Running head: EFFECTS OF HEARING LOSS ON MEMORY AND PARTICIPATION. activities

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1 Running head: EFFECTS OF HEARING LOSS ON MEMORY AND PARTICIPATION The effect of early age-related hearing loss on memory and participation in social leisure activities Henrik Danielsson 1,2, M Kathleen Pichora-Fuller 1,2,3,4,5, Kate Dupuis 3,4, Jerker Rönnberg 1,2, Alison L. Chasteen 3, Lars-Göran Nilsson 6,7 1 Department of Behavioural Sciences and Learning, Linköping University, Linköping, Sweden 2 Linnaeus Centre HEAD, Swedish Institute for Disability Research, Linköping University, Linköping, Sweden 3 Department of Psychology, University of Toronto, Toronto, Ontario, Canada 4 Toronto Rehabilitation Institute, Toronto, Ontario, Canada 5 Rotman Research Institute, Toronto, Ontario, Canada 6 Ageing Research Center, Karolinska Institutet, Sweden 7 Umeå Center for Functional Brain Imaging, Umeå University, Sweden This study was financed by an excellence grant from the Swedish Research council ( ) and a grant from The Swedish Research Council for Health, Working Life and Welfare ( ) awarded to Jerker Rönnberg. The Betula database was financed by Swedish Research Council ( , ). The Toronto Stigma study was supported by a Catalyst Grant (Pilot Projects in Aging; #224024) from the Canadian Institutes of Health Research. Preliminary results from this study have been presented at the following conferences: The 2013 Annual Scientific Meeting of the Gerontological Society of America in New Orleans, LA; the 2014 Annual Scientific and Technology Meeting of the American Auditory Society in Scottsdale, AZ; the 2015 International Conference on Cognitive Hearing Science for Communication in Linköping, Sweden; the 2015 International Aging and Speech

2 Communication Conference in Bloomington, IN, the 2016 World Congress of Audiology in Vancouver, BC, Canada. A pre-print version of this manuscript is posted on PsyArXiv. Correspondence concerning this article should be addressed to Henrik Danielsson, Department of Behavioural Sciences and Learning, Linköping University, Linköping, Sweden. henrik.danielsson@liu.se 2

3 Abstract Age-related declines in hearing, cognition and social participation are well recognized, as are associations between hearing loss and cognitive decline, hearing loss and increased risk for social isolation, and cognitive decline and lower participation in social leisure activities (PSLA). Nevertheless, little is known about how age and the three domains of hearing, cognition, and social participation relate to one other. In the current study, behavioural measures of hearing and memory and self-reported participation in common social leisure activities from two samples of adults with hearing loss (N=297, N=273) were analysed. Structural equation modelling on both samples yielded two models with good and similar statistical properties. The two models had the following in common: age effects on hearing and memory, an effect of hearing on memory, but no direct effect of hearing on PSLA. The models differed on the direction of the path between memory and PSLA and whether or not there was an effect of age on PSLA. The majority of participants in both samples were not candidates for hearing aids, but most of those who were candidates used them. Of note, typical pure-tone average thresholds did not contribute significantly to the models, but highfrequency hearing thresholds did, suggesting that even early stages of hearing loss can increase demands on memory that in turn may deter participation in social leisure activities. Keywords: social participation, age-related hearing loss, recall, memory, leisure activity Word count:

4 The effect of early age-related hearing loss on memory and participation in social leisure activities With increasing age there are reductions in hearing (e.g. ISO, 2000), cognition (e.g. Rönnlund, Nyberg, Bäckman, & Nilsson, 2005), and participation in social leisure activities (Marcum, 2013). Many studies have shown relationships between hearing loss and cognitive decline, between hearing loss and social isolation, and between participation in social leisure activities and cognition (see literature review below). However, few studies have included all four domains and different models of their associations have not been evaluated. The purpose of the present study is to evaluate different models of the associations among age, hearing, memory, and participation in social leisure activities. A better understanding about how they are inter-related may guide new approaches to stop or at least slow these declines. Hearing Loss and Memory Decline In the Betula study, a longitudinal Swedish study from which part of the data in the present study is drawn, age-related declines in memory have been investigated. Both crosssectional and longitudinal analyses of data from the Betula study showed age-related declines in episodic and semantic memory after 60 years of age, with episodic memory changing more with age than semantic memory (Rönnlund et al., 2005). For episodic memory, age-related decline was more pronounced for recall than for recognition (Nyberg et al., 2003). There is a connection between age-related sensory and cognitive decline (e.g., P. B. Baltes & Lindenberger, 1997; Humes, Busey, Craig, & Kewley-Port, 2013; Schneider & Pichora-Fuller, 2000), and between hearing loss and cognition (e.g., Harrison Bush, Lister, Lin, Betz, & Edwards, 2015; Rönnberg et al., 2011). In addition, many studies have examined the risk of dementia in individuals with hearing loss (e.g. Lin, Metter, et al., 2011; Teipel et al., 2015; Uhlmann, Larson, Rees, Koepsell, & Duckert, 1989). The current paper focuses on declines in memory function as a specific aspect of cognitive aging. Some studies that have 4

