Timothy Armstrong

Bio: Timothy Armstrong is an academic researcher from World Health Organization. The author has contributed to research in topics: Childhood obesity & Physical fitness. The author has an hindex of 15, co-authored 15 publications receiving 3826 citations.

Global Physical Activity Questionnaire (GPAQ) : nine country reliability and validity study

Abstract: Purpose: Instruments to assess physical activity are needed for (inter)national surveillance systems and comparison. Methods: Male and female adults were recruited from diverse sociocultural, educational and economic backgrounds in 9 countries (total n = 2657). GPAQ and the International Physical Activity Questionnaire (IPAQ) were administered on at least 2 occasions. Eight countries assessed criterion validity using an objective measure (pedometer or accelerometer) over 7 days. Results: Reliability coefficients were of moderate to substantial strength (Kappa 0.67 to 0.73; Spearman’s rho 0.67 to 0.81). Results on concurrent validity between IPAQ and GPAQ also showed a moderate to strong positive relationship (range 0.45 to 0.65). Results on criterion validity were in the poor-fair (range 0.06 to 0.35). There were some observed differences between sex, education, BMI and urban/rural and between countries. Conclusions: Overall GPAQ provides reproducible data and showed a moderate-strong positive correlation with IPAQ, a previously validated and accepted measure of physical activity. Validation of GPAQ produced poor results although the magnitude was similar to the range reported in other studies. Overall, these results indicate that GPAQ is a suitable and acceptable instrument for monitoring physical activity in population health surveillance systems, although further replication of this work in other countries is warranted.

Development of the world health organization global physical activity questionnaire (gpaq)

Abstract: The aim of developing the World Health Organization (WHO) Global Physical Activity Questionnaire (GPAQ) was to have a tool that would produce valid and reliable estimates of physical activity, especially relevant to developing countries where patterns of energy expenditure differ from developed countries because people experience diverse ways of life. The development of a standardized tool to measure physical activity that enables comparisons across culturally diverse populations is a challenging task. Comparable, valid, and reliable information on physical activity enables countries to follow trends over time, understand regional and global comparisons, and better inform physical activity policy decisions. A WHO expert working group on physical activity measurement provided a draft GPAQ for global consultation. The draft instrument was validated in nine countries. Validation studies and qualitative feedback on GPAQ were presented at an Expert Meeting on Global Physical Activity Surveillance held jointly by WHO and the US Centers for Disease Control and Prevention. A second round of global consultation led to minor revisions and preparation of a final GPAQ version 2 instrument (GPAQv2). Around 50 developing countries are now using GPAQ for physical activity data collection. GPAQv2 is a suitable physical activity surveillance instrument for developing countries.

Noncommunicable diseases country profiles 2011.

Abstract: The report features information about the noncommunicable diseases (NCDs) situation in 193 countries. This includes details of what proportion of each country's deaths are due to diseases such as cancer, heart and lung diseases, and diabetes. Using graphs, on a page-per country presentation format, the report provides information on prevalence, trends in metabolic risk factors (cholesterol, blood pressure, body mass index and blood sugar) alongside data on the country's capacity to address the challenges posed by NCDs. Countries will be able to benchmark progress to date and determine where more efforts are needed.

The Contribution of Physical Activity and Sedentary Behaviours to the Growth and Development of Children and Adolescents Implications for Overweight and Obesity

Abstract: The obesity epidemic is a global trend and is of particular concern in children. Recent reports have highlighted the severity of obesity in children by suggesting: "today's generation of children will be the first for over a century for whom life expectancy falls." This review assesses the evidence that identifies the important role of physical activity in the growth, development and physical health of young people, owing to its numerous physical and psychological health benefits. Key issues, such as "does a sedentary lifestyle automatically lead to obesity" and "are levels of physical activity in today's children less than physical activity levels in children from previous generations?", are also discussed.Today's environment enforces an inactive lifestyle that is likely to contribute to a positive energy balance and childhood obesity. Whether a child or adolescent, the evidence is conclusive that physical activity is conducive to a healthy lifestyle and prevention of disease. Habitual physical activity established during the early years may provide the greatest likelihood of impact on mortality and longevity. It is evident that environmental factors need to change if physical activity strategies are to have a significant impact on increasing habitual physical activity levels in children and adolescents. There is also a need for more evidence-based physical activity guidelines for children of all ages. Efforts should be concentrated on facilitating an active lifestyle for children in an attempt to put a stop to the increasing prevalence of obese children.

