Obesity and Medicare Expenditure: Accounting for Age‐Related Height Loss

To determine the relationship between BMI and Medicare expenditure for adults 65‐years and older and determine whether this relationship changes after accounting for misclassification due to age‐related height loss. Using a cross sectional study design, the relationship between BMI and fee‐for‐service Medicare expenditure was examined among beneficiaries who completed the Medicare Current Beneficiary Survey (MCBS) in 2002, were not enrolled in Medicare Health Maintenance Organization, had a self‐reported height and weight, and were 65 and older (n = 7,706). Subjects were classified as underweight, normal weight, overweight, obese (obese I), and severely obese (obese II/III). To adjust BMI for the artifactual increase associated with age‐related height loss, the reported height was transformed by adding the sex‐specific age‐associated height loss to the reported height in MCBS. The main outcome variable was total Medicare expenditure. There was a significant U‐shaped pattern between unadjusted BMI and Medicare expenditure: underweight $4,581 (P < 0.0003), normal weight $3,744 (P < 0.0000), overweight $3,115 (reference), obese I $3,686 (P < 0.0039), and obese II/III $4,386 (P < 0.0000). This pattern persisted after accounting for height loss: underweight $4,640 (P < 0.0000), normal weight $3,451 (P < 0.0507), overweight $3,165 (reference), obese I $3,915 (P < 0.0010), and obese II/III $4,385 (P < 0.0004) compared to overweight. In older adults, minimal cost is not found at “normal” BMI, but rather in overweight subjects with higher spending in the obese and underweight categories. Adjusting for loss‐of‐height with aging had little affect on cost estimates.     

The use of routine thoracoabdominal CT scans in the polytrauma patient to estimate obesity

Objective:

To utilize data from routine CT scans to quantify obesity in polytrauma patients without the need to obtain a height and weight.

Design and Methods:

We utilized a comprehensive database including multidetector CT thoracoabdominal images of all polytrauma patients admitted to a Level 1 trauma center. One thousand one hundred seventy‐four patients were reviewed from 2006 to 2008 and of these, 162 had previous documentation of Body Mass Index (BMI) or height and weight measurements as an outpatient within 6 months of trauma activation and with a truncal girth smaller than the scanning area of the CT machine. Truncal Adiposity Volume (TAV) was calculated from three dimensional reconstructions (3DRs) of the CT scans of the thorax and abdomen obtained in the emergency department.

Results:

Statistical analysis yielded a fairly good correlation between TAV and BMI (correlation coefficient = 0.77; p‐value < 0.0001). The intra‐observer and inter‐observer correlations in measuring TAV were high; 0.99 and 0.98 respectively. A linear regression equation of BMI on TAV was estimated and it had a form: 3DR BMI = 20.81+0.00064×TAV. In conclusion, TAV provides a reproducible means of evaluating obesity in trauma patients from routinely obtained CT scans.

Conclusions:

The TAV eliminates the often problematic task of obtaining a height and weight in a trauma patient and it correlates fairly well with the most commonly used clinical method of quantifying patient adiposity, BMI. This method may provide a more direct measurement of adiposity than does BMI, and holds promise for improving trauma care and research in the obese patient.     

BMI,Physical Activity,and Health Care Utilization/Costs among Medicare Retirees

Objective: To examine the influence of physical activity (PA) and BMI on health care utilization and costs among Medicare retirees. Research Methods and Procedures: This cross‐sectional study was based on 42, 520 Medicare retirees in a U.S.‐wide manufacturing corporation who participated in indemnity/perferred provider and one health risk appraisal during the years 2001 and 2002. Participants were assigned into one of the three weight groups: normal weight, overweight, and obese. PA behavior was classified into three levels: sedentary (0 time/wk), moderately active (1 to 3 times/wk), and very active (4+ times/wk). Results: Generalized linear models revealed that the moderately active retirees had $1456, $1731, and $1177 lower total health care charges than their sedentary counterparts in the normal‐weight, overweight, and obese groups, respectively (p < 0.01). The very active retirees had $1823, $581, and $1379 lower costs than the moderately active retirees. Health care utilization and specific costs showed similar trends with PA levels for all BMI groups. The total health care charges were lower with higher PA level for all age groups (p < 0.01). Discussion: Regular PA has strong dose‐response effects on both health care utilization and costs for overweight/obese as well as normal‐weight people. Promoting active lifestyle in this Medicare population, especially overweight and obese groups, could potentially improve their well‐being and save a substantial amount of health care expenditures. Because those Medicare retirees are hard to reach in general, more creative approaches should be launched to address their needs and interests as well as help reduce the usage of health care system.     

