing symmetric left ventricular (LV) hypertrophy, normal diastolic LV dimensions and volume, and mildly depressed LV ejection fraction (LVEF). Morphologic and functional abnormalities on echocardiogram were significantly more severe in subjects with cardiac (n'= 210), compared with a mixed (n = 298), phenotype: higher median (Q1-Q3) interventricular septal thickness [18 (16-21) vs. 16 (13-20) mm; P = 0.0006]; and more frequent incidence of LVEF <50% (38.1 vs. 17.5%; P = 0.0008). Subjects with cardiac mutations or ATTRwt (or cardiac or mixed phenotype) had a lower survival rate than subjects in other genotype (or the neurologic phenotype) categories (P < 0.0001, for both). CONCLUSION: ATTR amyloidosis genotypes and phenotypes are highly heterogeneous in continental Western Europe. A geographic map of the different disease profiles and awareness that a subset of subjects have a dominant cardiac phenotype, mimicking hypertrophic cardiomyopathy, at presentation can facilitate the clinical recognition of this underdiagnosed disease. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00628745.

Effect of varenicline on smoking cessation through smoking reduction: a randomized clinical trial.

IMPORTANCE: Some cigarette smokers may not be ready to quit immediately but may be willing to reduce cigarette consumption with the goal of quitting. OBJECTIVE: To determine the efficacy and safety of varenicline for increasing smoking abstinence rates through smoking reduction. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind, placebo-controlled, multinational clinical trial with a 24-week treatment period and 28-week follow-up conducted between July 2011 and July 2013 at 61 centers in 10 countries. The 1510 participants were cigarette smokers who were not willing or able to quit smoking within the next month but willing to reduce smoking and make a quit attempt within the next 3 months. Participants were recruited through advertising. INTERVENTIONS: Twenty-four weeks of varenicline titrated to 1 mg twice daily or placebo with a reduction target of 50% or more in number of cigarettes smoked by 4 weeks, 75% or more by 8 weeks, and a quit attempt by 12 weeks. MAIN OUTCOMES AND MEASURES: Primary efficacy end point was carbon monoxide-confirmed self-reported abstinence during weeks 15 through 24. Secondary outcomes were carbon monoxide-confirmed self-reported abstinence for weeks 21 through 24 and weeks 21 through 52. RESULTS: The varenicline group (n = 760) had significantly higher continuous abstinence rates during weeks 15 through 24 vs the placebo group (n = 750) (32.1% for the varenicline group vs 6.9% for the placebo group; risk difference (RD), 25.2% [95% CI, 21.4%-29.0%]; relative risk (RR), 4.6 [95% CI, 3.5-6.1]). The varenicline group had significantly higher continuous abstinence rates vs the placebo group during weeks 21 through 24 (37.8% for the varenicline group vs 12.5% for the placebo group; RD, 25.2% [95% CI, 21.1%-29.4%]; RR, 3.0 [95% CI, 2.4-3.7]) and weeks 21 through 52 (27.0% for the varenicline group vs 9.9% for the placebo group; RD, 17.1% [95% CI, 13.3%-20.9%]; RR, 2.7 [95% CI, 2.1-3.5]). Serious adverse events occurred in 3.7% of the varenicline group and 2.2% of the placebo group (P = .07). CONCLUSIONS AND RELEVANCE: Among cigarette smokers not willing or able to quit within the next month but willing to reduce cigarette consumption and make a quit attempt at 3 months, use of varenicline for 24 weeks compared with placebo significantly increased smoking cessation rates at the end of treatment, and also at 1 year. Varenicline offers a treatment option for smokers whose needs are not addressed by clinical guidelines recommending abrupt smoking cessation. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01370356.

Effect of varenicline on individual nicotine withdrawal symptoms: a combined analysis of eight randomized, placebo-controlled trials.

