Available via license: CC BY-NC-ND 4.0
Content may be subject to copyright.
Full Terms & Conditions of access and use can be found at
https://www.tandfonline.com/action/journalInformation?journalCode=camh20
Aging & Mental Health
ISSN: (Print) (Online) Journal homepage: https://www.tandfonline.com/loi/camh20
The association between loneliness, social
isolation and all-cause mortality in a nationally
representative sample of older women and men
Carin Lennartsson, Johan Rehnberg & Lena Dahlberg
To cite this article: Carin Lennartsson, Johan Rehnberg & Lena Dahlberg (2021): The association
between loneliness, social isolation and all-cause mortality in a nationally representative sample of
older women and men, Aging & Mental Health, DOI: 10.1080/13607863.2021.1976723
To link to this article: https://doi.org/10.1080/13607863.2021.1976723
© 2021 The Author(s). Published by Informa
UK Limited, trading as Taylor & Francis
Group
View supplementary material
Published online: 22 Sep 2021.
Submit your article to this journal
View related articles
View Crossmark data
AGING & MENTAL HEALTH
The association between loneliness, social isolation and all-cause mortality in a
nationally representative sample of older women and men
Carin Lennartssona,b, Johan Rehnberga,c and Lena Dahlberga,d
aAging Research Center, Karolinska Institutet, Solna, and Stockholm University, Stockholm, Sweden; bSwedish Institute for Social Research,
Stockholm University, Stockholm, Sweden; cDepartment of Public Health Sciences, Stockholm University, Stockholm, Sweden; dSchool of Health
and Welfare, Dalarna University, Falun, Sweden
ABSTRACT
Objectives:Individuals who feel lonely and those who are socially isolated have higher mortality risks
than those who are not lonely or socially isolated. However, the importance of loneliness and social
isolation for survival is rarely analysed in the same study or with consideration of gender differences.
The aim was to examine the separate, mutually adjusted, and combined effects of loneliness and
social isolation with mortality in older women and men.
Methods:Data from the SWEOLD study, a nationally representative sample of people aged 69+ years
living in Sweden, was combined with register data on mortality and analysed using Cox regressions.
Results:Mortality was higher among older women and men with higher levels of loneliness or social
isolation. Social isolation was more strongly associated with mortality than loneliness and the
association remained when controlling for health. The combined effects of loneliness and social
isolation did not surpass their independent effects.
Conclusion:Loneliness and social isolation is associated with an increased mortality risk, and social
integration should be a prioritised target for activities and services involving older adults.
Introduction
There has been a growing focus on loneliness and social isola-
tion among older adults in policy, with an acknowledgement
of their negative effects on health and well-being. This has
been further highlighted during the COVID-19 pandemic,
when many governments have enforced restrictions on social
contacts. People experiencing loneliness and social isolation
are not only at risk of poor health and well-being but also of
premature mortality (for reveiws including a broad age range,
see Leigh-Hunt et al., 2017; Nyqvist et al., 2014; Rico-Uribe et
al., 2018; Shor & Roelfs, 2015). It has been suggested that these
mortality risks are of similar magnitude as well-established risk
factors, such as obesity, substance abuse, physical inactivity
and mental health problems (Holt-Lunstad et al., 2015). Despite
an increasing number of studies, the respective associations
of loneliness and social isolation with mortality have rarely
been included in the same study and more research is needed
(Holt-Lunstad et al., 2015). This study aims to examine the sep-
arate and relative associations of loneliness and social isolation
with mortality in a nationally representative sample of older
adults in Sweden.
Loneliness is a negative feeling, that is, a subjective evalu-
ation of social relations. Loneliness has been defined as the
discrepancy between an individual’s desired and achieved
levels of social relationships (Perlman & Peplau, 1981), which
may concern the quantitative aspects of the relationships, such
as a desire for more social contacts or greater frequency of
contacts, or the quality of the relationships, such as a desire for
greater intimacy or trust in social relations. Social isolation on
the other hand is an objective assessment of social relations
and refers to infrequent or few contacts with family and friends
and may also include living alone (Holt-Lunstad et al., 2015).
There is a continuum from social isolation to social participa-
tion and integration in society (de Jong Gierveld et al., 2018;
Victor et al., 2008). Feelings of loneliness are related to social
isolation, although the association is only partial (e.g. Dahlberg
et al., 2018; Leigh-Hunt et al., 2017; Taylor, 2020; Tilvis et al.,
2012), that is, socially isolated people do not always experience
loneliness and lonely people are not always socially isolated
(Victor et al., 2008).
Previous research on loneliness, social isolation and
mortality
In a meta-analytic review, Holt-Lunstad et al. (2015) included
over 70 independent studies that covered a wide range of age
groups. The results showed that, while controlling for a variety
of factors such as age, gender, socioeconomic status, health,
physical activity and smoking, the odds of premature death
was 26% higher in the group experiencing loneliness, 29%
higher in the socially isolated group and 32% higher in the
group living alone. However, the authors concluded that so far
there is ‘no evidence to suggest that one involves more risk
than the other for mortality’ (Holt-Lunstad et al., 2015, p. 234).
Thus, the results are mixed in existing studies that directly com-
pare these predicting variables (Courtin & Knapp, 2017).
In another meta-analysis, also with a broad age range, the
consequences of loneliness and social isolation for public
health including mortality were examined (Leigh-Hunt et al.,
2017). The results showed that both loneliness and social iso-
lation have a significant association with increased risk of mor-
tality. Even though significant associations of loneliness and
social isolation with an increased risk for mortality were
© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
CONTACT Carin Lennartsson carin.lennartsson@ki.se
Supplemental data for this article can be accessed online at https://doi.org/10.1080/13607863.2021.1976723.
https://doi.org/10.1080/13607863.2021.1976723
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/),
which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.
