The cutaneous adverse drug reactions: risk factors, prognosis and economic impacts.

ABSTRACT

AIMS: The aim of this study was to explore the factors associated with the occurrence, subsequent prognoses and need for additional medications following cutaneous adverse drug reactions (ADRs) among inpatients. METHODS AND MEASURES: This is a case-control study, nested in a large cohort study of 473,446 inpatients hospitalised from 2005 to 2008, examined cutaneous ADRs. A 1 5 strategy of individually matching age and principal diagnosis was applied to the data of cases (n = 700) and corresponding controls (n = 3365).The severity of ADRs was evaluated using Naranjo algorithms by senior pharmacists in the medical centre. Medical chart reviews and claim data analyses were analysed to explore risk factors associated with the occurrence and impact of cutaneous ADRs. Economic impacts in terms of length of stay and medical expenses were also analysed. RESULTS: The number of drug prescriptions and secondary diagnoses, and the department to which the patient was admitted, significantly contributed to the risk of cutaneous ADRs and subsequent prognosis. In addition to physician's seniority, the Naranjo score was also positively associated with patients' prognosis. Medical expenses associated with cutaneous ADRs patients ($US 916) were more than 2.5-fold higher than those patients who were not afflicted ($US 318). CONCLUSION: The study identified risk factors for cutaneous ADRs in terms of both patient characteristics and drug complexity. The present analyses indicate characteristics and mechanisms of cutaneous ADRs among inpatients, which provide clues for future intervention strategies and management issues in healthcare settings.