Prevalence of drug use among the elderly in a local institutional home

X L Sun 孫曉玲, J A Dickinson 狄堅信

HK Pract 2003;25:243-248

Summary

Objective: To review drug use patterns and explore the implications, thus to identify potential improvements of medical care for the elderly in a nursing home (NH).

Design: Quantitative study using cross-sectional clinical data and making descriptive analysis.

Subjects: 195 residents in a local NH.

Main outcome measures: The residents' demographic characteristics and their drug use patterns were shown.

Results: Polypharmacy was a common phenomenon (42.5%) in the institutionalised long-stay setting. Use of cardiovascular (61.0%) and psychotropic (52.3%) agents were the most common; followed by gastro-intestinal (39.5%) agents, laxatives (36.9%), analgesic/anti-inflammatory (28.2%) agents, agents for metabolism (25.6%), vitamins/minerals (25.1%), agents for ENT/skin (23.6%) and respiratory agents (23.1%).

Conclusion: The study found that polypharmacy was prevalent regardless of the gender or age of the population. Cardiovascular and psychotropic agents were the most commonly used, followed by gastro-intestinal agents, laxatives, analgesics/anti-inflammatory agents, agents for metabolism, vitamins/minerals, agents for ENT/skin and respiratory agents. Further studies based on long-term observation are worthwhile in order to analyse the determinants of drug use and the circumstances in which the elderly are at risk of polypharmacy. There is a need to conduct research on inappropriate drug use as part of total quality care. This will improve the care of the elderly as well as reduce the medical costs.

Keywords: Polypharmacy, nursing home, inappropriate prescription and iatrogenic complication.

摘要

目的： 研究護養院老人用藥的情況及形式，探討改善醫療服務的可能性。

設計： 採用階段性臨床資料進行定性和描述性分析。

研究對象： 一間擁有200張床的護養院的195位院友。

主要測量內容： 院友的基本特徵，包括：年齡、性別、自我照顧能力、活動能力、認知功能、疾病的種類分佈及他們的藥物使用狀況。

結果： 195例院友中，使用過多藥物（即服用五種或以上藥物）的情況，非常普遍（42.5%）。其中服用心血管和抗精神病藥物的比例分別為： 61%和52.3%。其他依次為：消化系統藥物佔39.5%，輕瀉藥36.9%，止痛消炎藥28.2%，內分泌藥25.6%，維他命或礦物質 25.1%，耳鼻喉或皮膚科藥23.6%及呼吸系統藥佔23.1%。

結論： 研究發現，護養院內不同性別和年齡組（<80歲，80歲）中，過多使用藥物都普遍存在。為了提供高素質的醫療服務，減輕醫療成本，減少不適當用藥，需要針對長期慢性病患者的診斷和使用的藥物進 行考查和分析。

詞彙： 過多藥物，護養院，不適當處方和醫源性併發症。

Introduction

Elderly people are frequently prescribed drugs due to a number of chronic illnesses they have, and hence the likelihood of polypharmacy among them is high.^1,2

In Hong Kong, one study on drug use revealed that about 55 percent of the respondents among the community-dwelling elderly had taken medications in the previous month and the average number of drugs was 2.7.³ Another study showed that 70% of respondents were taking drugs, 20% of whom were taking 5 or more.⁴ Not unexpectedly, the number of drugs used is higher among the institutionalised elderly than the non-institutionalised.^5-7

The number of inappropriate medications correlates to the number of medications prescribed.^8-10 Not surprisingly, prescription of inappropriate medication is more common among institutionalised elderly persons, so institutionalised elderly are at high-risk of exposure to iatrogenic complications.^7,11-20 This also increases the costs of medical care. Studies have shown almost 25% of older outpatients received inappropriate medications, while 50% of inpatients have had inappropriate medication(s).¹⁶ Adverse drug reactions are responsible for about 20% of hospital admissions of the elderly.^1,4,5,15,16

Knowledge about polypharmacy and its implications in local NHs is limited. To study the prevalence of drug use and explore its implications on the care of the elderly in NH, this paper first describes the profile of drug use and then discusses some important health care concerns in community-based elderly care.

