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Volume 21, No.3 - 2000  

 

 

Public Health Agency of Canada (PHAC)

A Deprivation Index for Health and Welfare Planning in Quebec

Robert Pampalon and Guy Raymond

Volume 21, No. 3 - 2000  


Abstract

Given that one of the goals of public health policy in Quebec and Canada is to reduce social inequalities in health and well-being, it is surprising, to say the least, that most information systems in this field make no mention of people's socio-economic characteristics. The present article proposes an index to reflect the material and social dimensions of deprivation as this concept has been developed by Peter Townsend and other authors. The article describes the method used to create the index, which uses census data and tools developed by Statistics Canada to match postal codes with enumeration areas. Examples are provided of the use of the index in information systems covering three aspects of health and well-being in Quebec: deaths, hospitalizations and births. The value of the information provided by this index in planning health and social services is demonstrated.

Key words: births; deprivation; geography; hospitalization; mortality; Quebec; social inequalities


Introduction

The association between social inequalities and differences in people's health and well-being is now well known, and the struggle against inequalities has become a major public health policy issue throughout the world,1,2 in Canada3,4 and in Quebec.5,6 The strategies put forward in the Quebec policy for health and welfare5 include improving living conditions, such as level of education and income; providing support in people's environments (home, school and workplace); and working with groups that are considered vulnerable from the standpoint of their health and well-being.

Except for the general surveys on health and social issues that have been conducted recently,7 measuring social inequalities in health and welfare has always posed some problems in Quebec. These problems are due to the lack of socio-economic data in the main information systems used to determine the health and well-being of the population and to assess its consumption of health and social services, such as long-term care, home support and youth and children's services. Such information is lacking in the databases used to track deaths, hospitalizations and tumours in Quebec, and it is also absent from the database of the Quebec health insurance plan.

To get around these difficulties, researchers have turned to an ecological approach: to compensate for the lack of data on individuals, they substitute data on geographic areas such as neighbourhoods or CLSC (local community service centre) districts and analyze these data to determine the presence of socially based inequalities in health.8-12 This approach undeniably provides some valuable information, but it does have limitations. The populations of the areas analyzed are often not very homogeneous. This kind of analysis is used only for large urban centres, and it has no explicit conceptual reference, or at least no unique one.

We therefore intend to propose a deprivation index that has explicit conceptual foundations, that can be incorporated into databases in the health and social services sector, and that can be used to track those inequalities in health and well-being that are associated with deprivation. In particular, we intend to describe the way the index is constructed and, by way of examples, to illustrate the possibilities that it offers for analyzing inequalities and for planning health and social service interventions. We begin with a short description of the concept of deprivation and how it has been measured around the world. We then show how we have adapted this concept to the Quebec context and provide a few examples of its use. Last, we suggest how the index could contribute to health and social service policies and programs.


The Concept of Deprivation

The term "deprivation" emerged in Britain in the 1980s from a long tradition of analyzing social inequalities in health. Peter Townsend13 saw deprivation as "a state of observable and demonstrable disadvantage relative to the local community or the wider society or nation to which the individual, family or group belongs." This disadvantage may occur at various levels, for example, with regard to food, clothing, housing, education or work. In fact, a person is considered deprived to the extent that he or she falls below the level attained by the majority of the population or below what is considered socially acceptable.

Peter Townsend distinguishes two forms of deprivation: material and social. The first involves deprivation of the goods and conveniences that are part of modern life-for example, a car, a television or a neighbourhood with green space. Social deprivation refers to relationships among individuals in the family, the workplace and the community. According to Townsend, material deprivation should be distinguished from "poverty," which is more related to lack of the resources-especially the financial resources-needed to acquire modern goods and commodities. Social deprivation, on the other hand, is more closely related to the concept of "social capital,"14 reflecting certain characteristics of social organization, such as isolation or cohesion, individualism or co-operation, mutual assistance and trust.

