Which HIV patients should be screened for osteoporosis: an international perspective.

PURPOSE OF REVIEW: This review provides international insights into the real-world clinical approach to screening for bone mineral density (BMD) and osteoporosis in people living with HIV (PLWH) using opinions from HIV physicians from key regions around the world. RECENT FINDINGS: Although a significant proportion of PLWH are aged over 50, the relative importance of low BMD to clinical care differs significantly between countries and regions, based on factors such as the population at risk, access to adequate screening resources, and physicians' knowledge. Generally, management of osteoporosis in PLWH follows similar principals as for the general population, with risk factors for fracture combined with measurement of BMD by dual energy X-ray absorptiometry in algorithms such as Fracture Risk Assessment Tool, designed to provide an overall risk estimation. Although in most regions age is considered among the most important factors contributing to low BMD and fractures, considerable country and region-specific factors become apparent, such as malnutrition, inactivity and impact of comorbidities, substance abuse, and increasing use of tenofovir disoproxil fumarate. SUMMARY: These opinions highlight the diversity that still exists in the approach to the long-term management of PLWH and highlight challenges facing development of consensus guidelines that can be effectively implemented worldwide.

A review of potential methods of determining critical effect size for designing environmental monitoring programs.

The effective design of field studies requires that sample size requirements be estimated for important endpoints before conducting assessments. This a priori calculation of sample size requires initial estimates for the variability of the endpoints of interest, decisions regarding significance levels and the power desired, and identification of an effect size to be detected. Although many programs have called for use of critical effect sizes (CES) in the design of monitoring programs, few attempts have been made to define them. This paper reviews approaches that have been or could be used to set specific CES. The ideal method for setting CES would be to define the level of protection that prevents ecologically relevant impacts and to set a warning level of change that would be more sensitive than that CES level to provide a margin of safety; however, few examples of this approach being applied exist. Program-specific CES could be developed through the use of numbers based on regulatory or detection limits, a number defined through stakeholder negotiation, estimates of the ranges of reference data, or calculation from the distribution of data using frequency plots or multivariate techniques. The CES that have been defined often are consistent with a CES of approximately 25%, or two standard deviations, for many biological or ecological monitoring endpoints, and this value appears to be reasonable for use in a wide variety of monitoring programs and with a wide variety of endpoints.