Placental weight mediates the effects of prenatal factors on fetal growth: the extent differs by preterm status

Objective:

Elevated pre‐pregnancy BMI, excessive gestational weight gain (GWG), and gestational diabetes mellitus (GDM) are known determinants of fetal growth. The role of placental weight is unclear. We aimed to examine the extent to which placental weight mediates the associations of pre‐pregnancy BMI, GWG, and GDM with birth weight‐for‐gestational age, and whether the relationships differ by preterm status.

Design and Methods:

We examined 1,035 mother‐infant pairs at birth from the Boston Birth Cohort. Data were collected by questionnaire and clinical measures. Placentas were weighed without membranes or umbilical cords. We performed sequential models excluding and including placental weight, stratified by preterm status.

Results:

We found that 21% of mothers were obese, 42% had excessive GWG, and 5% had GDM. Forty‐one percent were preterm. Among term births, after adjustment for sex, gestational age, maternal age, race, parity, education, smoking, and stress during pregnancy, birth weight‐for‐gestational age z‐score was 0.55 (0.30, 0.80) units higher for pre‐pregnancy obesity vs. normal weight. It was 0.34 (0.13, 0.55) higher for excessive vs. adequate GWG, 0.67 (0.24, 1.10) for GDM vs. no DM, with additional adjustment for pre‐pregnancy BMI. Adding placental weight to the models attenuated the estimates for pre‐pregnancy obesity by 20%, excessive GWG by 32%, and GDM by 21%. Among preterm infants, GDM was associated with 0.67 (0.34, 1.00) higher birth weight‐for‐gestational age z‐score, but pre‐pregnancy obesity and excessive GWG were not. Attenuation by placental weight was 36% for GDM.

Conclusions:

These results suggest that placental weight partially mediates the effects of pre‐pregnancy obesity, GDM, and excessive GWG on fetal growth among term infants.     

Economic evaluation of the NET intervention versus guideline dissemination for management of mild head injury in hospital emergency departments

Background

Evidence-based guidelines for the management of mild traumatic brain injury (mTBI) in the emergency department (ED) are now widely available, and yet, clinical practice remains inconsistent with the guidelines. The Neurotrauma Evidence Translation (NET) intervention was developed to increase the uptake of guideline recommendations and improve the management of minor head injury in Australian emergency departments (EDs). However, the adoption of this type of intervention typically entails an upfront investment that may or may not be fully offset by improvements in clinical practice, health outcomes and/or reductions in health service utilisation. The present study estimates the cost and cost-effectiveness of the NET intervention, as compared to the passive dissemination of the guideline, to evaluate whether any improvements in clinical practice or health outcomes due to the NET intervention can be obtained at an acceptable cost.

