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

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: 438-48 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 Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

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):447-450. Johnson J, Bootman J. Drug-related morbidity and mortality: a cost-of-illness model. Archives of Internal Medicine. 1995;155:1949-1956. 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

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. 2008 Mar; 37(2):138-41. Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

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;34:338-346. 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;32:113-121. Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

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;163:2716-2724. 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;156:385-391. Laroche M, Charmes J, Merle L. Potentially inappropriate medications in the elderly: a French consensus panel list. Eur J Clin Pharmacol. 2007;63(725-731). 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;27:153-159. Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

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

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

Methods

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

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. Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

Results

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

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 Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

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. Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

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 (1.81-2.11) Prescribers working in the department of psychiatry: OR, 3.46 (3.01-3.98) Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

Conclusions & Implications

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.  Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

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. Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011

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

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 r.sruamsiri@gmail.com Third International Conference for Improving Use of Medicines, Antalya, Turkey, November 14-18,2011