INTRODUCTION: Concerns exist that varenicline may cause neuropsychiatric side effects. Some of these symptoms (e.g., depression, irritability) have been measured in clinical trials using nicotine withdrawal scales. This study assessed the effect of varenicline on neuropsychiatric and other symptoms, as measured by the Minnesota Nicotine Withdrawal Scale (MNWS). METHODS: We analyzed weekly individual MNWS symptom ratings in 8 randomized double-blind, placebo-controlled smoking cessation trials funded by Pfizer with similar methodology (n = 2,403 varenicline; n = 1,434 placebo). Ratings for the past 24hr were obtained prior to quitting and starting treatment and at Weeks 1-6 and 11 after the quit date. RESULTS: In repeated measures analyses controlling for baseline values, ratings for 5 neuropsychiatric symptoms (depressed mood, irritability, anxiety, difficulty concentrating, and restlessness) and urge to smoke were lower (p < .01) for varenicline than placebo at each timepoint. Worsening in scores from 0-2 (baseline) to 4 was less frequent on varenicline than placebo for all ratings except appetite- (significantly more frequent for varenicline, p < .0001) and sleep-related items. Repeated measures analysis for individuals with low levels of exhaled carbon monoxide revealed similar patterns except for a nonsignificant difference for increased appetite. CONCLUSIONS: Use of varenicline while trying to quit smoking reduces and does not increase neuropsychiatric symptoms such as depressed mood and irritability measured on the MNWS in smokers without current psychiatric disorders. It is associated with increases in sleep disturbance and appetite although the latter appears due to enabling more subjects to abstain from smoking.

Evaluating Treatment Efficacy by Combining Multiple Measures in Clinical Trial Applications.

A variety of clinical and laboratory measures can be used in clinical trials to assess the benefit of a new treatment over the standard of care. Data from clinical studies are often analyzed by combining individual outcomes into one primary outcome. That primary outcome is then referred to as a composite endpoint or a combined endpoint. We propose an analysis on the composite endpoint with Gehan's (1965) ranking approach where each subject in the treatment group is compared with each subject in the control group in a pair-wise manner. Our approach reduces computational time and complexity to construct a subject-level pairwise composite score. We develop a statistical testing procedure for the analysis of composite endpoints when using the hierarchical scores. In this article, we propose two tests (a parametric test and a non-parametric bootstrap procedure) for evaluating the effect of treatment. The proposed parametric test has an asymptotic F-distribution based on standard statistical assumptions. We conduct an extensive simulation study to assess the operating characteristics of the proposed methods and to compare them with an existing method. We illustrate the methods using publicly available data from two clinical studies.

The Fagerström Test for Nicotine Dependence as a predictor of smoking abstinence: a pooled analysis of varenicline clinical trial data.

INTRODUCTION: We explored the relationship between the Fagerström Test for Nicotine Dependence (FTND) and smoking abstinence rates in 10 randomized, double-blind placebo-controlled Phase 2-4 varenicline studies. METHODS: Participants were adult smokers (≥10 cigarettes/day) who were motivated to quit. Efficacy end points included continuous abstinence rate (CAR) for weeks 9-24 analyzed, by baseline FTND and Heaviness of Smoking Index (HSI) scores, and treatment. Data were analyzed using logistic regression models. RESULTS: Overall, 2,763 varenicline (M [SD] FTND score: 5.6 [2.2]) and 2,229 placebo subjects (5.5 [2.1]) were included in the analysis. An increase of one unit in baseline FTND or HSI score decreased the odds of abstinence at Week 24 by 11% (odds ratio [OR] 0.89, 95% CI 0.86-0.92, p < .0001) and 18% (OR 0.82, 95% CI 0.79-0.87, p < .0001), respectively. Treatment had a significant impact on CAR 9-24: odds of abstinence were increased threefold for varenicline versus placebo (OR 3.3, 95% CI 2.8-3.8, p < .0001). There was no interaction between treatment and FTND (p = .98) or HSI score (p = .97) for CAR 9-24. The HSI score predicted abstinence outcome as effectively as the FTND score. CONCLUSION: Abstinence rates decreased with increasing dependence scores. There was no interaction between treatment and baseline FTND or HSI score, suggesting that they have no effect on the efficacy of varenicline versus placebo. These results also suggest that the HSI may be as effective at predicting smoking cessation outcome as the whole FTND questionnaire.