Methods and findings

Study setting: The NET cluster randomised controlled trial [ACTRN12612001286831]. Study sample: Seventeen EDs were randomised to the control condition and 14 to the intervention. One thousand nine hundred forty-three patients were included in the analysis of clinical practice outcomes (NET sample). A total of 343 patients from 14 control and 10 intervention EDs participated in follow-up interviews and were included in the analysis of patient-reported health outcomes (NET-Plus sample). Outcome measures: Appropriate post-traumatic amnesia (PTA) screening in the ED (primary outcome). Secondary clinical practice outcomes: provision of written information on discharge (INFO) and safe discharge (defined as CT scan appropriately provided plus PTA plus INFO). Secondary patient-reported, post-discharge health outcomes: anxiety (Hospital Anxiety and Depression Scale), post-concussive symptoms (Rivermead), and preference-based health-related quality of life (SF6D). Methods: Trial-based economic evaluations from a health sector perspective, with time horizons set to coincide with the final follow-up for the NET sample (2 months post-intervention) and to 1-month post-discharge for the NET-Plus sample. Results: Intervention and control groups were not significantly different in health service utilisation received in the ED/inpatient ward following the initial mTBI presentation (adjusted mean difference $23.86 per patient; 95%CI ??$106, $153; p?=?0.719) or over the longer follow-up in the NET-plus sample (adjusted mean difference $341.78 per patient; 95%CI ??$58, $742; p?=?0.094). Savings from lower health service utilisation are therefore unlikely to offset the significantly higher upfront cost of the intervention (mean difference $138.20 per patient; 95%CI $135, $141; p?<?0.000). Estimates of the net effect of the intervention on total cost (intervention cost net of health service utilisation) suggest that the intervention entails significantly higher costs than the control condition (adjusted mean difference $169.89 per patient; 95%CI $43, $297, p?=?0.009). This effect is larger in absolute magnitude over the longer follow-up in the NET-plus sample (adjusted mean difference $505.06; 95%CI $96, $915; p?=?0.016), mostly due to additional health service utilisation. For the primary outcome, the NET intervention is more costly and more effective than passive dissemination; entailing an additional cost of $1246 per additional patient appropriately screened for PTA ($169.89/0.1363; Fieller’s 95%CI $525, $2055). For NET to be considered cost-effective with 95% confidence, decision-makers would need to be willing to trade one quality-adjusted life year (QALY) for 25 additional patients appropriately screened for PTA. While these results reflect our best estimate of cost-effectiveness given the data, it is possible that a NET intervention that has been scaled and streamlined ready for wider roll-out may be more or less cost-effective than the NET intervention as delivered in the trial.

Conclusions

While the NET intervention does improve the management of mTBI in the ED, it also entails a significant increase in cost and—as delivered in the trial—is unlikely to be cost-effective at currently accepted funding thresholds. There may be a scope for a scaled-up and streamlined NET intervention to achieve a better balance between costs and outcomes.

Trial registration

Australian New Zealand Clinical Trials Registry ACTRN12612001286831, date registered 12 December 2012.

     

Health and Economic Burden of Obesity in Brazil

Introduction

Higher and lower-middle income countries are increasingly affected by obesity. Obesity-related diseases are placing a substantial health and economic burden on Brazil. Our aim is to measure the future consequences of these trends on the associated disease burden and health care costs.

Method

A previously developed micro-simulation model is used to project the extent of obesity, obesity-related diseases and associated healthcare costs to 2050. In total, thirteen diseases were considered: coronary heart disease, stroke, hypertension, diabetes, osteoarthritis, and eight cancers. We simulated three hypothetical intervention scenarios: no intervention, 1% and 5% reduction in body mass index (BMI).

Results

In 2010, nearly 57% of the Brazilian male population was overweight or obese (BMI ≥25 kg/m²), but the model projects rates as high as 95% by 2050. A slightly less pessimistic picture is predicted for females, increasing from 43% in 2010 to 52% in 2050. Coronary heart disease, stroke, hypertension, cancers, osteoarthritis and diabetes prevalence cases are projected to at least double by 2050, reaching nearly 34,000 cases of hypertension by 2050 (per 100,000). 1% and 5% reduction in mean BMI will save over 800 prevalence cases and nearly 3,000 cases of hypertension by 2050 respectively (per 100,000). The health care costs will double from 2010 ($5.8 billion) in 2050 alone ($10.1 billion). Over 40 years costs will reach $330 billion. However, with effective interventions the costs can be reduced to $302 billion by 1% and to $273 billion by 5% reduction in mean BMI across the population.

Conclusion

Obesity rates are rapidly increasing creating a high burden of disease and associated costs. However, an effective intervention to decrease obesity by just 1% will substantially reduce obesity burden and will have a significant effect on health care expenditure.     

Cost-Effectiveness Analysis of Three Leprosy Case Detection Methods in Northern Nigeria

Background

Despite several leprosy control measures in Nigeria, child proportion and disability grade 2 cases remain high while new cases have not significantly reduced, suggesting continuous spread of the disease. Hence, there is the need to review detection methods to enhance identification of early cases for effective control and prevention of permanent disability. This study evaluated the cost-effectiveness of three leprosy case detection methods in Northern Nigeria to identify the most cost-effective approach for detection of leprosy.

