Table 3

Association between education and prevalence of undiagnosed diabetes, the Tromsø Study 1994–2016

Undiagnosed diabetes as % of people without known diabetesUndiagnosed as % of all diabetes
N*PrimarySecondaryTertiaryNPrimarySecondaryTertiary
Prevalence ratio (95% CI)Prevalence ratio (95% CI)
Pooled dataP valueP value
Crude (both sexes)26 3941 (reference)0.63 (0.54 to 0.75)0.34 (0.28 to 0.42)20991 (reference)0.87 (0.76 to 1.00)0.72 (0.61 to 0.85)<0.01
Model 1 (both sexes)†26 3941 (reference)0.71 (0.60 to 0.83)0.47 (0.38 to 0.57)<0.0120991 (reference)0.85 (0.73 to 0.98)0.77 (0.64 to 0.91)<0.01
Model 2 (both sexes)†26 3591 (reference)0.75 (0.63 to 0.88)0.54 (0.44 to 0.66)<0.0120861 (reference)0.85 (0.73 to 0.98)0.78 (0.65 to 0.93)<0.01
Crude men12 4871 (reference)0.68 (0.55 to 0.85)0.43 (0.34 to 0.55)<0.0111441 (reference)0.83 (0.69 to 0.99)0.72 (0.59 to 0.88)<0.01
Model 1 men‡12 4871 (reference)0.76 (0.61 to 0.94)0.56 (0.43 to 0.73)<0.0111441 (reference)0.83 (0.69 to 1.00)0.78 (0.64 to 0.97)0.02
Model 2 men‡12 4731 (reference)0.78 (0.63 to 0.98)0.62 (0.48 to 0.80)<0.0111361 (reference)0.83 (0.69 to 1.00)0.79 (0.64 to 0.98)0.02
Crude women13 9071 (reference)0.54 (0.42 to 0.70)0.23 (0.17 to 0.31)<0.019551 (reference)0.88 (0.71 to 1.09)0.65 (0.49 to 0.87)<0.01
Model 1 women‡13 9071 (reference)0.64 (0.49 to 0.83)0.34 (0.24 to 0.48)<0.019551 (reference)0.85 (0.68 to 1.06)0.72 (0.53 to 0.97)0.02
Model 2 women‡13 8861 (reference)0.69 (0.53 to 0.89)0.41 (0.29 to 0.58)<0.019501 (reference)0.85 (0.68 to 1.06)0.72 (0.53 to 0.98)0.02
  • Education categories, primary (primary and lower secondary education), secondary (high school or vocational school) and tertiary education (college and university level).

  • *Numbers vary slightly due to missing data for some covariates (see table 1); missing body mass index: 164 (0.6%).

  • †Model 1: adjustment for age, sex and period of survey. Model 2: adjustment for age, sex, body mass index and period of survey.

  • ‡Model 1: adjustment for age and period of survey. Model 2: adjustment for age, body mass index and period of survey.