Both of these forms of deprivation are closely linked with public health and welfare. They are related to mortality in the general population15,16 and to premature mortality (either general or due to ischemic heart disease or other causes related to tobacco use).17 They vary with all forms of morbidity, from cancer18 to restriction of activities,19 and from respiratory diseases and diabetes20 to tooth decay.21 Material and social deprivation are also associated with mental health, such as short-term and long-term use of psychiatric services22-25 and criminal behaviour.26 Finally these forms of deprivation may be used as a guide in managing public health services, especially in the area of medical resources.27,28


Measuring Deprivation

Many studies of deprivation (chiefly material deprivation) rely on two particular deprivation indices, one developed by Townsend13 and the other by Carstairs and Morris.29 Both indices involve four variables, three of which are the same in both cases: unemployment, lack of a car and overcrowded housing. The fourth variable in the Townsend index is home ownership; in the Carstairs index, it is lower social class. In the construction of these indices, the four variables are standardized and normalized, each variable being given an equal weight.

A third index, called the Under-privileged Areas (UPA) score, was developed by Jarman et al.30 and is extensively used in deprivation studies. (Incidentally, it is also used in determining remuneration for physicians in Britain.) The UPA score comprises eight variables, including the four already mentioned and four more: the proportion of single-parent families, children under age 5, retired persons living alone and recent immigrants. The weight given to each of these variables in constructing the index differs according to the perception that physicians have of that variable's impact on their workload. A comparative analysis of the three indices31 has shown that the first two correlate more closely with a set of health indicators than does the third.

Lastly, studies of deprivation sometimes use other kinds of indices or numerous individual variables, including income, education level, marital status and residential mobility as well as those already mentioned.13,22,31

These measures have been derived essentially from national census data on small geographic areas such as wards and enumeration districts in Britain,16-18,20,29 "small area market statistics" in Sweden28 and meshblocks in New Zealand.32 The measures can then be transposed into individual records in population surveys26 and surveys of specific client groups,20,22,23 or they can be used in ecological analyses.16-18,27,29 In such analyses, these small areas are usually grouped into larger, arbitrary statistical aggregates (such as quintiles or deciles) according to their level of deprivation, from lowest to highest.

What is important when creating such measures is to choose a basic geographic unit that is as small as possible and as homogeneous as possible in its socio-economic characteristics. The size of the social inequalities in health and well-being that will be observed and the accuracy of the observations will depend greatly on the basic geographic unit chosen. In Britain, for instance, it has been shown that basing analyses on enumeration districts (average population of about 500), rather than on wards (average population of over 5,000), reduces errors in classifying individuals, leads to higher correlations between social inequalities and health, and results in more stable funding of medical services from one census to the next.27,33,34


Data and Methods

Basic Geographic Unit

Our basic geographic unit, the enumeration area (EA), was chosen for two reasons. First, this is the smallest geographic unit for which census data are available in Canada. The average EA has a population of 750. Second, the postal code conversion file can be used to establish a link between information on EAs and the geographically based information, classified by 6-character postal codes, available in the health and welfare databases maintained in Quebec.35

Not all of the EAs in Quebec were used in the analysis. The EAs in Nunavik and the Cree territories of James Bay were excluded because of the poor quality of their census data. All EAs with fewer than 250 inhabitants (fewer than 68 households) were eliminated, because this is the minimum size of EA for which Statistics Canada produces income figures. Many of the EAs thus eliminated have no inhabitants and are classified as unorganized areas. Also, most of those EAs that consist of health and social service institutions, such as hospitals, psychiatric facilities, homes for the aged and rehabilitation centres, were eliminated since any group institution with 75 beds or more constitutes an EA, according to the census rules.36 The 9,058 EAs that remained and were included in the present analysis represent about 96% of the total population and of all households in Quebec.

