Abstract
Objective To determine if hearing loss, vision loss, and dual sensory loss were associated with social network diversity, social participation, availability of social support, and loneliness, respectively, in a population-based sample of older Canadians and to determine whether age or sex modified the associations.
Design Cross-sectional population-based study.
Setting Canada.
Participants The sample included 21 241 participants in the Canadian Longitudinal Study on Aging tracking cohort. The sample was nationally representative of English- and French-speaking, non-institutionalized 45- to 89-year-old Canadians who did not live on First Nations reserves and who had normal cognition. Participants with missing data for any of the variables in the multivariable regression models were excluded from analysis.
Main outcome measures Hearing and vision loss were determined by self-report. Dual sensory loss was defined as reporting both hearing and vision loss. Univariate analyses were performed to assess cross-sectional associations between hearing, vision, and dual sensory loss, and social, demographic, and medical variables. Multivariable regression models were used to analyze cross-sectional associations between each type of sensory loss and social network diversity, social participation, availability of social support, and loneliness.
Results Vision loss (in men) and dual sensory loss (in 65- to 85-year-olds) were independently associated with reduced social network diversity. Vision loss and dual sensory loss (in 65- to 85-year-olds) were each independently associated with reduced social participation. All forms of sensory loss were associated with both low availability of social support and loneliness.
Conclusion Sensory impairment is associated with reduced social function in older Canadians. Interventions and research that address the social needs of older individuals with sensory loss are needed.
The importance of social relationships to health is highlighted in a meta-analysis of 148 studies that found a 50% increased likelihood of survival in individuals with stronger social relationships, comparable with the effect on mortality of smoking and alcohol consumption and exceeding the influence of physical inactivity and obesity.1 Health effects might be mitigated through social network characteristics, participation in social activities, availability of social support,2 or reducing loneliness.3 An individual’s social network consists of the sum of his or her interpersonal relationships.2 A large network might foster participation in social activities, which might be therapeutic or help prevent health declines.4 Healthy relationships promote the exchange of social support, defined as “verbal and nonverbal communication between recipients and providers that helps manage uncertainty about the situation, the self, the other or the relationship and functions to enhance a perception of personal control.”5 Social support can be classified as emotional or informational (eg, empathy and advice), tangible (eg, money), affectionate (eg, love), and interactional (eg, a sense of belonging).6 It might reduce stress, improve psychological well-being, promote healthy behaviour, facilitate access to health care,2 enable self-management of chronic diseases,7 and have positive physiologic effects.8 Loneliness is the subjective feeling of isolation regardless of objective social network size, and is associated with psychological distress, functional decline, and mortality in the elderly.3 Strengthening social networks, encouraging social participation, increasing social support, and reducing loneliness in older adults are important public health goals, and might be achieved by treating modifiable risk factors or through interventions that strengthen social connections.9
Hearing and sight affect mobility and communication and thus, perhaps, a person’s social milieu. Studies examining relationships between sensory loss and social outcomes have been qualitative,10 have measured only single aspects of social function,11 have focused on hearing or vision loss in isolation, or have not been conducted in the Canadian population. Presbyacusis and uncorrectable age-related vision loss are common, increasing in prevalence,12,13 and associated with physical, mental, and cognitive declines14–18 but are rarely considered medical or public health priorities.19 Dual sensory impairment affects many aspects of a person’s life.20,21 Individuals are more likely to be depressed,22 struggle with activities of daily living and instrumental activities of daily living, and have limited social participation, increasing their dependence on others23 and diminishing their decision-making control.24,25 Effective treatments, such as hearing aids and auditory and visual rehabilitation, are underused.26–28 For these reasons, we sought to determine if hearing loss, vision loss, or dual sensory loss are associated with social network diversity, participation in social activities, availability of social support, and loneliness in a nationally representative sample of Canadians aged 45 to 85, and whether age or sex modified the associations.
METHODS
A cross-sectional population-based study was performed. Ethics approval was granted by the University of British Columbia clinical research ethics board.
