The Committee of Presidents of Statistical Societies ( COPSS )

Preface The Centers for Medicare and Medicaid Services (CMS), through a subcontract with Yale New is supporting a committee appointed by the Committee of Presidents of Statistical Societies (COPSS) to address statistical issues identified by the CMS and stakeholders about CMS's approach to mod-eling hospital quality based on outcomes. In the spring of 2011, with the direct support of YN-HHSC/CORE, COPSS formed a committee comprised of one member from each of its constituent societies, a chair, and a staff member from the American Statistical Association, and held a preliminary meeting in April. In June, YNHHSC/CORE executed a subcontract with COPSS under its CMS contract to support the development of a White Paper on statistical modeling. Specifically, YNHHSC/CORE contracted with COPSS to " provide guidance on statistical approaches. .. when estimating performance metrics, " and " consider and discuss concerns commonly raised by stake-holders (hospitals, consumer, and insurers) about the use of " hierarchical generalized linear models in profiling hospital quality. The committee convened in June and August of 2011, and exchanged a wide variety of materials. To ensure the committee's independence, YNHHSC/CORE did not comment on the white paper findings, and CMS pre-cleared COPSS' publication of an academic manuscript based on the White Paper. The committee thanks COPSS and especially its chair, Xihong Lin of the Harvard School of Public Health; and staff of the American Statistical Association, especially Steve Pierson and Keith Crank, for their efforts in establishing the committee and coordinating its work. We thank Darcey Cobbs-Yale New Haven Hospital who issued the contract on behalf of CMS. COPSS developed a special formal review process for this report with the goals of ensuring that it is objective and addresses the CMS charge. Consequently, this report was reviewed in draft form by professionals with a broad range of perspectives and expertise. Xihong Lin coordinated the review. We thank her and the following individuals for donating their time and expertise: Adal-charter member societies. The preamble to the COPSS charter states, " Whereas the various societies have distinct characteristics they also have some common interests and concerns that can benefit from coordinated effort. The purpose of the Committee of Presidents of Statistical Societies (COPSS) is to work on shared problems, to improve intersociety communication, and to offer distinguished awards. Other activities designed to promote common interests among the member societies may be undertaken from time to time. " See,