Undiagnosed diabetes based on HbA 1c by socioeconomic status and healthcare consumption in the Tromsø Study 1994-2016

• Published in: BMJ Open Diabetes Research & Care
• Main Authors: Lopez-Doriga Ruiz, Paz, Hopstock, Laila Arnesdatter, Eggen, Anne Elise, Njølstad, Inger, Grimnes, Guri, Stene, Lars Christian Mørch, Gulseth, Hanne Løvdal
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMJ Publishing Group 2021
• Subjects: VDP::Medical disciplines: 700::Health sciences: 800::Community medicine; Social medicine: 801; VDP::Medisinske Fag: 700::Helsefag: 800::Samfunnsmedisin; sosialmedisin: 801; Tromsø
• Online Access: https://hdl.handle.net/10037/23452; https://doi.org/10.1136/bmjdrc-2021-002423

Introduction - We aimed to investigate whether the proportion of undiagnosed diabetes varies by socioeconomic status and healthcare consumption, in a Norwegian population screened with glycated hemoglobin (HbA1c). Research - design and methods In this cohort study, we studied age-standardized diabetes prevalence using data from men and women aged 40–89 years participating in four surveys of the Tromsø Study with available data on HbA1c and self-reported diabetes: 1994–1995 (n=6720), 2001 (n=5831), 2007–2008 (n=11 987), and 2015–2016 (n=20 170). We defined undiagnosed diabetes as HbA1c ≥6.5% (48 mmol/mol) and no self-reported diabetes. We studied the association of education, income and contact with a general practitioner on undiagnosed diabetes and estimated adjusted prevalence ratio (aPR) from multivariable adjusted (age, sex, body mass index) log-binomial regression. Results - Higher education was associated with lower prevalence of diagnosed and undiagnosed diabetes. Those with secondary and tertiary education had lower prevalence of undiagnosed diabetes (aPR for tertiary vs primary: 0.54, 95% CI: 0.44 to 0.66). Undiagnosed as a proportion of all diabetes was also significantly lower in those with tertiary education (aPR:0.78, 95% CI: 0.65 to 0.93). Household income was also negatively associated with prevalence of undiagnosed diabetes. Across the surveys, approximately 80% of those with undiagnosed diabetes had been in contact with a general practitioner the last year, similar to those without diabetes. Conclusions - Undiagnosed diabetes was lower among participants with higher education. The hypothesis that those with undiagnosed diabetes had been less in contact with a general practitioner was not supported.