Oxazepam (11.90%). The most frequently prescribed class of drugs was Benzodiazepines (47.72%). There was a significant relationship between inappropriate ...
World Applied Sciences Journal 16 (6): 819-825, 2012 ISSN 1818-4952 © IDOSI Publications, 2012
An Investigation on Inappropriate Medication Applied among Elderly Patients 1
1
Leila Vali, 1Abolghasem Pourreza, 2Abbas Rahimi Foroushani, 1 Ali Akbari Sari and 3D. Hooshyar Honarmand Pharm
Department of Health Management and Economics, School of Public Health, Tehran University of Medical Sciences, Iran 2 Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Iran 3 Department of Clinical Pharmacy, School of Pharmacy, Tehran University of Medical Sciences, Iran
Abstract: Objective: Studies have shown that older people suffer from chronic diseases more than other age groups, resulting in more consumption of drugs. Age-related changes in the pharmacokinetics and pharmacodynamics of drugs alter drug disposition and response to medications in elderly patients. Recognizing these medications and avoiding their prescription for the elderly prevents the adverse effects and promotes the quality of medical services to them. This study aimed to assess inappropriate drug use in the elderly. Materials and Methods: In this descriptive- analytical study, we recruited 212 elderly patients aged 60 years and above who were admitted and then discharged from four public hospitals, including two teaching and two nonteaching hospitals, affiliated to Tehran University of Medical Sciences. The Beers Criteria were used as the assessment tool to determine inappropriate medication use in the elderly aged 60 and over. Results: The mean age of the participants was 69.32.The rate of inappropriate drug use was 20.75%. The most common inappropriately used drugs were Alprazolam (16.66%), Chlordiazepoxide (14.28%), Fluoxetine (11.90%) and Oxazepam (11.90%). The most frequently prescribed class of drugs was Benzodiazepines (47.72%). There was a significant relationship between inappropriate drug use and income (p=0.041). Conclusion: Inappropriate drug use was high in the study population in comparison with many other countries. Our findings showed the necessity of developing scientific guidelines for drug use, promoting the criteria for drug prescription and enhancing physicians' knowledge, which can result in careful monitoring of the drug regimens of the elderly. Key words: Inappropriate drug use Beers criteria
Elderly
INTRODUCTION
Inappropriate medication prescription for the elderly is a major concern because it increases the risk of adverse effects and health care costs [4]. Assessing drug-related problems in elderly patients and other vulnerable populations is a main health care and safety issue for the health care system [5].
Elderly people suffer from illnesses and disabilities more than other age groups and use more medications. Although most of the prescribed drugs undoubtedly help to alleviate illnesses and lower risk of death in the elderly, the balance between the benefits and risks is precarious. Moreover, adverse effects are more likely in the elderly. This risk results from age-related factors such as changes in drug distribution, metabolism, excretion and receptor sensitivity in the body, as well as from prescription of multiple drugs. Changes in absorption, dissemination and metabolism of drugs result from changes in the sensitivity of drug receptors and prescription of several drugs [1-3].
The elderly are at risk of drug -related problems for many reasons. Age-related changes in the pharmacokinetics and pharmacodynamics of drugs alter drug disposition and response to medications in elderly patients. Specifically, phase hepatic metabolism and renal elimination of drugs
Corresponding Author: Abolghasem Pourreza, Department of Health Management and Economics, School of Public Health, Tehran University of Medical Sciences, Iran. Tel: +98-9123722328.
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World Appl. Sci. J., 16 (6): 819-825, 2012
MATERIALS AND METHODS
is less efficient in the elderly; thus, the likelihood of adverse events and drug-drug interactions will be increased if appropriate dose adjustments are not considered [6]. Inappropriate medication prescriptions in the elderly have been recognized for at least two decades [7]. The concept of inappropriate medication prescription for older people has received much attention over the years. Studies have reported the rates of inappropriate prescription between 5% and 40%, depending on the setting and criteria used. These findings are not surprising since the high prevalence of chronic diseases in this population leads to taking several drugs which enhances the likelihood of inappropriate drug use. From an economic point of view, about 35% of all drug expenditure is attributable to older people despite the fact that they account for approximately 13% of the population [8]. In the United States and Canada, epidemiological studies have documented widespread use of potentially inappropriate medications among nursing home residents (up to 40%) and community-dwelling elderly persons (14% -37%). In general, these studies have adopted explicit criteria developed by panels of experts, which recommend avoiding medications with a high potential for adverse events and prefer alternatives with lower risks [9]. Stuart conducted a study on the American elderly to assess the rate of inappropriate drug use employing the Beers criteria between 1995 and 1999. The results showed that adherence of physicians to the Beers criteria decreased the rate of inappropriate drug prescription from 24.8% in 1995 to 21.3% in 1999 [10]. Van der hooft carried out a population-based cohort study on inappropriate drug prescription in older adults based on the updated 2002 Beers criteria between 1997 and 2001. The 1-year risk of receiving at least one inappropriate drug prescription for older adults ranged from 16.8% and 18.5% according to the 1997 criteria; and from 19.1% and 20.0% according to the updated Beers criteria [11]. According to the 2006 consensus, there are more than five million (7.3%) elderly (aged 60 and over) individuals in Iran [12]. To our knowledge, no studies have been conducted on inappropriate usage of drugs in the elderly. This study aimed to assess inappropriate medication use in the Iranians elderly using the Beers criteria.
