Periodic health examination, 1996 update: 2. Screening for chlamydial infections. Canadian Task Force on the Periodic Health Examination.

OBJECTIVE: To update the 1984 recommendations of the Canadian Task Force on the Periodic Health Examination on the routine screening of asymptomatic patients for infection with Chlamydia trachomatis. OPTIONS: Screening, with the use of culture or nonculture tests, of the general population, of certain high-risk groups or of all pregnant women; or no routine screening. OUTCOMES: Rates of asymptomatic and symptomatic chlamydial infection, perinatal complications, longterm complications of infection (i.e., pelvic inflammatory disease, infertility and ectopic pregnancy), coinfection with other sexually transmitted diseases, disease spread, hospital care, complications of therapy and costs of infection and of screening. EVIDENCE: Search of MEDLINE for articles published between Jan. 1, 1983, and Dec. 31, 1995, with the use of the major MeSH heading "chlamydial infections," references from recent review articles and recommendation by other organizations. VALUES: The evidence-based methods of the Canadian Task Force on the Periodic Health Examination were used. Advice from reviewers and experts and recommendations of other organizations were taken into consideration. Prevention of symptomatic disease and decreased overall costs were given high values. BENEFITS, HARMS AND COSTS: The greatest potential benefits of screening asymptomatic patients for chlamydial infections are the prevention of complications, especially infertility and perinatal complications, and the prevention of disease spread. There is no evidence that screening of the general population for chlamydial infections leads to a reduction in complications, and screening may increase costs. However, there is evidence that annual screening of selected high-risk groups and of pregnant women during the first trimester is beneficial in preventing symptoms and reducing the overall cost resulting from infection. RECOMMENDATIONS: There is fair evidence to support screening and treatment of pregnant women during the first trimester (grade B recommendation) as well as annual screening and treatment of high-risk groups (sexually active women less than 25 years of age, men or women with new or multiple sexual partners during the preceding year, women who use nonbarrier contraceptive methods and women who have symptoms of chlamydial infection: cervical friability, mucopurulent cervical discharge or intermenstrual bleeding; grade B recommendation). There is fair evidence to exclude routine screening of the general population (grade D recommendation). VALIDATION: These recommendations are similar to those of the US Preventive Services Task Force and the US Centers for Disease Control and Prevention, Atlanta. SPONSOR: These guidelines were developed and endorsed by the Canadian Task Force on the Periodic Health Examination, which is funded by Health Canada and the National Health Canada and the National Health Research and Development Program. The principal author (H.D.D.) was supported in part by the Ontario Ministry of Health and the Canadian Infectious Diseases Society Lilly Fellowship.     

Preventive health care, 1999 update: 2. Echocardiography for the detection of a cardiac source of embolus in patients with stroke

OBJECTIVE: To develop guidelines for the use of echocardiography in the investigation of patients with stroke. OPTIONS: (1) Routine transthoracic echocardiography (TTE); (2) routine transesophageal echocardiography (TEE); (3) routine TTE followed by TEE if the TTE findings are noncontributory; (4) selective TTE or TEE in patients with cardiac disease who would not otherwise receive anticoagulant therapy. OUTCOMES: This article reviews the available evidence on the yield of TTE and TEE in detecting cardiac sources of cerebral emboli in patients with stroke, the effectiveness of treatment for cardiac sources of emboli and the effectiveness of screening echocardiography for secondary stroke prevention. EVIDENCE: MEDLINE was searched for relevant articles published from January 1966 to April 1998; also reviewed were additional articles identified from the bibliographies and citations obtained from experts. BENEFITS, HARMS AND COSTS: Echocardiography can detect intracardiac masses (thrombus, vegetation or tumour) in about 4% (with TTE) to 11% (with TEE) of stroke patients. The yield is lower among patients without clinical evidence of cardiac disease by history, physical examination, electrocardiography or chest radiography (less than 2%) than among patients with clinical evidence of cardiac disease (less than 19%). The risks of echocardiography to patients are small. TTE has virtually no risks, and TEE is associated with cardiac, pulmonary and bleeding complications in 0.18%. Patients with an identified intracardiac thrombus are at increased risk for embolic events (absolute risk uncertain, range 0%-38%), and this appears to be reduced with anticoagulant therapy (absolute risk reduction uncertain). Anticoagulant therapy carries a risk of major hemorrhage of 1% to 3% per year. The overall effectiveness of echocardiography in the prevention of recurrent stroke is unknown. VALUES: The strength of evidence was evaluated using the methods of the Canadian Task Force on Preventive Health Care. RECOMMENDATIONS: There is fair evidence to recommend echocardiography in patients with stroke and clinical evidence of cardiac disease by history, physical examination, electrocardiography or chest radiography (grade B recommendation). There is insufficient evidence to recommend for or against TEE in patients with normal results of TTE (grade C recommendation). There is insufficient evidence to recommend for or against routine echocardiography in patients (including young patients) without clinical cardiac disease (grade C recommendation). Routine echocardiography is not recommended for patients with clinical cardiac disease who have independent indications for or contraindications to anticoagulant therapy (grade D recommendation). There is fair evidence to recommend anticoagulant therapy in patients with stroke and intracardiac thrombus (grade B recommendation). There is insufficient (no) evidence to recommend for or against any specific therapy for patent foramen ovale (grade C recommendation). VALIDATION: The findings of this analysis were reviewed through an iterative process by the members of the Canadian Task Force on Preventive Health Care.     

