The neighbourhood environment and use of neighbourhood resources in older adults with and without lower limb osteoarthritis: results from the Hertfordshire Cohort Study

The study sample comprised men and women who participated in the United Kingdom (UK) component of the European Project on OSteoArthritis (EPOSA) and who originally participated in the Hertfordshire Cohort Study (HCS). The HCS and the EPOSA study have been described in detail previously [25, 26]. In 1998–2004, men and women born in Hertfordshire (UK), between 1931 and 1939, and still living in the county were recruited to take part in the HCS to evaluate interactions between the genome, the intrauterine and early postnatal environment, and adult diet and lifestyle in the aetiology of chronic disorders in later life [25]. In 2010, a total of 592 participants from the HCS were invited by letter to participate in the EPOSA study. The EPOSA study focuses on the personal and societal burden of OA and its determinants in older adults in six European countries [26]. In total, 444 (75.0 %) persons from HCS agreed to participate in the EPOSA baseline study. Data on perceived neighbourhood cohesion and perceived neighbourhood problems were collected in 2008 using a postal survey. Hertfordshire is a stable county in terms of neighbourhood deprivation [27‐29]. In this study, it is assumed that perceptions of neighbourhood cohesion and neighbourhood problems remained stable between 2008 and 2010. The participants who moved between the postal survey (2008) and the EPOSA baseline study (2010) (n = 26) were excluded from the analyses. Moreover, those who had missing data on the presence of LLOA (n = 17) were omitted. In total, 401 participants were included in the current study. All included participants had data available on the use of neighbourhood resources. For all included participants, data on objectively measured neighbourhood deprivation in 2010 were available. Data from the postal survey on perceived neighbourhood cohesion and perceived neighbourhood problems were available for 303 and 299 participants, respectively. There were no significant differences in characteristics and neighbourhood measures between included and excluded participants (data not shown). In addition, there were no significant differences in characteristics and neighbourhood deprivation between participants who completed the postal survey and those who did not (data not shown). The study was approved by the Hertfordshire Research Ethics Committee.

In the EPOSA baseline study (2010), use of neighbourhood resources was assessed using a modified version of the Home and Community Environment (HACE) instrument [30]. The HACE is a standardized, self-report instrument designed to assess factors in a person’s environment that may influence levels of participation. The modified version included items pertaining to community mobility and transportation which have been shown to be important features of the neighbourhood environment for older adults with functional limitations [30, 31]. First, the availability of three resources was assessed by asking the participants: ‘Could you please indicate if any of the following facilities can be found in your neighbourhood?’ (1) parks and walking areas that are easy to get to and easy to use; (2) places to sit and rest at bus stops, in parks, or in other places where people walk; (3) public transportation close to home; and (4) public facilities. Response categories were ‘a lot’, ‘some’ and ‘not at all’. When participants answered ‘a lot’ or ‘some’, they were asked whether they made use of the resources (0 = no, 1 = yes).

In the postal survey (2008), perceived neighbourhood cohesion was assessed using eight items from the 18-item Neighbourhood Cohesion Scale, that was developed to measure sense of community, attraction to neighbourhood and social interaction within it [21, 22, 32, 33]. Examples of items that were included are the following: ‘I feel like I belong to this neighbourhood’ (sense of community), ‘I plan to remain a resident of this neighbourhood for a number of years’ (attraction-to-neighbourhood) and ‘I regularly stop and talk with people in my neighbourhood’ (social interaction within neighbourhood). Participants were asked to indicate how strongly they agreed or disagreed with each statement. Response options ranged from strongly disagree to strongly agree on a 5-point Likert scale. The overall index score ranged from 5 to 40, with higher scores indicating a higher sense of neighbourhood cohesion.

In the postal survey (2008), perceived neighbourhood problems were assessed by asking participants to consider a list of eight problems that people often have with the area where they live and indicate whether each one was not a problem (score 1), a small problem (score 2) or a big problem (score 3) for them [33, 34]. The problems were (1) vandalism, (2) litter/rubbish, (3) smells/fumes, (4) assaults/muggings, (5) burglaries, (6) disturbance by children/youngsters, (7) traffic and (8) noise. The overall index score ranged from 8 to 24, with higher scores indicating more problems.

The postal codes of the participants were linked to the 2001 census Lower Super Output Areas (LSOAs) using the GeoConvert online geography matching tool. On average, these LSOAs contain approximately 650 households and 1500 residents [29, 35]. The LSOAs were linked to scores on the Index of Multiple Deprivation 2010 (IMD-2010) [27, 29]. The IMD-2010 provides a measure of area-level multiple deprivation by combining information on seven domains of deprivation, including (1) income, (2) employment, (3) health/disability, (4) education/skills/training, (5) barriers to housing/services, (6) living environment and (7) crime. The lowest and highest IMD-2010 in England were 0.53 and 87.80, respectively. The higher the IMD-2010 score, the more deprived the area of residence.

A potential effect modifier was clinical LLOA. In the EPOSA baseline study (2010), the American College of Rheumatology (ACR) classification criteria were used to diagnose OA in the knee and hip [36]. The lower limb OA was defined as present when the participants had clinical OA in the knee and/or hip. An extensive description of the diagnosis of OA in the knee and hip is described elsewhere [26].

Potential confounders included age, sex (0 = men, 1 = women), partner status (0 = having no partner, 1 = having a partner), educational level (0 = lower educated than secondary education, 1 = secondary education or a higher level), anxiety, depression, comorbidity and physical activity, which were previously found to be associated with the use of neighbourhood resources and the three neighbourhood measures [37]. Data on these potential confounders were collected in the EPOSA baseline study in 2010.

Anxiety and depressive symptoms were examined by the Hospital Anxiety Depression Scales (HADS) [38]. The HADS is a self-report questionnaire comprising 14 four-point Likert scaled items, 7 for anxiety (HADS-A) and 7 for depression (HADS-D). Both scales ranged from 0 to 21, and a cut-off level of 8 or more was used for presence of anxiety and depression.

Comorbidity was measured through self-reported presence of the following chronic diseases or symptoms that lasted for at least three months or diseases for which the participant had been treated or monitored by a physician: chronic non-specific lung disease, cardiovascular diseases, peripheral artery diseases, stroke, diabetes, cancer and osteoporosis. The number of chronic diseases other than LLOA was categorized into 0, 1, 2 or more chronic diseases.

Physical activity was measured using the Longitudinal Aging Study Amsterdam Physical Activity Questionnaire (LAPAQ) [39]. The LAPAQ estimates the frequency and duration of participation in activities (walking, bicycling, gardening, light and heavy household tasks and sports activities) in the previous 2 weeks, resulting in a total physical activity time in minutes per week.

Logistic regression analyses were used to examine the associations of the three neighbourhood environment measures with the use of neighbourhood resources. First, LLOA was assessed for potential effect modification by examining interaction effects between LLOA and each of the neighbourhood environment measures in fully adjusted models. The interaction effects were considered significant at a p value below 0.10 [40]. If a statistically significant interaction term was observed, analyses were stratified for LLOA and group-specific associations between the use of neighbourhood resources and the neighbourhood environment were presented. If the interaction effect was not statistically significant, a pooled analysis (also adjusted for LLOA) was performed. Second, all associations between the use of neighbourhood resources and the neighbourhood environment measures were examined in models constructed step by step. Model 1 examined the association of each neighbourhood environment measure with the use of resources adjusted for sex and age. Model 2 assessed these associations, additionally adjusted for all other confounders. Because of multiple testing, the p value was set to 0.01 in all models. Statistical analyses were performed in the IBM SPSS Statistics (version 20.0).