ARTICLE HISTORY
Received 9 March 2021
Accepted 29 August 2021
KEYWORDS
Older people;
loneliness;
social contacts;
social activity;
quality of life/wellbeing
2 C. LENNARTSSON ET AL.
identified, the authors conclude that more research is needed
to confirm whether loneliness and social isolation have a direct
impact on mortality, or whether the association is indirect via
the cardiovascular system and psychological health (Leigh-Hunt
et al., 2017).
Scholars have theorised that although loneliness and social
isolation are different constructs there are similarities regarding
the mechanisms by which they lead to poor health (Cacioppo
et al., 2015; Elovainio et al., 2017; Hawkley & Cacioppo, 2010;
Victor et al., 2000). Therefore, it is plausible that synergistic
effects of loneliness and social isolation for mortality exist, since
both constructs are related to stress, decreased immune func-
tioning and poor health behaviours, e.g. alcohol consumption,
smoking and physical inactivity. However, loneliness and social
isolation have rarely been included in the same study and there
is therefore a lack of research on their combined effect on mor-
tality (Holt-Lunstad et al., 2015). Still, two recent studies have
examined this topic. A study from Ireland of community-dwell-
ing adults aged 50 years and older showed that social asymme-
try (the degree of overlap between loneliness and social
isolation) and the combination of loneliness and social isolation
were associated with an increased mortality (Ward et al., 2021).
A study of middle-aged and older adults (mean age 60) in
Germany showed synergistic effect between social isolation and
loneliness on mortality (Beller & Wagner, 2018). While findings
from these studies foremost applies to younger older adults,
we know less about the oldest old.
The associations of loneliness and social isolation with mor-
tality may also differ between women and men, since women
have longer life-expectancy and are more likely than men to
have disabling, non-lethal health conditions including func-
tional limitations and depressive symptoms (e.g. Crimmins et
al., 2011). In addition, loneliness is more prevalent in women
than men (e.g. Dahlberg et al., in press). Women have also
reported larger networks than men even in later life (McLaughlin
et al., 2010), at the same time as older women, at least in
Sweden, to a greater extent than men live in single households
(Statistics Sweden, 2020). It is therefore important to address
gender differences in the relation between loneliness, social
isolation, and mortality.
Aim
The aim of this study is to examine the association of loneliness
and social isolation with mortality in a nationally representative
sample of older adults, including persons living in the commu-
nity and in residential care. We include loneliness and social
isolation in the same study to address aspects that are fairly rare
in the current literature: 1) the separate and mutually adjusted
associations of loneliness and social isolation with mortality; 2)
the combined effects of loneliness and social isolation on mor-
tality; and 3) gender differences in these associations.
Methods
Sample
This study is based on the Swedish Panel Study of Living
Conditions of the Oldest Old (SWEOLD) (Lennartsson et al.,
2014) in combination with the Swedish Cause of Death Register.
SWEOLD is a national survey of the oldest old (born between
1892 and 1935) living in Sweden at the time of data collection.
This article is based on the 2004 wave of data collection
including older adults aged 69 years or older. Both older adults
living in residential care and in the community were included
in the analyses. In the 2004 sample, 13% of those aged 80 years
and older were living in residential care facilities.
Materials
The dependent variable was all-cause mortality. Information on
mortality (date of occurrence) was obtained from the Swedish
Cause of Death Register, which maintains records of all death
certificates in Sweden. Respondents were followed from 2004
through the end of 2009, thus resulting in a mortality follow-up
period of 5 years. Exposure time was measured in days.
The two variables of main interest for this study were: lone-
liness and social isolation. Loneliness was measured by one
direct question: ‘Are you ever bothered by feelings of loneli-
ness?’, with four response categories: almost never, seldom,
often, and nearly always. Information was imputed for a total
of 22 respondents who had missing values on the loneliness
variable. Seven of the respondents participated in the 2002
wave of data collection and the imputed values for these
respondents were taken from the 2002 study. The remaining 15
respondents had their missing value imputed with the mean
value of loneliness for women and men, respectively.
We measured social isolation by constructing a summary
index adopted from Tanskanen and Anttila (2016). The index
comprised four indicators: living alone; lack of social contacts
with relatives and friends; lack of social contacts with children
and grandchildren; and low level of social activity.
(1) Living alone was measured via the item ‘Do you live
alone?’ (yes; no). Respondents living in old age care homes/
institutions were considered to live alone.
(2) Lack of social contacts with relatives and friends was mea-
sured with four questions relating to: visiting relatives; having
relatives over to visit; visiting friends; and having friends over
to visit. These questions had three response alternatives: no;
yes, sometimes; yes, often. Responding ‘often’ on at least one of
these four questions and ‘sometimes’ on at least one question
or ‘sometimes’ on at least three questions were considered as
not socially isolated on this dimension.
(3) Lack of social contacts with children and grandchildren
was based on two items regarding frequency of contacts with
children and with grandchildren/great grandchildren, respec-
tively: ‘How often do you usually meet and spend time with your
child/children (or grandchildren/great grandchildren)?’ (daily;
several times a week; few times a week; a few times a month; a
few times a quarter; seldom or never). Those who did not meet
and spend time with their children or grandchildren at least
monthly were considered socially isolated on this dimension.
Not having children and grandchildren were also classified as
being socially isolated on this dimension.
