Epidemiology of Medication Use among the Elderly in an Urban Area of Northeastern Brazil

OBJECTIVE: To analyze medication use and associated factors among the elderly. METHODS: A population-based cross-sectional study was carried out with a sample of 400 elderly people aged over 60 living in the urban area covered by the Family Health Strategy program in Recife, Northeastern Brazil in 2009. Individuals were selected by systematic random sampling and household data were collected. Demographic, socioeconomic , lifestyle factors including nutrition practices and health variables were evaluated. Medication use was the independent variable. Univariate and multivariate statistical analysis were performed. RESULTS: The prevalence of medication use was 85.5%. Polypharmacy (> 5 drugs) occurred in 11% of cases. Of the 951 drugs reported, 98.2% were prescribed by doctors and 21.6% were considered unsafe for the elderly. The most commonly prescribed groups were: cardiovascular drugs (42.9%), central nervous system agents (20.2%) and drugs with an effect on the digestive tract and metabolism (17.3%). The use of polypharmacy was associated with education (p = 0.008), self-reported health (p = 0.012), self-reported chronic disease (p = 0.000) and the number of doctor appointments per year (0.000). CONCLUSIONS: The results of this study indicate a high proportion of medication use among the elderly, including of those considered unsuitable, and inequality among groups of elderly individuals regarding the use ofmedication, when education, number of doctor appointments and self-reported health are considered. 2 Medication use in the elderly Neves SJF et al Changes in quality of life, health care, patterns of consumption and behavior linked to fertility and mortality in the last century have led to an increase in longevity. Ageing populations have become a global pehnomenon. In Brazil, the population structure is considered aged, as the elderly make up 10.7% of the population (around 19 million people). a The ageing process leads to a progressive reduction in the organism's active tissue, a loss of functional capacity and signifi cant changes in metabolic functions. 17 Consequently, there is increased incidence of chronic disease, hospital admissions and medication use. High levels of medication use by the elderly population, in Brazil and worldwide, has been described. Biologically, the elderly have less capacity to meta-bolize medication, they suffer adverse effects more frequently and effi cacy of the treatment is reduced. This is due to a combination of factors: higher prevalence of chronic illness, polypharmacy and, often, malnutrition. There is no consolidated definition of the term polypharmacy. Bushardt et al, 3 in a revision of the …

Changes in quality of life, health care, patterns of consumption and behavior linked to fertility and mortality in the last century have led to an increase in longevity.Ageing populations have become a global pehnomenon. 18,22,25In Brazil, the population structure is considered aged, as the elderly make up 10.7% of the population (around 19 million people).a The ageing process leads to a progressive reduction in the organism's active tissue, a loss of functional capacity and signifi cant changes in metabolic functions. 17b High levels of medication use by the elderly population, in Brazil and worldwide, has been described. 7,9,15,16,20iologically, the elderly have less capacity to metabolize medication, they suffer adverse effects more frequently and effi cacy of the treatment is reduced.This is due to a combination of factors: higher prevalence of chronic illness, polypharmacy and, often, malnutrition. 4,10,21ere is no consolidated definition of the term polypharmacy.Bushardt et al, 3 in a revision of the literature, identifi ed a number of concepts; among the most commonly found were "taking medication inappropriate to the diagnosis", "taking multiple medications", "duplicating drugs and/or taking potentially inappropriate medication".In this study, polypharmacy is defi ned as taking fi ve or more medications simultaneously. 12lypharmacy linked to physiological and clinical conditions which are specifi c to the elderly makes taking medication a cause of concern for the health care sector. 8,9,21,26It is important to understand this population's patterns of medication use in order to establish rational use, improve quality of life and maintain functional capacity.
This study aimed to analyze medication use and associated factors among the elderly.