Methods

Operational definitions

1. Michocki et al defined polypharmacy as when a patient receives too many drugs, drugs for too long a time, or drugs in excessive doses.⁸
2. Polypharmacy also refers to use of five or more concomitant drugs.⁵
3. Inappropriate medication therapy is defined as a therapy whose adverse risk(s) exceeds the health benefits.¹⁰
4. In this study, polypharmacy was defined by use of 5 or more drugs, including the oral, topical, injection and nebuliser routes and pro re nata (p.r.n.) medications.

Characteristics of the residents in the NH

The NH in this study belongs to a Non-Government Organisation and has 200 beds. The total number of full-time staff was about 130, including 12 professionals (one registered social worker, eight registered nurses, one physiotherapist, one occupational therapist and one doctor). The residents were referred by the Community Geriatrics Assessment Team (CGAT) and had various chronic illnesses. They live permanently in the NH. Their demographic characteristics with their clinical conditions are shown in Table 1. There were 195 residents: 134 were female (68.7%) and 61 were male (31.3%). The mean age was 81.35 years (SD=8.28).

Table 1: Characteristics of the residents

Number   Percentage Sex           Female   134   68.7   Male   61   31.3             Age           65-74   48   24.6   75 147 75.4                     Activities of daily living (BI)           Severe to totally dependent (<60/100)   153   78.5   Moderately dependent (61-90/100)   40   20.5   Slightly dependent (>91/100)   2   1.0             Mobility (EMS)           Major assistance (<10)   163   83.6   Minor assistance (10-13)   19   9.7   Independent (14-20)   13   6.7             Mental status (MMSE)           Moderate to severe impairment (<10/30)   48   24.6   Mild impairment (<20/30)   75   38.5   Normal   72   36.9             BI = Barthel index EMS = Elderly morbility scale MMSE = Mini mental state examination

The over 75 years old made up the majority (75.4%) in the NH. Their functional status was poor, 78.5% of them ranging from severely incapacitated to being totally dependent. More than 83.6% were in need of some assistance to move about. There were more residents with impaired cognition (63.1%). The top ten-diseases profile is presented in Table 2. Ten percent of patients attended more than 5 different specialist clinics and 47% more than three. They attended their specialist follow up clinics once every four to 12 weeks.

Drug use

The drug-use data were obtained from the population's medication records during the month of June in year 2001. All prescribed drugs including those by the oral, topical, injection and nebuliser routes and p.r.n. medications were recorded. The nine chapter-headings in MIMS²¹ were used to categorise the drugs, namely: cardiovascular, psychotropic, gastro-intestinal, laxatives, respiratory, metabolism, analgesic/anti-inflammatory, vitamins/minerals and ENT/skin agents. The collected data were statistically analysed by the Statistic Package for Social Sciences.

Analysis and results

The total number of drugs prescribed was 813, with a mean of 4.17 (SD=2.31) drugs per patient shown in Figure 1. Only 4 (2.1%) residents did not use any medication. Out of 195 residents, 108 (55.4%) were prescribed less than 5 drug(s); while 5 or more medications were prescribed to 83 (42.5%) residents. Thus, by definition, polypharmacy occurred in 42.5% of all residents. Table 3 shows there was no significant difference in the mean drug-use by either gender (p = 0.992) or age group (<80 vs 80; p = 0.983). The mean number of drugs used by the females was 4.1 (SD=2.38) and the males was 4.2 (SD=2.17); by the <80 years old was 4.4 (SD=2.20) and the 80 age group was 4.1 (SD=2.40).