The World Health Organization STEPwise Approach to Noncommunicable Disease Risk-Factor Surveillance: Methods, Challenges, and Opportunities.

Abstract: Objectives. We sought to outline the framework and methods used by the World Health Organization (WHO) STEPwise approach to noncommunicable disease (NCD) surveillance (STEPS), describe the development and current status, and discuss strengths, limitations, and future directions of STEPS surveillance.Methods. STEPS is a WHO-developed, standardized but flexible framework for countries to monitor the main NCD risk factors through questionnaire assessment and physical and biochemical measurements. It is coordinated by national authorities of the implementing country. The STEPS surveys are generally household-based and interviewer-administered, with scientifically selected samples of around 5000 participants.Results. To date, 122 countries across all 6 WHO regions have completed data collection for STEPS or STEPS-aligned surveys.Conclusions. STEPS data are being used to inform NCD policies and track risk-factor trends. Future priorities include strengthening these linkages from data to action on NCDs at the co...

Prevalence and control of diabetes in Chinese adults.

Abstract: Importance Noncommunicable chronic diseases have become the leading causes of mortality and disease burden worldwide. Objective To investigate the prevalence of diabetes and glycemic control in the Chinese adult population. Design, Setting, and Participants Using a complex, multistage, probability sampling design, we conducted a cross-sectional survey in a nationally representative sample of 98 658 Chinese adults in 2010. Main Outcomes and Measures Plasma glucose and hemoglobin A 1c levels were measured after at least a 10-hour overnight fast among all study participants, and a 2-hour oral glucose tolerance test was conducted among participants without a self-reported history of diagnosed diabetes. Diabetes and prediabetes were defined according to the 2010 American Diabetes Association criteria; whereas, a hemoglobin A 1c level of Results The overall prevalence of diabetes was estimated to be 11.6% (95% CI, 11.3%-11.8%) in the Chinese adult population. The prevalence among men was 12.1% (95% CI, 11.7%-12.5%) and among women was 11.0% (95% CI, 10.7%-11.4%). The prevalence of previously diagnosed diabetes was estimated to be 3.5% (95% CI, 3.4%-3.6%) in the Chinese population: 3.6% (95% CI, 3.4%-3.8%) in men and 3.4% (95% CI, 3.2%-3.5%) in women. The prevalence of undiagnosed diabetes was 8.1% (95% CI, 7.9%-8.3%) in the Chinese population: 8.5% (95% CI, 8.2%-8.8%) in men and 7.7% (95% CI, 7.4%-8.0%) in women. In addition, the prevalence of prediabetes was estimated to be 50.1% (95% CI, 49.7%-50.6%) in Chinese adults: 52.1% (95% CI, 51.5%-52.7%) in men and 48.1% (95% CI, 47.6%-48.7%) in women. The prevalence of diabetes was higher in older age groups, in urban residents, and in persons living in economically developed regions. Among patients with diabetes, only 25.8% (95% CI, 24.9%-26.8%) received treatment for diabetes, and only 39.7% (95% CI, 37.6%-41.8%) of those treated had adequate glycemic control. Conclusions and Relevance The estimated prevalence of diabetes among a representative sample of Chinese adults was 11.6% and the prevalence of prediabetes was 50.1%. Projections based on sample weighting suggest this may represent up to 113.9 million Chinese adults with diabetes and 493.4 million with prediabetes. These findings indicate the importance of diabetes as a public health problem in China.