comparing sex inequalities in common affective disorders across countries: great britain and chile

11
Social Science & Medicine 60 (2005) 1693–1703 Comparing sex inequalities in common affective disorders across countries: Great Britain and Chile Graciela Rojas a , Ricardo Araya b, , Glyn Lewis b a Clinica Psiquiatrica, Facultad de Medicina, Universidad de Chile, Avda La Paz 1003, Santiago, Chile b Division of Psychiatry, University of Bristol, Cotham House, Cotham Hill, Bristol BS6 6JL, UK Abstract Most studies throughout the world have found that women report more psychological symptoms than men. Much less is known about possible variation between countries in the magnitude of these sex differences or the factors contributing to the increase of risk among women in countries with different levels of development. This study aimed to compare sex differences for common affective disorders (CAD) between Great Britain and Chile based on two large urban cross-sectional psychiatric household surveys that used similar methodology. Women in both countries reported more CAD than men but Chilean women had an increased risk in comparison to their British counterparts, a difference that became larger as symptom severity increased. Of all the main explanatory variables included in the analysis––education, employment status, children at home, marital status, and social support—the only statistically significant interaction that could account for this increased risk was education, with an increasingly larger risk for women with lower levels of educational attainments in Chile compared to Britain. Education is a powerful socio- economic indicator that is difficult to revert later in life, especially in countries where opportunities for women are less forthcoming, and it might act as powerful reminder of social entrapment. r 2004 Elsevier Ltd. All rights reserved. Keywords: Women; Mental disorders; Inequalities; Great Britain; UK; Chile Introduction Sex differences in the prevalence of common affective disorders across countries The commonest affective disorders (CAD), depression and anxiety, are frequent and disabling in rich as well as poor countries (Murray & Lopez, 1997). One of the most consistent findings in psychiatric epidemiology is that women, especially those living in urban settings, seem to be at an increased risk of suffering from CAD (Piccinelli & Wilkinson, 2002; Patel, Araya, Ludemir, Todd & Lima, 1999; Bebbington, 1998). However, less is known if the magnitude of these sex differences in the prevalence of CAD is comparable across countries or if the type of risk factors that might explain this increased risk among women are similar in countries with different levels of development. The use of different methodologies to ascertain the presence of psychological symptoms, the difficulties of comparing unadjusted or partially adjusted results, and the scarcity of large household surveys from developing countries have somehow hindered the making of valid comparisons across countries. This is an important issue that interferes with the possibility of gaining further ARTICLE IN PRESS www.elsevier.com/locate/socscimed 0277-9536/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.socscimed.2004.08.030 Corresponding author. Department of Psychiatry, Univer- sity of Bristol, Cotham house, Cotham Hill, Bristol BS6 6UJ, UK. Fax: +44-117-954-66721. E-mail address: [email protected] (R. Araya).

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Page 1: Comparing sex inequalities in common affective disorders across countries: Great Britain and Chile

ARTICLE IN PRESS

0277-9536/$ - se

doi:10.1016/j.so

�Correspond

sity of Bristol,

UK. Fax: +44

E-mail addr

Social Science & Medicine 60 (2005) 1693–1703

www.elsevier.com/locate/socscimed

Comparing sex inequalities in common affective disordersacross countries: Great Britain and Chile

Graciela Rojasa, Ricardo Arayab,�, Glyn Lewisb

aClinica Psiquiatrica, Facultad de Medicina, Universidad de Chile, Avda La Paz 1003, Santiago, ChilebDivision of Psychiatry, University of Bristol, Cotham House, Cotham Hill, Bristol BS6 6JL, UK

Abstract

Most studies throughout the world have found that women report more psychological symptoms than men. Much

less is known about possible variation between countries in the magnitude of these sex differences or the factors

contributing to the increase of risk among women in countries with different levels of development. This study aimed to

compare sex differences for common affective disorders (CAD) between Great Britain and Chile based on two large

urban cross-sectional psychiatric household surveys that used similar methodology. Women in both countries reported

more CAD than men but Chilean women had an increased risk in comparison to their British counterparts, a difference

that became larger as symptom severity increased. Of all the main explanatory variables included in the

analysis––education, employment status, children at home, marital status, and social support—the only statistically

significant interaction that could account for this increased risk was education, with an increasingly larger risk for

women with lower levels of educational attainments in Chile compared to Britain. Education is a powerful socio-

economic indicator that is difficult to revert later in life, especially in countries where opportunities for women are less

forthcoming, and it might act as powerful reminder of social entrapment.

r 2004 Elsevier Ltd. All rights reserved.