Methods

A cross-sectional study was carried out to evaluate the additional benefits of using several case detection methods in addition to routine practice in two north-eastern states of Nigeria. Primary and secondary data were collected from routine practice records and the Nigerian Tuberculosis and Leprosy Control Programme of 2009. The methods evaluated were Rapid Village Survey (RVS), Household Contact Examination (HCE) and Traditional Healers incentive method (TH). Effectiveness was measured as number of new leprosy cases detected and cost-effectiveness was expressed as cost per case detected. Costs were measured from both providers'' and patients'' perspectives. Additional costs and effects of each method were estimated by comparing each method against routine practise and expressed as incremental cost-effectiveness ratio (ICER). All costs were converted to the U.S. dollar at the 2010 exchange rate. Univariate sensitivity analysis was used to evaluate uncertainties around the ICER.

Results

The ICER for HCE was $142 per additional case detected at all contact levels and it was the most cost-effective method. At ICER of $194 per additional case detected, THs method detected more cases at a lower cost than the RVS, which was not cost-effective at $313 per additional case detected. Sensitivity analysis showed that varying the proportion of shared costs and subsistent wage for valuing unpaid time did not significantly change the results.

Conclusion

Complementing routine practice with household contact examination is the most cost-effective approach to identify new leprosy cases and we recommend that, depending on acceptability and feasibility, this intervention is introduced for improved case detection in Northern Nigeria.     

Impact of Mental Health Visits on Healthcare Cost in Patients with Diabetes and Comorbid Mental Health Disorders

Purpose

To assess the impact of mental health visits (MHV) on the cost of care for Veterans with diabetes and comorbid mental health conditions.

Methods

A national cohort of 120,852 Veterans with diabetes and at least one mental health diagnosis (i.e., substance abuse, depression or psychoses) in 2002 was followed through 2006. Outcomes were pharmacy, inpatient and outpatient costs in 2012 dollars.

Results

Least-square covariate adjusted estimates from the joint model of total VA costs of the number of MHV using December 31, 2012 value dollars indicate that relative to those with fewer MHV, those with 3+ MHV had the lowest mean inpatient cost ($21,406), but the highest mean outpatient and pharmacy cost ($9,727 and $2,015, respectively). If all Veterans who received zero MHV actually received 3+ MHV, we estimate through simulated scenarios that between $32,272,329 and $181,460,247 in inpatient costs would be saved. However, these savings would be offset by additional expenditures of between $1,166,017,547 and $1,166,224,787 in outpatient costs and between $151,604,683 and $161,439,632 in pharmacy costs.

Conclusions

Among Veterans with diabetes and comorbid mental disorders having three or more mental health visits is associated with marginally decreased inpatient cost, but these potential savings seem to be offset by increased outpatient and pharmacy costs.     

Costs of Dengue Control Activities and Hospitalizations in the Public Health Sector during an Epidemic Year in Urban Sri Lanka

Background

Reported as a public health problem since the 1960s in Sri Lanka, dengue has become a high priority disease for public health authorities. The Ministry of Health is responsible for controlling dengue and other disease outbreaks and associated health care. The involvement of large numbers of public health staff in dengue control activities year-round and the provision of free medical care to dengue patients at secondary care hospitals place a formidable financial burden on the public health sector.

Methods

We estimated the public sector costs of dengue control activities and the direct costs of hospitalizations in Colombo, the most heavily urbanized district in Sri Lanka, during the epidemic year of 2012 from the Ministry of Health’s perspective. The financial costs borne by public health agencies and hospitals are collected using cost extraction tools designed specifically for the study and analysed retrospectively using a combination of activity-based and gross costing approaches.

Results

The total cost of dengue control and reported hospitalizations was estimated at US$3.45 million (US$1.50 per capita) in Colombo district in 2012. Personnel costs accounted for the largest shares of the total costs of dengue control activities (79%) and hospitalizations (46%). The results indicated a per capita cost of US$0.42 for dengue control activities. The average costs per hospitalization ranged between US$216–609 for pediatric cases and between US$196–866 for adult cases according to disease severity and treatment setting.

Conclusions

This analysis is a first attempt to assess the economic burden of dengue response in the public health sector in Sri Lanka. Country-specific evidence is needed for setting public health priorities and deciding about the deployment of existing or new technologies. Our results suggest that dengue poses a major economic burden on the public health sector in Sri Lanka.     

