<prompt> Translate the following text to EnglishHata hivyo, haiwezekani kujua kiwango au mwelekeo wa athari ya jumla juu ya makadirio ya faida ya afya iliyowekwa kwa matumizi ya kazi moja ya C-R kwa Marekani nzima.  <response>: It is not possible, however, to know the extent or direction of the overall effect on health benefit estimates introduced by application of a single C-R function to the entire U.S. 