Keywords: Women; Mental disorders; Inequalities; Great Britain; UK; Chile

Introduction

Sex differences in the prevalence of common affective

disorders across countries

The commonest affective disorders (CAD), depression

and anxiety, are frequent and disabling in rich as well as

poor countries (Murray & Lopez, 1997). One of the

most consistent findings in psychiatric epidemiology is

that women, especially those living in urban settings,

e front matter r 2004 Elsevier Ltd. All rights reserve

cscimed.2004.08.030

ing author. Department of Psychiatry, Univer-

Cotham house, Cotham Hill, Bristol BS6 6UJ,

-117-954-66721.

ess: [email protected] (R. Araya).

seem to be at an increased risk of suffering from CAD

(Piccinelli & Wilkinson, 2002; Patel, Araya, Ludemir,

Todd & Lima, 1999; Bebbington, 1998). However,

less is known if the magnitude of these sex differences

in the prevalence of CAD is comparable across countries

or if the type of risk factors that might explain this

increased risk among women are similar in countries

with different levels of development. The use of

different methodologies to ascertain the presence of

psychological symptoms, the difficulties of comparing

unadjusted or partially adjusted results, and the

scarcity of large household surveys from developing

countries have somehow hindered the making of valid

comparisons across countries. This is an important issue

that interferes with the possibility of gaining further

d.

Page 2: Comparing sex inequalities in common affective disorders across countries: Great Britain and Chile

ARTICLE IN PRESSG. Rojas et al. / Social Science & Medicine 60 (2005) 1693–17031694

insight into the aetiology of psychiatric disorders

when examining similarities and differences between

countries.

How to explain differences between countries in the

prevalence of common affective disorders among women?

Although little is known of risk factors that could

differentially increase the risk of CAD among women in

some countries, it would seem unlikely that a biological

factor would be able to explain much of these

differences. There are no obvious discrepancies in the

biological make-up of women living in different

countries, other than those brought upon by living in

different social, cultural, and economic realities. Thus if

there were differences in the prevalence of CAD among

women from countries with different levels of develop-

ment, psychosocial factors are more likely to provide an

explanation for these differences. Psychosocial factors

that have been linked to an increased risk of psycholo-

gical morbidity and show unequal distribution between

countries are worth exploring, such as employment or

unemployment, socio-economic differences, the number

of dependent children, multiple roles, or low social

support (Araya, Lewis, Rojas & Fritsch, 2003; Piccinelli

& Wilkinson, 2002; Bebbington, 1998; Weich, Sloggett

& Lewis, 1998).

Several single-country studies, mostly from developed

countries, have investigated the effect of work on

women’s mental health. Most of these studies, but not

all, have been carried out as part of research investigat-

ing the impact of multiple roles (‘role strain hypothesis’)

on the mental health of women (Fokkema, 2002;

Matthews, Power & Stansfeld, 2001; Weich, Sloggett &

Lewis, 2001; Weich et al., 1998; Waldron, Weiss &

Hughes, 1998). As a whole, this research has failed to

provide good evidence in support of the ‘role strain’

hypothesis but, on the contrary, several of these studies

have shown that work was likely to have a positive effect

for the mental health of women, regardless of the

number of roles held simultaneously. Studies carried out

in the developing world (Iran, India, Brazil and Chile)

have failed to find differences in the mental health of

working and non-working women (Ahmad–Nia, 2002;

Araya, Rojas, Fritsch, Acuna & Lewis, 2001; Patel et al.,

1999). It is possible that the more unfavourable living

situation of women in developing countries might have

contributed to dilute any positive effects of employment

on women’s mental health. Other methodological issues,

such as for instance the possibility that psychologically

healthier women were more likely to take on employ-

ment, also interfere with reaching any firmer conclu-

sions. So in spite of the evidence suggesting beneficial

effects of employment it is not possible yet to assume

that work is beneficial for all women and under all

circumstances.

The evidence from developed countries suggesting

that education might be an important risk factor for

mental illness is scant and there is even less support for

an educational effect that could account for the gender

differences in the prevalence of CAD (Bebbington, 1996,

1998). Nonetheless, there are marked differences in

educational attainments within and between countries,

with women consistently achieving lower levels than

men especially in developing countries (World Bank,

2001a, b). There is stronger evidence to show that socio-

economic adversity is associated with the presence of

CAD (Lorant et al., 2003; Araya et al., 2001, 2003;

Weich, Lewis & Jenkins, 2001; Weich & Lewis, 1998;

Lewis et al., 1998); and that people, especially women, in

poorer countries are comparatively under more social

disadvantage than individuals in richer countries (World

Bank, 2001b; United Nations Population Fund, 2000;

Desjarlais, Eisenberg, Byron & Kleinman, 1995). Thus it

might be reasonable to expect that sex differences in

CAD could be larger in poorer than in richer countries.

British studies have also shown that the presence of two

or more young children at home and the lack of a

confiding partner were also associated with an increased

prevalence of depression in women (Bebbington, 1996;

Brown & Harris, 1978). Equally previous research had

consistently shown an inverse association between social

support and CAD, with less support associated with an

increased prevalence of CAD, but sex differences in this

association are less commonly reported (Berkman &

Glass, 2000).