(4) Low level of social activity was measured via the same
type of questions as social contacts with relatives and friends
(see above), using the following list of activities: going to mov-
ies, theatre, concerts, museums, exhibitions; eating out at
restaurants; going out dancing; participating in study circles or
courses; going on trips or excursions; or other activities, such
as exercise, playing boule, playing bridge, organisation/club
activities or engagement in pensioner organisations.
Respondents that did not engage in at least one social activity
often or at least two social activities sometimes were regarded
as socially isolated on this dimension.
AGING & MENTAL HEALTH 3
The respondents were scored either 0 or 1 on these four
indicators, where 1 indicated that they were socially isolated in
that specific dimension; resulting in a summary measure with
scores that ranged from 0 to 4, with higher scores indicating
higher levels of social isolation. Principal component analysis
(PCA) indicated that living alone; social contacts with relatives
and friends; and social activity correlated and loaded highly into
one dimension, while contact with children and grandchildren
showed lower correlation with the other three indicators.
Possibly because contacts with children often become more
regular with deteriorating health whereas other social contacts
and activities tend to decrease with poor health. Conceptually,
however, contacts with children/grandchildren indicate
whether the respondents are in fact socially isolated or not, and
we therefore decided to keep all four dimensions in the social
isolation summary index.
In order to separate the effects of social isolation and lone-
liness on mortality from the effects of poor health on mortality,
four measures of health status previously found to be associated
with social isolation and loneliness were included in our multi-
variable models: mobility limitations, self-rated health (SRH),
psychological distress, and problems related to cardiovascular
diseases.
Mobility limitations were measured via four self-reported
items: ‘Can you walk 100 metres?’; ‘Can you walk 500 metres?’;
Can you run 100 metres?’; and ‘Can you climb stairs without
difficulties?’ (for all items: yes (0); no (1); scale range 0-5, where
higher scores indicate greater mobility limitations).
Self-rated health (SRH) was assessed by the question: ‘How
would you rate your general health?’ with the response alter-
natives: good (0), neither good or bad (1) and poor (2).
Psychological distress was measured by two indicators: anxiety
and depression. Respondents were considered to have psycho
-
logical distress (coded 1) if they reported at least one severe
problem or two slight problems. Problems related to cardiovas-
cular diseases were measured with questions on whether or not
they had chest pain, heart attack, stroke, heart failure, and high
blood pressure in the last 12 months. Respondents were con-
sidered to have cardiovascular problems (coded 1) if they
reported at least one severe problem or three slight problems
with chest pain, heart problems, or high blood pressure, or a
slight or severe problem with heart attack or stroke.
Additional covariates included gender (women (0), men (1)),
age in years, and educational attainment (grade school, i.e. up
to 7 years depending on year of birth and school catchment
area (0), above grade school (1)).
Procedure
Telephone interviews were carried out as the main interview
mode. Informed consent was obtained prior to each interview.
A postal questionnaire was used if the respondent did not agree
to or was unable to conduct an ordinary interview due to, for
example, hearing problems. All items analysed in this article
were identical for both interview modes. For individuals not
able to complete an interview or questionnaire, proxy inter-
views were conducted with a relative or a member of staff. The
most common reason for an indirect interview was dementia
or frailty. The total response rate was 87.3% (n = 1180), of which
15.5% were proxy interviews. The high response rate, the inclu-
sion of institutionalised people and the use of proxy informants
ensure that the SWEOLD sample is highly representative of
older adults in Sweden in 2004 in terms of gender, age and
institutional living (see Lennartsson et al., 2014). Due to internal
missing the analytical sample used in this study comprised of
1161 persons.
Analysis
Cox proportional hazard regression was used to estimate the
effects of independent variables on mortality. The exponent of
the regression coefficients—the hazard ratios—from these
models were interpreted as the change in the hazard ratio asso-
ciated with a unit change in the independent variable. All
regression analyses were done on the total sample, and sepa-
rately for women and men. In the multivariable analyses, the
effect on mortality was first estimated separately for social iso-
lation and loneliness and then in a model where the effects of
social isolation and loneliness were mutually adjusted.
The combined effect of loneliness and social isolation was
tested by including an interaction term of loneliness and social
isolation. The interaction coefficients in a multiplicative model
are conditional on the estimated value of the other variables in
the model; therefore, it is uninformative to interpret the inter-
action coefficient as one point-estimate (see e.g. Brambor et al.,
2006). It has been recommended to predict marginal effects of
observed values on the independent variables of interest; we
followed this procedure and predicted marginal effects from a
regression model that included an interaction term between
loneliness and social isolation (Ai & Norton, 2003). Furthermore,
marginal effects are assessed on an additive scale, which more
closely resembles the theoretical notion of synergetic effects in
public health and social sciences (Rothman et al., 1980). All anal-
yses were performed in R (version 3.6.2) and the cox regression
models were fitted with the coxph command from the survival
package.
Results
Characteristics of the sample
Table 1 shows the demographic and social characteristics of the
total sample and for women and men separately. Of the analyt-
ical sample, 59.1% were women and 51.2% had basic education,
that is, grade school. More women than men had basic educa-
tion. The mean age was 78.7 years among women and 77.9 years
among men. Of the total analytic sample, 54.7% had weekly
contact with children, while 14.4% were childless, which means
that among those with children, 63.9% had weekly contact with
them. About half of the sample considered their health good
and 12.1% poor. The proportion who considered their health
to be poor was higher among women than men. Of the total
analytic sample, 22.3% had no mobility problems, with consid-
erable better mobility among men than women. Of the total
analytic sample, 15.5% had problems related to cardiovascular
diseases, the proportion was higher for women than men, and
12.3% had psychological distress. Nearly twice as many women
as men had psychological distress problems.