Assessing screening policies for childhood obesity

To address growing concerns over childhood obesity, the United States Preventive Services Task Force (USPSTF) recently recommended that children undergo obesity screening beginning at age 6. An Expert Committee recommends starting at age 2. Analysis is needed to assess these recommendations and investigate whether there are better alternatives. We model the age- and sex-specific population-wide distribution of BMI through age 18 using National Longitudinal Survey of Youth (NLSY) data. The impact of treatment on BMI is estimated using the targeted systematic review performed to aid the USPSTF. The prevalence of hypertension and diabetes at age 40 are estimated from the Panel Study of Income Dynamics (PSID). We fix the screening interval at 2 years, and derive the age- and sex-dependent BMI thresholds that minimize adult disease prevalence, subject to referring a specified percentage of children for treatment yearly. We compare this optimal biennial policy to biennial versions of the USPSTF and Expert Committee recommendations. Compared to the USPSTF recommendation, the optimal policy reduces adult disease prevalence by 3% in relative terms (the absolute reductions are <1%) at the same treatment referral rate, or achieves the same disease prevalence at a 28% reduction in treatment referral rate. If compared to the Expert Committee recommendation, the reductions change to 6 and 40%, respectively. The optimal policy treats mostly 16-year olds and few children under age 14. Our results suggest that adult disease is minimized by focusing childhood obesity screening and treatment on older adolescents.     

Provision of preventive care to unannounced standardized patients

OBJECTIVE: To examine the relation between physician, training and practice characteristics and the provision of preventive care as described in the guidelines of the Canadian Task Force on the Periodic Health Examination. DESIGN: Cross-sectional study. SETTING: Family practices open to new patients within 1 hour''s drive of Hamilton, Ont. PARTICIPANTS: A total of 125 family physicians were randomly selected from respondents to an earlier preventive care survey. Of the 125, 44 (35.2%) declined to participate, and an additional 19 (15.2%) initially consented but later withdrew when they closed their practices to new patients. Sixty-two physicians thus participated in the study. INTERVENTION: Unannounced standardized patients posing as new patients to the practice visited study physicians'' practices between September 1994 and August 1995, portraying 4 scenarios: 48-year-old man, 70-year-old man, 28-year-old woman and 52-year-old woman. OUTCOME MEASURES: Proportion of preventive care manoeuvres carrying grade A, B, C, D and E recommendations from the Canadian Task Force on the Periodic Health Examination that were performed, offered or advised. A standard score was computed based on the performance of grade A and B manoeuvres (good or fair evidence for inclusion in the periodic health examination) and the non-performance of grade D and E manoeuvres (fair or good evidence for exclusion from the periodic health examination). RESULTS: Study physicians performed or offered 65.6% of applicable grade A manoeuvres, 31.0% of grade B manoeuvres, 22.4% of grade C manoeuvres, 21.8% of grade D manoeuvres and 4.9% of grade E manoeuvres. The provision of evidence-based preventive care was associated with solo (v. group) practice and capitation or salary (v. fee-for-service) payment method. Preventive care performance was unrelated to physician''s sex, certification in family medicine or problem-based (v. traditional) medical school curriculum. CONCLUSIONS: Preventive care guidelines of the Canadian Task Force on the Periodic Health Examination have been incompletely integrated into clinical practice. Research is needed to identify and reduce barriers to the provision of preventive care and to develop and apply effective processes for the creation, dissemination and implementation of clinical practice guidelines.     

