Abstract
In old age, declining functional ability increases vulnerability to environmental demands
(Nahemow & Lawton, 1973). As
environmental press increases, individuals may, decrease task demands and minimize losses in
valued activities, modify their behavior or give up or reduce the frequency of doing a task
(Freedman et al., 2016; Nahemow & Lawton, 1973; Skantz et al., 2019)
Walking modifications are typical indicators of functional decline or preclinical disability
(Fried et al., 2000). At the same
time, some modifications may be adaptive and help individuals continue walking by reducing
task demands, whereas other modifications may be maladaptive and lead to task avoidance (Skantz et al., 2019). We categorized
self-reported modifications in walking 2 km distance into adaptive (e.g., reduced pace, using
an aid, and resting in the middle) and maladaptive (reduced frequency or giving up doing the
task). Adaptive walking modifications help to identify persons who strive to continue walking,
whereas maladaptive walking modifications indicate avoidance, that is, having reduced or given
up walking longer distances. In our previous study, the use of walking modifications that we
termed adaptive postponed decline in life-space mobility and helped individuals maintain
greater autonomy in outdoor participation, while the use of maladaptive walking modifications
was associated with restrictions in outdoor mobility at baseline and over time (Skantz et al., 2019)
Based on the ecological model of aging (Nahemow & Lawton, 1973) and the disablement process model (Verbrugge & Jette, 1994), it can be hypothesized that perceptions of the outdoor environment are related to the use of adaptive and maladaptive walking modifications. These models indicate that as personal competencies decline with aging, walking performance can be maintained in three ways: reducing task demands, increasing the person’s capacity, or lowering environmental demands. In reality, assuming that their living environment affords opportunities for doing so, reducing task demands via adaptive walking modifications is most readily available strategy for people facing functional decline.
Specific environmental features can either support or hinder older people’s mobility. For example, depending on individuals’ functional capacity, hills in the nearby environment can facilitate walking for fitness for some and hinder walking for others (Eronen et al., 2014a; Sakari et al., 2017). Previous studies have shown that older people who perceive a higher number of environmental mobility facilitators, such as nature in the nearby environment or peaceful walkways, have higher physical activity levels and a lower risk for developing walking difficulty over time (Eronen et al., 2014a; Keskinen et al., 2018b; Portegijs et al., 2017a). Thus, we expect that for individuals facing functional decline, perceiving facilitators for outdoor mobility may increase their likelihood of using adaptive walking modifications and decrease their likelihood of using maladaptive walking modifications. In contrast, environmental demands that exceed a person’s capacity are risk factors for physical inactivity and the development of functional limitations over time (Keskinen et al., 2018a; Portegijs et al., 2017b; Rantakokko et al., 2011). Previous studies have shown that environmental barriers to outdoor mobility, such as poor street conditions or lack of resting places, are associated with restricted outdoor mobility (Rantakokko et al., 2015; Tsai et al., 2013) and increased the risk for developing walking difficulty over time (Keskinen et al., 2018a; Rantakokko et al., 2016). Thus, we expect that perceiving environmental barriers to outdoor mobility may especially be associated with the use of maladaptive walking modifications and increased risk for adopting maladaptive walking modifications over the follow-up among those not reporting such modifications at the baseline.
The aim of this study was to investigate whether perceived environmental outdoor mobility facilitators and barriers are associated with the use of adaptive and maladaptive walking modifications among community-dwelling older people. In addition, we investigated whether perceived environmental outdoor mobility facilitators and barriers predict the development of adaptive or maladaptive walking modifications over a 2-year follow-up.
Methods
Design and Study Participants
This study includes cross-sectional and longitudinal data drawn from the “Life-Space
Mobility in Old Age” (LISPE) project, a 2-year prospective cohort study conducted between
the years 2012 and 2014. The purpose of the LISPE study was to investigate the
associations of the home and physical environment of older people with their health,
functioning, disability, quality of life, and life-space mobility. A more detailed
description of the LISPE study, including recruitment and nonrespondent analyses, has been
reported previously (Rantanen et al.,
2012)
Measurements
For the sensitivity analyses, participants were categorized based on their self-reported ability to independently walk 2 km (Mänty et al., 2007). Participants were considered unable to walk 2 km independently if they reported needing help or being unable to manage even with help.
