Background The prevalence of dietary supplement use in the pre-operative period ranges from 4.8 to 80%. According to the Food and Drug Administration, some dietary supplements may show side effects before, during and after surgery. Objective The main aim of the study was to determine the prevalence of dietary supplement use in patients before surgery at University Hospital Hradec Kralove and the predictors of use. The secondary aim was to determine patient awareness regarding the correct use of and possible risks associated with dietary supplements. Setting University Hospital Hradec Kralove. Methods Between March 2017 and June 2018, a cross-sectional study focused on patients in the pre-operative period in different departments at University Hospital Hradec Kralove was conducted. The questionnaires were anonymous and entirely voluntary. The obtained data were evaluated using descriptive statistics and a regression model in Microsoft Excel 2016 and IBM SPSS version 24. Main outcome measure The prevalence and predictors of dietary supplement use in patients before surgery. Results 256 questionnaires were returned (a response rate of 77.41%). 111 dietary supplements were used by a total of 42% of the respondents in the 30-day period prior to surgery. Patients with a higher probability of dietary supplement use included patients with urogenital (OR 3.8, 95% CI 1.2, 12.1), otorhinolaryngological (OR 3.9, 95% CI 1.1, 13.8) and musculoskeletal health problems (OR 3.9, 95% CI 1.1, 13.8). The proportion of dietary supplement users increased with the number of drugs taken concomitantly, with the probability of use being more than three times higher compared with non-dietary supplement users (OR 3.4, 95% CI 1.2, 9.4). A total of 45.8% of the respondents thought there was no risk associated with their current use of dietary supplements and drugs. Conclusions There is a high prevalence of dietary supplement use in hospitalized patients, with independent predictors being comorbidity and polypharmacy. No official recommendations or guidelines exist for physicians and anaesthesiologists in the Czech Republic which focus on patients that use dietary supplements in the pre-operative period. National guidelines focusing on dietary supplement use in the pre-operative period would be appropriate.
Keywords: Adverse reactions; Czech Republic; Dietary supplements; Herbal supplements; Herb–drug interaction; Surgery.