There are many difficulties, though, when trying to

determine the relative importance of individual

psychosocial factors to increase the risk of CAD across

countries. Some authors have argued for the need to

include into the analysis the socio-economic, cultural,

and political context under which these factors

operate (Janzen & Muhajarine, 2003). Contextual

differences cannot be underestimated when comparing

countries with different cultures and levels of socio-

economic development. However, contextual variables

are rarely incorporated into the analysis for this kind of

research in mental health. Among possible reasons for

this omission are (1) difficulties in obtaining reliable and

comparable contextual data across countries, (2) varia-

tion in the relative importance of contextual factors

across cultures and over time within countries, and (3)

methodological difficulties in analysing this kind of data

adequately. We are unaware of any study comparing

mental health between countries that incorporates

contextual as well as individual variables into the

analysis. However, most studies usually consider con-

textual differences when interpreting results and reach-

ing conclusions.

The social context under which sex differences in

CAD present is complex in the developing world. For

instance, many international agencies and governments

Page 3: Comparing sex inequalities in common affective disorders across countries: Great Britain and Chile

ARTICLE IN PRESSG. Rojas et al. / Social Science & Medicine 60 (2005) 1693–1703 1695

see development as closely linked to increasing produc-

tivity through an enlarged, better educated, and

healthier workforce. Women’s participation in the

workforce is rising in almost every developing country

but their share of the better jobs or educational

opportunities still lag far behind men, a gender gap

much wider than in most developed countries (World

Bank, 2001a, b; United Nations Population Fund,

2000). In most developing countries, there has been a

slow introduction of the necessary social changes to

support the incorporation of women into the workforce

(World Bank, 2001a, b; United Nations Population

Fund, 2000). Other important demographic changes

are also occurring such as a decrease in the size of

families, not only in terms of the number of children but

also in the size and ramifications of the extended family,

the traditional provider of social support. The rapid

social transformations that developing countries are

experiencing are likely to have an impact on the mental

health of their populations, an effect that might be more

pronounced among women who seemed to be enduring

more significant changes. Thus it is important to

understand this phenomenon in countries outside the

western world, where most of the world’s population

lives.

This study brings together data from two large and

well-conducted psychiatric household surveys carried

out in Great Britain and Chile (Araya et al., 2001;

Jenkins et al., 1997) using comparable methodologies

and thus allowing comparisons to be made. These

countries represent two contrasting cultures with differ-

ent levels of development. Whilst Great Britain is

considered a high-income country, Chile belongs to the

middle-income, emerging economies group. It is worth

noting, however, that these broad international classifi-

cation systems often fail to capture some aspects of the

social differences between countries. For instance, the

proportion of women participating in the labour force in

Chile is 33%, a figure lower than the average 40% found

in poorer countries (World Bank, 2001b). Equally,

although Chile is regarded as a middle-income country,

it is also one of the ten most unequal countries in the

world as far as income is concerned (World Bank,

2001b).

Our main hypothesis was that women in both

countries have increased risks of CAD in comparison

to men, but Chilean women would have an increased

risk of CAD compared to their British counterparts.

This risk difference between Chilean and British women

would be even more pronounced as symptoms become

more severe. If our hypothesis were correct, we would

undertake an exploratory analysis to find out if there

were differences also in the type of risk factors

associated with CAD in women. We focused this part

of the analysis on social variables that have previously

been related to CAD: educational attainments, working

status, number of children, marital status, and social

support.

Methods

Participants and sampling

This paper used data from the ‘Santiago Mental

Disorders Survey’ undertaken in 1996 in Santiago, Chile

(Araya et al., 2001), and the ‘Great Britain National

Survey of Psychiatry Morbidity’ (Jenkins et al., 1997)

undertaken in 1993. Both studies used similar meth-

odologies. However, the Chilean sample was restricted

to Santiago, capital of Chile, where more than 50% of

the total population lives, whereas the British study used

a nationally representative sample. For the purpose of

this paper, only data collected in urban British settings

was used in order to facilitate the comparisons.

Santiago, Chile: Households within sectors from all

the 35 boroughs of Santiago were randomly chosen with

a probability proportional to the size of the sampling

unit using a three-stage clustered design. A larger

sampling fraction was required in the most affluent

boroughs to allow testing for socio-economic differences

between groups. The sampling framework was the total

adult (aged 16–64) population living in private house-

holds of Santiago, representing 3,217,177 individuals.

Using Kish tables one person per household was chosen

at random. The response rate was 90%. Further details

of the sampling design can be found in previous

publications or requested from the authors (Araya et

al., 2001).

Urban, Great Britain: A stratified, cluster, probability

sample was drawn for the UK excluding the Highlands

and the Islands of Scotland. Two hundred postal sectors

were selected with probability proportional to size and

90 addresses were randomly selected from each sector.

One individual, aged 16–64, in each household was

interviewed. Individuals living in rural or semi-rural sites

as well as ‘proxy’ interviews were excluded. Experienced

interviewers from the Office of National Statistics

classified the households as urban, rural, or semi-rural

according to their pre-established criteria (Meltzer, Gill,

Petticrew & Hinds, 1995). The response rate was 79%

for the overall sample. The main findings have already

been published and further details can be obtained

elsewhere (Jenkins et al., 1997).