In this descriptive-analytical study, the Beers criteria were used to assess inappropriate medication use in the elderly individuals aged 60 years and over. The participants had been discharged from two public referral teaching hospitals with the highest number of beds and consequently the highest number of referred patients and two public non-teaching hospitals, all affiliated to Tehran University of Medical Sciences. They are the biggest hospitals in comparison with their counterparts. The researcher used different methods to access the exact number of the elderly people discharged from the hospitals due to the incompetent patient data systems: The reception log of all the wards in the hospitals Medical record office books Computer systems. The total number of the discharged elderly patients from surgical and internal wards in the first quarter of 2008 was 472 individuals. We used the cluster sampling method to recruit the participants. In each cluster, the individuals were selected by systematic sampling. We selected 235 elderly people. We contacted all the participants via telephone and explained the study protocol and the way they could contribute to the study. Some of the elderly people were not reachable because they had moved to unknown places, had passed away, were unwilling to participate, or because we did not have their correct address and phone number due to the receptionists’ careless data entry. Therefore, we performed the study on 212 elderly people. A trained interviewer was then dispatched to visit the participants at their houses. Consent forms were signed by the participants and the interviewer completed a questionnaire on demographic data such as age, sex, marital status, education, income, job and insurance coverage. After that, the interviewer asked the elderly people to bring their medications and documented their names. Data was collected using the Beers criteria. These criteria are based on experts’ consensus and developed through an extensive literature review with bibliography and questionnaires evaluated by nationally recognized experts in geriatric care, clinical pharmacology and 820
World Appl. Sci. J., 16 (6): 819-825, 2012
RESULTS
psychopharmacology, using the modified Delphi technique to reach a consensus. These criteria were first published by 13 experts in 1991 and were updated in 2002. Two items are noticed in these criteria: 1) medications or classes of medications which should generally be avoided in the elderly because they are either ineffective or pose unnecessary risks to the individuals whilst safer alternatives are available and 2) medications that should not be used in the elderly who have specific medical conditions. A 5-point Likert scale was used to determine whether a specific drug should be avoided or not. A list of 48 medications/medication classes was prepared to be avoided in older adults. Sixty-six of these potentially inappropriate drugs were considered by the panel to have adverse outcomes of high severity. New conditions and diagnoses that were addressed included depression, cognitive impairment, Parkinson’s disease, anorexia, malnutrition, syndrome of inappropriate anti-diuretic hormone secretion and obesity. A total of 15 medications/medication classes were dropped or modified in the 2002 update. Most of the medications which were dropped were associated with diagnosis or treatment [5]. We used Chi square test, Fisher's Exact test and Log regression to analyze data.