Covariates
As covariates, we included variables that are associated with the use of walking
modifications based on previous studies. Age and sex were obtained from national
registers. Years of education, number of chronic conditions, depressive symptoms, lower
extremity function, and ability to walk 2 km were assessed during the home interview.
Statistical Analyses
Baseline characteristics were described using means and standard deviations or percentages. Differences in the prevalence of perceived environmental outdoor mobility facilitators and barriers and in baseline characteristics between participants categorized according to their baseline walking modifications were tested with chi-square tests (χ2) and one-way analysis of variance. A Bonferroni test was used to compare means between participants using adaptive or maladaptive walking modifications. The sum of the environmental facilitators and barriers reported was calculated for each facilitator and barrier domain (nature, infrastructure, and safety) separately and then divided into those reporting 0, 1, and 2 or more facilitators or barriers. Analyses were run separately for each environmental facilitator and barrier domain (reporting 1 or ≥ 2 vs. 0) and for item-specific environmental facilitators for and barriers to outdoor mobility. The associations of perceived environmental outdoor mobility facilitators and barriers with walking modifications were assessed cross sectionally by using multinomial logistic regression analysis. The outcome variable was a nominal scale variable. Those with maladaptive walking modifications were used as a reference group when studying associations between environmental facilitators and categories of walking modifications. This was done to clarify whether the environmental facilitators reported by those using adaptive walking modifications differed from those using maladaptive walking modifications. In the analyses on environmental mobility barriers, those without walking modifications were used as a reference group. The cross-sectional models were first adjusted for age and sex and then, to control for individual differences, for age, sex, years of education, chronic conditions, depressive symptoms, and lower extremity function. Eight participants had missing information for years of education, four participants for depressive symptoms and nine participants for SPPB; these 21 participants were not included in the fully adjusted models.
In the longitudinal setting, logistic regression analyses were used to investigate the
associations between perceived environmental outdoor mobility facilitators and barriers
and the development of adaptive or maladaptive walking modifications. The development of
adaptive walking modifications was studied among those who reported no walking
modifications at baseline and who did not develop maladaptive modifications over the
two-year follow-up period (
Finally, to test the robustness of our findings, we conducted further sensitivity
analyses by excluding all participants unable to walk 2 km independently at baseline. This
eliminated 112 participants from the maladaptive walking modifications category, four
participants from the adaptive walking modifications category and one participant from the
no walking modifications category. The sensitivity analyses were not performed for the
development of adaptive walking modifications since all participants included in the model
constructed from the whole sample were able to walk 2 km independently at baseline. False
discovery rates (adjusted
The results were regarded as statistically significant, if the 95% confidence intervals
did not include one or the
Results
Participant Characteristics
Participant Characteristics and Proportion of Participants
Reporting Outdoor Mobility Facilitators and Barriers in Subgroups by Modifications
in Walking 2 km at Baseline (
Tested with one-way analysis of variance.
Tested with chi-square test.
Prevalence of Perceived Environmental Facilitators for and
Barriers to Outdoor Mobility by Modifications in Walking 2 km at Baseline
(
Cross-Sectional Associations of Environmental Outdoor Mobility Facilitators with Walking Modifications
Cross-Sectional Associations of
Perceived Environmental Facilitators for Outdoor Mobility with Walking Modifications
in Community-Dwelling Older People. Odds are Reported for those with No
Modifications (
Cross-Sectional Associations of Environmental Outdoor Mobility Barriers with Walking Modifications
Cross-Sectional Associations of
Perceived Environmental Barriers to Outdoor Mobility with Walking Modifications in
Community-Dwelling Older People. Odds are Reported for those with Adaptive
Modifications (
Finally, to test the robustness of our findings, we conducted sensitivity analyses by excluding participants who reported being unable to walk 2 km independently at baseline. The results showed that while most of the associations between environmental facilitators and walking modifications disappeared (Supplementary Table 1), no changes were observed in the associations between environmental barriers and walking modifications (Supplementary Table 2).
Longitudinal Associations of Environmental Outdoor Mobility Facilitators and Barriers with Walking Modifications
Perceived Environmental Facilitators for Outdoor Mobility as Predictors of Use of Adaptive or Maladaptive Walking Modifications over 2-Year Follow-Up in Community-Dwelling Older People.