Cost-effectiveness of a family-based GP-mediated intervention targeting overweight and moderately obese children

Objective

To assess from a societal perspective the incremental cost-effectiveness of a family-based GP-mediated intervention targeting overweight and moderately obese children. The intervention was modelled on the LEAP (live, eat and play) trial, a randomised controlled trial conducted by the Centre for Community Child Health, Melbourne, Australia in 2002-2003. This study was undertaken as part of the assessing cost-effectiveness (ACE) in obesity project which evaluated, using consistent methods, 13 interventions targeting unhealthy weight gain in children and adolescents.

Method

A logic pathway was used to model the effects of the intervention compared to no intervention on body mass index (BMI) and health outcomes (disability-adjusted life years—DALYs). Disease costs and health benefits were tracked until the cohort of eligible children reached the age of 100 years or death. Simulation-modelling techniques were used to present a 95% uncertainty interval around the cost-effectiveness ratio. The intervention was also assessed against a series of filters (‘equity’, ‘strength of evidence’, ‘acceptability’, ‘feasibility’, sustainability’ and ‘side-effects’) to incorporate additional factors that impact on resource allocation decisions.

Results

The intervention, as modelled, reached 9685 children aged 5-9 years with a BMI z-score of ≥3.0, and cost $AUD6.3M (or $AUD4.8M excluding time costs). It resulted in an incremental saving of 2300 BMI units which translated to 511 DALYs. The cost-offsets stemming from the intervention totalled $AUD3.6M, resulting in a net cost per DALY saved of $AUD4670 (dominated; $0.1M) (dominated means intervention costs more for less effect).

Conclusion

Compared to a ‘no intervention’ control group, the intervention was cost-effective under current assumptions, although the uncertainty intervals were wide. A key question related to the long-term sustainability of the small incremental weight loss reported, based on the 9-month follow-up results for LEAP.     

Disability prevalence among healthy weight,overweight, and obese adults

Objective:

Obesity is associated with adverse health outcomes in people with and without disabilities. However, little is known about disability prevalence among people who are obese. The purpose of this study is to determine the prevalence and type of disability among adults who are obese.

Design and Methods:

Pooled data from the 2003‐2009 National Health Interview Survey (NHIS) were analyzed to obtain national prevalence estimates of disability, disability type and obesity. The disability prevalence was stratified by body mass index (BMI): healthy weight (BMI 18.5‐<25.0), overweight (BMI 25.0‐<30.0), and obese (BMI ≥ 30.0).

Results:

In this pooled sample, among the 25.4% of US adults who were obese, 41.7% reported a disability. In contrast, 26.7% of those with a healthy weight and 28.5% of those who were overweight reported a disability. The most common disabilities among respondents with obesity were movement difficulty (32.5%) and work limitation (16.6%).

Conclusions:

This research contributes to the literature on obesity by including disability as a demographic in assessing the burden of obesity. Because of the high prevalence of disability among those who are obese, public health programs should consider the needs of those with disabilities when designing obesity prevention and treatment programs.     

Diagnostic Accuracy and Cost-Effectiveness of Alternative Methods for Detection of Soil-Transmitted Helminths in a Post-Treatment Setting in Western Kenya

Objectives

This study evaluates the diagnostic accuracy and cost-effectiveness of the Kato-Katz and Mini-FLOTAC methods for detection of soil-transmitted helminths (STH) in a post-treatment setting in western Kenya. A cost analysis also explores the cost implications of collecting samples during school surveys when compared to household surveys.

Methods

Stool samples were collected from children (n = 652) attending 18 schools in Bungoma County and diagnosed by the Kato-Katz and Mini-FLOTAC coprological methods. Sensitivity and additional diagnostic performance measures were analyzed using Bayesian latent class modeling. Financial and economic costs were calculated for all survey and diagnostic activities, and cost per child tested, cost per case detected and cost per STH infection correctly classified were estimated. A sensitivity analysis was conducted to assess the impact of various survey parameters on cost estimates.