5 used different types of memory measures have found associations between hearing loss and both episodic and semantic long-term memory, but not short-term memory (e.g., Rönnberg et al., 2011). This pattern is relatively consistent with previous evidence that hearing loss was associated with impaired episodic long-term memory, but not measures of short-term memory or word fluency, which may index semantic long-term memory (Deal et al., 2015; Lin, Ferrucci, et al., 2011). In the present study, episodic long-term recall measures of memory were chosen to maximize the possibility of observing the association of memory to hearing loss and age. Hearing Loss and Social Participation An extensive literature has examined changes in social behaviour as individuals age, with potential explanations including the changing role of an older individual in society (e.g., due to retirement), age-related problems such as health issues (M. M. Baltes & Lang, 1997), or an adaptive process due to the loss of social partners. Compared to younger people, older adults have smaller networks (Lang & Baltes, 1997), their networks are more family oriented (Antonucci & Akiyama, 1987), and they spend less time with others (Cornwell, 2011; Marcum, 2013). An important aspect of aging that may influence social participation is an individual s communication abilities (Arlinger, 2003). If an older adult encounters too much difficulty communicating in a meaningful way, they may cope by avoiding social situations. In particular, they may choose to withdraw from meaningful social leisure activities outside the home that may require communication, such as playing bridge or attending family dinners. The relationship between hearing loss and social participation has been shown for different aspects of social participation (see Pichora-Fuller, Mick, & Reed, 2015 for a review), including social support, social networks, and participation in social activities. Notably, social support predicts hearing aid adoption (Singh & Launer, 2016) and satisfaction (Singh, Lau, & 5

6 Pichora-Fuller, 2015). Hearing loss has been linked to reduced quality of life and increased social isolation (Arlinger, 2003; Gates & Mills, 2005). Older people with hearing loss, especially women, have smaller social networks compared with people with preserved hearing (Mick, Kawachi, & Lin, 2014), and hearing problems can limit their social life (Gopinath et al., 2012), and increase loneliness (Mick et al., in press). Memory and Social Participation A review of the association between lifestyle and cognition indicates that the three commonly investigated lifestyle components, namely social, mental, and physical functioning, may all reduce age-related cognitive decline and have a protective effect against dementia (Fratiglioni, Paillard-Borg, & Winblad, 2004). For the association between social networks and cognition, this same review (Fratiglioni et al., 2004) showed that most, but not all, of the included longitudinal studies found this association despite using a variety of both social and cognitive measures. One commonly used operationalization of social participation in the aging literature (e.g., Hicks & Siedlecki, 2016; Wang et al., 2013), which will also be used in the present study, is engagement in leisure activities. A recent study (Wang et al., 2013) suggests that different types of leisure activities may drive benefits in different cognitive domains. There is, however, a substantial number of studies that have not found an effect of leisure on cognition, and a few which showed negative influences of participation in leisure activities on cognitive function (see Salthouse, 2006 for a review). Some studies (Ghisletta, Bickel, & Lövdén, 2006; Lövdén, Ghisletta, & Lindenberger, 2005) have investigated the causal direction between cognition and leisure activities and found that increased leisure engagement may lessen age-related decline in perceptual speed, but have not found that declines in perceptual speed have an effect on leisure engagement. This type of unidirectional link has also been found from social leisure activities to episodic memory (Mousavi-Nasab, Kormi-Nouri, & Nilsson, 2013); however, no effect of social leisure activities was found on 6

7 semantic memory nor for cognitive leisure activities on either episodic or semantic memory. Thus, many, but not all, studies find a unidirectional effect from leisure activity engagement to cognition. The differences in findings are probably related to the use of inconsistent measures of both leisure activities and cognition between studies and further research to clarify the associations between cognition and leisure activity is warranted. Hearing loss, Memory and Social Participation Few studies have examined the interaction of age and all three of the domains included in the present study (i.e., age, hearing loss, memory and leisure activities or related concepts), but a better understanding of their interactions may provide important insights into how to promote healthy aging (Pichora-Fuller et al., 2015). In a multiple regression analysis, active participation was predicted by age and cognition, but not by self-reported hearing problems (Perlmutter et al., 2010). This suggests that hearing problems might not be directly related to active participation. However, a regression analysis has limitations insofar as inter-relations between the predictor variables are not allowed or analyzed. In the present paper a structural equation modelling (SEM) approach was used to address this problem. A broad range of cognitive measures were related to everyday functioning in both a sample of people with hearing impairment and a sample of people with vision impairment using SEM (Heyl & Wahl, 2012). They found that, for the most part, the number of various types of out-of-home leisure activities were not significantly correlated (.11 < r <.29) with the cognitive measures for the hearing impairment group. Notably, even though some of the included cognitive measures involved memory, none measured episodic memory (Heyl & Wahl, 2012). Using a different approach, Marsiske, Klumb, & Baltes (1997) conducted a rather complex SEM model that included age, hearing, intelligence, and participation in non- ADL IADL activities, together with other variables. The model had paths from age to hearing to intelligence to participation in leisure activities (called non-adl IADL activities 7

