The Prevalence of Natural Health Product Use in Patients with Acute Cardiovascular Disease

BACKGROUND: Natural health products (NHP) use may have implications with respect to adverse effects, drug interactions and adherence yet the prevalence of NHP use by patients with acute cardiovascular disease and the best method to ascertain this information is unknown. OBJECTIVE: To identify the best method to ascertain information on NHP, and the prevalence of use in a population with acute cardiovascular disease. METHODS: Structured interviews were conducted with a convenience sample of consecutive patients admitted with acute cardiovascular disease to the University of Alberta Hospital during January 2009. NHP use was explored using structured and open-ended questions based on Health Canada's definition of NHP. The medical record was reviewed, and documentation of NHP use by physicians, nurses, and pharmacists, compared against the gold-standard structured interview. RESULTS: 88 patients were interviewed (mean age 62 years, standard deviation [SD 14]; 80% male; 41% admitted for acute coronary syndromes). Common co-morbidities included hypertension (59%), diabetes (26%) and renal impairment (19%). NHP use was common (78% of patients) and 75% of NHP users reported daily use. The category of NHP most commonly used was vitamins and minerals (73%) followed by herbal products (20%), traditional medicines including Chinese medicines (9%), homeopathic preparations (1%) and other products including amino acids, essential fatty acids and probiotics (35%). In a multivariable model, only older age was associated with increased NHP use (OR 1.5 per age decile [95%CI 1.03 to 2.2]). When compared to the interview, the highest rate of NHP documentation was the pharmacist history (41%). NHP were documented in 22% of patients by the physician and 19% by the nurse. CONCLUSIONS: NHP use is common in patients admitted with acute cardiovascular disease. However, health professionals do not commonly identify NHP as part of the medication profile despite its potential importance. Structured interview appears to be the best method to accurately identify patient use of NHP.