Results

Both diagnostic methods exhibited comparable sensitivity for detection of any STH species over single and consecutive day sampling: 52.0% for single day Kato-Katz; 49.1% for single-day Mini-FLOTAC; 76.9% for consecutive day Kato-Katz; and 74.1% for consecutive day Mini-FLOTAC. Diagnostic performance did not differ significantly between methods for the different STH species. Use of Kato-Katz with school-based sampling was the lowest cost scenario for cost per child tested ($10.14) and cost per case correctly classified ($12.84). Cost per case detected was lowest for Kato-Katz used in community-based sampling ($128.24). Sensitivity analysis revealed the cost of case detection for any STH decreased non-linearly as prevalence rates increased and was influenced by the number of samples collected.

Conclusions

The Kato-Katz method was comparable in diagnostic sensitivity to the Mini-FLOTAC method, but afforded greater cost-effectiveness. Future work is required to evaluate the cost-effectiveness of STH surveillance in different settings.     

The obesity epidemic and changes in self‐report biases in BMI

Objective:

To assess time trends in measurement error of BMI and the sensitivity/specificity of classifying weight status in the United States by analyzing the difference in BMI between self‐reported and measured height and weight.

Design and Methods:

Data from 18,394 respondents aged 20‐89 years from the National Health and Nutrition Examination Survey (NHANES) from 1999 through 2008 were analyzed. Multiple linear regression and logistic regression models estimated trends in reporting bias and misclassification of weight status by BMI categories, sex, age, and racial/ethnic groups, adjusting for the sampling design.

Results:

We find no evidence that there are time trends in the accuracy of self‐report by BMI categories, sex, age, or racial/ethnic groups. The well‐known downward bias in self‐report has remained stable over the last decade; approximately one in six to seven obese individuals were misclassified as nonobese due to underestimation of BMI.

Conclusion:

Increases in obesity rates based on self‐reported height and weight are likely to reflect actual weight increases and are not inflated by changes in reporting accuracy.     

The Costs of Scaling Up HIV Prevention for High Risk Groups: Lessons Learned from the Avahan Programme in India

Objective

The study objective is to measure, analyse costs of scaling up HIV prevention for high-risk groups in India, in order to assist the design of future HIV prevention programmes in South Asia and beyond.

Design

Prospective costing study.

Methods

This study is one of the most comprehensive studies of the costs of HIV prevention for high-risk groups to date in both its scope and size. HIV prevention included outreach, sexually transmitted infections (STI) services, condom provision, expertise enhancement, community mobilisation and enabling environment activities. Economic costs were collected from 138 non-government organisations (NGOs) in 64 districts, four state level lead implementing partners (SLPs), and the national programme level (Bill and Melinda Gates Foundation (BMGF)) office over four years using a top down costing approach, presented in US$ 2011.

Results

Mean total unit costs (2004–08) per person reached at least once a year and per monthly contact were US$ 235(56–1864) and US$ 82(12–969) respectively. 35% of the cost was incurred by NGOs, 30% at the state level SLP and 35% at the national programme level. The proportion of total costs by activity were 34% for expertise enhancement, 37% for programme management (including support and supervision), 22% for core HIV prevention activities (outreach and STI services) and 7% for community mobilisation and enabling environment activities. Total unit cost per person reached fell sharply as the programme expanded due to declining unit costs above the service level (from US$ 477 per person reached in 2004 to US$ 145 per person reached in 2008). At the service level also unit costs decreased slightly over time from US$ 68 to US$ 64 per person reached.

Conclusions

Scaling up HIV prevention for high risk groups requires significant investment in expertise enhancement and programme administration. However, unit costs decreased with programme expansion in spite of an increase in the scope of activities.     

Parental obesity moderates the relationship between childhood appetitive traits and weight

Objective:

In this study, the independent and combined associations between childhood appetitive traits and parental obesity on weight gain from 0 to 24 months and body mass index (BMI) z‐score at 24 months in a diverse community‐based sample of dual parent families (n = 213) were examined.

Design and Methods:

Participants were mothers who had recently completed a randomized trial of weight loss for overweight/obese postpartum women. As measures of childhood appetitive traits, mothers completed subscales of the Children's Eating Behavior Questionnaire, including Desire to Drink (DD), Enjoyment of Food (EF), and Satiety Responsiveness (SR), and a 24‐h dietary recall for their child. Heights and weights were measured for all children and mothers and self‐reported for mothers' partners. The relationship between children's appetitive traits and parental obesity on toddler weight gain and BMI z‐score were evaluated using multivariate linear regression models, controlling for a number of potential confounders.