METHODS
A cross-sectional study with 432 elderly individuals aged 60 and over, living in the community, of both sexes, capable of communication, responsible for their own medication and living in areas covered by the Family Health Care Strategy (ESF) in Recife, PE, Northeastern Brazil between April and September 2009.The research took place in Health Care district IV, located in the west of Recife, micro region 4.2, with a registered population of 2,796 elderly individuals in the ESF.c Sample size was determined based on an 80% prevalence of "taking medication", with a variability of 5%, resulting in 246 individuals.In order to correct for potential losses and allow greater breakdown of independent variables, 432 elderly individuals were contacted, of which 27 refused to participate in the study (refusal rate of 6.2%) and fi ve were withdrawn as, after three attempts, they could not be contacted, giving a sample of 400 eligible elderly individuals.This tracking enabled the prevalence of medication use in the population in question to be estimated, as well as characterizing this use and associated factors.Individuals were recruited using probabilistic allocation, based on a list of names and addresses of elderly individuals registered with the ESF.Names were drawn to select the individual when there were two or more individuals fulfi lling the criteria in the same residence.Data, including a questionnaire and height and weight measurements, was collected by two interviewers in the individuals' homes.
Participants were questioned about what medication they had taken on the day of the interview.The interviewers asked to see prescriptions and packets to ensure the names of the medications were recorded accurately and to avoid any medications being forgotten and thus omitted.The name and dose of the medication was used in the identifi cation.The active ingredients were classifi ed according to the Anatomical-Therapeutical-Chemical Classifi cation System (ATC).d The dependent variable was the number of medications taken on the day of the interview.This variable was categorized into two groups: taking fewer than fi ve medications; taking fi ve or more medications (classifi ed as polypharmacy). 12dications taken were classified as: prescribed (prescribed by a doctor, including repeat prescriptions authorized by a nurse); non-prescribed (taken on the individual's own initiative, or recommended by a third party, not of the medical profession); medications unsafe for use by the elderly (should be avoided irrespective of INTRODUCTION dose, duration of treatment or clinical circumstances, either because ineffective or because they present an unacceptably high risk for the elderly -risk exceeds benefi t -according to the Beers-Fick criteria). 6dependent variables included: socio-demographic characteristics (age, sex, schooling -in completed years, marital status, family arrangements and monthly income -in national minimum wage at time of writing); health (perception of own health; self-reported chronic illness); 11 health related behavior (doing physical activity); use of health care services (number of doctor's appointments in the last 12 months); nutritional state (Body Mass Index, classifi ed according to the cutoff points adopted by Lipschitz). 13ight and weight were measured according to recommendations by Lohman et al. 14 Weight was measured using a Marte scale, capacity of 150 kg, and height was measured using an Alturaexata portable stadiometer, with a maximum extension of 2.00 m, divided into centimeters.
Data were entered twice and checked using the "validate" module of the EpiInfo program, version 6.04 (WHO/CDC; Atlanta, GE, USA), in order to identify any inconsistencies.Statistical Package for Social Sciences (SPSS) for Windows software, version 12.0 was used to analyze the data.
Uni-variate analysis was conducted in order to verify the link between characteristics of the study population and polypharmacy.The following tests were used: Kolmogorov-Sminorv to estimate the normal range for continuous variables, Pearson's Chi-squared test for categorical variables; and the Kruskal-Walis H test for the continuous variables.Multiple analysis (logistical regression) was used to identify factors associated with polypharmacy.The Wald test for trend and heterogeneity was used in the unadjusted analysis.Variables which had significance ≤ 0.20 in the unadjusted uni-variate analysis were considered when building the model.The stepwise method (variables selected in steps) with retrograde elimination was used in the adjusted analysis.Variable linked to p < 0.05 remained in the fi nal model.The level of signifi cance used was defi ned as α = 0.05 bi-caudal.
The research protocol was approved by the research ethics committee of the Universidade Federal de Pernambuco (Process No. 0388.0.172.000-08 and Protocol No. 396/08).Participants signed a consent form.
Low levels of schooling were common, and the sample was predominantly illiterate (36.6%).The highest percentage of the elderly individuals had a monthly income of two minimum wages (78.1%); 63.2% lived alone and the median number of individuals per family was 3.0 (2.00:5.00).
There were 83.5% of the elderly individuals who reported making use of the Brazilian Unifi ed Health System (SUS); of these, 64.5% had used the ESF exclusively in the last 12 months.The median number of appointments was 4 (2.00: 6.00) for the same period.Hospitalization in the four months preceding the interview was reported by 24.5% of the elderly individuals (Table 1).
The prevalence of taking medication was 85.5%.Of these, the proportion of elderly individuals who took at least one prescribed medication was 98.2%, and the proportion taking at least one non-prescribed medication was 6.7%.Polypharmacy occurred in 11.0% of cases.The use of at least one medication judged unsafe for use by the elderly occurred in 21.6% of cases.The most commonly used were: diazepan, digoxin, and mineral oil.
At the time of the interview, 951 medications, made up of 739 different drugs were being taken.The mean number of medications being taken by the elderly individuals at the time of the interview was 2.4 (SD = 1.78) and the median was 2.0 (1.00: 3.00), varying between zero and ten medications.The median was 2.0 (1.00: 3.00) in prescribed medication, varying between zero and ten, and 0 (0.00: 0.00), varying between 0 and 3 medications for non-prescribed medications.Men had a median of 2.0 (0.75: 3.00), whereas for women it was 2.0 (1.00: 3.00) (p = 0.001).
The medications most commonly taken by the elderly individuals were cardiovascular drugs, followed by medicine used for the central nervous system (Table 2).
Of the most commonly taken medications, hydrochlorothiazide 25 mg, Captopril 25 mg and AAS 100 mg stand out (Table 3).
Polypharmacy proved to be linked to lower levels of schooling (p = 0.008), to poor self-reported health (p = 0.012), to two or more self-reported chronic diseases (p = 0.000) and to the number of doctor's appointments per year (0.000).The other variables were not linked to polypharmacy (Table 4).Three variables remained in the model after adjustment for potential risk factors for polypharmacy, showing an independent association with polypharmacy.Having between one and four years of schooling was the factor most strongly linked to polypharmacy (OR = 5.276 95%CI 2.142;12.989)(p = 0.000).