8 in the article and consisted of physical activities and exercise, intellectual activities, television watching, and social activities). There were no direct paths from age to intelligence or participation in leisure activities, but there were indirect paths via other variables. Hearing had no direct or indirect path to participation in leisure activities. It is unclear from the article (Marsiske et al., 1997) if the non-existing paths mentioned above were tested and removed due to non-significance or if they were not included for theoretical reasons. All three of these studies (Heyl & Wahl, 2012; Marsiske, Klumb, & Baltes, 1997; Perlmutter et al., 2010) have shown that age, hearing loss, cognition and social participation are related, even though different patterns of associations were discovered, probably due to different research questions and different methodological approaches. In the present study, alternative possible relationships between the variables are systematically evaluated. Modelling the Inter-Relationships amongst Age, Hearing, Memory, and Participation in Social Leisure Activities Structural equation modelling has become a widely used methodology in social and behavioural research for specifying, estimating, and testing hypothesized interrelationships among variables (e.g. Anderson & Gerbing, 1988; Bentler, 1988; Jöreskog & Sörbom, 1993). In aging research, guidelines for the reporting of SEM results were published over 20 years ago (e.g. Raykov, Tomer, & Nesselroade, 1991) and it has continued to be a common tool in aging research, in particular when large datasets are analysed (e.g. Enmarker, Boman, & Hygge, 2006). SEM allows for the objective evaluation of the adequacy of fit of a theoretical model to data. Importantly, even if SEM involves theory testing and causal modelling, causal inferences should not be based on the results of a SEM-based analysis alone. Additional assumptions concerning the context of a study and its data are required to draw conclusions about causality (e.g. Bentler, 1989; Mulaik, 1987). 8

9 Based on the research findings describe above, in the current study, different models of the inter-relationships amongst age, hearing loss, memory, and participation in social leisure activities were proposed and tested. The models that were tested differed in how three latent variables (hearing loss, memory, and participation in social leisure activities) are related to each other. In all models, age is allowed to influence all three latent variables, with the assumption being that age is a cause of reductions in the three latent variables. Also common to all models are two more assumptions: 1) that hearing loss contributes to reductions in memory, either directly or indirectly, and 2) that hearing loss contributes to reductions in participation in social leisure activities, either directly or indirectly. The two main questions of interest were a) if the relationship between hearing loss and reduced memory is mediated by reduced participation in social leisure activities or b) if the relationship between hearing loss and reduced participation in social leisure activities is mediated by reduced memory. We label the models corresponding to these two main questions, respectively, the Social Leisure Mediator model and the Memory Mediator model. We also include a third model, the Bidirectional model, which has bidirectional paths between memory and participation in social leisure activities. The Bidirectional model can be seen as a combination of the other two models, see Figure 1 for an overview of the three models. Method Participants The participants in the present study were a subsample of participants from two different studies, the Betula study conducted in Sweden and the Toronto Stigma study conducted in Canada. The purposes of the two studies, the characteristics of their participants, and the social and physical environments in which the participants live differ in a number of ways. These differences were considered to be an asset because models could be assessed across distinctive subsamples of older adults living in different environments. 9