The equivalence that the postal code conversion file establishes between the 6-character postal code areas and the EAs is not perfect. Slightly less than 6% of the postal code areas cover more than one EA. For these areas, the EA was randomly and proportionally assigned, according to the population of each EA living in the same postal code area. This population figure comes from the Statistics Canada file for weighting the population by postal codes.37


Indicators

The deprivation index combines six indicators chosen for the following reasons: their relation to a large number of health and welfare issues; their association with one of the two forms of deprivation (material or social); and their availability by EA in the Canadian census data. The six indicators and the mnemonics that we have used for them are as follows: the proportion of persons who have no high-school diploma (SCOLAR); the ratio of employment to population (EMPLOI); average income (REVMOY); the proportion of persons who are separated, divorced or widowed (S_D_V); the proportion of single-parent families (F_MONO); and the proportion of people living alone (SEULES). All of these indicators except for the proportion of single-parent families have been adjusted according to the age and sex of the population so as to highlight the economic and social conditions of the persons concerned.32 In order to normalize the distribution, it was necessary to convert some of the indicators (REVMOY, S_D_V and SEULES) to their logarithms and one (F_MONO) to its square root.


Combining the Indicators

In general, there are two ways to combine indicators: the additive approach, with weighting, which has been used to create deprivation indices in Britain,13,29,30 and the factorial approach, which has been used to develop various socio-economic indices38-40 and, more recently, a deprivation index in New Zealand.32 We opted for the factorial approach because the weight assigned to each indicator is not determined arbitrarily on the basis of the perceptions of the researcher or of a group of professionals (for example, general practitioners),30 but is determined from the statistical relationships that exist among the indicators within the geographic area in question. More specifically, we used principal component analysis (a form of factor analysis), applying a Varimax rotation and retaining only those components whose eigenvalues exceeded 1.00. Two of the components that we analyzed satisfied this criterion, and it was from these two components and their cross-tabulations that we developed the deprivation index (Table 1).

 

 


TABLE 1
Principal components among indicators included in the deprivation index by enumeration area (
n = 9058)

Indicator

Component

1

2

Persons with no high-school diploma (SCOLAR)

-0.89-

-0.01-

Employment/population ratio (EMPLOI)

0.80

-0.27-

Average income (REVMOY)

0.86

-0.25-

Persons living alone (SEULES)

-0.13-

0.82

Separated, divorced, and widowed persons (S_D_V)

-0.16-

0.86

Single-parent families (F_MONO)

-0.14-

0.76

   Explained variance

37%

36%

   Cumulative variance

37%

73%

NOTE: The above values are the saturations between the indicator and the component. They are interpreted like correlation coefficients.

Source: 1996 Canadian census

   

Each of the two components accounts for slightly more than one third of the variations in the six indicators considered, for a total of 73%, and the two are sharply differentiated in their meaning. The first component reflects variations in education, employment and income in Quebec and thus tends to emphasize the material aspect of deprivation. The second component reflects variations in the indicators associated with the social aspect of deprivation-the proportions of widowed, separated and divorced persons, of single-parent families and of persons living alone.

To test the validity of this model for Quebec as a whole, we repeated the same principal component analysis for four distinct areas in Quebec: the Montreal Census Metropolitan Area (CMA), the other CMAs in Quebec (Quebec City, Sherbrooke, Hull, Chicoutimi-Jonquière and Trois-Rivières), the Census Agglomerations (CAs) of Quebec (cities with 10,000 to 100,000 inhabitants) and, finally, Quebec's small towns and rural areas. In every case, we found the same factorial structure, with the two principal components accounting for 72-75% of the variation in the indicators for the CMAs and CAs and 62% of the variation in the indicators for small towns and rural areas.


Grouping the Enumeration Areas

To ensure a certain statistical accuracy in the analysis of inequalities in health and welfare, we had to combine the EAs into sufficiently large groups while ensuring that these groups were homogeneous in terms of material and social deprivation. The EAs were therefore grouped according to their factor scores, which represent the importance of each component in each EA, and a conventional method16,18,27,29 was followed. For each component, the factor scores were ranked from least to most deprived EA, and then the resulting distribution was divided into quintiles, according to the size of the population of each EA. Thus, quintile 1 represents the least deprived segment of the population of Quebec, and quintile 5 represents the segment that is most deprived.

