1. The Prevalence of and Factors Associated with Potentially Inappropriate Medications Use in The Elderly Population in Thailand
Rosarin Sruamsiri1,
Nathorn Chaiyakunapruk1,
Napawan Jeanpeerapong2
1Center of Pharmaceutical Outcomes Research, Faculty of Pharmaceutical Sciences,
Naresuan University, Phitsanulok, Thailand
2Department of Pharmacy, Bhuddhachinaraj Hospital, Muang, Phitsanulok, Thailand
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

2. Background Elderly people are vulnerable to medical misadventures.
Inappropriate used of medications is considered one of the main causes of adverse drug reactions in the elderly.
Jano E and Aparasu RR. Healthcare outcomes associated with beers’ criteria: a systematic review. Ann Phamacother. 2007; 41:
Page et al. Inappropriate prescribing in the hospitalized elderly patient: Defining the problem, evaluation tools, and possible solutions.Clinical Intervention in Aging.2010;5:75-87
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3. Probability of having drug-drug interaction
Background
Risk of drug-drug interactions
Probability of having drug-drug interaction
Cost of drug-related morbidity and mortality : $76.6 billion annually.
Incremental healthcare costs related to inappropriate prescribing in older : $7.2 billion annually.
Goldberg R, Mabee J, Chan L, Wong S. Drug-drug and drug-disease interactions in the ED: analysis of a high risk population. Am J Emerg Med. 1996;14(5):
Johnson J, Bootman J. Drug-related morbidity and mortality: a cost-of-illness model. Archives of Internal Medicine. 1995;155:
Fu A, Jiang J, Reeves J, Fincham J, Liu G, Perri MI. Potentially inappropriate medication use and healthcare expenditures in the US community dwelling elderly. Medical Care. 2007;45:472–476.
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

4. Background
“Potentially Inappropriate Medications”(PIMs) or “Potentially Inappropriate Prescriptions”
Medications that have no clear evidence-based indication, carry a substantially higher risk of adverse side-effect or not cost-effective.
O’Mahony D, Gallagher PF. Inappropriate prescribing in the older population: need for new criteria. Age Aging Mar; 37(2):
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

5. Background
Prevalence of PIMs ranged from 5.8% to 51.4% in various settings and countries.
Aparasu R, Mort J. Inappropriate prescribing for the elderly: Beers criteria-based review. Ann Pharmacother. 2003;34:
F ialová D, Topinková E, Gambassi G, al e. Potentially inappropriate medication use among elderly home care patients in Europe. JAMA. 2005;293:1348–1358.
Gallagher P, Barry P, O’Mahony D. Inappropriate prescribing in the elderly. J Clin Pharm Ther. 2007;32:
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6. Background
Specific criteria for avoidable PIMs has later been developed in the USA, Canada, France, Ireland and Norway.
A list of PIMs called ‘the criteria for high-risk medications use in Thai older patients’ was developed in 2008.
Fick D, Cooper J, Wadw W, Waller J, Maclean R, Beers M. Updating the Beers criteria for potentially inappropriate medication use in older adults: result of a US consensus panel of experts. Arch Intern Med. 2003;163:
McLeod P, Huang A, Tamblyn R, Gayton D. Defining inappropriate practices in prescribing for eldely peoplr: a national consensus panel. Can Med Assoc J. 1997;156:
Laroche M, Charmes J, Merle L. Potentially inappropriate medications in the elderly: a French consensus panel list. Eur J Clin Pharmacol. 2007;63( ).
Gallanher P, Ryan C, Byrne S, Kennedy J, O'Mahony D. STOPP(Screening Tool of Older Person's Prescription) and START (Screening Tool to Alert doctors to Right Treatment).Consensus validation. Int J Clin Pharmacol Ther. 2008;46(72-83).
Rognstad S, Brekke M, Fetveit A, Spigset O, Wyller T, Straand J. The Norwegian General Practice (NORGEP) criteria for assessing potentially inappropriate prescriptions to elderly patients: A modified Delphi study. Scan J Prim Health Care. 2009;27:
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

7. Background
Understanding the epidemiology of PIMs among elderly population could enable clinicians to properly develop measures to maximize benefits of drug use and minimize adverse drug events
It is important to examine the prevalence of and identify factors associated with PIMs in Thailand.
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

8. Objectives
To determine the prevalence of PIMs in the Thai elderly population.
To identify factors associated with PIMs
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

9. Methods

10. Methods Retrospective databases analysis
Databases from a university-affiliated hospital
Out-patient diagnosis databases
Pharmacy databases
Inclusion criteria
Patients aged ≥ 65 year-old
Patients visited the outpatient department in 2008
PIMs evaluation
The criteria for high-risk medication use in Thai older patients (Winit-Watjana et al 2008)
Analysis
Descriptive statistics for prevalence of PIMs
Multivariate analysis using generalized estimation equations (GEE) to determine factors associated with PIMs
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

