Scoring System for the Development of the National List of Essential Drugs in Thailand.

Dr. Pisonthi Chongtrakul M. D Dr.Pisonthi Chongtrakul M.D. Thai Board of Pediatrics Department of Pharmacology The Faculty of Medicine Chulalongkorn University Bangkok, Thailand.

Introduction The concept of ‘Essential Drugs’ was first introduced by WHO in 1977 It addresses the problems of access, rational use and drug quality. Essential medicines are those that satisfy the priority health care needs of the population. Exactly which medicines are regarded as essential remains a national responsibility.

Background: Thailand has adopted the ED policy and produced several National List of Essential Drug (NLED) since 1979. A new method of scoring system has been introduced and officially used to assist the expert panels in 2004 NLED selection process. This 2004 NLED is also intended to be the reference list for all health care reimbursement schemes.

Objectives: To describe the scoring scheme (ISafE scoring system) that Thailand has adopted for the drug selection process for the 2004 NLED. To describe the evidence-based process included in the drug selection methodology.

Methods: ISafE score uses 5 criteria to assess drug’s overall quality when the drug is used in a pre-defined indication. These criteria are Information, Safety, patient compliance as represented by (drug) adminis- tration restriction + frequency of administration and Efficacy. A point of 0.5 to 1 is assigned to each of the criteria, final ISafE score is the multiplication of all points. Drugs which ranks were below the 50th percen- tile of the list was designated low priority, and high priority drugs should be considered first.

Example of Microsoft Excel Worksheet for ISaFE Score Calculation for Low-Ceiling Diuretics indicated for Hypertension  EV column shows that there are 221 RCTs, Meta-analyses and Academic reviews on HCTZ for Hypertension (from Pubmed search), with overall Excellent quality (from Micromedex CCIS evaluation).  I column is the point assigned to each of the drug in comparison using data in EV column. (Note 2N = 2 publications, no data in CCIS)  All drugs are effective (E) in MM (Micromedex database) column, except tripamide where the evaluation of effectiveness was not available.

Example of Microsoft Excel Worksheet for ISaFE Score Calculation for Low-Ceiling Diuretics indicated for Hypertension  EV column shows that there are 221 RCTs, Meta-analyses and Academic reviews on HCTZ for Hypertension (from Pubmed search), with overall Excellent quality (from Micromedex CCIS evaluation).  I column is the point assigned to each of the drug in comparison using data in EV column. (Note 2N = 2 publications, no data in CCIS)  All drugs are effective (E) in MM (Micromedex database) column, except tripamide where the evaluation of effectiveness was not available.

IES score is the multiplication of I, E and S points, the score closer to 1 represents excellent evidence, proven efficacy and better safety profile.  Drug Risk profiles are tallied from the quantity of Contraindi- cations, Severe ADR and Drug Interactions derived from 3 databases i.e. Micromedex CCIS + Medscape(M) and Clinical Pharmacology(C).  From the example below, there are 31 and 65 total risks of HCTZ manifested in M and C database respectively. (minimum S point = 0.8)  Drug Risk profiles are tallied from the quantity of Contraindi- cations, Severe ADR and Drug Interactions derived from 3 databases i.e. Micromedex CCIS + Medscape(M) and Clinical Pharmacology(C).  From the above example, there are 31 and 65 total risks of HCTZ manifested in M and C database respectively. (minimum S point = 0.8)

ISafE score is the multiplication of IES and af score ISafE score is the multiplication of IES and af score. Drugs with ISafE score not less than 50 percentile are first considered for inclusion into the NLED list, thus Tripamide is put aside.  Compliance is addressed by a (administration restriction e.g. the drug has to be taken on an empty stomach, a = 0.9) and f (frequency of drug administration, e.g. qd dosage, f = 1.0 is preferrable than tid dosage, f = 0.9). The af score is the product of a and f (possible minimum score = 0.9 x 0.85)

NLED score comes from dividing drug cost by ISafE score NLED score comes from dividing drug cost by ISafE score. The score is used to classify NLED list into Class 1 and Class 2 drugs.  Baht/PD = Cost of drug in Baht per day, using WHO defined daily dose and average cost of generic and original drugs.Thus NLED score for HCTZ = 0.13/0.88 = 1.0  A drug with low NLED score is in principle, a drug with high overall quality and low cost.

Criteria for NLED Class 1a (ก), 1b (ข), 2a (ค) and 2b (ง) comes from 25th, 40th, 55th and 70th percentile of the NLED Score respectively.  Class 1 = Basic essential drugs for all level of health care. Class 1a (ก) = Drug of First Choice / Class 1b (ข) = Alternative Drug.  Class 2 = Drugs which need to be prescribed using specialized diagnostic or monitoring facilities, and/or specialist medical care. Class 2a (ค) can be prescribed only by designated experienced physicians and Class 2b (ง) only by trained specialists.

Results: About 150 NLED score worksheets have been created. The list proposed by the scoring system was very well accepted by the expert panels. The scoring system could enhance the productivity and objectivity of the selection process for all parties involved.

Conclusions: A new method of scoring system, using evidence-based data has been adopted for drug selection in Thailand’s 2004 NLED list. The methodological and systematic approach of the scheme is essential for the transparency of the selection process. The drugs included on the list are assured of possessing high overall quality at a reasonable cost. The ISafE scoring system is a tool that can enhance the rational use of drugs.

Thank You