Geographic and social factors are related to increased morbidity and mortality rates in diabetic patients

SUMMARY Aims  To investigate differences in metabolic control, access to healthcare, clinical outcomes and mortality rates in people from different cultural and ethnic backgrounds living in different geographical areas within central London. Methods  Out of a cohort of 610 patients living within the Greater London boundary and having a first visit to St Thomas' hospital in 1982–1985, 332 patients (54%) were reviewed in 1995, 186 patients (30%) died between 1982 and 1995 and 92 patients (16%) were lost to follow-up. The patients' corresponding ‘electoral wards’ were ascertained in relation to postcodes of residence (Mapinfo). Each electoral ward has a Jarman ‘Underprivileged Area Score’ (UPA) so that patients can be clustered into prosperous, intermediate or deprived areas. Results  Patients living in deprived areas (n = 181) were older (61.3 years (95% confidence interval (CI) 59.5–63.1) vs. 58.6 years (95% CI 55.1–62.1), P = 0.01) and had a higher body mass index (29.2 kg/m2 (95% CI 28.4–30.0) vs. 25. 7 kg/m2 (95% CI 24.1–27.2), P = 0.003) and worse glycaemic control (HbA1 (%), 10.5 (95% CI 10.1–10.9) vs. 9.1 (95% CI 8.2–10.0), P = 0.003) than patients in prosperous areas (n = 59). Patients in deprived areas were more likely to be Caucasian (P < 0.005), and were less likely to be insulin-treated (P = 0.004). Smoking was more prevalent in deprived areas (P = 0.02). The prevalence of microvascular complications was related to geographical location and the age–sex adjusted mortality rate was significantly higher in deprived than prosperous areas (2.6 vs. 1.91 per 100 person-years). Conclusions  Environmental factors affect diabetes outcomes; increased morbidity and mortality rates in diabetic patients are related to socio-economic and ethnic status.