Loneliness and social isolation
Table 1 shows that 11.2% of the respondents ‘often’ or ‘nearly
always’ were bothered by feelings of loneliness. Women were
bothered by feelings of loneliness more often than men: 13.7%
4 C. LENNARTSSON ET AL.
of all women and 7.6% of all men were often or nearly always
bothered by feelings of loneliness. Nearly 19% of the respon-
dents were not socially isolated at all, that is, they had no points
on the social isolation index. This means that they were cohab-
iting; had contacts with children or grandchildren (or had no
children/grandchildren); had contacts with relatives or friends;
and were engaged in at least one social activity often or at least
two social activities seldom. While more men than women were
not socially isolated at all, it was equally common for women
and men to have four points on the social isolation index, that
is, to be socially isolated on all four dimensions.
The correlation between loneliness and social isolation was
close to moderate (Table 2). This implies that loneliness only
partly can be explained by the quantity of social relations and
social activity and may also be based on the quality and expec-
tations of social relationships. Moreover, some combinations of
loneliness and social isolation were rare. For example, of those
persons scoring low on social isolation (0 or 1 point on the social
isolation index), few were often or nearly always bothered by
feelings of loneliness.
Mortality
Between the baseline 2004 interview and the end of the obser-
vation period (December 2009), 30.3% of the sample died (Table
1). The time-dependent hazard of mortality showed a constant
mortality rate over time. A test of the proportionality assump-
tion in Cox regression indicated that the hazard rate was pro-
portionate over time (supplementary material Figure 1).
Multivariable analyses
In Table 3, the Cox proportional hazard regressions of loneliness
and social isolation on mortality are presented. In model 1, the
associations between loneliness and mortality adjusted for age,
gender and education are shown. The findings reveal that feel-
ings of loneliness were associated with higher mortality. Those
who were often or nearly always bothered by feelings of lone-
liness had a significantly higher mortality rate than those who
were almost never bothered by loneliness. In model 2, the
equivalent analyses for social isolation show that socially isola-
tion was also associated with an increased risk of mortality and
the association showed a linear pattern. Those who had 2 points
or more on the social isolation index had an increased risk of
mortality than those who were not socially isolated.
To establish the relative association of loneliness and social
isolation with mortality we mutually adjusted for these two risk
factors (model 3). When including both loneliness and social
isolation in the same model, the association of social isolation
with mortality remained, while the association of loneliness
with mortality was attenuated and become statistically
non-significant.
Table 1. Distribution of demographic and social characteristics and prevalence of loneliness and social isolation of total sample, women and men
Variable Category All (n = 1161) Women (n = 686) Men (n = 475)
Age Min 69 69 69
Max 100 100 100
Mean 78.4 78.7 77.9
n%n%n%
Education Grade school 594 51.2 370 53.9 224 47.2
>Grade school 567 48.8 316 46.1 251 52.8
Contact with No children 167 14.4 96 14.0 71 14.9
children Seldom 359 30.9 202 29.4 157 33.1
Weekly 635 54.7 388 56.6 247 52.0
Self-rated Good 569 49.0 327 47.7 242 50.9
health In-between 452 38.9 264 38.5 188 39.6
Poor 140 12.1 95 13.8 45 9.5
Mobility 0 no problems 259 22.3 117 17.1 142 29.9
1 312 26.9 181 26.4 131 27.6
2 159 13.7 105 15.3 54 11.4
3 174 15.0 115 16.8 59 12.4
4 257 22.1 168 24.5 89 18.7
Cardiovascular No 981 84.5 568 82.8 413 86.9
problems Yes 180 15.5 118 17.2 62 13.1
Psychological No 1018 87.7 583 85.0 435 91.6
distress Yes 143 12.3 103 15.0 40 8.4
Loneliness Almost never 806 69.4 423 61.7 383 80.6
Seldom 225 19.4 169 24.6 56 11.8
Often 93 8.0 66 9.6 27 5.7
Nearly always 37 3.2 28 4.1 9 1.9
Social 0 Not isolated 219 18.9 91 13.3 128 26.9
isolation 1 335 28.9 203 29.6 132 27.8
2 284 24.5 185 27.0 99 20.8
3 200 17.2 132 19.2 68 14.3
4 123 10.6 75 10.9 48 10.1
Mortality Death 352 30.3 186 27.1 166 34.9
Table 2. Cross-tabulation between loneliness and social isolation (%).
Social isolation
0 1 2 3 4 Total (n)
Loneliness Almost never 21.3 22.2 13.7 8.9 3.4 806
Seldom 1.6 7.0 5.4 4.1 1.3 225
Often 0.1 1.8 2.6 2.6 0.9 93
Nearly always 0.0 0.2 1.2 1.0 0.8 37
Total (n) 266 362 266 193 74 1161
Spearman’s rank correlation coecient: 0.323.
AGING & MENTAL HEALTH 5
When controlling for health, the coefficients for both social
isolation and loneliness diminished and having two point on
the social isolation scale was no longer significantly associated
with mortality ( Table 3). Respondents who had 3 or 4 points on
the social isolation index had significantly higher risks (HR 1.97
and HR 2.54, respectively) to die within five years than those
who were not socially isolated.
The results also showed that being older, female, having a
poor self-rated health, mobility impairment and problems
related to cardiovascular diseases were all significantly associ-
ated with an increased risk of mortality.
All regression analyses were performed separately for
women and men (see supplementary material Tables 1 and 2).
Overall, the results from these analyses showed similar results
for both women and men and these results were in line with
the main results presented in Table 3. Thus, for both women and
men, social isolation had a stronger association with mortality
than loneliness and remained significant in the full model, while
the association between loneliness and mortality was attenu-
ated and non-significant in the full model. Yet, some associa-
tions differed between women and men. The association
between loneliness and mortality was somewhat stronger for
men than for women. In contrast, social isolation showed a
slightly stronger association at each increased level of social
isolation below the highest level for women compared to men.