Figure 1: Distribution of medication use among the NH residents

Table 3: Prevalence of medication use by gender and age

No drug used   <5 drugs   5 drugs   Mean   SD   P-value       No. (%)   No. (%)   No. (%)           (t-test) Gender                           Female (134)   3 (2)   75 (56)   56 (42)   4.1   2.38   .992   Male (61)   1 (2)   33 (54)   27 (44)   4.2   2.17                                 Age                           <80 years (73)   1 (1)   37 (51)   35 (48)   4.4   2.2   .983   80 years (122)   3 (3)   71 (58)   48 (39)   4.1   2.4

The distribution and usage of the nine drug categories prescribed in the NH are shown in Table 4, as follows: cardiovascular (61.0%), psychotropic (52.3%), gastro-intestinal (39.5%), laxative (36.9%), analgesic/anti-inflammatory (28.2%), metabolic (25.6%), vitamins/minerals (25.1%), ENT/skin (23.6%) and respiratory (23.1%) agents.

Discussion

In Hong Kong, there are about 32,000 elderly persons living in residential places belonging to Non-Government Organisations. There is an even higher number living in private residential homes. The majority of them have chronic illnesses.²² The population in this setting is relatively homogenous in terms of the severity of their medical conditions. This NH has identical admission criteria as other NHs, since the CGAT acts as the gatekeeper to NH admissions. The findings in this study can be quite representative of all other NHs in Hong Kong.

This study shows that polypharmacy in the NH is prevalent and does not vary amongst the gender and the age group. Compared with previous studies based on community-living older persons in Hong Kong, the number of prescribed medications in this study is higher (4.17 vs 2.4).³ However, the mean number (4.17) is similar to a German study (4.3).⁵ and that in a medical/geriatric ward of a local hospital (4.65).⁹

The reasons for polypharmacy among the elderly are complex: multiple chronic medical problems, vague symptoms, patients' and caregivers' pressure to prescribe, use of additional medications to treat drug-related complaints, multiple attending physicians, follow-up by different specialists, lack of co-ordination of total care, size of NH and type of nursing staff all have been implicated as major contributing factors.^5,20,23-29

Cardiovascular and psychotropic agents

As the Hong Kong population ages so the disease pattern changes and prevalence of chronic disease increases.³⁰ In this study, the top five commonly diagnosed diseases among the elderly are noted to be dementia, hypertension, cerebrovascular accident, heart disease and fractures. Not surprisingly, cardiovascular and psychotropic medicines were among the most commonly prescribed drugs accounting for 61.5% and 52.3% respectively.

In Denmark, Nygaard found among 117 permanent NH residents, 75% used cardiovascular agents, and 66.7% used psychotropic drugs.³¹ In Sydney, Draper et al found that psychotropics were prescribed for 51.1% of residents.³² These findings may reflect the high prevalence of cardiovascular disease and cognitive impairment among patients in NH. However, there are remarkable variations in psychotropic drug use in different NHs with significant variability in treatment cultures.²⁷ There is epidemiologic evidence of misuse of psychotropic and cardiovascular agents in NH; these two kinds of drugs are regarded as the most misused classes in the geriatric population.^1,25

In a very busy clinic, it is always easier for a doctor to continue and prescribe the same drug at every treatment visit instead of considering reducing and rationalising the drug used during the follow up. It is essential to critically re-evaluate current diagnosis and management of a patient with cardiovascular disease.³³

NH staff are known to mould patients into their institutional routines. The role of psychotropic drugs in the management of the elderly patients with chronic dementing illness is currently unclear.²⁵ Staff perceptions of psychiatric morbidities and their norms as well as the treatment culture of NHs (nurses' beliefs, philosophies of care and their interactions with psychiatrists and mental health workers) have a great impact on the prescription of psychotropic drugs compared to what is the normal practice.^25-29 Larson's studies have documented that psychotropic drugs can contribute to global cognitive impairment among older persons.³⁴ It has been shown that residents taking anti-psychotic drugs had significantly more delusions, hallucinations, psychomotor disturbances and aggressiveness. This suggests that there is a role for a non-pharmacological approach, illustrating the need for more research into techniques for patient management in NHs which rely less on drugs. Many authorities now recommend that, among the institutionalised elderly, anti-psychotic drugs should be reserved only for the treatment of acute behavioural disorders, and their routine and long-term use is to be discouraged, even for those with known mental illness.²⁵