10 The Betula study is a prospective cohort study for which participants complete an extensive set of measures to evaluate memory, health, and social factors (Nilsson, Bäckman, Erngrund, Nyberg, & Adolfsson, 1997). The main purpose of the Betula study has been to investigate age-related changes in health and cognition in adulthood, risk factors for dementia, and premorbid changes in memory. The first wave of participants in the Betula study was tested in This randomly selected sample from the city of Umeå in Sweden has been tested every five years and new participants have been added and removed over time, with the total number of individual participants exceeding The study design, the samples tested in the different waves, the attrition rate, and the measures included in the Betula study have been documented previously (Nilsson et al., 2004, 1997). The subsample used for the present analysis is taken from the fifth wave of the Betula study (tested in ) because this was the first wave in which pure-tone audiometry was conducted as part of the test battery. To be included in the present study, participants were required to have a better-ear high-frequency pure-tone average (BE PTA HF ) based on the audiometric thresholds used in modelling (3, 4, 6 and 8 khz) greater than 10 db HL (i.e., at least a slight hearing loss; Clark, 1981) and no missing values on the selected social leisure and memory variables to be analysed. There were 297 participants out of the 2323 participants tested in the fifth wave of the Betula study who met these inclusion criteria. The Toronto Stigma study was designed to evaluate the influence of negative views of aging on self-reported and behavioral measures of memory and hearing in adults over the age of 55 years (Chasteen, Pichora-Fuller, Dupuis, Smith, & Singh, 2015; Dupuis et al., 2015). In 2011, participants were recruited from existing volunteer pools at the University of Toronto, by research invitations to audiology clients seen at the Canadian Hearing Society in Toronto, and by advertisements placed in local newspapers. A total of 301 healthy, community-living 10

11 older adults were tested in the Toronto Stigma study and of these 273 had no missing values on the selected social leisure and memory variables to be analysed. Both studies were conducted in urban settings in prosperous, developed countries with well-established and high-quality public education and health care systems. However, the cities in which the studies were conducted may offer different opportunities for participation in social leisure activities insofar as they differ in climate (Umeå about 2200 kilometres north of Toronto) and the size of the population (Umeå about 25 times fewer inhabitants than Toronto). Table 1 provides information on the demographic characteristics for both samples used in the present analyses. Most of the participants (> 80%) in both samples reported being in good health. Compared to the Toronto sample, the Umeå sample was significantly younger (by 4 years) and spanned a wider range of ages, including 15% who were middle-aged adults younger than 56 years of age, which was the minimum age for the Toronto sample. Compared to the Umeå sample, the Toronto sample had more years of education and a higher proportion of females, but a lower proportion of people who were married and a lower proportion of people who were employed. When the Toronto sample was compared to only those in the Umeå sample who were over 55 years of age, the differences between samples in age and the proportion employed were no longer significant, but the differences in education, gender and marital status remained significant. In all participants, pure-tone hearing thresholds were measured at standard frequencies from 250 to 8000 Hz under earphones following standard audiometric procedures (American National Standards Institute, 2004a, 2004b). The mean pure-tone air-conduction audiometric thresholds in the BE for each test frequency are shown in Figure 2 for the two samples. Table 2 provides descriptions of relevant hearing-related characteristics for the two samples. Participants were categorized as having normal hearing (NH) or hearing loss (HL). Based on 11

12 the WHO grades of hearing impairment (Mathers, Smith, & Concha, 2000), the criterion used to define hearing impairment was a BE PTA > 25 db HL based on an average of 0.5, 1, 2, and 4 khz, the frequencies considered to be the most important for speech perception. As shown in Table 2, compared to the Umeå sample, a larger percentage of the participants in the Toronto sample were categorized as having hearing loss. The Umeå sample had better hearing than the Toronto sample based on either the BE PTA used to categorize participants as having normal hearing of hearing loss or based on the high frequency (3, 4, 6, 8 khz) BE PTA HF used in modelling. These differences persisted when the Toronto sample was compared to only those in the Umeå sample who were older than 55 years of age. The average age of those with hearing impairment was similar in both the Toronto and Umeå samples. For both samples, the percentage of participants with hearing impairment was consistent with expected age-related increases in hearing impairment, with up to half of the population in their early 70s having hearing loss (Smith, Bennett, & Wilson, 2008; Swenor, Ramulu, Willis, Friedman, & Lin, 2013). In Table 2 it can also be seen that few participants in either sample had asymmetric hearing which was defined as > 20 db difference between PTAs for the left and right ears (i.e., differences between PTAs for the better and worse ears were minimal for almost all participants, consistent with the typical pattern of age-related hearing loss). Interestingly, of those who were categorized as having hearing loss, the majority (about 2/3) had hearing aids. Furthermore, the rate of hearing aid use was higher in both samples (about 4/5 for those who were deemed to be candidates for hearing aids based on an audiometric criterion) compared to 14% in a research study (Chien & Lin, 2012) and 20-24% according to experts in the hearing aid industry (Kochkin, 2005). Cognitive screening tests were administered to both samples. The Mini-mental State Examination (MMSE; Folstein, Folstein, & McHugh, 1975) was administered to participants 12