Reference category: no walking modifications.
Reference category: no and adaptive walking modifications.
Perceived Environmental Barriers to Outdoor Mobility as Predictors of Use of Adaptive or Maladaptive Walking Modifications over 2-Year Follow-Up in Community-Dwelling Older People.
Reference category: no walking modifications.
Reference category: no and adaptive walking modifications.
Of the 610 participants who did not report maladaptive walking modifications at baseline,
22.3% (
Discussion
The present findings suggest that perceived environmental features coincide with, rather than consistently preceding, walking modifications. Perceiving environmental facilitators for outdoor mobility was associated with the use of no walking modifications or adaptive walking modifications rather than with the use of maladaptive walking modifications, whereas perceiving environmental barriers to outdoor mobility increased the odds for using both adaptive and maladaptive walking modifications in the age- and sex-adjusted models. There are several plausible reasons for the different associations found between perceived environmental outdoor mobility facilitators and adaptive and maladaptive walking modifications. Perceiving environmental outdoor mobility facilitators may serve as a motivation or enabler for individuals to adopt strategies that allow them to continue rather than reduce or give up walking longer distances, even when experiencing functional decline (Portegijs et al., 2017a). For example, infrastructural mobility facilitators may compensate for the decline in physical capacity and alleviate the strain of walking longer distances by enabling the use of adaptive walking modifications, while the lack of such facilitators may fuel lower frequency of or giving up walking longer distances, that is, maladaptive walking modifications stemming from the absence of perceived opportunities to reduce the task demands of walking longer distances. The use of maladaptive walking modifications may indicate that the task demands exceed personal capacity, potentially leading to reduced striving to continue the activity (Nahemow & Lawton, 1973). Thus, long distances to services can be considered an excessively demanding task demand for older people with poor physical capacity.
The current findings accord with those of previous studies showing that perceiving environmental facilitators is associated with higher physical activity levels (Barnett et al., 2017; Cerin et al., 2017; Keskinen et al., 2019). Further support for environmental mobility facilitators as motivators of outdoor mobility was provided by the present multinomial logistic regression analysis. In the model, those who reported environmental facilitators for outdoor mobility had higher odds for using no or adaptive walking modifications than those using maladaptive walking modifications. The use of adaptive walking modifications helps in maintaining life-space mobility and autonomy in participation in outdoor activities (Skantz et al., 2019). This is essential since higher life-space mobility is associated with better quality of life among older people (Rantakokko et al., 2013).
In the present study, perceiving nature- and infrastructure-related environmental outdoor mobility barriers was associated with a higher likelihood for both adaptive and maladaptive walking modifications in the age- and sex-adjusted models. However, the associations across the individual environmental outdoor mobility barriers were not identical and most were attenuated when health and physical capacity were added into the models. For instance, reporting snow and ice in the winter as a barrier increased the odds for using adaptive, but not maladaptive, walking modifications. Unlike those who have given up or reduced their frequency of walking longer distances, older people with adaptive walking modifications are likely to walk outdoors during wintertime, and thus perceive snow and ice as barriers that can be overcome (Eronen et al., 2014b).
In our prospective analyses, perceived environmental outdoor mobility facilitators did not predict the use of adaptive or maladaptive walking modifications. The sole exception was that reporting a walking trail or skiing track as a facilitator for outdoor mobility protected the individual from developing maladaptive walking modifications over time. Moreover, when health and physical capacity were included in the models, none of the perceived environmental outdoor mobility barriers increased the risk for using maladaptive walking modifications over time. These weak and unsystematic prospective associations indicate that perceptions of environmental characteristics do not necessarily precede the onset of walking modifications. However, this finding seems to be reasonable. Perceiving outdoor mobility facilitators decreases the risk for functional decline over time, while at the same time, perceiving facilitators encourages the use of adaptive rather than maladaptive walking modifications, thereby weakening longitudinal associations.
