Physical Activity and Environment Perception among Older Adults: a Population Study in Florianópolis, Brazil

OBJECTIVE: To estimate the prevalence of the practice of leisure-time physical activity in older adults and to analyze its association with environment perception. METHODS: Cross-sectional population study conducted from September 2009 to June 2010 with 1.656 individuals aged 60 years or older, living in the urban zone of the city of Florianópolis, Southern Brazil. Leisure-time physical activity was measured using the long version of the International Physical Activity Questionnaire. Environment perception variables were measured by means of a modifi ed version of the Neighborhood Environment Walkability Scale. Crude and adjusted analyzes were carried out using Poisson regression with a 5% signifi cance level. The elderly who reported the existence of sidewalks, bike lanes, pedestrian paths and trails in the neighborhood, as well as those who reported receiving support from friends or neighbors to engage in physical activities, were more active in their leisure time. Concerning the infl uence of the climate, the elderly who reported that it was a barrier were rated as more active. CONCLUSIONS: The practice of leisure-time physical activity still has low prevalence among the elderly population of Florianópolis. Public spaces for the practice of physical activity and encouraging group activities may play a signifi cant role in the promotion of leisure-time physical activity in older adults.


INTRODUCTION
Regular physical activity can reduce the risk factors associated with morbidity and mortality among older adults.Being physically active can alter the course of many diseases that are prevalent in this population. 12,18,22 is known that the practice of physical activity decreases as age advances.Thus, a large part of the elderly population is physically inactive, mainly in leisure time. 1,13,25This population group has more available time due to retirement; therefore, the evaluation of the activities in this domain is an important indicator of their level of physical activity. 25is theme has been approached mainly in investigations of the association between levels of physical activity and sociodemographic 13,25 and health 22 factors, leaving a gap in the understanding of the variables related to the environmental factors that best explain this behavior in the elderly population.
Recent international studies 7,11,15 have shown constant associations between active behavior and environments that facilitate the practice of physical activity.However, only one study was found in Brazil about the theme with the elderly population. 21us, the aim of the present study was to estimate the prevalence of leisure-time physical activity in older adults and to analyze its association with environment perception.