DISCUSSION
The high prevalence of medication use among the elderly individuals (85.5%) concords with the literature and is within the expected range, with values close to those found in Fortaleza, CE, Northeastern Brazil (80.3%), 6 the South Region (82.0%) 7 and Belo Horizonte, MG, Southeastern Brazil (86.2% 15 and 89.6%). 20e mean number of medications being taken at the time of the interview was lower than that observed in Rio de Janeiro, RJ, 16 in the South Region 7 and in Belo Horizonte, MG. 15,20 However, it was higher than that found in Fortaleza, 5 the population which is closest to the population of this study, which suggests regional differences in the intensity of medication use.
Sex, age and access to health care services are highlighted as predictive factors for medication use among the elderly. 9,21,22In this study, women tended to take more medications than men, although the difference in prevalence of polypharmacy was not statistically signifi cant between the sexes.In general, women made more use of health care services and were better at reporting their conditions; 1 thus, they are more likely to take medication.This trend of taking larger quantities of medications is consistent with the results of other epidemiological investigations. 5,7,15,20However, this difference was not refl ected in the occurrence of polypharmacy.Likewise, there was no link between polypharmacy and age group.Elderly individuals receiving care from an ESF team makes access to medications linked to prescriptions based on standardized lists free, which results in smaller quantities of medications being taken as well as encouraging more rational use.This may mean that polypharmacy in all age groups and both sexes is reduced.The fi ndings here do not agree with those of studies conducted in Belo Horizonte. 15,20owever, these studies were carried out with elderly individuals in the general population, irrespective of registration with the ESF, suggesting that health teams monitoring the elderly tends to reduce polypharmacy in all age groups.
The most frequently used drugs were similar to those found in other research. 5,7,15Cardiovascular medication were the most commonly used, which agrees with the national epidemiological profi le, e and hypertension was the most commonly self-reported chronic condition.
A signifi cant proportion of the elderly individuals were taking prescribed medications and this reached a higher proportion than that found in research on elderly individuals in the general population. 5,6,15On the other hand, the proportion of elderly individuals using non-prescribed medication was lower than that reported in the literature. 5,6,15,16This may be linked to the fact that this study dealt with a population dependent on the SUS and therefore needing a prescription for any kind of medication.The frequency with which medications judged unsafe for use by the elderly 3 were found was greater than that found in Rio de Janeiro 16 and in Fortaleza, 5 but the values were lower than those obtained for elderly individuals not dependent on the SUS. 19Even so, it was observed that 2.2% of the elderly individuals took diazepam.This was a higher prevalence than that found by Bushardt et al, 3 although lower than that found in Fortaleza. 5According to the Beers-Fick 6 criteria and a panel of specialists, diazepam is judged to be not recommendable for use by the elderly, irrespective of diagnosis and clinical condition, as it has a long half-life, producing prolonged sedation and increased risk of falls and fractures.
The current practice of standardization of medicines in the SUS and dispensing drugs linked to prescription may be related to the increased use of prescription medication and the reduction in prescription medication that are unsafe for the elderly and the use of non-prescribed medications.The current ESF practice seems to have e Ministério da Saúde.Saúde Brasil 2009: uma análise da situação de saúde e da agenda nacional e internacional de prioridades em saúde.Brasília (DF): 2010.9.positive effect, given the low prevalence of elderly individuals using unsafe and non-prescribed medication, reducing the risk of iatrogenic effects, adverse reactions and drug interactions. 4,10 the socio-economic variables, only the level of schooling was directly linked to taking medication.Polypharmacy was more prevalent among elderly individuals with lower levels of schooling.Low levels of schooling is a predictive factor for the increase in chronic morbidities, 2 which may, in turn, be linked to increased medication use.
Frequency of doctor's appointments was higher among elderly individuals who practiced polypharmacy, reinforcing the importance of qualifying clinical protocols and the continuous professional development of health care professionals who prescribe medications, as primary care services were reported to be the main type of access to the health care system.Lebrão & Laurenti, 11 researching elderly individuals in the community, irrespective of access to the ESF, found a higher percentage of individuals seeking hospital care.This difference in access to the system shows the importance of establishing the ESF in order to facilitate access to health care services for the elderly, to educate and encourage continuous monitoring.