Comparison of adjustment methods for stratified two-sample tests in the context of ROC analysis.

We compare several nonparametric and parametric weighting methods for the adjustment of the effect of strata. In particular, we focus on the adjustment methods in the context of receiver-operating characteristic (ROC) analysis. Nonparametrically, rank-based van Elteren's test and inverse-variance (IV) weighting using the area under the ROC curve (AUC) are examined. Parametrically, the stratified t-test and IV AUC weighted method are applied based on a binormal monotone transformation model. Stratum-specific, pooled, and adjusted estimates are obtained. The pooled and adjusted AUCs are estimated. We illustrate and compare these weighting methods on a multi-center diagnostic trial and through extensive Monte-Carlo simulations.

Multivitamin/Multimineral Supplement Use is Associated with Increased Micronutrient Intakes and Biomarkers and Decreased Prevalence of Inadequacies and Deficiencies in Middle-Aged and Older Adults in the United States.

Micronutrient inadequacies are common in older adults and using a multivitamin/multimineral supplement (MVM) may improve their nutritional status. National Health and Nutrition Examination Survey data were analyzed to determine micronutrient intakes based on diet and MVM use in adults aged ≥51 years. Deficiencies were evaluated using nutrient biomarkers. The National Cancer Institute Method was used to estimate usual intakes of 18 micronutrients stratified by age and frequency of MVM use. Compared with food alone, MVM use was associated with higher nutrient intake and lower prevalence of inadequacies of almost all micronutrients examined and improved nutrient biomarker status of folate, iodine, selenium, and vitamins B6, B12, and D. Regular MVM use (≥16 days/month) decreased the odds of clinical deficiency (defined by biomarker status) of vitamins B6 and D but increased the proportion exceeding the tolerable upper intake level of folic acid. Vitamin B6 deficiency in MVM non-users was common and increased with age.

Efficacy and safety of bazedoxifene in postmenopausal Latino women with osteoporosis.

OBJECTIVE: Bazedoxifene (BZA) reduces fractures and bone turnover in postmenopausal women with osteoporosis. This report evaluates safety and efficacy of BZA in Latin American women in the global trial. METHODS: In the 3-year, phase 3, randomized, double-blind trial, postmenopausal women with osteoporosis (N = 7,492) received BZA 20 or 40 mg/d, raloxifene 60 mg/d, or placebo. Outcomes included vertebral fractures, bone mineral density, bone turnover markers, and safety. This post hoc analysis included 3,036 Latin American women. RESULTS: Incidence of vertebral fractures at month 36 with BZA 20 mg, BZA 40 mg, raloxifene, and placebo was 1.87%, 1.90%, 1.43%, and 2.83%, respectively (differences not significant). Adjusted mean percentage increases in bone mineral density were 2.49%, 2.79%, 3.18%, and 1.26% for lumbar spine, and 0.40%, 0.95%, 1.11%, and -0.41% for total hip (P < 0.001 for BZA 20/40 mg vs placebo). Adjusted median percentage reductions in osteocalcin at month 12 were -43.0%, -44.1%, -46.9%, and -27.0%, and C-telopeptide were -50.7%, -53.4%, -57.6%, and -32.1% (P < 0.001 for BZA 20/40 mg vs placebo). Common adverse events included pain and flu syndrome. CONCLUSIONS: BZA significantly improved bone mineral density and reduced bone turnover, and numerically reduced fractures, compared with placebo in postmenopausal Latin American women with osteoporosis. Results were similar to the global trial.

Efficacy of Varenicline for Cigarette Reduction Before Quitting in Japanese Smokers: A Subpopulation Analysis of the Reduce to Quit Trial.