Variables

Individuals who met ICD-10 criteria for depressive

episode or anxiety disorders (generalised anxiety, phobia

or panic) were classified as suffering from a Common

Affective Disorder, our main outcome variable. In view

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ARTICLE IN PRESSG. Rojas et al. / Social Science & Medicine 60 (2005) 1693–17031696

of the high co-morbidity of these disorders and the

questionable validity of some psychiatric diagnoses we

think it is appropriate to treat these disorders as a single

variable. Diagnostic criteria were assessed using the

Revised Clinical Interview Schedule (CIS-R) (Lewis,

Pelosi, Araya & Dunn, 1992), a structured interview that

has been fully standardised so that it can be adminis-

tered by lay interviewers. This interview has 14 sections,

each covering a specific neurotic dimension with its own

individual score. All scores can be summed to yield a

total score that provides a rough estimate of the severity

of psychiatric symptomatology. The CIS-R in its

English and Spanish versions has been used extensively

in primary care and community studies with validity and

reliability comparable to other commonly used struc-

tured interviews in mental health (Brugha et al., 2000;

Brugha, Bebbington & Jenkins, 1999; Andrews & Peters,

1998; Lewis et al., 1992).

Besides sex (male and female) the following variables

were included in the analysis:

1.

Education summarised in four categories according to

increasing levels of achievements in the British sample

(A-level, GCSE grade A–C, GCSE grade D–F, and

no qualifications) or increasing years of education in

Chile (primary incomplete, primary complete, sec-

ondary incomplete, and secondary complete or

greater). These are the classification systems used by

the Office of National Statistics in both countries

with the purpose of measuring educational level.

Even though these are probably valid ways of

measuring educational achievements in each country,

it does not mean that there is equivalence in the

categories across countries. For instance, we do not

know if these categories are equivalent in terms of the

opportunities arising out of achieving a certain level,

a problem that would persist even if we had used the

number of years of education completed in both

countries. Similarly, the equivalence of categories

between countries for almost all other potential risk

factors included in this study could be questioned on

similar grounds. Educational systems are different

across the world and we have to find ways of

comparing the impact of education on various

outcomes of interest. There will be limitations on

whatever method is chosen to compare different

populations, an issue that invites caution when

interpreting the results. However, we think that, on

balance, our educational categories represent differ-

ent levels of educational achievements in both

countries and allow our samples to be sufficiently

spread in categorical sub-groups.

2.

Working status: Individuals were classified in the

following categories: employed, unemployed, house-

keeper, inactive representing students and pensioners,

and permanently unable to work for health reasons.

In order to qualify for the unemployment category,

the individual had to be out of work and actively

seeking it. Individuals temporarily out-of-work for

health reasons were also included as unemployed as

well as those who were working informally and

concomitantly seeking a job.

3.

The number of young children comprised own children

aged 15 or less living in the household. This variable

was divided into four categories: no kids, one kid,

two kids, and more than two kids.

4.

Marital status divided into married, co-habiting,

single, widowed, and divorced/separated.

5.

Social support representing the self-reported number

of people (friends and/or relatives) who could provide

either practical or emotional support if needed

grouped in three categories: low (less than three),

middle (between three and four), and high (more than

four).

In addition, the following variables were also included

for adjustment in the analysis:

1.

Age treated as a continuous variable.

2.

The presence of a self-reported physical disease in

response to this question: ‘Do you have any long-

standing illness, disability, or infirmity?’

3.

The number of units of alcohol consumed weekly

subdivided into five categories: abstained, low,

middle, high, and very high.

Statistical analysis

The association between the dependent variable—

CAD—and sex was examined by calculating crude and

adjusted odds ratios and their 95% confidence intervals

using logistic regression models. Confidence intervals

were calculated using Huber White Robust estimator of

variance, which takes account of the clustered nature of

the samples (Huber, 1981). All models were also

adjusted for household size to take account of the

different sampling fractions. In order to test for an

increased risk of suffering from CAD among Chilean

women, we tested for interactions between country and

sex using likelihood ratio tests (LR tests). We also

investigated if this increased risk could be due to

symptom severity differentials in these two countries

by using different thresholds for caseness according to

CIS-R scores.

Subsequently, we carried out an exploratory analysis

restricting our sample to women only in order to test for

interactions between country and some other variables

of interest that could account for the possible increased

risk among Chilean women. We only tested for

interactions after ensuring there was no co-linearity

between variables. Testing for interactions also allowed

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ARTICLE IN PRESSG. Rojas et al. / Social Science & Medicine 60 (2005) 1693–1703 1697

us to explore for an association between women holding

more than one role and the presence of CAD in each

country separately. For instance, we were able to test for

an increase in the risk of being employed among

housewives in Chile, which could have been larger than

the sum of the two independent risks. Although weights

can be applied to adjust for sampling procedures and

obtain population estimates, we decided to use un-

weighted data because our main focus was to establish

associations between groups and countries rather than

making population estimates. All analysis was per-

formed using STATA Version 7.0 (STATA, 2001).

