BAKER, Laurence C. et al. Do health plans influence quality of care? International Journal for Quality in Health Care, v. 16, n. 1, p. 19-30, 2004.

There are activities that plans can undertake which influence their HEDIS (Health Plan Employer Data and Information Set) scores. On the face of it, there results suggest that plans can independently improve quality, in contrast to hypotheses that plans would be “too far” from patients to have an influence. Continued attention to collecting plan level data is warranted. Further work should address other possible sources of variations in HEDIS scores, such as variability in the quality of plan administrative databases.