PURPOSE: This prospective analysis of the Japanese subpopulation of the varenicline reduce to quit study was conducted to evaluate whether results for Japanese participants were consistent with the full study population. METHODS: Patients received varenicline or placebo for a 24-week treatment period (12-week smoking reduction phase then a 12-week smoking abstinence phase) followed by a 28-week nontreatment, follow-up phase. Participants were to reduce the daily number of cigarettes smoked by at least 50% by week 4 and by a further 50% by week 8, with the goal of achieving complete abstinence by week 12. The primary efficacy end point was the carbon monoxide-confirmed continuous abstinence during weeks 15 to 24. FINDINGS: Overall, 210 Japanese patients were randomly assigned to 1 of the 2 study groups (varenicline, 107; placebo, 103). Continuous abstinence rates for weeks 15 to 24 were higher for participants in the varenicline group versus the placebo group (46.7% vs 12.6%; odds ratio = 14.68; 95% CI, 5.38-40.05), and the 7-day point prevalence of abstinence rates were higher for varenicline versus placebo at week 12 (odds ratio = 13.76; 95% CI, 5.28-35.86). The number of participants with a ≥50% reduction in the number of daily cigarettes smoked from baseline to week 4 and a ≥75% reduction by week 8 was greater in the varenicline group versus the placebo group (week 4: 59.8% vs 30.1%; week 8: 38.3% vs 12.6%). Serious adverse events were reported in 3.7% of varenicline participants and 1.0% of placebo participants. IMPLICATIONS: The efficacy and tolerability results of this analysis are consistent with those of the full varenicline reduce to quit study. Varenicline treatment and cigarette reduction before quitting may provide an alternative approach to smoking cessation in Japanese smokers who are not ready to quit immediately. ClinicalTrials.gov identifier: NCT01370356.

In vivo measurement of PDE10A enzyme occupancy by positron emission tomography (PET) following single oral dose administration of PF-02545920 in healthy male subjects.

Phosphodiesterase 10A (PDE10A) is an enzyme highly enriched in the striatal medium spiny neurons. It is involved in the regulation of cytoplasmic levels of cAMP and cGMP and signaling within the basal ganglia. This study with PDE10A radioligand [18F]MNI-659 was designed to measure the enzyme occupancy of PF-02545920 in 8 healthy male volunteers (48 ± 4 years) after a single oral dose (10 mg or 20 mg) and to evaluate safety and tolerability. Arterial blood sampling was performed to obtain a metabolite-corrected plasma input function for the quantification of [18F]MNI-659 binding to PDE10A. The occupancy of PF-02545920 was calculated with two different methods: In Method 1, [18F]MNI-659 enzyme occupancy was calculated from the estimates of binding potential, using the cerebellum as a reference region; in Method 2, occupancy was estimated from the slope of the revised Lassen's plot. Serum concentrations of PF-02545920 were measured to determine the relationship between concentration and occupancy. Based on Method 1, striatal PDE10A occupancy increased with increasing PF-02545920 dose: 14-27% at 10 mg dose (N = 4) and 45-63% at 20 mg dose (N = 3). Comparable occupancies were observed using Lassen's plot Method 2: 10 mg: 14-37%; 20 mg: 46-55%. The relationship between exposure and occupancy was best described using an Emax model. The serum concentration associated with 50% occupancy was estimated to be 93.2 ng/mL. Single oral doses of 10 mg or 20 mg of PF-02545920 were safe and well tolerated in healthy male volunteers [NCT# 01918202].

Timing and persistence of effect of conjugated estrogens/bazedoxifene in postmenopausal women.