Results

In the British sample, 3434 individuals living in rural

or semi-urban sites as well as 117 ‘proxy’ interviews were

excluded. Thus the total British sample of urban living

interviewees comprised 6556 individuals. In the Chilean

sample, all 3870 completed interviews were from people

living in urban settings and thus were used for the

comparisons. The characteristics of the samples can be

seen in Table 1.

Table 1

Characteristics of the samples by sex and country Santiago, Chile, an

Chile

Women

(N=2332)

Mean age (95% CI) 37.8 (37.2–3

Education (%) Lowest 19

Middle low 24

Middle high 36

Highest 22

Marital status (%) Married 54.8

Cohabiting 4.0

Single 27.4

Widowed 4.9

Separated 8.8

Working status (%) Employed 36.2

Housekeeper 38.1

Pensioner/student 15.7

Retired ill-health 0.8

Unemployed 9.2

Perceived social support (%) High 41.5

Middle 36.2

Low 22.4

Number of young children (%) No child 60.4

One child 17.8

Two children 14.2

4Two children 7.6

There were some important differences in the samples

between and within countries. When comparing the two

countries, the British sample was older than the Chilean

[mean 39 (95% CI 39–40) vs. 37 (36–37); p ¼ 0:000).

Within countries, women were older than men in Chile

whereas in the British sample mean ages were similar for

both sexes. In both countries, males had achieved higher

levels of education than females. Official statistics using

indicators such as enrolment in primary education tend

to show a smaller educational gap between sexes in both

countries (World Bank, 2001b). Comparisons of educa-

tional achievements between men and women within

countries are not affected by the different methods used

to classify education in this study.

Also in keeping with official statistics, a higher

proportion of British women and men were co-habiting

and separated in comparison to their Chilean counter-

parts. The largest differences between the two countries

were to be found in working status and levels of

perceived social support. More British women were

employed whereas more Chilean women were house-

keepers, a finding compatible with other international

datasets (World Bank, 2001b). There were more

students among the Chileans and more people retired

d urban Great Britain. Un-weighted data

Great Britain

Men Women Men

(N=1538) (N=3548) (N=3008)

8.3) 35.4 (34.7–36.1) 39.4 (38.9–39.8) 39.2 (38.7–39.7)

15 36 27

25 11 10

29 26 23

31 26 39

50.8 49.8 52.2

2.4 7.2 7.3

39.6 22.1 29.5

1.8 5.5 1.4

5.4 15.5 9.6

63.7 58.9 71.4

2.0 21.2 1.2

22.2 9.7 7.6

1.2 4.0 6.2

10.9 6.2 13.6

48.5 54.6 61.7

33.9 37.2 29.6

17.6 8.2 8.7

69.3 57.5 67.3

14.4 18.4 13.5

10.7 16.5 13.8

5.7 7.6 5.4

Page 6: Comparing sex inequalities in common affective disorders across countries: Great Britain and Chile

ARTICLE IN PRESSG. Rojas et al. / Social Science & Medicine 60 (2005) 1693–17031698

on health-grounds among the British, possibly reflecting

the age structure of the two samples. Levels of

unemployment were in keeping with seasonally adjusted

official statistics in the British sample. However,

unemployment rate was marginally higher than officially

reported at the time of data collection in Chile

(Ministerio de Planificacion Nacional, 1998). However,

it must be noted that in Chile official reports do not

include as unemployed those working informally but

still seeking employment as we did in this study. A much

larger proportion of the Chilean sample reported low

levels of social support compared to their British

counterpart. Men reported higher levels of perceived

social support than women in both countries. The

number of young children at home in both countries was

similar.

Chilean and British women were significantly more

likely to be suffering from a CAD than their male

counterparts in both countries, even after adjusting for

all other variables in the models (Table 2). Most

importantly, there was a statistically significant interac-

tion between sex and country for CAD before and after

adjustments (LR test w2 ¼ 13:19; p ¼ 0:001 after adjust-

ments in the full model), in which Chilean women

showed an increased likelihood of suffering from a CAD

in comparison to British women.

Chilean women were increasingly more likely to be

psychiatric cases than their male counterparts as the

CIS-R threshold increased; in other words,

treating milder conditions as non-cases only contributed

to accentuate gender differences in Chile. On the

contrary, no major sex differences in the likelihood of

being a case were found with different CIS-R thresholds

for caseness in the British sample. As a result of

these differences between sexes in the severity of

symptoms in each country, the strength of the interac-

tions between sex and country became more prominent

at the most severe end of the symptom severity spectrum

(Table 3).

Table 2

The association between common affective disordersa (CAD) and sex

logistic regression modelling. Un-weighted data

Common affective disorders

Prevalence % (95% CI) Cr

Chile Men 6.8 (5.6–8.2) 1.0

Women 15.3 (13.9–16.8) 2.5

Great Britain Men 8.2 (7.2–9.2) 1.0

Women 11.3 (10.3–12.4) 1.4

aICD-10 depressive, generalised anxiety, panic, and phobia disordebAdjusted by age, marital status, education, employment status,

consumption, and household size.