In the present study, adjusting the models for physical capacity and other health characteristics attenuated most of the associations between the environmental barriers to outdoor mobility and walking modifications. This finding underlines the importance of individual characteristics in person–environment fit models. This was also supported by our sensitivity analyses, which showed that the exclusion of participants who were unable to walk 2 km independently attenuated most of the associations between the environmental facilitators for outdoor mobility and walking modifications. Thus, in line with ecological model of aging (Nahemow & Lawton, 1973), the use of adaptive and maladaptive walking modifications seems to be the result of person–environment interaction. When older people with intermediate physical capacity start to perceive environmental barriers, they are able to overcome them by modifying their walking in an adaptive way and thus continue walking. However, as their physical capacity further declines, environmental press increases and compensation for functional loss via adaptive walking modifications is more difficult. In such a situation, because compensation requires at least some resources (Saajanaho et al., 2016), older people may turn to loss-based selection (Baltes & Baltes, 1990) and use maladaptive walking modifications. Previous studies have shown that multiple factors, such as age, family context, and functional capacity, are associated with the use of compensatory strategies (Gitlin et al., 2017; Hoenig et al., 2006; Lang et al., 2002). Our analyses complement these factors with that of the outdoor environment, which, depending on the individual’s level of physical or psychological functioning, seems to have specific impacts on the use of walking modifications.
The strengths of this study are the large population-based sample, with a 2-year follow-up, and the LISPE study design, which was optimized for the purpose of investigating the associations between environmental factors and outdoor mobility. However, the study has some limitations. First, perceptions of environmental facilitators for and barriers to outdoor mobility are individuals’ subjective feelings about their living environment and are expressed differently in different contexts. For example, our findings concern community-dwelling older adults mainly living in urban or suburban areas and hence might not be applicable to older adults living in rural areas. Second, participants relocating or experiencing changes in their living environment during the follow-up period might have had a minor effect on our longitudinal findings. It seems reasonable to expect that older people who relocate are likely to move from a more to a less challenging environment. If so, this might attenuate the longitudinal results. However, only 31 participants relocated during the follow-up and thus, any such effect is likely to be small. Similarly, it is possible that during the follow-up changes in the built environment, such as changes related to the availability of benches or to improvements or deterioration in sidewalks, or changes in the natural environment may have influenced the adoption of walking modifications. However, such changes in the study area were minor and not likely to have exerted a major impact on the longitudinal findings. Third, based on their SPPB scores, our participants were relatively well-functioning older people. This may have led to underestimation of the use of maladaptive walking modifications in the community-dwelling older population. However, the main purpose was to study the associations between features of the outdoor environment and walking modifications rather than the prevalence of walking modifications. Moreover, task limitations initially affect the most demanding tasks, such as walking longer distances (Weiss et al., 2007), and therefore using a measure of walking modifications in walking a distance of 2 km was appropriate in this group. Finally, our results may have been influenced by the fact that older people with severe mobility limitations rarely report environmental outdoor mobility barriers (Eronen et al., 2014a) owing to their lack of exposure to such barriers and hence unawareness of them.
Conclusion
Whereas previous research findings have mainly concerned individual determinants of adaptive strategies, the present study, in line with the ecological model of aging, shows that the use of adaptive and maladaptive walking modifications seems to be the result of the person–environment interaction. Older people with adaptive walking modifications reported more environmental facilitators to outdoor mobility than people using maladaptive walking modifications. This indicates that perceived environmental facilitators, such as the availability of good quality walkways and good lighting, motivate individuals to continue walking in an adaptive way despite functional decline. The present finding of an association between perceived environmental barriers to outdoor mobility and the use of maladaptive walking modifications highlights the importance of a safe and walkable environment for increasing outdoor mobility among older people. It would, therefore, be prudent to reduce environmental barriers, especially for those with poorer physical capacity. For example, ensuring snow removal during wintertime (in localities with persistent snowy conditions) and providing resting places in streets and parks would benefit this group of people.
Supplemental Material
Supplemental_tables – Supplemental Material for Associations between Perceived Outdoor Environment and Walking Modifications in Community-Dwelling Older People: A Two-Year Follow-Up Study
Supplemental Material, Supplemental_tables for Associations between Perceived Outdoor Environment and Walking Modifications in Community-Dwelling Older People: A Two-Year Follow-Up Study by Heidi Skantz, Taina Rantanen, Timo Rantalainen, Kirsi E. Keskinen, Lotta Palmberg, Erja Portegijs, Johanna Eronen and Merja Rantakokko in Journal of Aging and Health
Footnotes
Acknowledgments
Declaration of Conflicting Interests
Funding
ORCID iDs
Supplemental Material
References
Supplementary Material
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