OBJECTIVE: The aim of the study was to determine the time course of effect with conjugated estrogens/bazedoxifene (CE/BZA) in nonhysterectomized postmenopausal women in five phase 3 trials. METHODS: This post hoc analysis identified when CE 0.45 mg/BZA 20 mg and CE 0.625 mg/BZA 20 mg first achieved a statistically significant difference (P < 0.05) versus placebo in individual trials and the duration the difference persisted for prespecified efficacy endpoints. RESULTS: CE/BZA significantly reduced hot flush frequency beginning at weeks 2 to 4 and severity at weeks 3 to 6; benefits were maintained through month 24. Significant improvements in lumbar spine, total hip, femoral neck, and femoral trochanter bone mineral density were evident at month 6 or 12 and changes in bone turnover markers at month 3 or 6; benefits were maintained throughout the studies (12 or 24 mo). In symptomatic women with less than 5% vaginal superficial cells at baseline, vaginal maturation index was significantly improved by week 4. Reductions in parabasal cells were maintained throughout the studies (through months 3 and 24), but superficial cell count changes persisted only with the higher CE/BZA dose. Menopause-Specific Quality of Life total and vasomotor domain scores were improved at all assessments, from months 3 through 24. Some measures of sleep, especially quality and time to fall asleep, improved during weeks 4 to 8 and were maintained in a majority of weeks thereafter. CONCLUSIONS: In the context of studies designed primarily to evaluate efficacy at final study endpoints, both doses of CE/BZA achieved significance versus placebo at early assessments for most outcomes, and benefits were well maintained.

Conjugated estrogens and bazedoxifene in minority populations: pooled analysis of four phase 3 trials.

OBJECTIVE: The aim of the study was to compare efficacy of conjugated estrogens (CE)/bazedoxifene (BZA) for treatment of menopausal symptoms and prevention of postmenopausal osteoporosis in minorities (black/Hispanic) versus whites. METHODS: In a post hoc analysis, data were pooled from 3,424 white or minority nonhysterectomized postmenopausal women randomized to CE 0.45 or 0.625 mg/BZA 20 mg or placebo in four double-blind, phase 3 Selective Estrogens, Menopause, and Response to Therapy (SMART) trials. Outcomes included hot flush frequency/severity (daily diary) in women with at least seven moderate-to-severe hot flushes per day (SMART-1, -2), vaginal cytology in women with at most 5% superficial cells (SMART-1, -3), lumbar spine and total hip bone mineral density (BMD) (SMART-1, -5), and the Menopause-Specific Quality of Life (MENQOL) questionnaire (SMART-1, -2, -3, -5). RESULTS: The analysis included 2,907 white (84.9%), 315 black (9.2%), and 202 Hispanic (5.9%) women. The reduction in hot flush frequency/severity versus placebo (P < 0.05; week 12) was similar in white and minority women. In both populations, both doses significantly (P < 0.05 vs placebo) improved MENQOL vasomotor function, sexual function, and total scores at 3 months; decreased the percentage of parabasal cells at 2 years; and increased the percentage of BMD responders at 12 and 24 months. Significant differential treatment effects by race/ethnicity were observed only for effects on vaginal superficial cells at month 24 and vaginal pH at month 3. CONCLUSIONS: Notwithstanding a limited sample size, CE/BZA had a similar and beneficial impact on hot flushes, MENQOL, and BMD in minorities and whites.

The effect of conjugated estrogens/bazedoxifene therapy on body weight of postmenopausal women: pooled analysis of five randomized, placebo-controlled trials.

OBJECTIVE: This post hoc analysis compared body weight, body mass index (BMI), and BMI category changes in postmenopausal women treated with conjugated estrogens/bazedoxifene (CE/BZA) versus placebo in the Selective Estrogens, Menopause, and Response to Therapy (SMART) trials. METHODS: Data were pooled from five randomized, double-blind, placebo- and active-controlled studies in postmenopausal women aged 40 to 75 years with a uterus given CE 0.45 mg/BZA 20 mg (n = 1,607), CE 0.625 mg/BZA 20 mg (n = 1,598), or placebo (n = 1,256) for at least 12 weeks and up to 2 years. Changes from baseline in body weight, BMI (kg/m(2)), and World Health Organization BMI category (underweight <18.5; normal 18.5 to <25; overweight 25 to <30; obese ≥30) during treatment were evaluated. RESULTS: Mean body weight increased less than 0.9 kg and mean BMI increased less than 0.4 kg/m(2) in all treatment groups at all time points. There were no statistically significant between-group differences, except for significantly greater increases in weight (P = 0.015) and BMI (P = 0.014) with placebo versus CE 0.625 mg/BZA 20 mg at month 12. Approximately, 10% of women in the CE/BZA groups and 11% in the placebo group had increases in body weight greater than 7% of baseline. The majority of BMI changes were within ±7%, and there were no statistically significant between-group differences in BMI category distributions during treatment. CONCLUSIONS: Significant increases in body weight or BMI were not observed in postmenopausal women receiving CE 0.45 mg/BZA 20 mg or CE 0.625 mg/BZA 20 mg for up to 2 years in the Selective Estrogens, Menopause, and Response to Therapy trials.