Gastro-instestinal agents

Chan et al found that gastro-intestinal drugs are the most frequently misused in Hong Kong.⁹ The H₂-receptor antagonists and other antacids are routinely used in asymptomatic patients who are on NSAID and aspirin treatments. Patients and health care workers request these drugs even for asymptomatic patients believing that these drugs can prevent and treat gastro-intestinal bleeding.³⁵ This concomitant therapy has not shown significant benefit in preventing gastric ulcers in patients who have osteoarthritis and are receiving NSAID therapy. A recent prospective study found that asymptomatic patients with rheumatoid arthritis who are taking H₂-receptor antagonists had a significantly higher risk of gastro-intestinal complications than those not taking these drugs. The explanation for this interesting observation is unknown.^35,36 Although H₂-receptor antagonist is effective in reducing NSAID-related dyspepsia, the routine use in asymptomatic patients taking NSAID cannot be recommended.³⁵ Misoprostol, however, can prevent NSAID associated ulcers, but the risks and costs of adding another drug should be borne in mind.¹

Laxatives

Constipation is a common complaint in the elderly. A Hong Kong study revealed that laxatives were being prescribed to three-quarters of the elderly population in long-term care facilities.³⁷ Only 36.9% of the population in our NH was using laxatives. The low rate of laxative usage was because we were applying a non-pharmacological method in managing our elderly residents and we found this to be effective. We frequently reviewed our residents case by case. Complete cessation of use of oral laxatives may not be successfully achieved. However, the aim should be to reduce these agents and they should not routinely be given without clinical examination. For residents with chronic constipation, bowel dilatation (idiopathic megacolon) is common. The colon should be emptied regularly and enemas or suppositories may be needed sometimes based on the clinical condition. Regular physical examination including per rectum is important; otherwise constipation, leaking stool and faecal incontinence and painless progressive abdominal distension will be missed and intestinal obstruction may occur.³⁷

Conclusion

The study found that polypharmacy is a common phenomenon in NHs and does not show any difference between the genders and different age groups. Cardiovascular and psychotropic agents are the most commonly used, followed by gastro-intestinal agents, laxatives and the rest. Further studies are worthwhile to analyse the determinants of drug use and the circumstances in which old people are at risk of polypharmacy. There is a need to find ways to reduce inappropriate drug use as part of the total quality care of the elderly. This will also reduce medical care costs. Since collecting the data in this study and searching through the literatures, the first author has become actively involved in organising and reviewing otherwise unco-ordinated drug treatment regimes. This important role for a family physician is made difficult by the number of specialists the residents attend in order to obtain treatment, and a lack of co-ordination and failure to communicate among caregivers which results in duplicated and conflicting drugs being given to our elderly patients.

Acknowledgement

We would like to acknowledge our thanks to our reviewers for their constructive comments and to Dr Ho Kin Sang, Consultant of Department of Health for his suggestions. Our special thanks go to Dr Shi Xinping, Associate Professor, Department of Finance and Decision Sciences, Hong Kong Baptist University, for his help with statistics and scrutiny of this manuscript.

Key messages

1. Polypharmacy is a common phenomenon among the institutionalised elderly.
2. Cardiovascular and psychotropic agents are the most frequently used in the population.
3. A community-based doctor should regularly review patient's current diagnoses and medications acting as a pivot communicating professional with other relevant parties.
4. Involvement of the institution's management by providing certain facilities, maintaining a good environment, adopting a professional consultation culture and educating staff can reduce polypharmacy.