Bender RH, Lance TX, Guess LL. Including disenrollees in CAHPS managed care health plan assessment reporting. Health Care Financ Rev. 2003 Sep;25(1):67-79.

This study addresses the question whether basing plan quality ratings on the data of both enrollees and disenrollees provides more accurate reporting. We test whether including disenrollee data in calculating the CAHPS scores, reported in health plan assessments, will result in lower scores indicating lower plan quality. Adding disenrollees results in statistically significant score decreases. Factors likely to result in larger score changes when disenrollees are included are explored. The study concludes that though final determinations should rest on more extensive data, that there is evidence to suggest that including disenrollee feedback improves accuracy.