Preventive health care, 1999 update: 3. Follow-up after breast cancer

OBJECTIVE: To make recommendations to physicians who provide follow-up care for women who have been treated for early-stage breast cancer. OPTIONS: Combination of blood tests, bone scans, liver echography and chest radiography for detection of distant disease; physical examination with or without mammography for detection of contralateral breast cancer; and physical examination with or without mammography for detection of ipsilateral recurrent disease after breast-conserving therapy. OUTCOMES: Survival, disease recurrence and quality-of-life measures for distant disease, local recurrence of disease and disease in the contralateral breast. EVIDENCE: A MEDLINE search for relevant articles published between January 1966 and January 1998 with the MeSH terms "breast neoplasms" and "neoplasm recurrence" (local and distant) with limits to "human" was done. A subsequent MEDLINE search using the MeSH terms "breast neoplasms," "neoplasm recurrence," "local/diagnosis" and "mammography" was done to address issues of mammography. The literature search was reviewed by a medical librarian and 2 breast cancer specialists to ensure completeness. BENEFITS, HARMS AND COSTS: Breast cancer is the most common cancer in Canadian women and is the second leading cause of death after lung cancer. Even with early-stage breast cancer, recurrence after treatment for primary breast cancer is frequent. Traditionally, follow-up has been felt to facilitate early detection and improve survival. Randomized controlled trials (RCTs) have shown that routine screening (blood tests and diagnostic imaging) for distant disease does not alter survival or quality of life over routine physical examination. In an underpowered secondary analysis of RCT data, the detection of contralateral breast cancer did not affect survival. However, there have been no RCTs examining the role of mammography and physical examination and their effect on survival in the detection of contralateral breast cancer. The sensitivity and specificity of mammography after local excision and radiotherapy is unknown. There have been no RCTs examining the role of mammography or physical examination, or both, and their effect on survival in the detection of ipsilateral breast recurrence. VALUES: The strength of evidence was evaluated using the methods of the Canadian Task Force on Preventive Health Care. A high value was placed on interventions that changed survival. When evidence was available, high value was also placed on interventions that affected quality of life. RECOMMENDATIONS: There is good evidence not to include blood work and diagnostic imaging as part of screening for distant disease (grade E recommendation). There is no evidence to suggest that mammography decreases mortality by detecting ipsilateral disease in the conservatively treated breast; however, there is indirect evidence that it may be beneficial (grade C recommendation). There is no direct evidence to suggest that physical examination or mammography, or both, should be used to detect contralateral breast cancer; however, there is indirect evidence that it may be beneficial (grade C recommendation). VALIDATION: The findings of this analysis were reviewed through an iterative process by the members of the Canadian Task Force on Preventive Health Care.     

Obesity reduction within a generation: the dual roles of prevention and treatment

In 2010, the White House Task Force on Childhood Obesity provided benchmark goals for reducing childhood obesity. We evaluated the balance of prevention and treatment required for achieving Task Force goals in benchmark years 2015, 2020, and 2030. We created a simulation of US birth cohorts (2-19 years) born 2008-2030. For each year, we assumed "old" birth cohorts (part of previous benchmark obesity estimates) would benefit from obesity treatment strategies, and "new" birth cohorts would benefit from obesity prevention strategies. We assessed obesity prevalence that must be achieved through prevention strategies, under varying assumptions of treatment effectiveness. When we assumed a 1% absolute reduction in prevalence through treatment, we found that prevention strategies would need to achieve an obesity prevalence of 12% by 2015, 8% by 2020, and 0.3% by 2030. Because of higher obesity prevalence among minority children, prevention strategies would need to achieve a negative prevalence by 2030, which is implausible. Under more generous assumptions of treatment effectiveness, estimates became positive but remained low. Task Force goals are more difficult to achieve with each benchmark year. Policies must focus on obesity treatment interventions, particularly targeted to racial/ethnic minority children, to make progress in stemming the epidemic.     

