During the eighteen months after January 2007, cereal prices doubled, setting off a world food crisis. In the United States, rising food prices have been a pocketbook annoyance. Most Americans can opt to buy lower-priced sources of calories and proteins and eat out less frequently. But for nearly half of the world’s population—the 2.5 billion people who live on less than $2 per day—rising costs mean fewer meals, smaller portions, stunted children, and higher infant mortality rates. The price explosion has produced, in short, a crisis of food security, defined by the Food and Agriculture Organization (FAO) as the physical and economic access to the food necessary for a healthy and productive life. And it has meant a sharp setback to decades-long efforts to reduce poverty in poor countries.

The current situation is quite unlike the food crises of 1966 and 1973. It is not the result of a significant drop in food supply caused by bad weather, pests, or policy changes in the former Soviet Union. Rather, it is fundamentally a demand-driven story of “success.” Rising incomes, especially in China, India, Indonesia, and Brazil, have increased demand for diversified diets that include more meat and vegetable oils. Against this background of growing income and demand, increased global consumption of biofuels and the American and European quest for energy self-sufficiency have added further strains to the agricultural system. At the same time, neglected investments in productivity-improving agricultural technology—along with a weak U.S. dollar, excessive speculation, and misguided government policies in both developed and developing countries—have exacerbated the situation. Climate change also looms ominously over the entire global food system.

In short, an array of agricultural, economic, and political connections among commodities and across nations are now working together to the detriment of the world’s food-insecure people...

The main aim of this paper is to describe and estimate a new decomposition of disability trends among working age populations into two parts -- the part of the trend explained by changes in the prevalence of chronic disease and obesity and the part of the trend explained by changes in the prevalence of disability among people with chronic diseases. If most of the changes in disability in this population are due to change in chronic disease prevalence, then there is little room for statutory incentives as an explanation for ADL disability trends. More importantly, such a result would suggest that recent changes in disability in this population are permanent for the affected age cohorts. If this cohort survives to old age, the use of medical care by this group will place great demands on Medicare financing.

On the other hand, if an increase in disability prevalence among those with chronic disease is the explanation, then there arise two possibilities: that chronic diseases have become more severe over time, or that the incidence of even ADL-style disabilities are dependent on cultural, social, and economic determinants such as the disability insurance payments. Such a result would suggest that the increases in ADL disability seen among working age populations might not be permanent.

BACKGROUND: Recent work has shown that rates of severe disability, measured by the inability to perform basic activities of daily living, have been rising in working age populations. At the same time, the prevalence of important chronic diseases has been rising, while others falling, among working age populations. Chronically ill individuals are more likely than others to have activity of daily living limitations.

OBJECTIVE: We examine the extent to which chronic disease trends can explain these disability trends. DATA: We use nationally representative survey data from the 1984-1996 National Interview Survey, which posed a consistent set of questions regarding limitations in activities of daily living over that period.

METHODS: We decompose trends in disability into 2 parts-1 part due to trends in the prevalence of chronic disease and the other due to trends in disability prevalence among those with chronic disease.

RESULTS:: Our primary findings are that for working age populations between 1984 and 1996: (1) disability prevalence fell dramatically among the nonchronically ill; (2) rising obesity prevalence explains about 40% of the rise in disability attributable to trends chronic illness; and (3) rising disability prevalence among the chronically ill explains about 60% of the rise in disability attributable to trends in chronic illness.

CONCLUSIONS: Disability prevention efforts in working age populations should focus on reductions in obesity prevalence and limiting disability among chronically ill populations. Given the rise in disability among these population subgroups, it is unclear whether further substantial declines in elderly disability can be expected.

Context: Without detailed evidence of their effectiveness, pedometers have recently become popular as a tool for motivating physical activity.

Objective: To evaluate the association of pedometer use with physical activity and health outcomes among outpatient adults.

Data Sources: English-language articles from MEDLINE, EMBASE, Sport Discus, PsychINFO, Cochrane Library, Thompson Scientific (formerly known as Thompson ISI), and ERIC (1966-2007); bibliographies of retrieved articles; and conference proceedings.

Study Selection: Studies were eligible for inclusion if they reported an assessment of pedometer use among adult outpatients, reported a change in steps per day, and included more than 5 participants.

Data Extraction and Data Synthesis: Two investigators independently abstracted data about the intervention; participants; number of steps per day; and presence or absence of obesity, diabetes, hypertension, or hyperlipidemia. Data were pooled using random-effects calculations, and meta-regression was performed.

Results: Our searches identified 2246 citations; 26 studies with a total of 2767 participants met inclusion criteria (8 randomized controlled trials [RCTs] and 18 observational studies). The participants' mean (SD) age was 49 (9) years and 85% were women. The mean intervention duration was 18 weeks. In the RCTs, pedometer users significantly increased their physical activity by 2491 steps per day more than control participants (95% confidence interval [CI], 1098-3885 steps per day, P .001). Among the observational studies, pedometer users significantly increased their physical activity by 2183 steps per day over baseline (95% CI, 1571-2796 steps per day, P .0001). Overall, pedometer users increased their physical activity by 26.9% over baseline. An important predictor of increased physical activity was having a step goal such as 10,000 steps per day (P = .001). When data from all studies were combined, pedometer users significantly decreased their body mass index by 0.38 (95% CI, 0.05-0.72; P = .03). This decrease was associated with older age (P = .001) and having a step goal (P = .04). Intervention participants significantly decreased their systolic blood pressure by 3.8 mm Hg (95% CI, 1.7-5.9 mm Hg, P .001). This decrease was associated with greater baseline systolic blood pressure (P = .009) and change in steps per day (P = .08).

