Purpose: Neighbourhood walkability indices have been developed and linked to behavioural and health outcomes elsewhere in the world, but not yet for the Netherlands. We aimed to compose a theory-based walkability index for the Netherlands, elucidate its cross-sectional association with adults’ walking behaviours and assess how it performed across different strata of demographics. 

Methods: The Dutch walkability index consists of seven components: population density, retail- and service destination density, land-use mix, street connectivity, green space, sidewalk density and public transport density. These components were composed and aggregated to three Euclidean buffer sizes (150m, 500m and 1000m) around every postal code or to administrative neighbourhood boundaries. The resulting walkability index, the sum of its componental z-scores, was rescaled to range between 0-100. Data on self-reported demographic characteristics and walking behaviors of adult participants (aged 18-65, n=15,702) were extracted from the Dutch Travel Survey 2017. Using censored regression analysis tobit model adjusted for individual and survey-related confounders (age, sex, race, education level, work status, household income, car possession, household composition, season, urbanization degree, day of the week, survey mode, bike use), we assessed the association between increase in walkability and the following outcomes: total time spent walking, walking for non-discretionary purpose (work- and study-related) and discretionary purpose (e.g., groceries shopping). The main association was also examined across various urbanization degrees, socioeconomic levels, age groups and sexes. 

Results: In fully-adjusted models, a 1% increase in walkability was associated with an increase of 0.49 minutes of walking (95%CI: 0.4-0.58), corresponding to 37 meters walked (95%CI: 29-44). This association was consistent across buffer sizes and between discretionary and non-discretionary walking. In terms of components, sidewalk density was most strongly associated with non-discretionary walking, while land use mix was most strongly associated with discretionary walking. Stratified results showed that associations for minutes of walking were stronger in rural (0.90, 95%CI: 0.54-1.26) compared to highly urbanized areas (0.41, 95%CI 0.23-0.59), for discretionary walking in females (0.53, 95%CI: 0.38-0.67), and non-discretionary walking in males (0.64, 95%CI: 0.44-0.84).

Conclusion: The walkability index was associated with walking behaviours of Dutch adults, indicating its value for further use in the Netherlands.

Purpose: To investigate the association of neighborhood walkability with change in glycemic outcomes in people with T2D, and whether this association was mediated by physical activity (PA).

Methods: For 1230 people with T2D (68.9 ± 9.0 years old, 63% male) from the Diabetes Care System Cohort, the Netherlands, we objectively assessed the residential walkability within 500m buffers around their house. The walkability index included population density, retail density, land-use mix, street connectivity, sidewalk density and green space surface. As a sensitivity analysis 250 – 1000 m buffers were investigated. A subjective walkability index was constructed based on the Assessing Levels of Physical Activity and fitness (ALPHA) questionnaire. Total PA was device-measured (ActiGraph), and levels of HbA1c and fasting plasma glucose were measured at baseline and 1 year follow-up. Linear regression coefficients (β) with 95% confidence intervals (95%CI) were computed for each outcome, and estimated for the mediating pathway via total PA, adjusted for baseline HbA1c or FPG, follow-up duration, age, sex, education, smoking, car ownership, bike ownership, garden and residential self-selection. Sex was also investigated for effect modification.

Results: Objective and subjective neighborhood walkability were poorly correlated. We observed significant interaction by sex in the association between subjective walkability and HbA1c. No meaningful associations were observed between a unit increase in objective (β: -0.15 mmol/mol (95%CI: -0.59; 0.28)) or subjective (β_men: 0.04 mmol/mol, 95%CI: -1.33; 1.41, β_women: -1.43 mmol/mol, 95%CI: -3.11; 0.05) walkability and change in HbA1c levels. Similar patterns were observed for glucose. We observed a statistically significant association between higher objective walkability with lower levels of total PA (β: -0.95 h/week, 95%CI: -1.51; -0.38), which was not the case with subjective walkability (β_men: -0.12 h/week, 95%CI: -1.79; 1.55, β_women: 0.73 h/week, 95%CI: -1.86;3.31). No associations were found between total PA and glycemic markers (β_HbA1c: 0.00 (95%CI: -0.05; 0.05), β_FPG: -0.01 (95%CI: -0.01; 0.02)). Sensitivity analyses confirmed the main association.

Conclusions: In this study no meaningful association was observed between walkability with changes in glycemic outcomes in people with T2D. Physical activity was not a mediator in this association.

Purpose: Supporting older adults to engage in active lifestyles requires supporting environments. Walkable environments may increase walking activity in older adults, but evidence for this subgroup is scarce, and longitudinal studies are lacking. This study therefore examined whether changes in neighbourhood walkability were associated with changes in walking activity in older adults, and whether this association differed by individual-level characteristics and by contextual conditions beyond the built environment. In particular, the use of a composite exposure measure in a longitudinal environment-physical activity study in older adults is an innovative aspect of this research. Methods: Data from 668 participants (57.8-93.4 years at baseline) across three waves (2005/06, 2008/09 and 2011/12) of the Longitudinal Aging Study Amsterdam (LASA) were used. These individuals did not relocate during follow-up. Self-reported outdoor walking activity in minutes per week was assessed using the LASA Physical Activity Questionnaire. Composite exposure measures of neighbourhood walkability (range: 0 (low)-100 (high)) within 500-meter Euclidean buffers around each participant’s residential address were constructed by combining objectively measured high-resolution Geographic Information System data on population density, density of retail and service destinations, land use mix, street connectivity, green space density, and sidewalk density. Fixed effects linear regression analyses were applied, adjusted for relevant time-varying confounders. Results: Changes in neighbourhood walkability were not significantly associated with changes in walking activity (β=-0.99, 95% CI=-6.17-4.20) in older adults. The association of changes in neighbourhood walkability with changes in walking activity did not differ by any of the individual-level characteristics (i.e., age, sex, educational level, cognitive impairment, mobility disability, and season) and area-level characteristics (i.e., road traffic noise, air pollution, and socioeconomic status). Conclusions: This study did not show evidence for an association between changes in neighbourhood walkability and changes in walking activity in older adults. If neighbourhood walkability and walking activity are causally linked, then changes in neighbourhood walkability between 2005/06 and 2011/12 might have been not substantial enough to produce meaningful changes in walking activity in older adults.