Study cohort
The Canadian Longitudinal Study on Aging (CLSA)29 comprises English- and French-speaking Canadians who, at baseline, were 45 to 89 years of age, did not live on First Nations reserves, were not institutionalized, and had normal cognition. Our analysis was conducted using the first wave of data released for the CLSA tracking cohort, a nationally representative sample of 21 241 adults who completed a telephone survey.30 Participants were excluded from the current analysis if they had missing data for any of the variables used in the multivariable models.
Outcome variables
Associations were analyzed between hearing, vision, and dual sensory loss and social network diversity, social participation, availability of social support, and loneliness.
Social network diversity was determined using a slightly modified version of the Social Network Index (SNI),31 a validated measure of social network diversity. The SNI, as originally described, measures 12 possible social roles. In the present analyses participants were scored on the SNI out of 10 roles instead of 12 because the CLSA did not measure the frequency of contact with parents or parents-in-law. Participants scored 1 point if they were married or in a domestic partnership. They also received 1 point (each) if they had interpersonal contact at least every 1 to 2 weeks (during the past year) with children, other close family members, friends, neighbours, work colleagues, schoolmates, fellow volunteers, members of nonreligious community groups, and members of religious groups.
Social participation was measured using 8 items developed for the Canadian Community Health Survey.32 A composite scale comprising a combination of responses to the social participation items has not been validated, so we classified individuals as having low social participation if they did not participate in any social activities at least once per week. Activities included family or friendship activities outside of the household, church or religious activities, sports or physical activities with others, educational or cultural activities with others, service club activities, community or professional association activities, volunteer work, or any other recreational activity involving other people.
Availability of social support was determined using the Medical Outcomes Study Social Support Survey,6 a validated scale of overall social support and 4 domains of social support (emotional or informational, tangible, affectionate, and positive interactions). For the overall score and the score for each domain, participants were categorized as having low availability of social support if their scores were below the median.
Loneliness was determined using the following questionnaire item: “In the past week, how often did you feel lonely?” Participants were classified as lonely if they responded “some of the time” (1 to 2 days), “occasionally” (3 to 4 days), or “all of the time” (5 to 7 days). Those who responded “rarely or never” (< 1 day) were considered not lonely. To our knowledge, the CLSA loneliness item has not been validated against other measures of loneliness.
Sensory variables
Self-reported hearing was determined using the following multiple-choice item: “Is your hearing, using a hearing aid if you use one …” Participants were classified as having hearing loss if they responded “fair” or “poor, nonexistent, or deaf” (vs “good,” “very good,” or “excellent”). Self-reported vision was determined using the following multiple-choice item: “Is your eyesight, using glasses or corrective lenses if you use them …” Participants were classified as having vision loss if they responded “fair” or “poor, nonexistent, or blind” (vs “good,” “very good,” or “excellent”). Individuals were considered to have dual sensory loss if they had both hearing loss and vision loss defined according to these criteria.
Covariates
In multivariable models, we adjusted for age, sex, race or ethnicity (white or non-white), annual household income (< $20 000, $20 000 to $49 999, $50 000 to $99 999, $100 000 to $149 999, ≥ $150 000), education level (some secondary, secondary graduate, some postsecondary, postsecondary graduate), smoking status (never a smoker, former smoker, current smoker), and dichotomous self-reported medical history of diabetes, hypertension, angina, myocardial infarction, peripheral vascular disease, transient ischemic attack, stroke, cancer, kidney disease, hypothyroidism, or hyperthyroidism.
Statistical analysis
Univariate analyses were performed to assess cross-sectional associations between hearing, vision, and dual sensory loss, and social, demographic, and medical variables. The
2 test was used to assess differences in proportions for categorical variables. Analysis of variance (ANOVA) was used to test for differences between groups (defined by sensory status) in means for continuous variables.
Multivariable regression models were used to analyze associations between sensory loss (hearing, vision, dual) and SNI score, lack of social participation, low availability of social support, and loneliness. Linear regression was used for SNI score and logistic regression was used for the other outcomes.