Negative perception of own health was linked to polypharmacy, as seen in other epidemiological studies. 11,15,20There was a high prevalence of negative self-evaluated health.In contrast to this study, in the studies by Lebrão & Laurenti 11 and Paskulin & Vianna the elderly individuals tended to rate their own health positively. 18However, such studies were carried out in the Southeast and South of the country, and regional differences may have infl uenced this result.More studies in the Northeast are necessary to confi rm this trend.
The prevalence of chronic illness was close to that observed by other authors. 11,18High blood pressure was the most commonly reported disease, as in the Brazilian epidemiological profile and as seen in other studies. 5,7,11,18The VI Brazilian Hypertension Guidelines 23 highlight how.In spite of the high prevalence of hypertension, there are low levels of control.
It is considered one of the principal modifi able risk factors for mortality related to cardiovascular disease, which in turn has been one of the main causes of death in Brazil over the last few years.f Taking medication, albeit necessary, constitutes a risk for elderly individuals, especially polypharmacy or taking medications judged unsafe. 6lypharmacy is linked to worsening physical and mental health among the elderly. 10Access to medication should be viewed as an achievement by the SUS, as prescription should be based on elderly patients' overall health conditions and not solely on the treatment for a specific disease, adopting standards that minimize polypharmacy and use of unsafe medications.
The low percentage of losses is one of the positive aspects of this study, as it helps to reduce the possibility of selection bias and contributes to the study's internal validity.Limitations inherent to the crosssectional design stand out: diffi culty identifying the chronological relationship of the events, reduced by using a previously validated questionnaire; data on current exposure do not represent data of past exposure, minimized for some variables in which the elderly individual was asked about the chronic nature of their condition; and interpretation complicated by the presence of confounding variables, outlined in the statistical analysis, adjusted to minimize the infl uence of these variables.
As there are multiple, unknown risk factors linked to polypharmacy, using only the usual indicators may not be the most appropriate way of investigating causality of polypharmacy in the context in question.
It is diffi cult to determine the isolation from the environment, personality and age (memory bias), as it is a phenomenon which includes a complex network of causal determinants.Other risk factors which were not analyzed but should have been, in this investigation, may play a crucial role in the prevalence of medication use.Investigating psychological stress and of the use of specifi c medications is worth investigating, together with physiological changes due to senescence.
The data in this study indicate a high percentage of medication use among the elderly, including medications judged unsafe, and inequality in medicine use between groups of elderly individuals when schooling, doctor's appointments and self-reported health are taken into account.The proportion of elderly individuals taking prescribed medications was higher than that found in other studies of the elderly with populations not registered with the ESF.The fact that around 11% of the population practice polypharmacy, linked to the ageing population in Brazil, is a cause for concern, considering the potential risks of medication use for the elderly.Broad discussion on the need to adopt measures for encouraging the rational use of medication in this segment of the population is needed, as is the continuous professional development of health care professional prescribing medications, qualifying the health care systems in order to provide permanent education and appropriate information at the correct moment, the adoption of measures in the area of pharmaceutical care, drawing up and establishing lists of medications and clinical protocols appropriate to the needs of the elderly population.The high prevalence of taking medication, mainly for CVD, shows the need to adopt measures to encourage physical activity and healthy eating.Moreover, it is essential that continual guidance is given to the elderly and their carers as to the risks of taking medications and that measures are adopted in the area of pharmaceutical care.

Table 1 .
Demographic, socio-economic, lifestyle and health characteristics of elderly individuals living in the community.Recife, PE, Northeastern Brazil, 2009.
MV: minimum wage; BMI: body mass index the 60 to 69 years old age group was the most frequent (51.3%) (Table

Table 3 .
Medications taken by elderly individuals in the community.Recife, PE, Northeastern Brazil, 2009.

Table 2 .
Medications taken by the elderly individuals living in the community according to therapeutic group and pharmacological group.Recife, PE, Northeastern Brazil, 2009.(N = 951)

Table 4 .
Link between taking medication, sociodemograohic characteristics, health related aspects, and use of health care services among elderly individuals in the community.Recife, PE, Northeastern Brazil, 2009.
MW: minimum wage; BMI: body mass index a Chi-squared

Table 5 .
Final model of the multivariate analysis for polypharmacy among elderly individuals living in the community.Recife, PE, Northeastern Brazil, 2009.