11. Methods
The criteria for high-risk medication use in Thai older patients
(Winit-Watjana et al 2008)
Categorized into 3 categories
4 severities classification
Categories
Examples
High-risk medications
Diazepam
Drug-disease interactions
Peptic Ulcer and NSAIDs*
Drug-drugs interactions
Warfarin and NSAIDs*
* NSAIDs : Non-Steroidal anti-inflammatory drug
Severity
Description 1
drug or pair should be avoid 2
drug or pair rarely appropriate 3
drug or pair with some indications for elderly patients UC
un-classified
Winit-Watjana W, Sakulrat P, Kespichayawattana J. Criteria for high-risk medication use in Thai older patients. Arch Gerontol Geriatr2008 Jul-Aug;47(1):35-51.
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12. Results

13. Results Characteristics Total n (%) Total 14,994 Age mean(SD) 73 (6.6)
73 (6.6)  
65-74
9,360 (62.42)
75-84
4,810 (32.08)
≥85
824 (5.50)
Sex
  Male
6,533 (43.57)
  Female
8,461 (56.43)
Status of treatment
  Universal Coverage (UC)
7,532 (50.23)
  Social Security Scheme (SSS)
46 (0.31)
  Civil Servants Medical Benefit Scheme (CSMBS)
7,347 (49.00)
  Others
69 (0.46)
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

14. Results
58% (8,676/14,994) of included patients were prescribed at least 1 PIMs.
Of 8,676 PIMs users
4 % received drug or pair should be avoid.
8 % received drug or pair rarely appropriate
29 % received drug or pair with some indications for elderly patients
59% unclassified
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15. High- risk medication used criteria
Results
Table 1. The Most Common Potentially Inappropriate Medications (PIMs) Use among Elderly Thai Patients
High- risk medication used criteria
Classification*
Prevalence in year 2008 (%)
Medications
NSAIDs 2
1,492/8,676
(17.2)
NSAIDs, COX II inhibitors
651/8,676
(7.5)
ACEIs 3
2,605/8,676
(30.0)
Short-acting Benzodiazepines
1,732/8,676
(20.0)
Alpha-blockers
1,061/8,676
(12.2)
Drug-Disease Interactions
Peptic ulcer-NSAIDs 1
64/8,676
(0.7)
Glaucoma-tricyclic antidepressant
30/8,676
(0.3)
Coronary artery disease – testosterone
83/8,676
(1.0)
Drug-Drug Interactions
Aspirin-NSAIDs
214/8,676
(2.5)
Warfarin-NSAIDs
81/8,676
(0.9)
*Classification of high-risk medication use: 1= drug or pair should be avoid; 2= drug or pair rarely appropriate; 3= drug or pair with some indications for elderly patients; UC=un-classified.
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16. Results Factors associated with PIMs Individual factors System factors
Polypharmacy
6-9 medications: OR, 3.32 (3.17 – 3.48)
≥ 10 medications: OR, 6.94 (6.39– 7.53) compared with patients taking ≤ 5 medications.
Higher morbidities:
CCI* score 2-3: OR, 5.04 (4.69 – 5.51)
CCI* score >4: OR, 8.78 (8.86 – 8.90) compared with CCI score of 0-1
System factors
Universal Coverage (UC): OR, 1.77 (1.72 – 1.82) compared with CSMBS
Prescribers under training: OR, 1.95 ( )
Prescribers working in the department of psychiatry: OR, 3.46 ( )
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17. Conclusions & Implications

18. Conclusions
Using country’s specific criteria can determine the magnitude of problem in local context.
PIMs used among elderly remains a major public health concern in Thailand.
Both individual characteristics and health system factors were associated with PIMs.
Proper managements are needed especially among those with co-morbidities and receiving muli-medications. 
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19. Implications
Further researches are needed to target extended, clinical practices and policy implementations to reduce PIMs.
Reduction strategies should be implemented from both bottom-up and top-down.
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20. Acknowledgement Our research team: Dr. Nathorn Chiyakunapruk
Napawan Jeanpeerapong
World Health Organization
Thailand Research Fund through the Royal Golden Jubilee PhD program
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

21. Rosarin Sruamsiri, B.Pharm , M.B.A.
Contact information
Rosarin Sruamsiri, B.Pharm , M.B.A.
Center for Pharmaceutical Outcomes Research (CPOR)
Faculty of Pharmaceutical Sciences
Naresuan University
Muang, Phitsanulok, Thailand 65000
Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011