Resource-use measurement based on patient recall: issues and challenges for economic evaluation

Accurate resource-use measurement is challenging within an economic evaluation, but is a fundamental requirement for estimating efficiency. Considerable research effort has been concentrated on the appropriate measurement of outcomes and the policy implications of economic evaluation, while methods for resource-use measurement have been relatively neglected. Recently, the Database of Instruments for Resource Use Measurement (DIRUM) was set up at http://www.dirum.org to provide a repository where researchers can share resource-use measures and methods. A workshop to discuss the issues was held at the University of Birmingham in October 2011. Based on material presented at the workshop, this article highlights the state of the art of UK instruments for resource-use data collection based on patient recall. We consider methodological issues in the design and analysis of resource-use instruments, and the challenges associated with designing new questionnaires. We suggest a method of developing a good practice guideline, and identify some areas for future research. Consensus amongst health economists has yet to be reached on many aspects of resource-use measurement. We argue that researchers should now afford costing methodologies the same attention as outcome measurement, and we hope that this Current Opinion article will stimulate a debate on methods of resource-use data collection and establish a research agenda to improve the precision and accuracy of resource-use estimates

The role of wood ants (Formica rufa group) in carbon and nutrient dynamics of a boreal Norway spruce forest ecosystem

Wood ants (Formica rufa group) are regarded as keystone species in boreal and mountain forests of Europe and Asia by their effect on ecosystem carbon (C) and nutrient pools and fluxes. To quantify the impact of their activity on boreal forest ecosystems, C, nitrogen (N), phosphorus (P), potassium (K) and calcium (Ca) pools and fluxes in wood ant nests (WAN), and soil were assessed along a 5-, 30-, 60-, and 100-year-old Norway spruce (Picea abies L. Karsten) dominated successional gradient in eastern Finland. Amounts of C and nutrients in WAN increased with stand age, but contained less than 1% of total C and nutrient pools in these stands. The CO2-efflux from nests was also insignificant, as compared to CO2-efflux from the forest floor. Annually, the amount of C brought by wood ants into their nests as honeydew, prey and nest-building materials ranged from 2. 7 to 49. 3 kg ha-1 C, but this is only 0. 1-0. 7% of the combined net primary production of trees and understorey in boreal forests. The difference between wood ant nest C inputs and outputs was very small in the younger-aged stands, and increased in the older stands. Carbon accumulation rates in nests over a 100 year period are estimated to be less than 10 kg ha-1 a-1. In contrast to C, annual inputs of N, P, and K are larger compared to wood ant nest nutrient pool size, ranging from 3 to 6% of the annual tree stand and understorey uptake. This indicates a more rapid turnover and transport of N, P, and K out of WAN, and suggests that wood ants increase the cycling rate of these nutrients in boreal forests. © 2012 Springer Science+Business Media New York

Stress-induced facilitation of host response to bacterial challenge in F344 rats is dependent on extracellular heat shock protein 72 and independent of alpha beta T cells

Activation of the in vivo stress response can facilitate antibacterial host defenses. One possible mechanism for this effect is stress-induced release of heat shock protein 72 (Hsp72) into the extracellular environment. Hsp72 is a ubiquitous cellular protein that is up-regulated in response to cellular stress, and modulates various aspects of immune function including macrophage inflammatory/bactericidal responses and T-cell function when found in the extracellular environment. The current study tested the hypothesis that in vivo extracellular Hsp72 (eHsp72) at the site of inflammation contributes to stress-induced restricted development of bacteria, and facilitated recovery from bacteria-induced inflammation, and that this effect is independent of alpha beta (αβ) T cells. Male F344 rats were exposed to either inescapable electrical tail-shocks or no stress, and subcutaneously injected with Escherichia coli (ATCC 15746). The role of eHsp72 was investigated by Hsp72-immunoneutralization at the inflammatory site. The potential contribution of T cells was examined by testing male athymic (rnu/rnu) nude rats lacking mature αβ T cells and heterozygous thymic intact control (rnu/) rats. The results were that stressor exposure increased plasma concentrations of eHsp72 and facilitated recovery from bacterial inflammation. Immunoneutralization of eHsp72 at the inflammatory site attenuated this effect. Stressor exposure impacted bacterial inflammation and eHsp72 equally in both athymic and intact control rats. These results support the hypothesis that eHsp72 at the site of inflammation, and not αβ T cells, contributes to the effect of stressor exposure on subcutaneous bacterial inflammation. © 2012 Informa Healthcare USA, Inc