Objective: To assess whether use of oral glucocorticoids is associated with ca rdiovascular and cerebrovascular morbidity. Design and setting: Nested case-con trol study within a cohort of patients (≥50 years old) with at least one prescr iption for oral or non-systemic glucocorticoids. Data were from the general pra ctice research database. Patients: 50 656 patients were identified with a first record for ischaemic heart disease (International classification of diseases, ni nth revision (ICD-9) codes 410, 411, 413, and 414), ischaemic stroke or transie nt ischaemic attack (ICD-9 codes 430-436), or heart failure (ICD-9 code 428) between 1988 and 1998. One control was matched to each case by sex, age, general practice, underlying disease, and calendar time. Main outcome measure: Odds rat io (OR) of cardiovascular or cerebrovascular events in patients using oral gluco corticoids compared with non-users. Results: There was a significant associatio n between ever use of oral glucocorticoids and any cardiovascular or cerebrovasc ular outcome (adjusted OR 1.25, 95%confidence interval (CI) 1.21 to 1.29). The association was stronger for current use of oral glucocorticoids than for recent or past use. Among current users, the highest ORs were observed in the group wi th the highest average daily dose, although the dose-response relation was not continuous. Current use was associated with an increased risk of heart failure ( adjusted OR 2.66, 95%CI 2.46 to 2.87), which was consistent between patients wi th rheumatoid arthritis, patients with chronic obstructive pulmonary disease, an d patients without either of the two conditions. Also, current use was associate d with a smaller increased risk of ischaemic heart disease (OR 1.20, 95%CI 1.11 to 1.29). Conclusions: Oral glucocorticoid use was identified as a risk factor for heart failure. However, the evidence remains observational and only a random ised controlled trial of glucocorticoid treatment versus other disease modifying agents is likely to distinguish the importance of the underlying disease activi ty from its treatment in predicting cardiovascular outcomes. Objective: To assess whether use of oral glucocorticoids is associated with ca rdiovascular and cerebrovascular morbidity. Design and setting: Nested case-con trol study within a cohort of patients (≥50 years old) with at least one prescr iption for oral or non- Patients: 50 656 patients were identified with a first record for ischaemic heart disease (International classification of diseases, ni nth revision (ICD-9) codes 410, 411, 413, and 414), ischaemic stroke or transie nt ischaemic attack (ICD-9 codes 430-436), or heart failure (ICD-9 code 428) between 1988 and 1998. One control was matched to each case by sex, age, general practice, underlying disease, and calendar time. Main outcome measure: Odds rat io (OR) of cardiovascular or cerebrovascular events in patients using oral gluco corticoids compared with non-users. Results: There was a significant associatio n between ever use of oral glucocortico ids and any cardiovascular or cerebrovasc ular outcome (adjusted OR 1.25, 95% confidence interval (CI) 1.21 to 1.29). The association was stronger for current use of oral glucocorticoids than for recent or past use. Among current users, the highest ORs were observed in the group wi th the highest average daily dose, although the dose-response relation was not continuous. Current use was associated with an increased risk of heart failure (adjusted OR 2.66, 95% CI 2.46 to 2.87), which was consistent between patients wi th rheumatoid arthritis, patients with chronic obstructive pulmonary disease, an d patients without either of the two conditions. Also, current use was associate d with a less increased risk of ischaemic heart disease (OR 1.20, 95% CI 1.11 to 1.29) . Conclusions: Oral glucocorticoid use was identified as a risk factor for heart failure. However, the evidence remains observational and only a randomized controlled trial of glucocorticoid treatment versus other disease modif ying agents is likely to distinguish the importance of the underlying disease activi ty from its treatment in predicting cardiovascular outcomes.