The CLSA is a complex sample survey requiring mathematical variance approximation procedures to estimate sampling errors and produce estimates representative of the Canadian population. Inverse probability weights were used in univariate and multivariable analyses as per CLSA guidelines.33
Effect measure modification
To test for effect modification according to sex and age (45 to 64 years old vs 65 to 85 years old), multiplicative interaction terms were created with the sensory variables in each multivariable model. The interaction terms were entered into the main effects models one at a time. Analysis of variance was performed to determine a global partial F test for the presence of interaction. If interaction was present, the multivariable regression was repeated but stratified according to levels of the effect modifier.
Statistical significance was defined as a P value less than .05.
RESULTS
Of 21 241 participants, 1916 (9.0%) had missing data and were excluded. Participant characteristics are summarized in Table 1.
Participant characteristics
Univariate analysis
Hearing impairment and dual sensory loss were more common in men, while vision loss was more common in women (Table 2). Individuals with any type of sensory loss were more likely to be older and have a history of metabolic, cardiovascular, and renal disease, have lower SNI scores, decreased social participation, lower social support (overall and in all subscales), and a higher prevalence of loneliness relative to those who reported no sensory loss.
Sensory loss among participants
Multivariable analysis
Social network diversity.
Hearing loss was not associated with social network diversity (Table 3). Vision loss was independently associated with lower social network diversity among men but not women (P = .022). Dual sensory loss was significantly associated with reduced social network diversity among 65- to 85-year-olds but not 45- to 64-year-olds (P = .037).
Mean difference in SNI score (out of 10) between participants with and without sensory loss
Social participation.
Vision loss, but not hearing loss, was independently associated with reduced social participation (Table 4). Dual sensory loss was also associated with low social participation, but only in the 65- to 85-year-old age group (P = .032).
Adjusted relative odds of not participating in any social activities at least once per week during the past 12 months
Availability of social support.
Hearing, vision, and dual sensory loss were each independently associated with lower overall availability of social support and with nearly all domains of social support (Table 5).
Adjusted relative odds of having a social support score lower than the median between participants with and without sensory loss
Age significantly modified the associations between vision loss and availability of affectionate social support (P = .025) and tangible social support (P = .037). The associations were present in both age groups but were stronger in the 45- to 64-year-old age group than they were in the 65- to 85-year-old age group.
There was also a significant effect modification by sex for the association between hearing loss and tangible social support (P = .03). The association was stronger in women than in men.
Loneliness.
Hearing, vision, and dual sensory loss were each independently associated with loneliness (Table 6). There were no significant interactions with age or sex.
Adjusted odds ratios of loneliness among participants with sensory loss compared with participants without sensory loss: Loneliness was defined as reporting feeling lonely “some of the time,” “occasionally,” or “all of the time” (vs “rarely or never”).
DISCUSSION
Vision loss (in men) and dual sensory loss (in 65- to 85-year-olds) were independently associated with low social network diversity. Vision loss and dual sensory loss (in 65- to 85-year-olds) were independently associated with low social participation. Hearing, vision, and dual sensory losses were each independently associated with loneliness and reduced availability of social support, respectively.
Vision loss and dual sensory loss might curtail the frequency of social interactions and activities by compromising physical function, mobility, mental well-being, or the ability to communicate using visual cues.34 In addition, others might not understand the implications of vision loss and underestimate or overestimate what a person with visual impairment can or cannot see or do.35 Coping strategies might help (eg, people might readjust their behaviour to maintain relationships and activities) or compound the problem (eg, they might isolate themselves35). A greater tendency among men for harmful coping strategies might explain the sex interaction. Although this proclivity has not been specifically observed in the literature, women might have more pre-existing positive coping strategies (eg, self-efficacy, planning for the future, positive attitudes) than men do to help adjust to new-onset vision loss.36
Hearing loss is a risk factor for falls37 and driving accidents,38 but might affect mobility (and thus opportunities for social interaction) less than visual impairment does. Individuals with hearing loss might be able to adjust their social activities to accommodate their disabilities more easily, rather than abandoning activities altogether. For example, they might participate in more one-on-one interactions rather than group interactions to reduce the communication challenges of attending to multiple speakers with background noise, or they might attend activities but not engage in communication. In contrast, it might be harder to find alternative social activities that can be maintained with even partial success for those with poor vision.
