title: Incidence, risk factors and risk prediction of hospital-acquired suspected adverse drug reactions: a prospective cohort of Ugandan inpatients.
abstract: To determine the incidence and risk factors of hospital-acquired suspected adverse drug reactions (ADRs) among Ugandan inpatients. We also constructed risk scores to predict and qualitatively assess for peculiarities between low-risk and high-risk ADR patients.
  
  
  
  Prospective cohort of consented adults admitted on medical and gynaecological wards of the 1790-bed Mulago National Referral Hospital. Hospital-acquired suspected ADRs were dichotomised as possible (possible/probable/definite) or not and probable (probable/definite) or not, using the Naranjo scale. Risk scores were generated from coefficients of ADR risk-factor logistic regression models.
  
  
  
  The incidence of possible hospital-acquired suspected ADRs was 25% (194/762, 95% CI: 22% to 29%): 44% (85/194) experienced serious possible ADRs. The risk of probable ADRs was 11% (87/762, 95% CI 9% to 14%): 46% (40/87) had serious probable ADRs. Antibacterials-only (51/194), uterotonics-only (21/194), cardiovascular drugs-only (16/194), antimalarials-only (12/194) and analgesics-only (10/194) were the most frequently implicated. Treatment with six or more conventional medicines during hospitalisation (OR=2.31, 95% CI 1.29 to 4.15) and self-reported herbal medicine use during the 4 weeks preadmission (OR=1.96, 95% CI 1.22 to 3.13) were the risk factors for probable hospital-acquired ADRs. Risk factors for possible hospital-acquired ADRs were: treatment with six or more conventional medicines (OR=2.72, 95% CI 1.79 to 4.13), herbal medicine use during the 4 weeks preadmission (OR=1.68, 95% CI 1.16 to 2.43), prior 3 months hospitalisation (OR=1.57, 95% CI 1.09 to 2.26) and being on gynaecological ward (OR=2.16, 95% CI 1.36 to 3.44). More drug classes were implicated among high-risk ADR-patients, with cardiovascular drugs being the most frequently linked to possible ADRs.
  
  
  
  The risk of hospital-acquired suspected ADRs was higher with preadmission herbal medicine use and treatment with six or more conventional medicines during hospitalisation. Our risk scores should be validated in large-scale studies and tested in routine clinical care.
authors.affiliation: Department of Pharmacology and Therapeutics, Makerere University College of Health Sciences, Kampala, Uganda.
authors.forename: Ronald
authors.initials: R
authors.lastname: Kiguba
authors.affiliation: Clinical Epidemiology Unit, Makerere University College of Health Sciences, Kampala, Uganda.
authors.forename: Charles
authors.initials: C
authors.lastname: Karamagi
authors.affiliation: Medical Research Council Biostatistics Unit, Cambridge, UK.
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Bird
mesh_terms: D000328:Adult; D000700:Analgesics / Q000009:adverse effects; D000890:Anti-Infective Agents / Q000009:adverse effects; D002317:Cardiovascular Agents / Q000009:adverse effects; D004347:Drug Interactions; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006760:Hospitalization; D006761:Hospitals; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D010936:Plant Extracts / Q000008:administration & dosage; D019338:Polypharmacy; D011446:Prospective Studies; D012307:Risk Factors; D014454:Uganda; D055815:Young Adult
chemical_list: D000700:Analgesics; D000890:Anti-Infective Agents; D002317:Cardiovascular Agents; D010936:Plant Extracts
keywords: CLINICAL PHARMACOLOGY; EPIDEMIOLOGY; GENERAL MEDICINE (see Internal Medicine); GYNAECOLOGY