METHODS
This is a cross-sectional, population, household-based study conducted from September 2009 to June 2010, with a sample composed of elderly individuals aged 60 or older living in the urban zone of the city of Florianópolis, Southern Brazil.The study is part of a comprehensive inquiry a into the health conditions of the elderly people of Florianópolis, carried out in 2009/2010, and called EpiFloripa Idoso.
The municipality of Florianópolis, the capital city of the State of Santa Catarina, had in 2009 b an estimated population of 408,163 inhabitants.Of this total, 44,460 belonged to the group with age equal to or above 60 years (10.8% of the overall population).The city presented a municipal human development index of 0.88 in 2000, which placed it in the fourth position among the Brazilian municipalities, and life expectancy at birth was 72.8 years.c Sample size estimation considered population's size of 44,460, estimate of prevalence of leisure-time physical activity of 26%, 6 sampling error of 4 percentage points, a 95% confi dence interval, design effect of 2.6, addition of 20% for possible losses and refusals and 15% to control for confounding factors in association studies.Therefore, a sample of 1,604 individuals was necessary.The total sample of EpiFloripa Idoso was used, calculated in 1,599 individuals.The calculations were made in the program EpiInfo, version 6.04.Two-stage cluster sampling was carried out.In the fi rst stage, the 420 urban census tracts were stratifi ed according to income deciles of the head of household.Eight sectors were drawn in each decile (a total of 80 sectors).The sampling units of the second stage were the households, which were drawn in a systematic way.It was necessary to have a stage to update the number of households inhabited in each sector, as the most recent Census had been performed in 2000.The number of inhabited households varied from 61 to 725.To reduce the coeffi cient of variation among the number of households of the sampling units, the sectors were merged and divided, respecting the correspondent income decile.Thus, the initial coeffi cient of variation was reduced from 52.7% (n = 80 sectors) to 35.2% (n = 83 sectors).It was estimated that 60 households should be visited per sector, in order to fi nd 20 elderly individuals.All the elderly living in the drawn households were considered eligible for the study.
Institutionalized elderly individuals were excluded.Interviews that were not performed after four attempts (including the evening period and weekends) were considered losses, and subjects who did not answer the questionnaire as a personal option were considered refusals.No substitutions were made.
Data was collected by trained interviewers who had completed Secondary Education and were fully available to perform the fi eldwork.A structured questionnaire with pre-coded questions was administered in the form of face-to-face interviews.Personal digital assistants were used, which eliminated the manual keyboarding of the data.Before the data collection, a pre-test with 30 elderly people and a pilot study with approximately 100 elderly people were carried out, in sectors that were not sampled to the research.
Data consistency was verifi ed on a weekly basis and incomplete or inconsistent information was corrected in a second interview whenever necessary.Quality control was performed once a week by means of the administration of a reduced questionnaire, by telephone, to 10% of the interviews (which were randomly selected).
The outcome variable of the present study was level of leisure-time physical activity, measured by the long version of the International Physical Activity Questionnaire (IPAQ), adapted and validated to older adults of Brazil. 5Individuals who practiced 150 minutes per week or more of leisure-time physical activity were classifi ed as physically active in this domain. 18e exploratory variable was environment perception, collected by means of an adapted version 21 of the Neighborhood Environmental Walkability Scale (NEWS), validated to Brazil. 16The alternatives of answers of the adapted version of the NEWS scale were standardized as dichotomic (yes or no).Environment perception was composed of 22 questions related to the individual's perception of the physical and environmental structures close to his/her home, like the presence and quality of the sidewalks; presence of green areas, parks, squares; safety in traffi c and safety in the neighborhood.The opportunities for the practice of physical activities, like the presence of bike lanes, trails, walking paths, sports courts, and the occurrence of sports events and guided walks in the neighborhood, as well as the social support for the practice of physical activities and weather aspects were also obtained.The elderly were instructed to consider "close to their homes" the places at which they were able to arrive in up to 15 minutes on foot.
The control variables that were included were: sex; age group; self-reported skin color, excluding yellow and Indian because of the low number of occurrences (n=12, 0.73%; n = 16, 0.97%); marital status; level of schooling; per capita family income (1 st quartile: ≤ R$ 327.50; 2 nd quartile: between R$ 327.50 and R$ 700.00; 3 rd quartile: between R$ 700.00 and R$1,500.00; and 4 th quartile: > R$ 1,500.00);cognitive status investigated by the Mini-Mental State Examination (MMSE), dichotomized in absence or probable cognitive defi cit, using cut-off points that take the level of schooling into account. 10Functional capacity was determined by the scale of basic and instrumental activities of daily living (ADL) with 15 items, and was categorized into: absence of dependence, mild dependence (incapacity/ diffi culty in performing 1-3 activities) and moderate/ severe dependence (incapacity/diffi culty in four or more activities). 19scriptive analyses were conducted (calculation of means, medians and standard-deviation [SD]) for numeric variables.Calculation of proportions and 95% confi dence intervals (95%CI) were performed for categorical variables.
To verify the association between the outcome and the independent variables of environment perception, Poisson regression was used to estimate prevalence ratios (PR) in the bivariate and multiple analyses, and 95% confi dence interval (95%CI). 4Based on the results of the bivariate regression, all the variables that presented p<0.20 were included in the multiple analysis, and those with p<0.05 and/or that adjusted the model remained in the fi nal model.The Poisson regression model was built with the variables being included in the model one by one, organized from the lowest to the highest p value.
The effect of each variable of environment perception on leisure-time physical activity was adjusted by demographic variables (sex and age group), socioeconomic variables (level of schooling and per capita income) and health status (functional capacity).
All the analyses were conducted in the Stata 9.0 statistical package, using the svy command, which considers the effect of cluster sampling design.
The project was approved by the Ethics Research Committee of Universidade Federal de Santa Catarina under the protocol no.352/2008 on December 23, 2008.The subjects were informed of the study's objectives and were asked to sign a consent document.