Communication difficulties alone might mediate associations between sensory impairment and reduced social support and loneliness.5,39 Individuals with hearing loss might struggle to listen for missing words and meaning during conversations, leading to fatigue, frustration, stress, anger, or resentment in relationships.6 For people with vision loss, interpersonal communication might be restricted by loss of nonverbal cues including facial expressions, body language, and lip movement. In single sensory loss, some aspects of communication are spared. Those with hearing loss might compensate by using lip reading or sign language, while those with vision loss can rely on spoken language. The combination of hearing and vision loss, however, creates a compounded problem such that cross-modal compensation is more difficult.40 The ubiquitous use of visual and auditory communication methods leads to barriers, exclusion, and isolation of individuals with vision and hearing impairments. Beyond restrictions in communication strategies, inaccessible environments and activities might reduce the range of topics that individuals with dual sensory loss are able to communicate about.41 Communication partners might not pay adequate attention to or understand people with dual sensory loss,42 or might not want to make the perceived extra effort of communicating with them.43
It was not possible to determine whether treating hearing and vision loss moderated the associations with social outcomes because CLSA sensory variables reflect self-reported abilities using amplification devices or lenses if used by the participants. Therefore, participants who benefit from such devices might have classified their hearing or vision as “good” or better. Observational studies using objective measures of sensory function (eg, audiometry or visual acuity testing) or randomized controlled trials could be performed to determine if treatments of sensory loss reduce the risk of social decline.
The findings are concerning because social support facilitates positive coping mechanisms that mitigate the effects of sensory loss44,45 and other chronic disabling conditions.7 Living with a chronic health condition often entails relying on others for help with instrumental tasks and emotional support. Unfortunately, individuals with clinically diagnosed sensory loss typically receive little, if any, relationship and communication counseling. The focus of therapy is usually on augmenting the sensory abilities (eg, with hearing aids or lenses) without addressing activity and participation consequences (eg, with auditory or visual rehabilitation programs).46,47 Individuals with sensory impairments might also be targeted for community interventions that aim to increase engagement and reduce loneliness and isolation.9
One challenge in trying to improve access to such services is that many doctors or health policy decision makers do not prioritize sensory problems.19 Diagnosis is often delayed and barriers to effective treatments are rarely addressed in public health campaigns. Hearing aids remain underused because of cost, stigma, or delayed diagnosis of hearing problems. Auditory and visual rehabilitation programs are underused because of lack of availability, awareness, and funding.48 In most jurisdictions, implementation of universal design features that help people adapt to their sensory impairments in public spaces, buildings, technologies, or transportation systems is insufficient or not mandated.49,50 Public health campaigns that address these deficiencies are needed.
Family doctors play an important role in the management of sensory losses. Screening adults for hearing loss has been shown to reduce delays in seeking help for hearing problems and to increase the uptake of hearing aids, leading to benefits in speech communication.51 The early detection of vision impairment has been shown to contribute to the reduction of falls in the elderly.52 Screening is a 2-step process. First, older patients should be asked if they have noticed a hearing or vision problem. If they reply yes, then they should be examined and, in the absence of a medically treatable cause, referred to an audiologist or optometrist for further workup. If they reply no, then a screening test can be performed (eg, audioscope,53 whisper,54 or visual acuity testing55). Patients whose screening test results suggest hearing or vision loss should be referred to an audiologist or optometrist for further evaluation and treatment. A basic audiologic workup includes an assessment to determine the degree and type of hearing loss as well as counseling about management of hearing problems. Note that a referral to audiology does not necessarily imply that a hearing aid will be recommended, so willingness to try a hearing aid is not a prerequisite to referral. The basic optometric examination includes refraction, tests of visual acuity and visual field, and a thorough inspection of the anterior and posterior structures of the eye with a fundus examination through a dilated pupil. If needed, a prescription for glasses or contact lenses is issued. Referrals to otolaryngologists or ophthalmologists are initiated in case of further medical or surgical requirements. In most Canadian provinces, audiologists and optometrists are regulated health professionals and directories of registrants are publicly available.56,57
The results of the present study suggest possible explanatory mechanisms behind the observed associations between sensory loss and cognitive decline, dementia,14,58 frailty, depression,59,60 and mortality,15 insofar as poorer social networks, social support, social participation, and loneliness have also been linked to these outcomes.61–63 Consistent with this hypothesis, a recent population-based Dutch study demonstrated that social network size mediated the association between vision loss and depression.59
Limitations
Limitations prevent causal inference. The study was cross sectional, and therefore the level of social functioning might have affected ratings of sensory ability. Residual confounding by unmeasured factors cannot be excluded. Exposure misclassification might have occurred, as hearing and vision were assessed by self-report. On the other hand, self-report might be the best method of assessing functional disability, as objective measures such as audiometry or visual acuity testing do not take into account how individuals compensate for their losses.64 This might be why, in a population-based multivariable analysis of older adults, lower 36-Item Short Form Health Survey quality of life scores were better predicted by self-reported hearing loss than by audiometric performance.65 Another limitation of our study is that the results might not be generalizable to specific subpopulations or populations outside of Canada.