Furthermore, an additional test of interaction terms between
gender and the independent variables in the main analysis were
performed and showed no significant results (results not shown).
Finally, we examined whether there was a combined effect
of experiencing loneliness and being social isolated, that is, if
the mortality risk was higher in people who were both socially
isolated and bothered by feelings of loneliness. This was tested
by including an interaction term between loneliness and social
isolation, the results from this analysis are presented in supple-
mentary material Table 3. The interaction term was close to 1
and not significant (HR: 0.928, p-value: 0.227). In order to assess
the possible synergetic effects across the entire range of
observed values we estimated average marginal effects for both
loneliness and social isolation (see supplementary material
Figures 1 and 2). These analyses indicated no increased effects
across higher levels of either variable. Thus, the mortality risk
was not further elevated beyond the additive effect of each
separate variable when people were simultaneously bothered
by feelings of loneliness and socially isolated.
Discussion
This study focused on the separate, mutually adjusted, and com-
bined associations of loneliness and social isolation with mor-
tality in a nationally representative sample of older (+69) women
and men.
The results showed that mortality was higher among older
women and men who were often or nearly always bothered by
feelings of loneliness, when controlling for age, gender and edu-
cation, whereas there was no significant association between less
frequent feelings of loneliness and mortality. The mortality risk
also increased with higher levels of social isolation, and the asso-
ciation showed a linear pattern. This result is in line with the find-
ings from a meta-analysis concluding that most research suggests
a linear association between social isolation and mortality (Holt-
Lunstad et al., 2015) and a Finnish study also concluded that iso-
lation, even from only a few spheres of social relationships, can
have an adverse effect on mortality (Tanskanen & Anttila, 2016).
Consistent with previous research (Steptoe et al., 2013;
Tanskanen & Anttila, 2016), this study found that the association
between social isolation and mortality remained when loneli-
ness was included in the same multivariate model while the
association between loneliness and mortality became insignif-
icant when including social isolation in the model. Thus, social
isolation seems to be of higher relative importance for mortality
than feelings of loneliness. The association between social iso-
lation and mortality remained, although to some degree atten-
uated, when four different health measures were adjusted for.
Health problems can be considered as both mediators and
confounders in the association between loneliness, social iso-
lation, and mortality. There is evidence that poor health such as
limited functional ability is a risk factor for loneliness (Dahlberg
et al., in press) and social isolation (National Academies of
Sciences, Engineering, and Medicine , 2020). However, loneliness
and social isolation also increases the risk of declining health
that in turn increases the risk of death (Holt-Lunstad et al., 2015).
The design of this study does not allow us to disentangle the
Table 3. Cox proportional hazard regressions of loneliness and social isolation on mortality between 2004 and 2009. (n = 1161, deaths = 352).
Model 1: Loneliness Model 2: Social isolation
Model 3: Loneliness and social
isolation
Model 4: Loneliness social
isolation and health
HR LCI UCI pHR LCI UCI pHR LC I UCI pHR LCI UCI p
Loneliness
(ref = 0)
1 0.893 0.675 1.180 0.429 0.842 0.637 1.114 0.229 0.820 0.619 1.085 0.165
2 1.421 1.015 1.990 0.041 1.182 0.842 1.660 0.335 1.017 0.711 1.453 0.929
3 1.894 1.207 2.970 0.005 1.408 0.893 2.220 0.140 1.201 0.740 1.949 0.459
Social isolation (ref = 0)
1 1.313 0.889 1.940 0.171 1.335 0.902 1.974 0.148 1.150 0.775 1.706 0.487
2 1.530 1.023 2.287 0.038 1.524 1.016 2.286 0.042 1.330 0.884 2.002 0.171
3 2.885 1.946 4.276 0.000 2.808 1.881 4.192 0.000 1.966 1.295 2.986 0.002
4 3.394 2.154 5.348 0.000 3.271 2.065 5.182 0.000 2.544 1.585 4.084 0.000
Age 1.122 1.104 1.140 0.000 1.104 1.086 1.123 0.000 1.104 1.086 1.123 0.000 1.098 1.079 1.118 0.000
Gender 1.625 1.308 2.010 0.000 1.713 1.383 2.121 0.000 1.707 1.371 2.125 0.000 1.848 1.484 2.302 0.000
Education 0.975 0.941 1.010 0.158 0.976 0.942 1.012 0.191 0.979 0.944 1.015 0.240 0.992 0.956 1.029 0.661
Self-rated
health
1.255 1.054 1.494 0.011
Mobility 1.205 1.102 1.317 0.000
Psychological distress 0.870 0.620 1.223 0.423
Cardiovascular
problems
1.317 1.018 1.704 0.036
HR = hazard ratio, LCI = lower condence interval, UCI = upper condence interval, p = signicance.
6 C. LENNARTSSON ET AL.
exact pathways of these complex relationships. Nonetheless, a
substantial and significant association remained, indicating
independent effects between social isolation and mortality that
could not be fully explained by other variables included in
the models.
In contrast to the findings by Beller and Wagner (2018), and
in line with Tanskanen and Anttila (2016) our study found no
combined effects of loneliness and social isolation with mortal-
ity. This means that among socially isolated individuals, the risk
of mortality did not further increase if they experienced loneli-
ness. Furthermore, although Ward et al. (2021) demonstrated
that the combination of loneliness and social isolation is most
harmful for premature mortality, a discordance between the two
measures was also found to be associated with mortality. Their
findings also indicated that social isolation was more strongly
associated with premature mortality than loneliness, since the
group reporting low loneliness and high social isolation had a
higher mortality risk than the group with high loneliness and
low social isolation. These findings indicate that social isolation
and feelings of loneliness might operate in different ways and
have independent pathways to mortality (Tanskanen & Anttila,
2016). However, given the conflicting results, more research is
needed to fully understand the complex nature of these
relationships.
