Search Results Use the search box below to revise your search, or start a new search. Studies (2) Variables Publications Your query returned 2 studies. Series results are grouped under the most relevant study. Ungroup series results to view all 2 results. Sort by: Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. 1. National Study of Physician Organizations and the Management of Chronic Illness II (NSPO2), 2006-2007 (ICPSR 29801) Shortell, Stephen M. 2. National Study of Physician Organizations and the Management of Chronic Illness (NSPO), 2000-2001 (ICPSR 4455) Shortell, Stephen M.