RESULTS
In the drawn households, 1,911 eligible elderly individuals were found, of whom 1,705 were interviewed, resulting in a response rate of 89.2% (206 losses and/ or refusals).There were 49 interviews answered by caregivers (for elderly people who were unable to answer due to severe cognitive impairment) and it was decided to exclude them from the analysis, as the study aimed to analyze individual perception in relation to environment factors.The reproducibility of some questions used in the study presented kappa values between 0.3 and 0.9.
The sample included more women than men (63.9%).More than 86% of the elderly reported white skin color and 58.8% stated they were married or living with partners.As for the other demographic characteristics, more than half of the elderly were aged between 60 and 69 years, with variation between 60 and 102 years (mean of 70.4; SD = 7.8 and median of 69 years), approximately 40% stated having low level of schooling (≤ 4 years of schooling), with a mean of 7.6 years of schooling (SD = 5.8).The mean per capita income was R$ 1,348.97(SD = R$ 2,596.28;median of R$ 700.00).In relation to health conditions, the proportion of elderly people with absence of cognitive defi cit was of 53.2%, while 72.3% of the sample's subjects reported some dependence to perform activities of daily living (Table 1).
The prevalence of elderly people who are physically active in leisure time (≥ 150 minutes of leisure-time physical activity per week) was 29.7% (95%CI 26.0;33.Concerning environment perception, the existence of public lighting at night (90.4%), the sensation of safety during the day (77.5%), the existence of sidewalks (77.3%) and of green areas (67%) and the presence of pedestrian tracks (62.4%) were the perceived environment factors most reported by the elderly.Approximately 70% considered the quality of the sidewalks as regular or poor (Table 2).the existence of sidewalks (32.1%), of pedestrian tracks (32%), bike lanes, paths and trails (38.7%) and the absence of steep areas (32.0%) in the neighborhood; it was also more expressive among those who reported being invited by friends or relatives to practice physical activities (34.9% and 35.3%, respectively) and among those who perceived the weather as a barrier to the practice of physical activity (33.3%).
Table 3 presents the crude and adjusted values of the PR of the outcome.In the crude analysis, signifi cantly higher prevalence ratios were observed for elderly individuals who reported the existence of sidewalks  3).