With separate analyses for women and men, this study con-
tributes to research by addressing gender differences. The sep-
arate analyses for women and men did, however, not deviate
by any substantial degree from the findings for the total sample.
Thus, for both women and men, social isolation was of more
relative importance for mortality than feelings of loneliness (cf.
Steptoe et al., 2013). However, this does not mean that the asso
-
ciation between feelings of loneliness and mortality should be
ignored. Previous research has found that loneliness, not social
isolation, is associated with mortality (Holwerda et al., 2012;
Iecovich et al., 2011) and there are indications of direct effects
between loneliness and mortality in younger age groups (Holt-
Lunstad et al., 2015). There is thus a need for further research
on the association between social isolation, loneliness and mor-
tality in older adults.
Strengths and limitations
A key strength of this study is that it is based on a nationally
representative sample of older adults living in Sweden. The
inclusion of people living in the community and in residential
care facilities, the use of proxy informants for people unable to
be interviewed directly, and a high response rate ensure the
representativeness of this age group in Sweden. The data are,
thus, highly representative of the population, including frail and
cognitive impaired older adults (Lennartsson et al., 2014).
Furthermore, our data on mortality is drawn from a national
register with complete coverage of the population.
Although the use of proxy informants is a strength in relation
to representativeness it can also be a limitation, since there is a
risk that indirect interviewees report more health problems and
poorer quality of life in the older person than older adults them-
selves would do (Graske et al., 2012; Moyle et al., 2012). However,
other research has shown that responses from a person with
good knowledge about the living conditions of the older person
demonstrate good concordance with responses from older
adults themselves when measuring, for example, social isolation
(Boyer et al., 2004) and quality of life (McKee et al., 2002). In
addition, the exclusion of those who are not able to conduct an
interview by themselves would underestimate many difficulties
and problems (Kelfve et al., 2013).
A potential limitation of this study is the use of a single-item
measure of loneliness. Still, while there may be advantages of
using validated instruments, single items of loneliness are fre-
quently used and accepted in research on loneliness in old age
(e.g. Jylhä & Saarenheimo, 2010; Luanaigh & Lawlor, 2008; Victor
et al., 2008). While being less sensitive than scales, single items
are regarded to have good face validity, as they ‘present an
everyday life concept that is routinely used in daily interactions’
(Victor et al., 2008, p. 65).
Although this study included a broad set of indicators to
measure social isolation there are aspects of social contacts and
social activity not covered, which may have implications for the
analysis of the association of social isolation and mortality.
We tested whether there was a combined effect of loneliness
and social isolation that was larger than the separate effects.
The results indicated no effect of the interaction between these
two variables. However, only a small number of respondents
experienced both high levels of loneliness and high levels of
isolation. Therefore, there is a need for these findings to be com-
plemented by further research examining the possibility of a
combined effect of loneliness and social isolation on mortality
in samples where these conditions are more prevalent.
Finally, results from observational studies may be affected
by reverse causality. Health problems limit individuals’ potential
to participate in society across various life domains. Thus, social
isolation and/or loneliness may be more common among older
adults with health problems and the risk of mortality may be
higher because of higher levels of health problems, not because
of social isolation and/or loneliness.
Implications for policy and practice
This study adds to previous literature by showing that social
isolation and loneliness have consequences for mortality. In
addition to the risk of mortality, social isolation and loneliness
are important for health and well-being. Interventions to com-
bat these conditions in older adults should, thus, be highly pri-
oritised. Such risks are particularly important to consider at
times such as the COVID-19 pandemic, when many govern-
ments have restricted physical social contacts.
Currently, there is a lack of evidence for effective interven-
tions to reduce loneliness and social isolation (Fakoya et al.,
2020; Victor et al., 2018). To support evidence-based practice,
there is a need for studies of high quality that examines the
separate effects of interventions on loneliness and social isola-
tion. In the design of interventions, it is important to address
risk factors of these conditions separately, and to target vulner-
able groups of older adults identified in previous research.
Further research to disentangle the association between
social isolation and loneliness and how these, in turn, are asso-
ciated with various health outcomes would give insight into
how older adults may benefit from different interventions
(Newall & Menec, 2019).
Older adults with poor health and functional limitations are
at an increased risk of loneliness and social isolation and for
those who receive social care services, policies and strategies
to prevent and reduce these conditions could be an integrated
part of already existing social services. In Sweden, this is sup-
ported in the Social Service Act, which states that social services
AGING & MENTAL HEALTH 7
should support older adults in leading an active life together
with other people. However, due to financial pressure on these
services, in practice work to address health needs is often pri-
oritised over work to prevent and or reduce social isolation and
loneliness.
As social isolation has implications for mortality, the health
care sector also needs to take older adults’ social situation into
account, for example, when assessing health care needs. A pre-
vious study found that socially excluded individuals did not
receive higher levels of social care than socially included indi-
viduals, but that they had an increased risk of health care visits,
which offers an opportunity to identify this group and refer
them to appropriate social care providers and/or other provid-
ers of support for social integration (Dahlberg & McKee, 2016).
Conclusions
For both women and men, social isolation showed stronger
associations with mortality than loneliness in mutually adjusted
models. Interventions to reduce or prevent social isolation are
therefore likely to have greater direct benefits for mortality than
interventions targeting loneliness. It is of utmost importance
that social integration and social relations are a prioritised target
for social services and activities involving older adults.