Effect of conjugated estrogens/bazedoxifene on postmenopausal bone loss: pooled analysis of two randomized trials.

OBJECTIVE: Conjugated estrogens/bazedoxifene reduces vasomotor symptoms and prevents postmenopausal bone loss without stimulating the breast and endometrium. We analyzed changes in bone mineral density (BMD) and bone markers using pooled data from two phase-3 trials. METHODS: Selective Estrogens, Menopause, and Response to Therapy (SMART)-1 and SMART-5 were randomized, double-blind, placebo- and active-controlled studies conducted in postmenopausal nonhysterectomized women. BMD and turnover marker data were pooled for women given conjugated estrogens (0.45 or 0.625 mg) plus bazedoxifene 20 mg or placebo over 12 months. Sensitivity analyses were conducted using baseline Fracture Risk Assessment Tool score, age, years since menopause, body mass index, race, and geographic region. RESULTS: There were 1,172 women, mean age 54.9 years, mean 6.21 years since menopause, mean lumbar spine, and total hip T scores -1.05 and -0.58; 58.8% had a Fracture Risk Assessment Tool score less than 5% indicating low fracture risk. At 12 months, adjusted differences (vs placebo) in BMD change in the groups taking conjugated estrogens 0.45 or 0.625 mg plus bazedoxifene 20 mg were 2.3% and 2.4% for lumbar spine, 1.4% and 1.5% for total hip, and 1.1% and 1.5% for femoral neck (all P < 0.001 vs placebo). These increases were unrelated to baseline Fracture Risk Assessment Tool score, age, years since menopause, body mass index, or geographic region. Both doses reduced bone turnover markers (P < 0.001). CONCLUSIONS: Conjugated estrogens/bazedoxifene significantly improved BMD and turnover in a large population of younger postmenopausal women at low fracture risk and is a promising therapy for preventing postmenopausal bone loss.

Pooled Analysis of the Effects of Conjugated Estrogens/Bazedoxifene on Vasomotor Symptoms in the Selective Estrogens, Menopause, and Response to Therapy Trials.

OBJECTIVES: Conjugated estrogens/bazedoxifene (CE/BZA) reduced menopause-related hot flashes (HFs) in the Selective estrogens, Menopause, And Response to Therapy (SMART) trials. This post hoc pooled analysis of SMART-1 and -2 further characterized effects of CE/BZA on HFs in the overall population and patient subgroups. METHODS: Data from two randomized, double-blind, placebo- and active-controlled, phase 3 studies were pooled for nonhysterectomized postmenopausal women with moderate/severe HFs given CE 0.45 mg/BZA 20 mg, CE 0.625 mg/BZA 20 mg, or placebo for 12 weeks. HF frequency and severity were assessed by daily diary. RESULTS: The pooled analysis included 403 participants. At 12 weeks, CE 0.45 mg/BZA 20 mg and CE 0.625 mg/BZA 20 mg significantly (all p < 0.001) decreased moderate/severe HF frequency versus placebo (-7.9, -8.2, -4.1), reduced adjusted average daily HF severity score versus placebo (-1.0, -1.3, -0.3), increased the percentage of women who had a ≥50% (81.2%,87.1%, 50.6%) and ≥75% (62.4%, 74.8%, 26.4%) reduction from baseline in daily frequency of moderate/severe HFs, increased the percentage with ≥50% (38.3%, 58.1%, 11.0%) and ≥75% (24.2%, 38.1%, 5.5%) reductions in average daily HF severity score, and improved MENQOL vasomotor function versus placebo (adjusted mean change-3.08, -3.69, -1.37). CE/BZA was significantly more effective than placebo irrespective of time since menopause, with some evidence of a lower placebo response in women in later menopause (>5 years) versus early menopause (≤5 years). CONCLUSIONS: CE/BZA effectively reduces moderate/severe HFs in postmenopausal women. NCT#'s: NCT00675688; NCT00234819.