Periodic health examination, 1996 update: 1. Prenatal screening for and diagnosis of Down syndrome. Canadian Task Force on the Periodic Health Examination.

OBJECTIVE: To make recommendations to physicians providing prenatal care on (1) whether prenatal screening for and diagnosis of Down syndrome (DS) is advisable and (2) alternative screening and diagnosis manoeuvres. OPTIONS: "Triple-marker" screening of maternal serum levels of alpha-fetoprotein, human chorionic gonadotropin and unconjugated estriol; fetal ultrasonographic examination; amniocentesis; and chorionic villus sampling (CVS). OUTCOMES: Accuracy of detection of DS in fetuses, and risks to the mother, including psychologic distress, and to the fetus from the screening and diagnostic interventions. EVIDENCE: A MEDLINE search for relevant articles published from Jan. 1, 1966, to Mar. 31, 1994, with the use of MeSH terms "Down syndrome," "prenatal diagnosis," "screening," "prevention," "amniocentesis," "chorionic villus sampling," "ultrasonography," "anxiety," "depression" and "psychological stress" and a manual search of bibliographies, recent issues of key journals and Current Contents. VALUES: The evidence-based methods and values of the Canadian Task Force on the Periodic Health Examination were used. A high value was placed on providing pregnant women with the opportunity to determine whether they are carrying a fetus with DS and to make choices concerning the termination of the pregnancy. The economic issues involved are complex and were not considered. BENEFITS, HARMS AND COSTS: Triple-marker screening identifies an estimated 58% of fetuses with DS, but it has an estimated rate of true-positive results of 0.1% and of false-positive results of 3.7% (given a risk cut-off of one chance in 190 of DS). These rates vary with maternal age and the risk cut-off chosen. Women with a known risk of having a fetus with DS (e.g., those who have had a previous child with DS) may benefit from a reduction in anxiety after confirmation that their fetus does not have DS. Screening allows women at low risk of having a child with DS to detect fetuses with the syndrome, but may cause psychologic distress if there is a false-positive screening test result. Up to 20% of women with positive results of screening tests may decline to undergo a subsequent amniocentesis. Amniocentesis and CVS are very accurate in diagnosing DS in fetuses and have a very low rate of serious complications for the mother. Amniocentesis is associated with a 1.7% rate of fetal loss when it is performed after 16 weeks'' gestation, whereas the rate among controls is 0.7% (for a difference of 1%, 95% confidence interval 0.3% to 1.5%). CVS entails a greater risk of fetal loss than amniocentesis (odds ratio 1.32, 95% confidence interval 1.11 to 1.57). There is little evidence from controlled trials of significant associations between amniocentesis or CVS and neonatal morbidity or malformations; however, samples have been too small to show differences in rare outcomes. Results from some case-control studies suggest that CVS increases the risk of transverse limb deficiency. Costs were not considered because they are beyond the scope of this review. RECOMMENDATIONS: There is fair evidence to offer triple-marker screening through a comprehensive program to pregnant women under 35 years of age (grade B recommendation). Women given detailed information about serum-marker screening show more satisfaction with the screening than those not given this information. There is fair evidence to offer amniocentesis or CVS to pregnant women 35 years of age and older and to women with a history of a fetus with DS or of a chromosome 21 anomaly (grade B recommendation). Information on the limitations and advantages of each procedure should be offered. Triple-marker screening may be offered as an alternative to CVS or amniocentesis to pregnant women over 35. VALIDATION: Recommendations concerning prenatal diagnosis are similar to those of the US Preventive Services Task Force, the Society of Obstetricians and Gynaecologists of Canada, the Canadian College of Medical Geneticists and the Cochrane Pregnancy and Childbirth Group. No previous specific recommendations concerning triple-maker screening exist. SPONSORS: These guidelines were developed and endorsed by the Canadian Task Force on the Periodic Health Examination, which is funded by Health Canada and the National Health Research and Development Program.     