Results:

Having two obese parents was related to greater weight gain from birth to 24 months independent of childhood appetitive traits, and although significant associations were found between appetitive traits (DD and SR) and child BMI z‐score at 24 months, these associations were observed only among children who had two obese parents. When both parents were obese, increasing DD and decreasing SR were associated with a higher BMI z‐score.

Conclusions:

The results highlight the importance of considering familial risk factors when examining the relationship between childhood appetitive traits on childhood obesity.     

Impact of Body Mass Index on Plasma N-Terminal ProB-Type Natriuretic Peptides in Chinese Atrial Fibrillation Patients without Heart Failure

Background

An inverse relationship between body mass index (BMI) and circulating levels of N-terminal proB-type natriuretic peptide (NT-proBNP) has been demonstrated in subjects with and without heart failure. Obesity also has been linked with increased incidence of atrial fibrillation (AF), but its influence on NT-proBNP concentrations in AF patients remains unclear. This study aimed to investigate the effect of BMI on NT-proBNP levels in AF patients without heart failure.

Methods

A total of 239 consecutive patients with AF undergoing catheter ablation were evaluated. Levels of NT-proBNP and clinical characteristics were compared in overweight or obese (BMI≥25 kg/m²) and normal weight (BMI<25 kg/m²) patients.

Results

Of 239 patients, 129 (54%) were overweight or obese. Overweight or obese patients were younger, more likely to have a history of nonparoxysmal AF, hypertension, and diabetes mellitus. Levels of NT-proBNP were significantly lower in overweight or obese than in normal weight subjects (P<0.05). The relationship of obesity and decreased NT-proBNP levels persisted in subgroup of hypertension, both gender and both age levels (≥65 yrs and <65 yrs).Multivariate linear regression identified BMI as an independent negative correlate of LogNT-proBNP level.

Conclusions

An inverse relationship between BMI and plasma NT-proBNP concentrations have been demonstrated in AF patients without heart failure. Overweight or obese patients with AF appear to have lower NT-proBNP levels than normal weight patients.     

Cost‐Effectiveness of a Low‐Carbohydrate Diet and a Standard Diet in Severe Obesity

Objective: Low‐carbohydrate diets have become a popular alternative to standard diets for weight loss. Our aim was to compare the cost‐effectiveness of these two diets. Research Methods and Procedures: The patient population included 129 severely obese subjects (BMI = 42.9) from a randomized trial; participants had a high prevalence of diabetes or metabolic syndrome. We compared within‐trial costs, quality‐adjusted life years (QALYs), and the incremental cost‐effectiveness ratio (CER) for the two study groups. We imputed missing values for QALYs. The CER was bootstrapped to derive 95% confidence intervals and to define acceptability cut‐offs. We took a societal perspective for our analysis. Results: Total costs during the one year of the trial were $6742 ± 6675 and $6249 ± 5100 for the low‐carbohydrate and standard groups, respectively (p = 0.78). Participants experienced 0.64 ± 0.02 and 0.61 ± 0.02 QALYs during the one year of the study, respectively (p = 0.17 for difference). The point estimate of the incremental CER was $?1225/QALY (i.e., the low‐carbohydrate diet dominated the standard diet). However, in the bootstrap analysis, the wide spread of CERs caused the 95% confidence interval to be undefined. The probabilities that the low‐carbohydrate diet was acceptable, using cut‐offs of $50, 000/QALY, $100, 000/QALY, and $150, 000/QALY, were 72.4% 78.6%, and 79.8%, respectively. Discussion: The low‐carbohydrate diet was not more cost‐effective for weight loss than the standard diet in the patient population studied. Larger studies are needed to better assess the cost‐effectiveness of dietary therapies for weight loss.     