Disclosure statement
The authors declare that they have no conict of interest.
Ethical approval
Ethical approval was obtained from the Stockholm Regional Ethical
Review Board (reg.no. 2004-314/5; 2010/403-31/4).
Funding
This work was supported by Swedish Research Council for Health,
Working Life and Welfare (FORTE), grant numbers 2015-00440, 2016-
07206, and 2017-00668.
References
Ai, C., & Norton, E. C. (2003). Interaction terms in logit and probit models.
Economics Letters, 80(1), 123–129. https://doi.org/10.1016/S0165-
1765(03)00032-6
Beller, J., & Wagner, A. (2018). Loneliness, social isolation, their synergistic inter-
action, and mortality. Health Psychology: Ocial Journal of the Division of
Health Psychology, American Psychological Association, 37(9), 808–813.
Boyer, F., Novella, J. L., Morrone, I., Jolly, D., & Blanchard, F. (2004).
Agreement between dementia patient report and proxy reports using
the Nottingham Health Prole. International Journal of Geriatric
Psychiatry, 19(11), 1026–1034. https://doi.org/10.1002/gps.1191
Brambor, T., Clark, W. R., & Golder, M. (2006). Understanding interaction
models: Improving empirical analyses. Political Analysis, 14(1), 63–82.
[Database] https://doi.org/10.1093/pan/mpi014
Cacioppo, J. T., Cacioppo, S., Capitanio, J. P., & Cole, S. W. (2015). The neuroendo-
crinology of social isolation. Annual Review of Psychology, 66, 733–767.
Courtin, E., & Knapp, M. (2017). Social isolation, loneliness and health in old age:
A scoping review. Health & Social Care in the Community, 25(3), 799–812.
Crimmins, E. M., Kim, J. K., & Solé-Auró, A. (2011). Gender dierences in
health: Results from SHARE, ELSA and HRS. European Journal of Public
Health, 21(1), 81–91.
Dahlberg, L., McKee, K. J. , Frank, A.,& Naseer, M. (i pressen). En system-
atisk genomgång av longitudinella riskfaktorer för ensamhet hos äldre
vuxna. Åldrande & Psykisk hälsa. https://doi.org/10.1080/13607863.202
1.1876638
Dahlberg, L., Andersson, L., & Lennartsson, C. (2018). Long-term inuences
on loneliness in old age: Results of a 20-year national study. Aging &
Mental Health, 22(2), 190–196. https://doi.org/10.1080/13607863.2016.
1247425
Dahlberg, L., & McKee, K. J. (2016). Living on the edge: Social exclusion and
the receipt of informal care in older people. Journal of Aging Research,
2016, 6373101. https://doi.org/10.1155/2016/6373101
de Jong Gierveld, J., van Tilburg, T. G., & Dykstra, P. A. (2018). New ways of
theorizing and conducting research in the eld of loneliness and social
isolation. In A. L. Vangelisti & D. Perlman (Eds.), The Cambridge hand-
book of personal relationships (pp. 391–404). Cambridge University
Press.
Elovainio, M., Hakulinen, C., Pulkki-Råback, L., Virtanen, M., Josefsson, K.,
Jokela, M., Vahtera, J., & Kivimäki, M. (2017). Contribution of risk factors
to excess mortality in isolated and lonely individuals: An analysis of
data from the UK Biobank cohort study. The Lancet. Public Health, 2(6),
e260–e266. https://doi.org/10.1016/S2468-2667(17)30075-0
Fakoya, O. A., McCorry, N. K., & Donnelly, M. (2020). Loneliness and social
isolation interventions for older adults: A scoping review of reviews.
BMC Public Health, 20(1), 1-14. https://doi.org/10.1186/s12889-020-
8251-6
Graske, J., Fischer, T., Kuhlmey, A., & Wolf-Ostermann, K. (2012). Quality of
life in dementia care - dierences in quality of life measurements per-
formed by residents with dementia and by nursing sta. Aging & Mental
Health, 16(7), 819–827.
Hawkley, L., & Cacioppo, J. (2010). Loneliness matters: A theoretical and
empirical review of consequences and mechanisms. Annals of
Behavioral Medicine : A Publication of the Society of Behavioral Medicine,
40(2), 218–227.
Holt-Lunstad, J., Smith, T. B., Baker, M., Harris, T., & Stephenson, D. (2015).
Loneliness and social isolation as risk factors for mortality: a meta-ana-
lytic review. Perspectives on Psychological Science : a Journal of the
Association for Psychological Science, 10(2), 227–237.
Holwerda, T. J., Beekman, A. T. F., Deeg, D. J. H., Stek, M. L., van Tilburg, T. G.,
Visser, P. J., Schmand, B., Jonker, C., & Schoevers, R. A. (2012). Increased
risk of mortality associated with social isolation in older men: Only
when feeling lonely? Results from the Amsterdam Study of the Elderly
(AMSTEL). Psychological Medicine, 42(4), 843–853. https://doi.
org/10.1017/S0033291711001772
Iecovich, E., Jacobs, J. M., & Stessman, J. (2011). Loneliness, social networks,
and mortality: 18 years of follow-up. International Journal of Aging &
Human Development, 72(3), 243–263.
Jylhä, M., & Saarenheimo, M. (2010). Loneliness and aging: Comparative
perspectives. In C. R. Phillipson & D. Dannefer (Eds.), The SAGE Handbook
of Social Gerontology (pp. 317–328). Sage Publication Ltd.