Childhood obesity: genetic and environmental overlap with normal-range BMI

Objective: To understand the overlap between the etiology of obesity and normal variation in BMI in children. Methods and Procedures: Height and weight data were available from a large UK representative sample of twins: 2,342 same‐sex pairs at 7 years and 3,526 same‐sex pairs at 10 years. The twin method and model‐fitting techniques were used to estimate genetic and environmental contributions to BMI. DeFries‐Fulker (DF) extremes analysis was used to investigate genetic and environmental influences on the mean difference between obese and normal‐weight children. Obesity was classified using the International Obesity Task Force (IOTF) criteria. Results: At both ages, BMI and obesity were highly heritable (0.60–0.74) and only modestly influenced by shared environmental factors (0.12–0.22). Extremes analyses indicated that genetic and environmental influences on obesity are quantitatively and qualitatively similar to those operating across the range of BMI. Discussion: Obesity is the extreme of the same genetic and environmental factors responsible for variation throughout the distribution of BMI. This finding implies that genes that influence obesity will also be associated with BMI in the normal range, and similar environmental influences will affect BMI in the clinical and normal range. Knowing that obesity is influenced by the same genetic and environmental factors that affect weight at all levels has implications for investigating the mechanisms for weight gain and developing interventions for weight control.     

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.     

Obesity and physical activity among Aboriginal Canadians

Objective: To investigate ethnic differences in obesity and physical activity among Aboriginal and non‐Aboriginal Canadians. Methods and Procedures: The sample included 24,279 Canadians (1,176 Aboriginals, 23,103 non‐Aboriginals) aged 2–64 years from the 2004 Canadian Community Health Survey (CCHS). Adult participants were classified as underweight/normal weight, overweight (BMI 25–29.9 kg/m²) or obese (BMI ≥ 30 kg/m²). Children and youth 2–17 years of age were classified as normal weight, overweight or obese based on the International Obesity Task Force criteria. Leisure‐time physical activity levels over the previous 3 months were obtained by questionnaire in those aged 12–64 years. Results: The prevalence of obesity in adults was 22.9% (men: 22.9%; women: 22.9%), and the prevalence was higher among Aboriginals (37.8%) compared to non‐Aboriginals (22.6%). The prevalence of obesity in children and youth was 8.2% (boys: 9.2%; girls: 7.2%), and the prevalence was higher among Aboriginals (15.8%) compared to non‐Aboriginals (8.0%). In both youth and adults, the odds for obesity were higher among Aboriginals (youth: OR = 2.3 (95% CI: 1.4–3.8); adults: OR = 2.4 (95% CI: 1.6–3.6)) after adjustment for a number of covariates. There were no ethnic differences in the prevalence of physical inactivity; however, physical inactivity was a predictor of obesity in both the Aboriginal and non‐Aboriginal samples. Discussion: The prevalence of obesity is higher among Canadian Aboriginals compared to the rest of the population. Further research is required to better delineate the determinants of obesity and the associated health consequences in this population.     

Missed opportunities for prevention in general internal medicine

BACKGROUND: According to the Canadian Society of Internal Medicine, the Canadian general internist is in the ideal position to promote patient health through disease prevention. To explore the general internist''s contribution to disease prevention, the authors quantified the extent to which opportunities for prevention were addressed by the general internal medicine (GIM) service in an acute care teaching hospital in Calgary. METHODS: The authors interviewed 100 adult patients before discharge from the hospital''s GIM service between May 14, 1997, and Dec. 2, 1997. The number of potential opportunities for preventive intervention were identified for each patient from 10 possible interventions recommended by the Canadian Task Force on the Periodic Health Examination (now the Canadian Task Force on Preventive Health Care): breast cancer screening, Papanicolaou smear for cervical cancer, counselling on menopausal hormone replacement therapy, digital rectal examination for prostate cancer, smoking cessation counselling, cholesterol measurement, therapy or monitoring for hypertension, influenza vaccination, pneumococcal vaccination and colorectal cancer screening. The authors determined which interventions the patient had undergone before the current admission to hospital and, using patient recall and postdischarge medical chart review, which opportunities for intervention were addressed by the GIM service during the current admission. An opportunity for preventive intervention was considered as addressed by the GIM service if it was performed during the current admission or if the general internist informed the patient or the patient''s family physician of the need for such intervention in the near future. RESULTS: Among the 10 preventive interventions considered, a mean of 3.8 potential opportunities for prevention were identified for each patient. Of these, 46.5% had been addressed before the current admission, and 8.7% were addressed by the GIM service during the admission. Therefore, at the time of discharge, a mean of 55.2% of opportunities had been addressed. Among the opportunities not previously addressed, the GIM service most frequently addressed digital rectal examination for prostate cancer and cholesterol measurement. INTERPRETATION: General internists are discharging patients without sufficiently addressing opportunities for disease prevention. Preventive care protocols may be needed to limit the frequency of missed opportunities for prevention in patients admitted to tertiary care GIM services.     