In view of these statistically significant interactions

showing an increased risk for Chilean women, we

proceeded with the exploratory analysis, restricted to

women only, to investigate possible explanations that

could account for these findings. Among all the

variables examined, education was the only one that

showed a statistically significant interaction with coun-

try, in which Chilean women had an increasingly greater

risk of CAD than British women as levels of educational

attainments decreased (LR test w2 ¼ 12:95; p ¼ 0:005; in

the fully adjusted model). The group of British women

with the lowest educational levels did show a statistically

significant increase in the prevalence of CAD compared

to the best-educated women, but this effect disappeared

in the fully adjusted model. We were unable to find any

other statistically significant interaction (po0:05) be-

tween the other explanatory variables studied and

countries that could account for the increased risk

among Chilean women. The only exception was marital

status and country, in which, contrary to what we

expected, Chilean widows showed a much lower like-

lihood of suffering from CAD than their British

counterparts (LR test w2 ¼ 13:3; p ¼ 0:01 in the fully

adjusted model). In the unadjusted model, we found a

statistically significant interaction (LR test w2 ¼ 11:9;p ¼ 0:02) between working status and country also,

mainly as a result of unemployed Chilean women having

a decreased risk in comparison to their British counter-

parts.

A more descriptive approach investigating risk factors

for women in each country separately revealed more

similarities than disparities across countries (Table 4).

Although differences in risk between countries are better

captured when testing for interactions, studying risk

factors within countries is useful to provide a more

comprehensive picture as to where some of the

differences might lie.

Poor levels of social support, separation, and retire-

ment due to illness showed consistent associations with

by country. Prevalence, crude and adjusted odds ratios using

ude odds ratio (95% CI) Adjusted odds ratiob (95% CI)

0 1.00

2 (2.00–3.18) 2.16 (1.64–2.85)

0 1.007 (1.24–1.74) 1.29 (1.04–1.62)

rs.

children under 15, social support, physical disease, alcohol

Page 7: Comparing sex inequalities in common affective disorders across countries: Great Britain and Chile

ARTICLE IN PRESS

Table

3

The

ass

oci

ation

and

inte

ract

ions

bet

wee

nse

x,co

untr

ies,

and

the

sever

ity

of

psy

chia

tric

sym

pto

ms

(CIS

-Rsc

ore

s)using

diffe

rent

thre

shold

s.A

dju

sted

odds

ratios

using

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a

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G. Rojas et al. / Social Science & Medicine 60 (2005) 1693–1703 1699

CAD in both countries. Some other associations with

CAD differed between the countries but most of these

differences did not reach statistical significance

(po0:05). For instance, housekeeping or co-habitation

among British and Chilean women, respectively, were

associated with an increased risk in their own countries

but these factors did not help to account for the

increased risk among Chilean women over and above

the risk in Great Britain.

Discussion

In keeping with most previous literature, women in

both countries showed an increased prevalence of CAD

compared to men, but this risk was much larger for

Chilean women, especially for those with more severe

symptomatology. Of all the variables examined, educa-

tional level showed the only statistically significant

interaction that could somehow account for this

difference in the prevalence of CAD between Chilean

and British women, with less educated Chilean women

showing the largest risk after adjusting for other

variables.

The main strength of this study was the use of similar

methodologies in both sites, including a detailed

psychiatric interview administered to a large and

representative sample with high response rates in both

surveys. Nonetheless, the cross-sectional design used

limited the conclusions about causality. Although this

study compared only urban samples from two countries,

these samples represented contrasting social, cultural,

and economic realities. There are obvious limitations in

terms of the depth of knowledge that can be obtained

about a particular risk factor when conducting large

general household surveys. Although much of the

interview used with both samples was the same, there

were some inevitable differences, for example when

measuring educational achievements, because categories

have to represent meaningful local constructs.

Sex differences, common affective disorders, and

variations between countries

Women in both countries showed an increased risk of

CAD compared to men, but Chilean women showed a

larger risk of suffering from CAD in comparison to their

British counterparts even after adjusting for a wide

range of variables. This finding was even more

pronounced when restricting the analysis to more severe

cases, suggesting that these differences were not due to

an excess of ‘the worried but well’ cases within the

Chilean sample. Thus, it is conceivable that other

developing countries with large gender gaps in education

and socio-economic status will have similar differences

in mental illness.