Conclusion
This is the first population-based study investigating the association between sensory impairment and the social lives of Canadians. The finding of modality-specific associations between sensory loss and different domains of social function is novel. Our study contributes to a growing literature implicating sensory impairments as important determinants of health. Further research is needed to determine mechanisms underlying the associations, and whether addressing sensory impairment yields benefits outside of simply improving sensory function.
Acknowledgments
This research was made possible using data and samples collected by the Canadian Longitudinal Study on Aging. Funding for the Canadian Longitudinal Study on Aging was provided by the Government of Canada through the Canadian Institutes of Health Research and the Canada Foundation for Innovation. The study is supported by the Canadian Consortium on Neurodegeneration in Aging and is funded by a grant from the Canadian Institutes of Health Research, with funding from several partners.
Notes
Editor’s key points
▸ In this analysis of data from the Canadian Longitudinal Study on Aging, vision loss (in men) and dual sensory loss (in 65- to 85-year-olds) were independently associated with low social network diversity. Vision loss and dual sensory loss (in 65- to 85-year-olds) were independently associated with low social participation. Hearing, vision, and dual sensory losses were each independently associated with loneliness and reduced availability of social support, respectively.
▸ These findings are concerning because social support facilitates positive coping mechanisms that mitigate the effects of sensory loss and other chronic disabling conditions. Living with a chronic health condition often entails relying on others for help with instrumental tasks and emotional support. Unfortunately, individuals with clinically diagnosed sensory loss typically receive little, if any, relationship and communication counseling.
Points de repère du rédacteur
▸ Dans cette analyse des données de l’Étude longitudinale canadienne sur le vieillissement, la perte de la vue (chez les hommes) et la perte sensorielle double (chez les 65 à 85 ans) étaient associées indépendamment à une faible diversité du réseau social. La perte de la vue et la perte sensorielle double (chez les 65 à 85 ans) étaient indépendamment associées à une faible participation sociale. La perte de l’ouïe, la perte de la vue et la perte sensorielle double étaient chacune indépendamment associées respectivement à la solitude et à un accès réduit au soutien social.
▸ Ces constatations sont inquiétantes parce que le soutien social facilite les mécanismes d’adaptation positive qui atténuent les effets de la perte sensorielle et des autres problèmes incapacitants chroniques. Vivre avec un problème de santé chronique exige souvent de se fier à autrui pour des tâches instrumentales et du soutien émotionnel. Malheureusement, les personnes qui reçoivent un diagnostic clinique de perte sensorielle ne reçoivent habituellement que peu ou pas de counseling en relations et en communication.
Footnotes
Contributors
Dr Mick conceived the study, designed the study, acquired data from the Canadian Longitudinal Study on Aging, performed the statistical analysis, interpreted the results, and edited the manuscript. Dr Parfyonov interpreted the results, and wrote and edited the manuscript. Dr Wittich designed the study, interpreted the results, and edited the manuscript. Dr Phillips designed the study, interpreted the results, and edited the manuscript. Dr Pichora-Fuller conceived the study, designed the study, interpreted the results, and edited the manuscript.
Competing interests
None declared
This article has been peer reviewed.
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