The mean age of the participants was 69.32 years. Most of the participants belonged to the age group 66-75 years (46.7%). The majority were male (56.1%) and illiterate (42.5%). Of all the participants, 92% were unemployed, 82.5% were married and 91.5% had health insurance. Moreover, 25.9% had no income and 66.5% had an income ranged 2-5 million Rials per month. Only, 0.5% had an income more than 10 million Rials. The rate of inappropriate drug use in the elderly was 20.75%. The most common inappropriately used drugs were as follow: Alprazolam (16.66%), Chlordiazepoxide (14.28%), Fluoxetine (11.9%), Oxazepam (11.9%). Benzodiazepines were recognized as the most frequently used class of medication (47.72%). Table 1 shows the rate of inappropriate drug use. Table 2 demonstrates the rate of drug-disease interactions. According to the table, the rate of drugdisease interactions of high severity was 8.1% and the highest rate was for the interaction between heart failure and Clopidogrel (23.8%). The Fisher's exact test showed a significant relationship between the number of drugs used by the elderly, the occurrence of the drug-disease
Table 1: Frequency of inappropriate drug use in the elderly using Beers criteria (2002) Severity rating Inappropriate drug Drug classification Low Dipyridamole Antiplatelet Cimetidine H2-blocker Total High Methocarbamol Muscle Relaxant Indomethacin NSAID Oxybutynin Antispasmodic; Anticholinergic Fluoxetine Antidepressant; SSRI Amitriptyline Antidepressant; TCA Bisacodyl Laxative Chlordiazepoxide Benzodiazepines (BZD) Lorazepam BZD Oxazepam BZD Alprazolam BZD Diazepam BZD Clidinium Antispasmodic; Anticholinergic Hydroxyzine Anticholinergic; Antihistamine Total Table 2: Drug/disease interactions in the elderly Disease Depression COPD Gastric or duodenal Ulcers Bladder outflow obstruction
Lood clotting disorders or receiving anticoagulant therapy
Drug Chlordiazepoxide Chlordiazepoxide Diclofenac Indomethacin Hydroxyzine Ipratropium Oxybutynin Clopidogrel Alendronate
Total
821
No (%) 1 (4.7) 1 (4.7) 2 (9.5) 1 (4.7) 2 (9.5) 2 (9.5) 1 (4.7) 5(23.8) 1(4.7) 17(100)
N (%) 1 (50) 1 (50) 2 (100) 1 (2.38) 3 (7.14) 4 (9.52) 5 (11.90) 1 (2.38) 2 (4.76) 6 (14.28) 2 (4.76) 5 (11.90) 7 (16.66) 1 (2.38) 1 (2.38) 4 (9.52) 42 (100)
Severity rating High High High High
High
World Appl. Sci. J., 16 (6): 819-825, 2012 Table 3: The association between inappropriate drug use and demographic characteristics in the elderly Inappropriate medication ---------------------------------------------------------------------------------------------------------------------------Consumed N (%) Non- consumed N (%) Total P-value
Demographic variables Age
60-65 66-75 76-91
67 (85.9) 81 (81.8) 29 (82.9)
11 (14.1) 18 (18.2) 6 (17.1)
100 100 100
0.764
Sex
Male Female Illiterate Less than 6 years 6-12 years University degree
104 (87.4) 73 (78.5) 71 (78.9) 68 (85) 26 (89.7) 12 (92.3)
15 (12.6) 20 (21.5) 19 (21.1) 12 (15) 3 (10.3) 1 (7.7)
100 100 100 100 100 100
0.083
Hosing
Owner Tenant Other Unemployed
131 (80.9) 27 (96.4) 19 (86.4) 162 (83.1)
31 (19.1) 1 (3.6) 3 (13.6) 33 (16.9)
100 100 100 100
0.108*
Marital status
Single Married Other
1 (50) 147 (84) 29 (82.9)
1 (50) 28 (16) 6 (17.1)
100 100 100
0.345*
Income
Low High
14 (26.4) 21 (13.2)
39 (73.6) 138 (86.8)
100 100
0.041*
Insurance coverage
No Yesýý
16 (88.9) 161 (83)
2 (11.1) 33 (17)
100 100
0.744*
Education
*0.480
Table 4: The results of logistic regression for inappropriate drug use with demographic characteristics in the elderly
Demoghrapic variables
CI 95% -------------------------------High Low
B
SE
P-Value
Odds Ratio
Age
60-65 66-75 76-91
0.713 0.457 _
0.502 0.771 _
0.156 0.553 _
2.040 1.579 1
0.762 0.349 _
5.462 7.151 _
Sex
Female Male
0.530 _
0.546 _
0.332 _
1.699 1
0.583 _
4.951 _
Education
Illiterate Less than 6 years 6-12 years University degree
0.034 0.294 0.227 _
1.241 1.221 1.355 _
0.978 0.810 0.867 _
1.035 1.342 1.254 1
0.091 0.122 0.088 _
11.785 14.696 17.857 _
Housing
Tenant Other Owner
-1.937 -0.596 _
1.152 0.876 _
0.093 0.496 _
0.144 0.551 1
0.015 0.099 _
1.378 3.069 _
Job
Unemployed Employed
-0.828 _
1.021 _
0.417 _
0.437 1
0.059 _
3.232 _
Marital status
Married Other Single
-2.270 -2.115 _
1.780 1.715 _
0.202 0.218 _
0.103 0.121 1
0.003 0.004 _
3.383 3.480 _
0.858 _ -0.022 _
0.390 _ 0.905 _
0.028 _ 0.259 _
2.359 1 0.360 1
1.099 _ 0.061 _
5.064 _ 2.119 _
Income Insurance coverage Low High No Yes
interactions (p=0.009); and the number of drugs used inappropriately (p