Page 8: Comparing sex inequalities in common affective disorders across countries: Great Britain and Chile

ARTIC

LEIN

PRES

S

Table 4

The association between CAD, marital and working status, social support, and number of young children among urban women in Chile and Great Britain

Chile Great Britain

Crude ORa Adj. ORa,b Adj. ORa,c Crude ORa Adj. ORa,b Adj. ORa,c

Education Highest 1.00 1.00 1.00 1.00 1.00 1.00

Middle high 2.66 (1.78–3.96) 2.64 (1.77–3.96) 2.18 (1.44–3.29) 1.05 (0.78–1.41) 1.05 (0.79–1.41) 0.91 (0.67–1.22)

Middle low 3.10 (2.05–4.61) 3.23 (2.12–4.93) 2.40 (1.55–3.70) 1.18 (0.79–1.76) 1.15 (0.76–1.73) 0.86 (0.57–1.31)

Lowest 3.85 (2.49–5.96) 4.15 (2.58–6.67) 2.68 (1.64–4.37) 1.81 (1.44–2.28) 1.74 (1.36–2.23) 1.15 (0.89–1.51)

Marital status Married 1.00 1.00 1.00 1.00 1.00 1.00

Cohabiting 2.02 (1.25–3.26) 1.84 (1.12–3.04) 1.57 (0.96–2.56) 1.28 (0.84–1.95) 1.42 (0.91–2.23) 1.36 (0.87–2.14)

Single 0.87 (0.67–1.13) 0.86 (0.60–1.23) 1.06 (0.73–1.54) 1.19 (0.91–1.56) 1.28 (0.92–1.78) 1.10 (0.78–1.55)

Widowed 0.72 (0.40–1.30) 0.86 (0.46–1.60) 0.77 (0.41–1.46) 2.43 (1.58–3.73) 2.17 (1.38–3.41) 1.77 (1.12–2.82)

Separated 1.66 (1.15–2.40) 1.63 (1.11–2.39) 1.66 (1.11–2.47) 1.77 (1.32–2.36) 1.83 (1.37–2.45) 1.23 (0.89–1.72)

Working status Employed 1.00 1.00 1.00 1.00 1.00 1.00

Housekeeper 1.41 (1.08–1.84) 1.49 (1.14–1.94) 1.23 (0.91–1.65) 1.83 (1.38–2.41) 1.82 (1.38–2.41) 1.46 (1.05–2.02)

Inactive 0.74 (0.50–1.09) 0.72 (0.44–1.20) 0.84 (0.50–1.41) 1.17 (0.78–1.77) 1.07 (0.68–1.69) 1.01 (0.63–1.61)

Retired ill-health 4.73 (1.97–11.3) 4.05 (1.47–11.2) 3.46 (1.19–10.0) 6.17 (4.37–8.70) 5.60 (3.83–8.19) 4.30 (2.77–6.68)

Unemployed 1.11 (0.72–1.72) 1.08 (0.69–1.67) 0.95 (0.60–1.48) 2.93 (1.99–4.31) 3.01 (2.02–4.49) 2.48 (1.64–3.76)

Social support High 1.00 1.00 1.00 1.00 1.00 1.00

Middle 1.75 (1.28–2.39) 1.67 (1.22–2.28) 1.52 (1.10–2.10) 1.61 (1.26–2.05) 1.62 (1.27–2.06) 1.42 (1.11–1.82)

Low 3.75 (2.74–5.13) 3.58 (2.59–4.94) 2.99 (2.13–4.19) 3.49 (2.54–4.79) 3.49 (2.51–4.86) 2.57 (1.78–3.71)

Number of young children No child 1.00 1.00 1.00 1.00 1.00 1.00

One child 1.24 (0.91–1.67) 1.13 (0.80–1.58) 0.91 (0.64–1.28) 1.16 (0.81–1.67) 1.46 (0.99–2.14) 1.15 (0.78–1.69)

XTwo children 1.42 (1.04–1.94) 1.26 (0.86–1.84) 1.04 (0.70–1.53) 1.47 (0.96–2.25) 2.12 (1.31–3.42) 1.41 (0.85–2.35)

aAll models estimated using Huber-White robust variance estimator adjusting standard errors for clustering of geographical areas.bAdjusted by age, physical disease, alcohol consumption, and household size.cAdjusted by age, physical disease, alcohol consumption, household size, and other variables in the table.

G.

Ro

jas

eta

l./

So

cial

Scien

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60

(2

00

5)

16

93

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70

31700

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ARTICLE IN PRESSG. Rojas et al. / Social Science & Medicine 60 (2005) 1693–1703 1701

How to explain the increased risk among Chilean women?

Biological mechanisms are unlikely to explain these

sex differences across countries. Yet it is likely that

Chilean women were exposed to more adverse environ-

mental conditions, increasing the risk for organic injury

or physical illnesses. Against this line of reasoning, we

found that the proportion of women who self-reported

poor general health was similar in both countries.

Incidentally, this argues against the response-bias claim

that Chilean women have higher rates because they are

more likely to acknowledge the presence of symptoms or

illnesses than their British counterparts (Macintyre,

Ford & Hunt, 1999). Nonetheless, we cannot rule out

the possibility of a more specific response bias for

psychological questions, though we attempted to mini-

mise this by using a psychiatric interview rather than a

questionnaire. Thus, on balance, we think it is unlikely

that a response bias can account for the reported

differences.