13 in the Betula study and a normal score was defined as >26/30. The Montreal Cognitive Assessment (MoCA; Nasreddine et al., 2005) was administered to participants in the Toronto Stigma study and a normal score was defined as >25/30. The majority of participants in both samples passed the cognitive screening test for dementia; however, the percentage passing cognitive screening was higher in the Umeå sample (85%) than in the Toronto sample (52%). It is known that the criterion for passing the MMSE is less strict than the criterion for passing the MoCA (Larner, 2012; Sweet et al., 2011). The Larner (2012) study tested a sample without known cognitive impairment on both MoCA and MMSE and their mean MoCA score happens to be the same as in the present study (25.2). The mean Larner (2012) MMSE score was 27.7, which is comparable to the 28.0 (SD = 1.6) in the present study. Overall, the distributions of hearing and cognitive impairments for both samples were consistent with population prevalence estimates, but it is possible that the models tested in the present study could differ between the samples insofar as the Toronto sample was older and included a higher proportion of participants who had hearing impairments compared to the Umeå sample. Procedure and Tasks In the Betula study, the health measures were tested on one day and the cognitive measures on another day (see L. G. Nilsson et al., 2004; L.-G. Nilsson et al., 1997 for details about the procedures used in the Betula study). In the Toronto Stigma study, participants were tested in a single session. For the purpose of the models investigated in the current study, variables were selected as indicators of the three latent factors of interest: hearing loss, memory, and participation in social leisure activities (see Table 3). The two studies measured basic audiometric thresholds in the same way using standard clinical procedures, but they differed in the specific measures of memory and participation in social leisure activities that were used. For the purposes of the present study, variables were selected to be as similar as 13

14 possible for the two samples. It was considered an asset that the measures of memory and participation in leisure social activities were similar but not identical so that the models assessed were not dependent on specific measures for these latent variables. Hearing loss. As described above in the section on participants, for both samples, puretone hearing thresholds were obtained at standard octave frequencies from 250 to 8000 Hz following internationally accepted clinical procedures. In addition to the standard octaves, 3000 Hz was also measured in both studies because of its importance in speech perception. In addition, if there was a 20 db or more difference between adjacent octave frequencies then it is typical clinical practice to measure a threshold at the intermediate frequency (e.g., if the thresholds obtained at 4000 Hz and 8000 Hz differ by 20 db or more, then a threshold should be obtained at 6000 Hz so that the slope of the change between standard octave test frequencies can be further specified) 1. On average, both samples had normal hearing thresholds for frequencies up to 2000 Hz (see Figure 2). Therefore, the models were based on higher frequencies where the average BE hearing thresholds of one or both of the samples dropped into the range greater than 25 db HL that is used to define clinically significant hearing impairment (Clark, 1981). Thus, thresholds at four frequencies (3000, 4000, 6000, and 8000 Hz) were selected for use in modelling. Notably, the hallmark of age-related hearing loss is threshold elevation beginning at high frequencies; therefore, these high-frequency thresholds provide an early indication of the onset of age-related hearing loss (ISO, 2000). Thresholds in the BE were used because few participants in either sample had clinically significant inter-aural PTA asymmetries (defined above) and for those who did have significantly asymmetric thresholds, their ability to communicate and participate in everyday 1 Values were imputed for 24% of the cases in the Toronto sample for 6000 Hz. Thresholds were only measured at 6000 Hz when there was more than a 20 db difference between the thresholds measured at 4000 Hz and 8000 Hz. 14

15 activities would depend more on their hearing abilities in the better ear rather than the worse ear. Memory. For the Umeå sample, the following six free recall measures from the Betula study were selected for the memory latent variable: 1-4) Free recall of words in four different conditions with or without a concurrent task at encoding and retrieval, 5) free recall with enactment and 6) free recall of activities. Each of the conditions involving free recall of words used lists of 12 nouns that were read by the tester one at a time every 2 seconds. The four conditions differed by either having or not having a concurrent task at encoding and/or retrieval. The number of correctly recalled nouns was scored (maximum 12 per condition). In the free recall with enactment task, 16 noun-verb sentences were presented on a card at the same time as the experimenter read the sentence aloud and enacted the sentence (e.g., touch the nose), and the sentences were later recalled. The number of correctly recalled noun-verb combinations was scored (maximum 16). In the free recall of activities task, the participants were asked to recall all of the tests (describe what they did during the test, not the test names) that had been carried out during the testing session. The score was the number of correctly recalled tests (maximum 22). For the Toronto sample, the three recall tasks completed by participants were selected for the memory latent variable. Two recall tasks (one visual and one auditory) measured free recall for lists of 15 words. For the Visual Free Recall test, the list of words was presented as text on a 17-inch computer screen in size 72, black Calibri font on a white background using Powerpoint. For the Auditory Free Recall test, a different word list was presented over headphones at either 80 (for individuals with BE PTAs at 500, 1000, and 2000 Hz < 40 HL) or 90 db SPL (for individuals with BE PTAs at 500, 1000, and 2000 Hz > 40 db HL). For each task, participants were then given three minutes to write down as many words as they could recall after the presentation of the list. The third recall task was the delayed recall item 15