Kelfve, S., Thorslund, M., & Lennartsson, C. (2013). Sampling and non-re-
sponse bias on health-outcomes in surveys of the oldest old. European
Journal of Ageing, 10(3), 237–245.
Leigh-Hunt, N., Bagguley, D., Bash, K., Turner, V., Turnbull, S., Valtorta, N., & Caan,
W. (2017). An overview of systematic reviews on the public health conse-
quences of social isolation and loneliness. Public Health, 152, 157–171.
Lennartsson, C., Agahi, N., Hols-Salén, L., Kelfve, S., Kåreholt, I., Lundberg,
O., Parker, M. G., & Thorslund, M. (2014). Data resource prole: The
Swedish Panel Study of Living Conditions of the Oldest Old (SWEOLD).
International Journal of Epidemiology, 43(3), 731–738. https://doi.
org/10.1093/ije/dyu057
McKee, K. J., Houston, D. M., & Barnes, S. (2002). Methods for assessing
quality of life and well-being in frail older people. Psychology & Health,
17(6), 737–751. https://doi.org/10.1080/0887044021000054755
McLaughlin, D., Vagenas, D., Pachana, N. A., Begum, N., & Dobson, A. (2010).
Gender dierences in social network size and satisfaction in adults in
their 70s. Journal of Health Psychology, 15(5), 671–679.
Moyle, W., Mureld, J. E., Griths, S. G., & Venturato, L. (2012). Assessing
quality of life of older people with dementia: A comparison of quantita-
tive self-report and proxy accounts. Journal of Advanced Nursing, 68(10),
2237–2246. https://doi.org/10.1111/j.1365-2648.2011.05912.x
National Academies of Sciences, Engineering, and Medicine. (2020). Social
isolation and loneliness in older adults: Opportunities for the health
care system. Chapter 4. Risk and protective factors for social isolation
and loneliness. The National Academies Press. https://doi.
org/10.17226/25663.
8 C. LENNARTSSON ET AL.
Newall, N. E., & Menec, V. H. (2019). Loneliness and social isolation of older
adults: Why it is important to examine these social aspects together.
Journal of Social and Personal Relationships, 36(3), 925–939. https://doi.
org/10.1177/0265407517749045
Nyqvist, F., Pape, B., Pellfolk, T., Forsman, A., & Wahlbeck, K. (2014).
Structural and cognitive aspects of social capital and all-cause mortali-
ty: A meta-analysis of cohort studies. Social Indicators Research, 116(2),
545–566. https://doi.org/10.1007/s11205-013-0288-9
Luanaigh, C. O., & Lawlor, B. A. (2008). Loneliness and the health of older
people. International Journal of Geriatric Psychiatry, 23(12), 1213–1221.
Perlman, D., & Peplau, L. A. (1981). Toward a social psychology of loneli-
ness. Personal Relationships, 3, 31–56.
Rico-Uribe, L. A., Caballero, F. F., Martín-María, N., Cabello, M., Ayuso-
Mateos, J. L., & Miret, M. (2018). Association of loneliness with all-cause
mortality: A meta-analysis. PLoS One, 13(1), e0190033. https://doi.
org/10.1371/journal.pone.0190033
Rothman, K. J., Greenland, S., & Walker, A. M. (1980). Concepts of interac-
tion. American Journal of Epidemiology, 112(4), 467–470.
Shor, E., & Roelfs, D. J. (2015). Social contact frequency and all-cause mor-
tality: A meta-analysis and meta-regression. Social Science & Medicine,
128, 76–86. https://doi.org/10.1016/j.socscimed.2015.01.010
Statistics Sweden. (2020). http://www.statistikdatabasen.scb.se/
Steptoe, A., Shankar, A., Demakakos, P., Wardle, J. (2013). Social isolation,
loneliness, and all-cause mortality in older men and women.
Proceedings of the National Academy of Sciences of the United States
of America, 110(15), 5797–5801.
Taylor, H. O. (2020). Social isolation’s inuence on loneliness among older
adults. Clinical Social Work Journal, 48(1), 140–151. https://doi.
org/10.1007/s10615-019-00737-9
Tanskanen, J., & Anttila, T. (2016). A prospective study of social isolation,
loneliness, and mortality in Finland. American Journal of Public Health,
106(11), 2042–2048.
Tilvis, R., Routasalo, P., Karppinen, H., Strandberg, T., Kautiainen, H., &
Pitkala, K. (2012). Social isolation, social activity and loneliness as sur-
vival indicators in old age; a nationwide survey with a 7-year follow-up.
European Geriatric Medicine, 3(1), 18–22. https://doi.org/10.1016/j.eurg-
er.2011.08.004
Victor, C. R., Manseld, L., Kay, T., Daykin, N., Lane, J., L., G. D.,. Meads, C.
(2018). An overview of reviews: The eectiveness of interventions to
address loneliness at all stages of the life-course. https://whatwork-
swellbeing.org/resources/tackling-loneliness-review-of-reviews/
Victor, C., Scambler, S., & Bond, J. (2008). The social world of older people:
Understanding loneliness and social isolation in later life. McGraw-Hill
Education.
Victor, C., Scambler, S., Bond, J., & Bowling, A. (2000). Being alone in later life:
Loneliness, social isolation and living alone. Reviews in Clinical Gerontology,
10(4), 407–417. https://doi.org/10.1017/S0959259800104101
Ward, M., Maj, P., Normand, C., Kenny, R. A. , & Nolan, A. (2021). Dödlighetsrisk
i samband med kombinationer av ensamhet och social isolering.
Resultat från den irländska longitudinella studien om åldrande (TILDA).
Ålder och åldrande, 50, 1329–1335. https://doi.org/10.1093/ageing/
afab004
