ABSTRACT
OBJECTIVE: To determine the prevalence of acetylsalicylic acid therapy and effect of the drug on hemoglobin concentration over time. DESIGN: Retrospective, observational study. SETTING: Primary care population in a university-affiliated family medicine clinic. PATIENTS: A population-based sample of 80 patients receiving low-dose ASA for secondary prevention of cardiovascular disease was studied. Of 84 patients receiving the drug after a cardiovascular problem, four were excluded: one man died of a recurrent stroke during the study; the file of a second man was unavailable; another man developed a bleeding ulcer; and one woman had been taking ASA for only 1 month when the data were collated. MAIN OUTCOME MEASURES: Demographic variables of patients taking low-dose ASA, duration of ASA use, and two successive measures of hemoglobin level. RESULTS: The frequency of ASA administration was 7.7% for men aged 60 and older and 2.9% for women. Women had no significant change in hemoglobin levels, while men had a mean loss of 0.472 g/dL (95% confidence interval, .198 to .746; P = .009). For the study population as a whole (80 patients), the average decline was 0.294 g/dL (95% confidence interval, .039 to .549; P = .029). CONCLUSIONS: Although the clinical significance of these findings is uncertain, they suggest the need for a prospective investigation of the influence of low-dose ASA on hemoglobin levels.
