数学中国 Ww. madio. net 142 The UMAP Journal 29.2 Strengths and Limitations of Meta-Metrics Our meta-metrics demonstrate the following advantages: Flexibility. Additional metrics can be easily incorporated into the meta- metrics Relevance. Meta-metrics convey the average performance of a country's healthcare system relative to the rest of the worl Accuracy. The WHO and our meta-metrics both rank the US, Sweden, and Nigeria in the same relative order. These meta-metrics also demonstrate the following disadvantages Data is not concurrent. Data sets reported by the WHOcan often be several older than other data Demanding Data are required from a large number of countries in order to determine the worldwide maximum and minimum values for metrics Simplicity. It may be wiser to weight the metrics in the calculation of meta metrics instead of taking just their mean A Model for a Healthcare System Assumptions We assume that for a given nation: Wealth is not distributed equally. This is especially true for the U. S. Wolff 2004, which is the focus of most of our attention wHO data for that nation is recent and reliable. This assumption is not entirely valid, since some statistics from the wHO that we use date back to 2000. However, this should be less of a problem as data become more widely and frequently reported. The healthcare system operates in a consistent way. This is not at all true, but for the sake of simplicity we must assume that the system is pre- dictable Meta-metrics accurately reflect the performance of the health system Our results for the U.S, Sweden, and Nigeria support this assumption for all but the treatment meta-metric Certain meta-metrics scale with income. Measures taken by a healthcare system to prevent illness affect all people equally [Torrens 1978]. To ac- count for economic factors, we assume that accessibility and treatment scale with wealth. That is, an individual with more money has an easier time finding care and paying for treatment. This is a gross oversimplifi cation, but it allows the model to convey more information.数学中国ww.madio.net