Overweight and obesity in an ethnically diverse rural school district: the Healthy Kids Project

Objective: Data on Native American children and adolescents are rarely reported along with other racial and ethnic groups. The Healthy Kids Project is part of an effort to describe the prevalence of overweight and obesity in a racially mixed rural area where Native American, Hispanic, African American, and white children reside. Methods and Procedures: We measured height and weight of students in Anadarko, Oklahoma public schools (n = 1,980) in 2002–2003. All available students (95.7%) whose parents had not opted out of school health assessments were included. From these data, we calculated BMI (weight (kg) / height (m²)) and used the International Obesity Task Force reference to classify children into BMI categories. Results: Native American, Hispanic, African American, and white children who live and attend school in the same surroundings are at risk of overweight and obesity. White children had the lowest combined prevalence of overweight and obesity (37.6%), and Native American children had the highest (53.8%) followed closely by African American (51.7%) and Hispanic children (50.5%). Discussion: The childhood obesity epidemic includes all racial and ethnic groups to different degrees. In a rural public school, Native American, Hispanic, and African children had higher rates of overweight/obesity than white children.     

Refined analysis of the critical age ranges of childhood overweight: implications for primary prevention

Prevention-interventions would certainly benefit from a precise knowledge of the age range when the most pronounced increases in prevalence of overweight and obesity occur in the general population. Data of 15,662 subjects aged 2-18 years were obtained from a national representative health survey (German Health Interview and Examination Survey for Children and Adolescents (KiGGS)) conducted in Germany. Weight, height, and BMI z-scores were calculated relative to the UK 1990 reference, and prevalence of overweight and obesity was defined according to the IOTF (International Obesity Task Force) age- and sex-specific cut-offs. Univariate ANOVAs for overweight, obesity, weight, height, and BMI z-scores as dependent variables were employed to assess significant differences for these measures across various age levels. Significant analysis was followed by post-hoc comparisons using Bonferroni adjustments. The main effect of age was estimated using a multinomial logistic regression model, and by defining the first derivative of a polynomial spline function. Different eclectic slopes over the entire age range from 2 to 18 years have been observed. Prevalence of overweight substantially increases between the 5th and the 8th year (12.5-21.4%; P ≤ 0.001). Maximum increase of the polynomial fit was detected at 7.2 years. Our findings suggest a relatively narrow age range at the first school year when overweight in German children especially increases. We therefore propose that psychosocial correlates may be related to the general life-time event around the age of entering school.     

The High Prevalence of Overweight and Obesity in Mexican Children

Objective: To establish the prevalence of overweight and obesity in Mexican children 10 to 17 years of age according to the percentiles from both the Centers of Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF). Research Methods and Procedures: Heights and weights were measured in children from nationally representative, randomly chosen households in the Mexican National Health Survey 2000. The study population consisted of 7862 boys and 8947 girls, 10 to 17 years of age. Measurements used were the percentage of children in the corresponding BMI categories for overweight and obesity specified by the CDC and the IOTF BMI percentiles. Results: The children were short, with mean Z scores for height by age varying from ? 0.62 ± 1.26 to ?1.12 ± 1.06 in boys and from ?0.45 ± 1.25 to ?1.19 ± 1.12 in girls. CDC‐based overweight prevalences varied by age from 10.8% to 16.1% in boys and 14.3% to 19.1% in girls, with obesity prevalences from 9.2% to 14.7% in boys and 6.8% to 10.6% in girls; these prevalences did not relate to stunting. IOTF‐based excess weight prevalences were similar, with higher overweight rates (boys, 15.4% to 18.8%; girls, 18.4% to 22.3%) but lower obesity rates (boys, 6.1% to 9%; girls, 5.9% to 8.2%). Discussion: Mexican children have one‐half the overweight/obesity prevalences of U.S. Mexican‐American children; however, there are higher rates in Northern Mexico, which is closer to the U.S. These escalating rates of excess weight demand new prevention, as well as management, policies.     

