Pattern of Adverse Drug Reactions and Their Economic Impact on Admitted Patients in Medicine Wards of a Tertiary Care Hospital

Abstract

Objective: Adverse drug reactions (ADRs) have recently emerged as a leading cause of illness and death, as well as a significant strain on the healthcare system. The important objectives of the research were to identify and assess the pattern of ADRs, analyse the ADRs based on their causality, severity, and preventability and also find out the economic impact of ADRs.

Method: A prospective observational study was carried out for six months in three hospital wards specifically designated for general medicine. The definition of ADR by the World Health Organization was adopted. The severity, preventability, and causality of each adverse drug reaction (ADR) were evaluated using Naranjo's scale, the Hartwig et al. criteria, and the modified Shumock and Thornton's criteria. The medication cost induced by ADR was estimated using the available resources at the study site.

Result: 31 patients were removed from the 540 patients' data set because of incomplete information and medical-legal cases (MLC) that were recorded throughout the study duration. 509 patients' data were analysed and 52 ADRs were detected in 49 patients across three hospital medical wards of the 49 patients suffering from 52 ADRs, only 3 patients had two ADRs and 46 patients had only one ADR, respectively. It was noted that the occurrence of ADRs was 10.2% (52/509). Based on the Rawlins and Thompson system, the greatest number of ADRs (86.54%) were identified as type A reactions. As per the Anatomical and Therapeutic Classification (ATC) system, the drug class typically linked with ADRs was anti-infectives for systemic use (26.92%) followed by cardiovascular systems (25%). MedDRA terminology was used for ADR coding and the most frequently existing reactions were constipation (25%), Skin Rash (10%), and cough (8%). As per Naranjo’s causality assessment scale, the maximum percentage of ADRs was probable (61%), followed by possible (37%). Based on the Hartwig et al. severity scale, ADRs were evaluated and approximately 50% of ADRs were of the moderate type, followed by 48% of ADRs of mild type ADRs and according to modified Shumock and Thornton's criteria, Most ADRs (94%) were not preventable. The economic burden per patient due to ADRs was ₹102.31 and the average drug cost induced in mild, moderate, and severe reactions was ₹75.9, ₹89.4, ₹658, respectively.

Conclusion: The outcomes of this study will minimize costs to the healthcare system and improve patient safety.