DISCUSSION
The main fi ndings of the present study show important associations between factors of the perceived environment and leisure-time physical activity, independently of the effects of sociodemographic and health variables.The presence of infrastructure in the neighborhood and of social support increased the prevalence of the practice of leisure-time physical activity.Specifi cally, the existence of bike lanes, pedestrian paths or trails next to the households and being invited by friends or neighbors to practice physical activities were positively associated with higher level of physical activity in this domain.In the same way, although the weather was referred as a barrier to the practice of physical activities, the group who reported this situation was more active.
The proportion of elderly individuals who were physically active in leisure time was 29.7%, slightly higher than the one observed in a previous study (25.7%) carried out in the same city, with the same instrument and cut-off point. 6 a study 1 conducted in the Northeast of Brazil, using the short version of the IPAQ, the authors found similar proportions of active elderly people.In the international context, the prevalence of leisure-time physical activity was also similar, 26.9% in the USA and 30.2% in Canada. 2,13However, the utilization of different instruments or criteria to classify the levels of physical activity hinders the comparison between the results of the studies.
An interesting fi nding was the association between existence of sidewalks and practice of leisure-time physical activity, an information that corroborates the results of the existing literature; 11,23 however, this variable lost association in the adjusted analysis.It is possible that the regular or poor quality of the sidewalks in the neighborhoods, reported by approximately 70% of the elderly, has infl uenced this result.The main physical activity reported by this population was walking 13,21 and the places that were frequently chosen for this activity are streets and sidewalks in the surroundings and other public spaces.These fi ndings illustrate the importance of the presence of good quality sidewalks and streets as an environment that facilitates physical activity, as well as the relevance of researching and intervening in the characteristics of urban spaces that favor leisure activities. 9,14,20is research showed that proximity to leisure structures, like bike lanes, pedestrian paths or trails was signifi cantly associated with higher level of leisure-time physical activity, in agreement with the literature. 8,14,15hese urban spaces that offer easy-to-access leisure To be continued structures for the practice of physical activity can also play an important role in the active behavior patterns of the elderly population.
Previous studies 14,15 have identifi ed positive associations between accessibility to leisure structures, like parks, green areas, trails and bike lanes, as well as the quality of these environments in the neighborhood, with active behavior.On the other hand, Booth et al 8 (2000) have confi rmed that the structural limitations in the environment represent obstacles to the practice of physical activity, verifying that older adults who do not live close to leisure structures and spaces tend to be less physically active.
The positive role played by social support in the elderly individuals' practice of physical activity has been observed in other studies. 3,17,21According to these researchers, physical activity becomes more pleasant when one has company, and social support acts intrinsically by means of the incentive and of partnerships between friends and neighbors, and extrinsically, motivating other people to exercise in the neighborhood's environment.
Elderly people in the present study who reported that the weather is a barrier to the practice of physical activities presented higher prevalence of the outcome.It is possible that active elderly individuals expose themselves more frequently to adverse weather conditions and thus reported this fact as a barrier, but not an impediment to the practice of physical Conversely, a recent systematic review of the theme 24 has shown that the weather has a signifi cant impact on this outcome and that bad or extreme weather is recognized as a barrier to the practice of physical activity.
Some methodological limitations of the present study should be considered, mainly the cross-sectional design, which does not allow to defi ne causality relations between leisure-time physical activity and the environment factors.Objective information on the environment was not collected, only information about individual perception.However, this form of questioning has been widely used in studies of this nature with the aim of observing information reported by the elderly based on the perceptions of the environment in which they are inserted.Moreover, the physical activity assessment instrument that was employed (IPAQ) is recommended to individuals aged 18-64 years, although it has been validated and frequently applied to populations of Brazilian elderly people. 1,5,6,21ong the positive points, it is possible to mention that the study was carried out in a large and representative sample of older adults of a Brazilian capital city.Also, it reproduced the population structure of the municipality d according to gender and age group and ensured the extrapolation of the results to the population as a whole.Another positive point was the high return rate in all income strata, which contributed to the study's internal validity, reducing the odds of occurrence of systematic errors.
Ascertaining that adequate environments to the practice of leisure-time physical activity in the neighborhoods contribute to an active behavior represents an important fi nding that may subsidize urban planning and public health policies.These policies include the design of interventions in the construction and maintenance of public leisure spaces, as well as social support, by means of group activities.
In view of the relevance of this theme, it is suggested that longitudinal studies are conducted aiming at a better understanding of the environmental factors, by means of objective information and of elderly people's individual perception, as well as their relation to the practice of physical activity during leisure time and in other contexts.

Table 2
also shows that leisure-time physical activity was more prevalent among the elderly who perceived d Instituto Brasileiro de Geografi a e Estatística.Perfi l dos idosos responsáveis pelos domicílios no Brasil 2000.Rio de Janeiro; 2002.

Table 2 .
Distribution of variables of environment perception and leisure-time physical activity in elderly individuals.Florianópolis, Southern Brazil, 2009-2010.

Tabela 3 .
Crude and adjusted prevalence ratios of the association between leisure-time physical activity and environment perception variables among elderly individuals.Florianópolis, Southern Brazil, 2009-2010.

Table 3
Adjusted by sex, age group, level of schooling, income and functional capacity.
a b Variables included in the multivariable analysis.c Variables that remained in the fi nal model.