The socioeconomic correlates of global complication prevalence in type 1 diabetes (T1D): A multinational comparison Michael G. Walsh a , Janice Zgibor a , Thomas Songer a , Knut Borch-Johnsen b , Trevor J Orchard a, * on behalf of all DiaComp Investigators 1 a Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, DLR Building, 3512 Fifth Avenue, 2nd Floor, Pittsburgh, PA 15213, USA b Steno Memorial Hospital, Copenhagen, Denmark Received 28 May 2004; received in revised form 17 November 2004; accepted 2 March 2005 Available online 25 April 2005 Abstract We sought to determine the extent to which the geographic variation in the complications of type 1 diabetes (T1D) may reflect the socioeconomic status (SES) conditions and health care performance (HCP) of countries around the world. The World Health Organization (WHO) DiaMond complications study (DiaComp) is a multinational, cross-sectional study of complications in T1D. Information on complications was identified for 892 subjects from 14 clinical centers in 12 countries. All participants were diagnosed with diabetes in childhood (<15 years of age) and had disease duration of 5–24 years. Complications were assessed by self-report, and by clinical exam, with microalbuminuria identified by Micral II dipstick, neuropathy by the Michigan Neuropathy Screening Instrument exam and hypertension using the HDFP protocol. These data were linked to center-specific information on the local social and economic landscape, health care access and diabetes management practices and health care costs. Country-specific indicators of social and economic development were also linked to the complications data. Both diabetes complications and economic and health care factors vary widely across the DiaComp centers. Health system performance, as measured by disability adjusted life expectancy (DALE), gross national investment (GNI) per capita and purchasing power all showed strong consistent correlations with complications, and significant independent associations with complication pre- valence after controlling for HbA1c and hypertension. In conclusion, health system performance, social distribution of wealth and purchasing power may play important roles in explaining the geographic variation of diabetes complications. # 2005 Elsevier Ireland Ltd. All rights reserved. Keywords: Type 1 diabetes; Diabetes complications; Global complications prevalence; Socioeconomic status; Health care practice www.elsevier.com/locate/diabres Diabetes Research and Clinical Practice 70 (2005) 143–150 * Corresponding author. Tel.: +1 412 383 1032; fax: +1 412 383 1020. E-mail address: thegowda@hotmail.com (T.J. Orchard). 1 A list of DiaComp Investigators is provided in the Appendix A. 0168-8227/$ – see front matter # 2005 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.diabres.2005.03.026