16 from the MoCA. Participants were asked to remember five words. They heard and repeated these five words twice during a learning phase (performance on these learning trials was recorded but there is no score for the learning trials). After about a five-minute delay with intervening test items, participants were asked to repeat as many of the five words as they could remember, in any order. Participation in social leisure activities. For the Umeå sample, the measures used for the participation in social leisure activities latent variable were selected from items on a questionnaire used in the Betula study that asked how often a specific activity had been carried out over/in the last 3 months. Participants answered on a 5-point scale with the labels: never, occasionally, a few times per month, sometime per week, and daily. The social leisure activities selected were the same four as had been used to tap social activity in prior research on the Betula study (Mousavi-Nasab et al., 2013): going on a journey, going to the cinema, going to a restaurant, and visiting with friends or family. Note that these activities involve leaving one s own home to interact socially in situations that are likely to depend on spoken communication. Other leisure activities that a person could do alone in their own home (e.g., watching TV) were not included. In the Toronto Stigma study, participants were asked if they had done thirteen different activities over/in the last year (yes, no, or don t know). The list of activities and response options used in the Toronto Stigma study had been used previously (Gonsalves & Pichora- Fuller, 2008) and were modelled on those used by Statistics Canada (Statistics Canada, 1998). Four activities related to social activity that were similar to those selected for the Umeå sample were selected for the Toronto sample for the present analyses: going to a movie or drive-in, going to a live-entertainment show such as a concert, theatrical play or dance performance, going to a cultural or arts festival, and going to a museum or art gallery. Statistical Testing Strategy 16

17 Structural equation modeling was performed with AMOS 17.0 using maximum likelihood estimation. The two samples were analyzed in separate models, where the latent variables Hearing Loss had the same indicators and the latent variables Memory and Social Leisure had different indicators for the two samples. Factor scaling was accomplished by fixing one item for each factor to a value of 1 in the pattern matrix and the same items were used to scale factors among all models for each sample. Differential item functioning was found for age on the latent Hearing Loss variable. This was to be expected since it is well known that there is typically a decline in hearing thresholds with age, especially for the higher frequencies (Agrawal et al., 2008; Cruickshanks et al., 1998). This was solved using the multiple indicators multiple causes (MIMIC) approach (Muthén, 1988) by letting age affect the latent Hearing Loss variable first and subsequently as many of the hearing loss indicators as possible as long as the new model was significantly better. Translated into less technical words, we model a general age effect on hearing loss plus a specific age effect on the highest frequency measures. There is a plethora of indices for evaluation of model fit in SEM and no consensus on which to report. We have picked five indices that 1) assess different aspects of the model (Hooper, Coughlan, & Mullen, 2008), 2) are appropriate for the (in SEM context) relatively small sample size, and 3) have cut-off criteria for when a model is considered good. The most commonly used index is the Chi-square fit statistic (χ2). χ2 is sensitive to sample size and we choose p >.05 as the criterion for significance because both samples had relatively small sample sizes. In addition, the normed Chi2 statistic (χ2/df) that minimizes the impact of sample size (Hooper et al., 2008) is used with the cut-off criteria of <2 for a good model (Tabachnick & Fidell, 2007). The other three measures were the root mean square error of approximation (RMSEA; Browne & Cudeck, 1993), the comparative fit index (CFI; Bentler, 1990), and the non-normed fit index (NNFI). RMSEA values less than or equal to.08 are 17

18 preferred. CFI and NNFI values greater than.90 are generally considered to be acceptable. Besides meeting all of the above criteria, there was a criterion that all path coefficients in the model must be significant (p <.05) for the model to be accepted. If a non-significant path coefficient was found, that path was deleted and the new model without that path was evaluated instead. Results Means and standard deviations for all variables used in the modeling can be found in Table 3, correlations for the Umeå sample in Table 4, and correlations for the Toronto sample in Table 5. The variables that build up the latent variables in the modeling show internal correlations, which is essential for a reliable modeling result. It can also be noted that there are low correlations between the hearing loss and social leisure variables in both samples. This is an indication that these latent variables will probably not be related in the modeling. The different models of the inter-relationships amongst age, hearing loss, memory, and participation in social leisure activities outlined in the introduction were tested according to the strategies outlined above. The best two models will be presented first and later alternative models are discussed. Two models fulfilled almost all criteria for being a good model for both samples. The models are presented in Figures 3 and 4. Please note that the models in Figure 1 are not identical to the models in Figure 3 and 4 because insignificant paths has been removed as outlined in the testing strategies presented above. In the first model, called the Memory Mediator model, Hearing loss has an indirect effect on Social Leisure via Memory, but no direct effect. Age has a direct effect on Hearing loss and Memory, but not Social Leisure. In the second model, called the Social Leisure Mediator model, both Hearing loss and Social Leisure have direct effects on Memory, but Hearing loss and Social Leisure are unrelated. Age has direct effects on all latent variables. All path coefficients, co-variances and variances for the four models can be found in Tables 6 and 7. 18

