Frequency, types, severity, preventability and costs of Adverse Drug Reactions at a tertiary care hospital

IntroductionHospital-based adverse drug reaction (ADR) monitoring and reporting studies are conducted to identify, quantify and minimize such risks associated with the use of drugs particularly on long-term basis. Kashmir province of Indian state of Jammu and Kashmir presents a huge market for medicines that runs into millions of rupees. Yet there was no provision to monitor these drugs for their adverse effects prior to this study in any of the leading hospitals of the province. As such the present study, which was first of its kind in the valley, was undertaken to assess the frequency, preventability, category, severity, causality, extension of hospital stay and costs of drug-related adverse effects in Kashmiri patients at a Srinagar-based tertiary care hospital.MethodsA prospective, observational, cohort study on 5482 patients was undertaken over a 270 day period. Adult patients admitted in Internal Medicine in-patient department (IPD), presenting to the Internal Medicine out-patient department (OPD) and those visiting the Accident and Emergency Department of the study hospital were included in the study. Patients belonging to both the sexes were screened and monitored on a daily basis for the occurrence of any ADRs. Definition of ADR given by the World Health Organization (WHO) was used and causality of suspected ADRs was determined using Naranjo's algorithm whereas severity was assessed using modified Hartwig's scale and preventability was determined using Hallas methodology. Costs of ADRs and extension in hospital stay were calculated as per Lagnaou and Nicholas methodology respectively.ResultsADRs accounted for 6.23% of adult Kashmiri patients visiting the tertiary care hospital under study, either for referral or hospitalization, with the majority (81.57%) of these ADRs being preventable; 23.68% of patients had mild ADRs, 69.29% had ADRs of moderate severity, and 7.01% had severe ADRs. Four classes of drugs most frequently suspected in admissions due to ADRs were anti-infective agents (40.92%) including anti-tubercular drugs (13.15%), steroids (14.03%), anti-coagulants (8.77%), and NSAIDs (7.89%). Increasing age and female gender were identified as risk factors. The total cost to the hospital due to hospitalization of patients presenting with ADRs over the 9-month period in the internal medicine IPD was found to be USD 22469 at the time of this study.Discussion/conclusionThe present work is the maiden pharmacovigilance study conducted on Kashmiri patients, especially at a tertiary care teaching hospital that has provided baseline information about the prevalence of ADRs and their distribution among different age groups, genders, organ systems affected, and therapeutic classes of medicines. The data collected will be useful for long term and more extensive ADR monitoring on Kashmiri patients and will also be useful in framing policies toward the rational use of drugs. This study led to the establishment of a full-fledged pharmacovigilance centre and initiation of pharmaceutical care services in the study hospital.