Willingness to pay for obesity prevention

The purpose of this paper is to estimate consumers’ willingness to pay (WTP) and investigate factors that affect participation in therapy to reduce weight or prevent obesity. As for the decision to participate in obesity prevention therapy, the results show that the price charged for therapy is the key factor. Furthermore, the gender, education, income, the concern that work achievement is affected by obesity, and health condition variables are found to be important and significant determinants of the decision to participate in the therapy. The average willingness to pay for obesity reduction therapy which could reduce weight by 5 kg in 3 months is estimated to be NT$12,531 (US$362) among the sample respondents. The results of the profile analysis suggest that obese females with high education, high income, who think that obesity affects work achievement, and who have tried to control their weight are the most likely to be willing to pay the greatest amount for the weight-reduction therapy.     

Characterizing Long-Term Patterns of Weight Change in China Using Latent Class Trajectory Modeling

BackgroundOver the past three decades, obesity-related diseases have increased tremendously in China, and are now the leading causes of morbidity and mortality. Patterns of weight change can be used to predict risk of obesity-related diseases, increase understanding of etiology of disease risk, identify groups at particularly high risk, and shape prevention strategies.MethodsLatent class trajectory modeling was used to compute weight change trajectories for adults aged 18 to 66 using the China Health and Nutrition Survey (CHNS) data (n = 12,611). Weight change trajectories were computed separately for males and females by age group at baseline due to differential age-related patterns of weight gain in China with urbanization. Generalized linear mixed effects models examined the association between weight change trajectories and baseline characteristics including urbanicity, BMI category, age, and year of study entry.ResultsTrajectory classes were identified for each of six age-sex subgroups corresponding to various degrees of weight loss, maintenance and weight gain. Baseline BMI status was a significant predictor of trajectory membership for all age-sex subgroups. Baseline overweight/obesity increased odds of following ‘initial loss with maintenance’ trajectories. We found no significant association between baseline urbanization and trajectory membership after controlling for other covariates.ConclusionTrajectory analysis identified patterns of weight change for age by gender groups. Lack of association between baseline urbanization status and trajectory membership suggests that living in a rural environment at baseline was not protective. Analyses identified age-specific nuances in weight change patterns, pointing to the importance of subgroup analyses in future research.     

Changes in the Regional Prevalence of Child Obesity in 4th, 8th,and 11th Grade Students in Texas From 2000–2002 to 2004–2005

Although national and state estimates of child obesity are available, data at these levels are insufficient to monitor effects of local obesity prevention initiatives. The purpose of this study was to examine regional changes in the prevalence of obesity due to statewide policies and programs among children in grades 4, 8, and 11 in Texas Health Services Regions (HSRs) between 2000–2002 and 2004–2005, and nine selected counties in 2004–2005. A cross‐sectional, probability‐based sample of 23,190 Texas students in grades 4, 8, and 11 were weighed and measured to obtain BMI. Obesity was >95th percentile for BMI by age/sex using Centers for Disease Control and Prevention growth charts. Child obesity prevalence significantly decreased between 2000–2002 and 2004–2005 for 4th grade students in the El Paso HSR (?7.0%, P = 0.005). A leveling off in the prevalence of obesity was noted for all other regions for grades 4, 8, and 11. County‐level data supported the statistically significant decreases noted in the El Paso region. The reduction of child obesity levels observed in the El Paso area is one of the few examples of effective programs and policies based on a population‐wide survey: in this region, a local foundation funded extensive regional implementation of community programs for obesity prevention, including an evidence‐based elementary school‐based health promotion program, adult nutrition and physical activity programs, and a radio and television advertising campaign. Results emphasize the need for sustained school, community, and policy efforts, and that these efforts can result in decreases in child obesity at the population level.     

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.