Conclusions: The results suggest that the use of a pedometer is associated with significant increases in physical activity and significant decreases in body mass index and blood pressure. Whether these changes are durable over the long term is undetermined.

BACKGROUND: To provide quantitative insight into current U.S. policy choices for cervical cancer prevention, we developed a model of human papillomavirus (HPV) and cervical cancer, explicitly incorporating uncertainty about the natural history of disease. METHODS: We developed a stochastic microsimulation of cervical cancer that distinguishes different HPV types by their incidence, clearance, persistence, and progression. Input parameter sets were sampled randomly from uniform distributions, and simulations undertaken with each set. Through systematic reviews and formal data synthesis, we established multiple epidemiologic targets for model calibration, including age-specific prevalence of HPV by type, age-specific prevalence of cervical intraepithelial neoplasia (CIN), HPV type distribution within CIN and cancer, and age-specific cancer incidence. For each set of sampled input parameters, likelihood-based goodness-of-fit (GOF) scores were computed based on comparisons between model-predicted outcomes and calibration targets. Using 50 randomly resampled, good-fitting parameter sets, we assessed the external consistency and face validity of the model, comparing predicted screening outcomes to independent data. To illustrate the advantage of this approach in reflecting parameter uncertainty, we used the 50 sets to project the distribution of health outcomes in U.S. women under different cervical cancer prevention strategies. RESULTS: Approximately 200 good-fitting parameter sets were identified from 1,000,000 simulated sets. Modeled screening outcomes were externally consistent with results from multiple independent data sources. Based on 50 good-fitting parameter sets, the expected reductions in lifetime risk of cancer with annual or biennial screening were 76% (range across 50 sets: 69-82%) and 69% (60-77%), respectively. The reduction from vaccination alone was 75%, although it ranged from 60% to 88%, reflecting considerable parameter uncertainty about the natural history of type-specific HPV infection. The uncertainty surrounding the model-predicted reduction in cervical cancer incidence narrowed substantially when vaccination was combined with every-5-year screening, with a mean reduction of 89% and range of 83% to 95%. CONCLUSION: We demonstrate an approach to parameterization, calibration and performance evaluation for a U.S. cervical cancer microsimulation model intended to provide qualitative and quantitative inputs into decisions that must be taken before long-term data on vaccination outcomes become available. This approach allows for a rigorous and comprehensive description of policy-relevant uncertainty about health outcomes under alternative cancer prevention strategies. The model provides a tool that can accommodate new information, and can be modified as needed, to iteratively assess the expected benefits, costs, and cost-effectiveness of different policies in the U.S.

This issue of CHP/PCOR's Quarterly Update covers news from the Summer 2007 quarter and includes articles about:

• two reports on care coordination -- one on care coordination strategies in general, and a second on care coordination specifically for children with special health care needs;

• an international health section that features work done by undergraduates this summer (with mentorship and guidance from CHP/PCOR staff) on the GOBI initiative, as well as a summary of a the new Children's Project established by core faculty member Paul H. Wise;
• two Research in Brief selections -- one highlights the impact of pay for performance reimbursement structures on end-stage renal disease care, and the second examines the link between obesity and wages in Europe;
• a Medicare restructuring and refinancing piece that highlights the work of director and core faculty member Alan M. Garber, core faculty member Victor R. Fuchs, and colleagues;
• a piece on the effect of chronic illnesses such as obesity on disability trends in the near-elderly population;
• a Staff Spotlight feature on two CHP/PCOR research assistants.

Note to the reader:

The newsletter is fully-navigational. Any text that is surrounded by a dashed box is clickable and will allow the reader to navigate the newsletter more efficiently. The end of each article contains a special symbol (§) that, when clicked, will take the reader back to the table of contents. Please feel free to contact Amber Hsiao with any questions.

Purpose: Lung cancer is a leading cause of cancer death worldwide. Although smoking remains the predominant cause of lung cancer, lung cancer in never smokers is an increasingly prominent public health issue. However, data on this topic, particularly lung cancer incidence rates in never smokers, are limited.

Methods: We reviewed the existing literature on lung cancer incidence and mortality rates among never smokers and present new data regarding rates in never smokers from the following large, prospective cohorts: Nurses' Health Study; Health Professionals Follow-Up Study; California Teachers Study; Multiethnic Cohort Study; Swedish Lung Cancer Register in the Uppsala/Orebro region; and First National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study.

Results: Truncated age-adjusted incidence rates of lung cancer among never smokers age 40 to 79 years in these six cohorts ranged from 14.4 to 20.8 per 100,000 person-years in women and 4.8 to 13.7 per 100,000 person-years in men, supporting earlier observations that women are more likely than men to have non-smoking-associated lung cancer. The distinct biology of lung cancer in never smokers is apparent in differential responses to epidermal growth factor receptor inhibitors and an increased prevalence of adenocarcinoma histology in never smokers.

Conclusion: Lung cancer in never smokers is an important public health issue, and further exploration of its incidence patterns, etiology, and biology is needed.

This issue of CHP/PCOR's Quarterly Update covers news from the Fall 2006 quarter and includes articles about:

• the effect of health insurance on obese individuals' behaviors, as well as possible approaches and policy questions with regards to the obesity epidemic;
• the state of disaster preparedness in the United States. Are we ready yet? Experts provided comments at a fall conference and presented data on the intricacies of the topic;
• the state of children's health -- two pieces provide broad coverage of international and U.S.-based news on current policies and debates surrounding children's health;
• the health services and policy research scholarly concentration within the School of Medicine, with a special profile piece from a third-year medical student; and
• two Research in Brief selections, a new feature that highlights recently-published CHP/PCOR research and how such research is informing health care practices and public perceptions.