Diabetes mellitus among older people in rural Sidama, Ethiopia: a two-step community-based cross-sectional study

ObjectiveTo determine the prevalence of undiagnosed diabetes and identify associated factors using a two-step diagnostic method combining fasting blood sugar with confirmatory glycated haemoglobin A1c (HbA1c) testing among older adults in rural Sidama, Ethiopia. DesignA community-based cross-sectional design was conducted from April 1 to July 31, 2024. Data were collected through a census of adults aged [≥] 45 years using a pretested WHO-STEPwise questionnaire. Physical and biochemical tests were performed following standard protocols. Data were analysed using Stata version 17. SettingSelected rural kebeles of Shebedino district, Sidama, Ethiopia. Participants2,875 adults aged [≥] 45 years. Primary outcome measuresUndiagnosed diabetes confirmed by haemoglobin A1c levels ([≥]48 mmol/mol). ResultsThe prevalence of undiagnosed diabetes confirmed by haemoglobin A1c was 1.2% (35 of 2,871; 95% CI: 0.9 - 1.7%). Previously diagnosed diabetes was found in in 0.5% (14 of 2,875; 95% CI: 0.3% - 0.8%). The total diabetes prevalence, confirmed by haemoglobin A1c or prior diagnosis, was 1.7% (49 of 2871; 95% CI: 1.3% - 2.3%). Nearly half, 46.2% (1,327 of 2,875), were undernourished. Advanced age ({beta} = 0.18; 95% CI: 0.06, 0.30, p = 0.004), estimated annual income ({beta} = 0.14; 95% CI: 0.01, 0.27; p = 0.039), and waist-to-body mass index ({beta} = 0.08; 95% CI: 0.01, 0.16; p = 0.032) were significantly associated with elevated fasting blood sugar levels. ConclusionThe prevalence of undiagnosed diabetes in this rural setting was low. Increasing age, higher income, and waist-to-body mass index were associated with elevated fasting blood sugar. Routine community-based diabetes screening, health education, and nutrition-focused interventions are recommended to sustain the low burden and address undernutrition. Strengths and limitations of this studyO_LIA two-step diagnostic approach (fasting blood sugar and confirmatory HbA1c) enhanced the diagnostic accuracy compared with fasting blood sugar alone. C_LIO_LICensus-based sampling of a large rural population aged 45 years and above improved representativeness and reduced selection bias. C_LIO_LIStandardised tools (WHO-STEPwise protocol) and trained field teams were used to ensure data quality. C_LIO_LIDiabetes types were not differentiated with additional biomarkers (e.g., autoantibody or C-peptide testing), potentially causing misclassifications. C_LIO_LISelf-reported behaviours (smoking, khat chewing, and alcohol use) may be prone to recall or social desirability bias. C_LI