World Health Organization

About: World Health Organization is a government organization based out in Islamabad, Pakistan. It is known for research contribution in the topics: Population & Public health. The organization has 13330 authors who have published 22232 publications receiving 1322023 citations. The organization is also known as: World Health Organisation & WHO.

Longitudinal monitoring of bone mass accumulation in healthy adolescents: evidence for a marked reduction after 16 years of age at the levels of lumbar spine and femoral neck in female subjects.

Abstract: The amount of skeletal mass acquired during adolescence is one of the most important determinants for the risk of postmenopausal and involutional osteoporosis. In both sexes, a large variance in bone mineral density (BMD) and content (BMC) is observed among healthy individuals at the beginning of the third decade. To determine the crucial pubertal years during which bone mass accumulation mainly occurs, we longitudinally monitored the gain in BMD/BMC at clinically important sites, such as lumbar spine and femoral neck, with respect to osteoporotic fracture risk. The changes in BMD (grams per cm2) and BMC (grams) were determined at 1-yr intervals at the level of lumbar spine vertebrae (L2-L4), femoral neck, and midfemoral shaft, using dual energy x-ray absorptiometry (Hologic QDR 1000), in 198 healthy adolescents (98 females and 100 males), aged 9-19 yr. Mean daily energy and calcium intakes, height, weight, and body mass index of the studied cohort were within the normal range for age. In females, the increment rate in BMD/BMC was particularly pronounced over a 3-yr period, i.e. from 11-14 yr of age. This increment dramatically fell after 16 yr and/or 2 yr after menarche. The mean gains in lumbar, femoral neck, and midfemoral shaft BMD were not statistically significant between 17-20 yr. In males, the gain in BMD/BMC was particularly high over a 4-yr period, i.e. from 13-17 yr. Then the increment rate markedly declined, but remained significant between 17-20 yr for L2-L4 BMD/BMC and midfemoral shaft BMD. In contrast, no significant increase was observed for femoral neck BMD. An impressive interindividual variation was observed between the yearly height increment and the bone mass accumulation. The bone mass-height gains relationship during puberty evolved according to a loop pattern, with maximal variance at Tanner stages P3-P4. This longitudinal study delineates the crucial pubertal years during which the skeletal mass accumulates at high, but various, rates at skeletal sites where the consequences of the osteoporosis are particularly dramatic. Furthermore, the results indicate that in a cohort of healthy females with apparently adequate intakes of energy and calcium, bone mass accumulation is drastically reduced by 16 yr of age in both lumbar spine and femoral neck.

Drug Resistance Mutations for Surveillance of Transmitted HIV-1 Drug-Resistance: 2009 Update

Abstract: Programs that monitor local, national, and regional levels of transmitted HIV-1 drug resistance inform treatment guidelines and provide feedback on the success of HIV-1 treatment and prevention programs. To accurately compare transmitted drug resistance rates across geographic regions and times, the World Health Organization has recommended the adoption of a consensus genotypic definition of transmitted HIV-1 drug resistance. In January 2007, we outlined criteria for developing a list of mutations for drug-resistance surveillance and compiled a list of 80 RT and protease mutations meeting these criteria (surveillance drug resistance mutations; SDRMs). Since January 2007, several new drugs have been approved and several new drug-resistance mutations have been identified. In this paper, we follow the same procedures described previously to develop an updated list of SDRMs that are likely to be useful for ongoing and future studies of transmitted drug resistance. The updated SDRM list has 93 mutations including 34 NRTI-resistance mutations at 15 RT positions, 19 NNRTI-resistance mutations at 10 RT positions, and 40 PI-resistance mutations at 18 protease positions.

A framework for assessing the performance of health systems

Abstract: Health systems vary widely in performance, and countries with similar levels of income, education and health expenditure differ in their ability to attain key health goals. This paper proposes a framework to advance the understanding of health system performance. A first step is to define the boundaries of the health system, based on the concept of health action. Health action is defined as any set of activities whose primary intent is to improve or maintain health. Within these boundaries, the concept of performance is centred around three fundamental goals: improving health, enhancing responsiveness to the expectations of the population, and assuring fairness of financial contribution. Improving health means both increasing the average health status and reducing health inequalities. Responsiveness includes two major components: (a) respect for persons (including dignity, confidentiality and autonomy of individuals and families to decide about their own health); and (b) client orientation (including prompt attention, access to social support networks during care, quality of basic amenities and choice of provider). Fairness of financial contribution means that every household pays a fair share of the total health bill for a country (which may mean that very poor households pay nothing at all). This implies that everyone is protected from financial risks due to health care. The measurement of performance relates goal attainment to the resources available. Variation in performance is a function of the way in which the health system organizes four key functions: stewardship (a broader concept than regulation); financing (including revenue collection, fund pooling and purchasing); service provision (for personal and non-personal health services); and resource generation (including personnel, facilities and knowledge). By investigating these four functions and how they combine, it is possible not only to understand the proximate determinants of health system performance, but also to contemplate major policy challenges.