19 The model statistics for all four models can be found in Table 8. Both the Memory Mediator model and the Social Leisure Mediator model fulfilled all criteria for a good model in the Toronto sample and almost all criteria in the Umeå sample. In the Umeå sample, the Social Leisure Mediator model nearly reached the p >.05 criterion of.047, whereas the Memory Mediator model just passed the criterion with.051. The difference between the models is very small and we will not treat them as different given that both were close to the criterion. In the introduction, a third model called the Bidirectional model with bidirectional paths between Memory and Social Leisure was also outlined. When examining the Bidirectional model, one of the two paths was non-significant in both samples, but there were different paths in the two different samples. Following the strategy outlined earlier, non-significant paths were removed. In the Toronto sample, this meant that the Bidirectional model became identical to the Social Leisure Mediator model. In the Umeå sample, the Bidirectional model became identical to the Memory Mediator model. Therefore, no separate results for the Bidirectional model are presented. Some alternative models were also evaluated. In the models above, high-frequency hearing loss is used for the latent variable hearing loss. In the alternative models, lower frequencies (500, 1000, 2000, and 4000 Hz) were used. As can be seen in Table 8, the alternative models using thresholds at lower audiometric frequencies met all but one criterion for being a good model. The models using the average of lower audiometric frequencies approached but did not reach the p >.05 criterion. That these alternative models were relatively good indicates that the general patterns of the Memory Mediator model and the Social Leisure Mediator model are robust, but that hearing loss is more pronounced for the models using the high-frequency hearing thresholds than for those using thresholds for lower frequencies. This pattern likely reflects the relatively low rates and mild degrees of hearing 19

20 loss in both samples and the earlier manifestation of age-related hearing loss at the higher frequencies. Discussion Analyses on both samples yielded two models with good and similar statistical properties. The two models had the following in common: direct effects of age on hearing loss and memory; a direct effect of hearing loss on memory; no direct effect of hearing loss on participation in social leisure activities. The models differed on the direction of the path between memory and participation in social leisure activities, and whether or not there was an effect of age on participation in social leisure activities. The discussion will focus on the effects that were found in both models since we consider those to be the most robust. The effects of age on hearing loss and memory are both in line with a large and comprehensive existing literature. The effect of age on hearing loss is so well documented that there is even an ISO standard for it (ISO, 2000). The effect of age on declarative memory in general and on episodic long-term memory in particular is also well documented (e.g., Rönnlund et al., 2005). Notably, one study found that the age-related changes in cognition were totally mediated by sensory processing (Humes et al., 2013), which was not the case in the present study. The path coefficients between hearing loss and memory varied between -.24 and -.40 in magnitude across the Social Leisure Mediator model and the Memory Mediator model in the two samples. This magnitude is similar to that found by Rönnberg et al. (2011) who used the same type of analysis and model as in the present study. Marsiske et al. (1997) used a different model insofar as the cognitive variable was intelligence and age was not related to intelligence in their model so their magnitude of.11 is not directly comparable with our results. In general, the present results are consistent with there being a relationship between 20

21 hearing loss and cognition as other studies have found (e.g., Deal et al., 2015; Heyl & Wahl, 2012; Humes et al., 2013; Lin, Ferrucci, et al., 2011). The three effects discussed above were expected since the literature is relatively consistent in those areas. Nevertheless, the non-significant direct effect of hearing loss on participation in social leisure activities was unexpected. An emerging literature suggests that a variety of social psychological factors influence the experiences of people who have hearing loss (see Pichora-Fuller, Mick, & Reed, 2015 for a review) and may be related to cognitive functioning in everyday life (Pichora-Fuller, 2016), including stigma, social support, social networks, and participation in social activities. Negative views of aging affect self-reported and behavioural measures of hearing and memory (Chasteen et al., 2015). Social support predicts hearing aid satisfaction (Singh et al., 2015). Hearing loss has been linked to reduced quality of life and increased social isolation (Arlinger, 2003; Gates & Mills, 2005; Mick & Pichora-Fuller, 2016). It has also been shown that older people with hearing loss, especially women, had smaller social networks compared with people with preserved hearing (Mick et al., 2014) and that hearing problems limit their social life (Gopinath et al., 2012). However, (Perlmutter et al., 2010) when active participation was predicted with a regression analysis, hearing was not a significant predictor whereas significant predictors were distant vision, cognition (memory) and age. In the Marsiske et al. (1997) study, there was no direct path between hearing and activities, but there was an indirect effect via intelligence. It is possible that the effect hearing loss has on social participation could be explained either in terms of a common cause (P. B. Baltes & Lindenberger, 1997) with age affecting both hearing loss and social participation or in terms of an indirect effect mediated via memory, consistent with one of the models in the present study. In a recent study (Dawes et al., 2015), a significant path was found from hearing to social isolation; however, hearing was measured with the Digit Triplet test, a speech-in-noise 21

