Author Name: Kannika Inpra Presenter Name: Kannika Inpra Authors: Inpra K., Suwankesawong W., Kaewvichit S. Institution: Phrae Hospital, Phrae, Thailand Title: Preventable Adverse Drug Reactions in Hospitalized Patients: A Study in 21 Selected Thai Hospitals Problem Statement: The high incidence of and costs associated with adverse drug reactions (ADRs) have influenced health care policy and economics. To minimize this problem, it is essential to gain knowledge of preventable ADRs and develop intervention programs to tackle the problem. In this study, the extent of preventable ADRs in Thailand was explored. Objective: To determine the incidence and characteristics of preventable ADRs in hospitalized patients. Design: Prospective observational study. Setting and Study Population: All case report forms of patients more than 18 years old admitted to the Department of Medicine in 21 secondary and tertiary care hospitals located throughout Thailand from February 1, 2002, through March 8, 2002, were examined. Results: From 13,781 case reports, 363 ADR reports were analyzed. From this group, 114 (31.4%) were classified with Schumock and Thornton criteria as preventable ADRs. Mean age ± SD was ± 6.44 years. More than twice as many females as males (68:31) had ADRs. The top three underlying diseases were hypertension, diabetes mellitus, and tuberculosis. Eighty-one (71.1%) preventable ADRs were related to hospital admission. The median length of stay was four days (range, 0–34 days), with 82 (71.9%) reports considered severe enough to require initial or prolonged hospitalization.[1] The relationship of preventable ADRs to drug exposure was determined to be probable or possible in 100%. Half of ADRs occurred in the gastrointestinal, metabolic and nutritional, central and peripheral nervous, liver and biliary, and skin and appendages systems. The most common outcome (65.7%) was recovery without sequelae. Other chemotherapeutics, metabolism, and miscellaneous were the top three classes of drugs causing preventable ADRs. The four highest-priority causes of preventable ADRs accounted for 89% of all reports: (1) required therapeutic drug monitoring or other necessary laboratory tests were not performed or not performed frequently enough (46.8%); (2) dose, route, or frequency of administration was not appropriate for the patient’s age, weight, or disease criteria (16.0%); (3) drugs prescribed were not appropriate for the patient’s clinical condition criteria (13.2%); and (4) noncompliance was associated with the reaction criteria (13.2%). Conclusions: Further studies are needed to identify and determine ADR- associated factors and to develop strategies to avoid preventable ADRs in hospitalized patients.

Problem Statement The high incidence and costs associated with adverse drug reactions : ADRs have influenced health care policy and economics. To minimize this problem, it is essential to gain knowledge of preventable ADRs and develop intervention programs to tackle the problem. In this study, the extent of preventable ADRs in Thailand were explored.

Objectives To determine the incidence and characteristics of preventable ADR in hospitalized patients. Design Prospective observational study

Setting and Population All case report forms of patient more than 18 years old admitted to the department of medicine in secondary and tertiary care hospitals located through out Thailand during February 1, 2002 to March 8, 2002 were explored. Adverse Drug Reaction : ADR WHO definition (1966 )

Criteria for Determining Preventability of an ADR Answering “YES” to one or more of the questions Was the dose, route, and frequency of administration not appropriate for the patient’s age, weight and disease state ? Was required therapeutic drug monitoring or other necessary laboratory test not performed ? Was the drug involved in the ADR not considered appropriate for the patient’s clinical condition ? Schumock GT and Thornton JP. Focusing on the preventability of adverse drug reactions. Hosp Pharm. 1992;27:538-9.

Criteria for Determining Preventability of an ADR cont. Was there a history of allergy or previous reactions to the drug ? Was a drug interaction involved in the reaction ? Was a toxic serum drug level documented ? Was poor compliance involved in the reaction ? Schumock GT and Thornton JP. Focusing on the preventability of adverse drug reactions. Hosp Pharm. 1992;27:538-9.

Results From 13,781 case reports, 363 ADRs reports were analyzed. From this group, 114 (31.4 %) were classified with Schumock and Thornton criteria as preventable ADRs. The relationship of preventable ADRs to drug exposure was determined to be probable or possible in 100%. Most outcome (65.7%) was recovered without sequelae.

VariableNo.( %) Preventable ADR ( n = 114, 31.40% ) No.( %) Non-preventable ADR ( n = 249, 68.60% ) Age group ( ) 35 ( ) 51 ( ) 6 ( 5.26 ) 60 ( ) 78 ( ) 92 ( ) 19 ( 7.63 ) Age Mean  SD Range Mode Median   Gender Male Female 36 ( ) 78 ( ) 123 ( ) 126 ( ) Table l Preventable and Non-preventable Adverse Drug Reaction ( ADRs ) Categorized by Patient and ADR Variables

Preventabilit y Code CriteriaNo. times code used (% total uses) 1Drugs involved were not appropriate for the patient’s clinical condition. 22 ( ) 2Dose, route, or frequency of administration was not appropriate for the patient’s age, weight or disease. 27 ( ) 3Required therapeutic drug monitoring or other necessary laboratory tests were not performed or not performed frequently enough. 79 ( ) 4Patient has a history of allergy or previous reaction to the drug 13 ( 7.69 ) 5A known drug interaction was the suspected cause of the reaction 2 ( 1.18 ) 6A serum drug concentration above the therapeutic range was documented 4 ( 2.37 ) 7Noncompliance was associated with the reaction 22 (13.02 ) Table ll Distribution of preventability Code

Most top three underlying diseases Most top three classes of drugs causing preventable ADRs Other chemotherapeutics metabolism miscellaneous Half of them occurred in Gastro-intestinal Metabolic and nutritional Central & peripheral nervous Liver and biliary Skin and appendages system Hypertension Diabetes mellitus Tuberculosis

VariableNo. ( %) Preventable ADR No. ( %) Non-preventable ADR Admissions due to ADR Yes No 81 ( ) 33 ( ) 115 ( ) 134 ( ) Length of stay Min – Max Mean  SD Median Range  missing data = 3 0 –  missing data = 9 Drug Allergy History Yes No 14 ( ) 100 ( ) 28 ( ) 212 ( ) missing data = 9 Table II Preventable and Non-preventable Adverse Drug Reaction ( ADRs ) Categorized by Admissions due to ADR, Length of stay and Drug Allergy History

Discussion The percentage of pADRs 31% The percentage of admission that were classified as preventable 71.05% Values previously reported as being preventable 28-80% Conclusions Further studies are needed to identify and determine ADR associated factors and to develop strategies for prevention of preventable ADRs in hospitalized patients