The effects of bazedoxifene on bone structural strength evaluated by hip structure analysis.

Bazedoxifene (BZA) is a selective estrogen receptor modulator that has been shown to prevent and treat postmenopausal osteoporosis. Hip structure analysis (HSA) can be used to extract bone structural properties related to strength from hip bone mineral density (BMD) scans. This exploratory analysis used HSA to evaluate changes in hip structural geometry in postmenopausal women enrolled in a phase 3 osteoporosis treatment study who were treated with BZA 20mg or placebo for 2 years. This analysis cohort included women at increased fracture risk based on known skeletal risk factors (n = 521); 1 or more moderate or severe fractures or 2 or more mild vertebral fractures and/or femoral neck BMD T-score ≤ -3.0 at baseline combined with additional women from the overall study population (n = 475); a subgroup analysis included just those women at increased fracture risk. HSA was applied to duplicate hip dual-energy X-ray absorptiometry (DXA) scans acquired at screening and 24 months. Percent change from baseline was evaluated using an analysis of covariance for BMD and geometric parameters including section modulus (SM), cross-sectional area (CSA), outer diameter (OD), and buckling ratio (BR). In all regions, BZA was associated with increased BMD and improvements in hip structural geometry. In the narrow neck, BZA 20mg significantly increased SM, CSA, OD, and BMD compared with placebo (P < 0.05 for all). In the intertrochanter region, BZA 20mg significantly increased CSA and BMD and decreased BR compared with placebo (P < 0.05 for all). Other than BMD (P < 0.05), effects of BZA 20mg at the shaft did not reach statistical significance. Similar trends toward improvement in structural geometry with BZA 20mg were observed in all three regions of the hip for the subgroup of women at increased fracture risk. Overall, BZA was associated with geometry-related improvements in bone strength with regard to resistance to bending and compressive forces and to local buckling. These improvements were evident at common fracture locations such as the femoral neck and intertrochanter regions, and are consistent with the significant treatment effect reported for BZA on nonvertebral fractures in higher-risk postmenopausal women with osteoporosis.

A comparison of nonparametric and parametric methods to adjust for baseline measures.

When analyzing the randomized controlled trial, we may employ various statistical methods to adjust for baseline measures. Depending on the method chosen to adjust for baseline measures, inferential results can vary. We investigate the Type 1 error and statistical power of tests comparing treatment outcomes based on parametric and nonparametic methods. We also explore the increasing levels of correlation between baseline and changes from the baseline, with or without underlying normality. These methods are illustrated and compared via simulations.

Optimal thresholds by maximizing or minimizing various metrics via ROC-type analysis.

RATIONALE AND OBJECTIVES: Based on imaging features, the optimal thresholds are typically determined as cutoff points to dichotomize the corresponding measurement scales. MATERIALS AND METHODS: Five metrics (ie, the Youden index, Euclidian distance, percent of correct diagnosis, kappa statistic, and mutual information) are individually maximized or minimized to derive the corresponding optimal threshold. These optimal thresholds are estimated under the parametric binormal assumption. Monte Carlo simulation studies are conducted to compare the performances of these different methods. A published radiological example on the choice of treatment outcomes following ureteral stones is used to illustrate and compare the estimated thresholds both empirically and parametrically. RESULTS: The optimal threshold can be a "moving target" because it would depend on modeling assumptions, metrics, and variability in the data. Even with large samples, disease prevalence has an impact on the robustness of the metrics. CONCLUSIONS: It is recommended that researchers compare different optimal cutoff points using several metrics and select one that is most clinically relevant. The ultimate goal is to maximize diagnostic performances that are clinically meaningful to achieve improved global health.