Our most important finding in this respect was a

statistically significant interaction between education

and country for women, in which Chilean women with

lower educational achievements had a significantly

higher risk of CAD than less educated British women.

Our results showed a robust, dose–response, and

independent inverse association between education and

CAD even after adjusting for all other variables among

Chilean women. Although we found that British women

with the lowest educational level were significantly more

likely to suffer from CAD than the best educated, this

difference disappeared in the fully adjusted model.

Admittedly, we used different methods to measure

educational attainments in the two countries, an

inevitable move in view of the different educational

systems. Although it is not known whether the educa-

tional groupings are equivalent in terms of their impact

on mental health in the two countries, we are confident

that our groupings represent different levels of educa-

tional attainments with practical implications for future

opportunities in each country. Nonetheless, we advise

caution when interpreting this finding.

Bearing in mind these limitations, how could

education account for this greater risk among Chilean

women? Education is a relatively frozen socio-economic

indicator of earlier life that continues to exert its

effect throughout life; for instance, through giving

access to opportunities. It is possible that social

disadvantage in earlier life might have a long-lasting

effect on mental health or that individuals with poorer

education have an increased likelihood of accumulating

more adversity throughout life. Equally it is possible

that lower levels of education might simply be another

indicator of lower socio-economic status and it is this

overall position of social disadvantage that increases the

risk of CAD.

Regardless of the possible explanations for and

limitations to interpreting this finding, the difference in

educational attainment between Chilean and British

women is noteworthy. At a time when the gender gap at

the primary educational level seems to be decreasing,

women are still less likely to receive secondary and

post-secondary education in most developing

countries (United Nations Population Fund, 2000).

Even though the comparability of educational achieve-

ments in the two countries is debatable, our results,

together with those from other studies, should motivate

further research into the impact of education on mental

health.

Can we learn something from the similarities between the

two countries?

Although shared risk factors did not help us to

explain the increased risk among Chilean women, they

provided an interesting insight into situations of risk

that seemed to transcend national boundaries. In

keeping with this predicament, the most important

similarity was that employment did not increase the

likelihood of suffering from CAD in either of these two

countries, a finding which is common with other

research from developed (Fokkema, 2002; Weich et al.,

1998) as well as developing countries (Ahmad-Nia,

2002). So it seems that employment could have more

advantages than disadvantages for women’s mental

health, even in countries where women might be

working under worse conditions (Loewenson, 1999).

Along similar lines, the more difficult conditions under

which women might be working in Chile could have

somehow attenuated the positive effect of employment

when compared with other working status categories.

The association between working women and mental

health is a complex issue and many studies so far

undertaken, including this one, might have not had

adequate depth to be able to explain how, for instance,

holding multiple roles can affect the mental health of

working women. Likewise, it is possible that the more

resourceful and healthy women were more likely to be

employed; thus confounding our results (Emslie et al.,

2002; Matthews et al., 2001). Contrary to this, we found

that the proportion of employed women who self-

reported poor general health was much larger among

British than Chilean women (33% vs. 18%). We also

adjusted our results for the presence of ill health when

testing for interactions. We found no statistically

significant interactions (po0:05) in each country sepa-

rately between working status and being a mother,

regardless of the number of children.

We found that in both countries poorer social support

was strongly associated with an increased likelihood of

suffering from a CAD. However, we found that this

association was also present among men and there were

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ARTICLE IN PRESSG. Rojas et al. / Social Science & Medicine 60 (2005) 1693–17031702

no interactions between social support and country

among women, in keeping with other studies (Piccinelli

& Wilkinson, 2002). We also found that in both

countries there was no association between CAD and

the presence of young children at home either, before or

after adjusting for other socio-demographic variables.

The presence of two or more children under the age of

11 had been previously considered a risk factor for

depression among British women (Brown & Harris,

1978; Bebbington, 1996).

Conclusion

The most important finding of this study is the

confirmation that women’s mental health in Chile and

possibly other less developed countries could be at

much-increased risk in comparison to women in more

westernised societies. This is an issue with immense

humanitarian, political, and economic consequences

that has been poorly researched so far. Health research

programmes for developing countries have often had a

narrow focus on reproductive health, a priority that is

not necessarily shared by local communities. For

instance, in Ghana almost three-quarters of women

identified psychosocial but not reproductive health

problems as their most important health concerns

(Avotri & Walters, 1999). The scope of research on

women’s health needs to be broadened; it is no longer

acceptable to conceive women mainly from a reproduc-

tive point of view. Women play much more diverse and

important roles in modern developing societies. It is time

that other more complex social issues affecting the

health and welfare of women, particularly from the

developing world, are properly addressed.

Acknowledgements

We would like to thank Drs. R. Fritsch, J. Acuna, and

M. Horvitz-Lennon for their participation in the field-

work. We would also like to express our gratitude to all

the interviewers who participated in this study and, most

important of all, to the people who took unpaid time to

answer our questions. This study was funded by the

European Community (EC).

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