Economic evaluation of weight loss interventions in overweight and obese women

Objective: To conduct a clinical and economic evaluation of outpatient weight loss strategies in overweight and obese adult U.S. women. Research Methods and Procedures: This study was a lifetime cost‐use analysis from a societal perspective, using a first‐order Monte Carlo simulation. Strategies included routine primary care and varying combinations of diet, exercise, behavior modification, and/or pharmacotherapy. Primary data were collected to assess program costs and obesity‐related quality of life. Other data were obtained from clinical trials, population‐based surveys, and other published literature. This was a simulated cohort of healthy 35‐year‐old overweight and obese women in the United States. Results: For overweight and obese women, a three‐component intervention of diet, exercise, and behavior modification cost $12,600 per quality‐adjusted life year gained compared with routine care. All other strategies were either less effective and more costly or less effective and less cost‐effective compared with the next best alternative. Results were most influenced by obesity‐related effects on quality of life and the probabilities of weight loss maintenance. Discussion: A multidisciplinary weight loss program consisting of diet, exercise, and behavior modification provides good value for money, but more research is required to confirm the impacts of such programs on quality of life and the likelihood of long‐term weight loss maintenance.     

The Costs of Preventing and Treating Chagas Disease in Colombia

Background

The objective of this study is to report the costs of Chagas disease in Colombia, in terms of vector disease control programmes and the costs of providing care to chronic Chagas disease patients with cardiomyopathy.

Methods

Data were collected from Colombia in 2004. A retrospective review of costs for vector control programmes carried out in rural areas included 3,084 houses surveyed for infestation with triatomine bugs and 3,305 houses sprayed with insecticide. A total of 63 patient records from 3 different hospitals were selected for a retrospective review of resource use. Consensus methodology with local experts was used to estimate care seeking behaviour and to complement observed data on utilisation.

Findings

The mean cost per house per entomological survey was $4.4 (in US$ of 2004), whereas the mean cost of spraying a house with insecticide was $27. The main cost driver of spraying was the price of the insecticide, which varied greatly. Treatment of a chronic Chagas disease patient costs between $46.4 and $7,981 per year in Colombia, depending on severity and the level of care used. Combining cost and utilisation estimates the expected cost of treatment per patient-year is $1,028, whereas lifetime costs averaged $11,619 per patient. Chronic Chagas disease patients have limited access to healthcare, with an estimated 22% of patients never seeking care.

Conclusion

Chagas disease is a preventable condition that affects mostly poor populations living in rural areas. The mean costs of surveying houses for infestation and spraying infested houses were low in comparison to other studies and in line with treatment costs. Care seeking behaviour and the type of insurance affiliation seem to play a role in the facilities and type of care that patients use, thus raising concerns about equitable access to care. Preventing Chagas disease in Colombia would be cost-effective and could contribute to prevent inequalities in health and healthcare.     

Prediction of measured weight from self‐reported weight was not improved after stratification by body mass index

Objective:

Self‐reported weight may underestimate measured weight. Researchers have tried to reduce the error using statistical models to predict weight from self‐reported weight. We investigate whether deriving equations within separate BMI categories improves the prediction of weight compared with an equation derived regardless of an individual's BMI.

Design and Methods:

The analysis included self‐reported and measured data from 20,536 individuals participating in the EPIC‐Norfolk study. In a derivation set (n = 15,381) two approaches were used to predict weight from self‐reported weight: (1) using a linear regression model with measured weight as outcome and self‐reported weight and age as predictors, and (2) using the same model fit separately within 3 strata defined by BMI (< 25, 25‐30, ≥30 kg m^?2). The performance of these approaches was assessed in a validation set (n = 5,155). Measured weight was compared to self‐reported weight and predicted weight.

Results:

Self‐reported weight underestimated measured weight (P < 0.0001): mean difference ?1.2 ± 3.1 kg (men), ?1.3 ± 2.5 kg (women). Underestimation was greater in obese participants (P < 0.0001). Predicted weight using approach 1 was not significantly different from measured weight (P < 0.05). However, in individuals with BMI < 25 kg m^?2, weight was overestimated in men (0.90 ± 3.87 kg) and women (0.57 ± 2.06 kg), but underestimated in overweight (?0.29 ± 3.58, ?0.20 ± 2.62 kg) and obese (?1.46 ± 5.05 kg, ?0.73 ± 3.54 kg) men and women.

Conclusions:

Using separate prediction equations in strata of BMI did not further improve prediction of weight. In conclusion, predicted weight was closer to measured weight compared with self‐reported weight, but using equations derived in strata of BMI did not further improve the prediction and are not recommended for prediction of weight.