22 test that stresses auditory and cognitive processing demands during listening and that may reflect a combination of hearing and cognition. It should also be mentioned that the standardized path coefficient in the (Dawes et al., 2015) study was only 0.02, which is so small that it would not be significant with our sample size and likely has no practical relevance. Overall, the results of prior studies are consistent with our results since we found a relation between memory and participation in social leisure activities, but no direct link between hearing loss and participation in social activities in our sample of older adults in the early stages of age-related hearing loss. These findings do not preclude the following possibilities: an association between self-reported hearing loss (rather than audiometry) and various measures of social participation; a direct effect of early hearing loss on participation in specific social activities in which listening is effortful and demands on auditory and cognitive processing are heightened; a direct effect of hearing loss on participation in social activities for older adults with greater degrees of hearing loss. A recent study of over 20,000 people from the Canadian Longitudinal Study on Aging (Mick et al., in press), examined the effects of self-reported sensory loss on four different social factors (participation in activities, social network size, social support and loneliness) and found reductions in all four social domains for those with self-reported vision or dual sensory loss, whereas self-reported hearing loss was independently associated only with low availability of social support and loneliness (Mick et al., in press). The relationship with loneliness and lack of social support may indicate that people who have hearing loss participate in social activities but with reduced quality of social interaction during those activities. Furthermore, the nature of social support could influence motivation to participate in activities. For example, older people may give priority to quality vs. quantity of social interactions compared to younger adults (Carstensen, Fung, & Charles, 2003) or they may tend to spend time with others participating in leisure activities when the type of activity is 22

23 inherently social, while younger people may tend to engage in leisure activities whether or not the activities are necessarily social (Marcum, 2013). Interestingly, the first activities that older adults drop out of are similar to the activities investigated in the present study (Strain et al., 2002). It could be that the measures used in the present study (i.e., frequency of participation in this set of leisure activities) only capture a part of the change in social functioning in aging that may be influenced by hearing loss alone or in combination with concurrent changes in vision and cognition. Further studies are needed to investigate this. There are limitations of this study in that cross-sectional data has been used. A stronger case could be made with longitudinal data since the statistical modeling technique used here would need additional assumptions concerning the context of a study and its data to draw conclusion about causality (see e.g. Bentler, 1989; Mulaik, 1987). In the present study, this has been handled by arguing based on the findings of previous studies concerning which paths are reasonable to assume. Other limitations for generalizability are that both samples in the current paper were more advantaged than the general population. Few participants in both samples were candidates for hearing aids, but most of those who were candidates used them, suggesting that their hearing problems may have been minimal or addressed better than for most older adults. Nevertheless, it is provocative that even in sub-clinical degrees of hearing loss there are direct associations to memory and indirect associations to participation in social activities. It is possible that other types of models could be confirmed with more people who have greater severity of hearing loss or those who have not sought rehabilitation. The possibility that variation might be seen depending on stage of age-related hearing loss is suggested by the finding that the models we tested starting with a bidirectional path between cognition and social participation yielded different models for the two samples. It could be that one model would be better in the Umeå sample (with a smaller degree of hearing loss) than in the Toronto sample (with larger degree of hearing loss). The current data and analyses are not 23

24 appropriate for examining this suggestion further, but future studies could investigate this question. The present study also has strengths in that, despite the fact that different measures were used for memory and social leisure, similar models were found in both samples. This replication across samples indicates that the conclusions are robust both in relation to how the concepts are operationalized and measured and in relation to two samples with slightly different characteristics (e.g., degrees of hearing loss, age, sex, years of education, and marital status). It should be noted that typical lower-frequency pure-tone average thresholds did not contribute significantly to the models, but high-frequency hearing thresholds did. This suggests that even early stages of hearing loss can increase demands on memory that in turn may deter participation in social leisure activities. Indeed, older adults with unacknowledged or unaddressed hearing loss are at greater risk of cognitive decline and social isolation (Mick & Pichora-Fuller, 2016). The practical implication is that milder degrees of age-related hearing loss may warrant earlier efforts to preserve and promote active social participation by combining functional approaches to hearing and cognitive health. 24

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