Lastly, the two sets of quintiles (for material and social deprivation) were cross-tabulated, for a total of 25 cells. We could then see which population segments were not deprived according to either of these measures, which ones were deprived according to one but not the other and which ones were deprived according to both. For example, the cell in which quintile 1 for component 1 intersects quintile 1 for component 2 represents the population segment that is most privileged both materially and socially; the cell for quintile 5 for both components represents the segment that is the most deprived.


Health and Welfare Indicators

The deprivation values were entered into three information systems, covering deaths, hospitalizations and births. Various measures were then produced by quintiles and cross-tabulated deprivation quintiles. Some of the measures were general, such as life expectancy at birth, the standardized mortality ratio (SMR) for the years 1995-1997 and the hospitalization rate adjusted for population age and sex and for the level of resource use (APR-DRG: classification and weighting system for short-term patients) for the year 1997/98. In the case of the SMR, chi-squared tests were used to determine the significance of any differences between the values by quintiles and cross-tabulated quintiles and the values for Quebec as a whole.41

The other measures were more specific and were designed to test the sensitivity of the index by associating it with problems known to be largely determined by material and social living conditions.7,17,24,25,42,43 These measures were as follows: standardized mortality ratio for premature deaths (at ages 35-74) due to tobacco use, adjusted rate of hospitalization for mental illness and two measures regarding births-the fertility rate for teenage girls (< 20 years old) and the birth rate of infants with low birth weight (< 2500 g) among all women in Quebec for the years 1995-1997.

For most of the deaths, hospitalizations and births analyzed (89-96%), a corresponding deprivation value was obtained (Table 2). For the remaining events no deprivation value was obtained, either because the associated EA had been excluded for being too small or because the postal code in the database was invalid (less than 3% of the events had invalid postal codes).


TABLE 2
Deaths, hospitalizations and births by type of database record: numbers and percentages
of records for which deprivation values were/were not obtained

Database record

Deprivation value obtained

No deprivation value obtained

TOTAL

Excluded EAs

Invalid postal codes

n

%

n

%

n

%

n

%

Deaths

121,217

89

11,415

8

 3,892

3

136,524

100

 - tobacco usea

 10,928

94

   506

4

   191

2

 11,625

100

Hospitalizations

716,668

92

40,907

5

19,731

3

777,306

100

 - mental illnessb

 38,074

92

 2,198

5

 1,184

3

 41,456

100

Births

239,786

95

 9,215

4

 3,111

1

252,112

100

 - mothers < age 20

 10,891

91

   828

7

   197

2

 11,916

100

 - weight < 2500 g

 14,250

96

   505

3

   166

1

 14,921

100

a Cancers of the lips, mouth, pharynx, esophagus, trachea, bronchi and lungs; bronchitis, emphysema and obstruction of airways in persons age 35 to 74. ICD-9: 140 to 149, 150,161,162,491,492, 496.
b Various psychoses and neuroses. ICD-9: 290 to 316.

Sources: Deaths database 1995-1997; Med-Echo database 1997/98; births database 1995-1997

   

Results

In Quebec the geographic pattern of deprivation was very distinct (Table 3), and the patterns for material and social deprivation showed both similarities and dissimilarities. Material deprivation was especially high in small towns and rural areas, dropped off in the suburbs of the larger cities and then rose again in the urban core. In contrast, social deprivation was a largely urban reality, increasing steadily from the suburbs into the downtown metropolitan areas. This pattern is fairly similar to the results of Quebec health and social surveys concerning people's satisfaction with their social life.44,45 To sum up, the population segment with the highest indices of both material and social deprivation (quintile 5 in both cases) was found in the downtown areas of larger cities, while material deprivation was highest in small towns and rural areas of Quebec and social deprivation was highest in urban areas.


TABLE 3
General characteristics of the population by deprivation quintile: number, age group
and selected places of residence, Quebec, 1996

     

Place of residence

Deprivation
quintile

Population
(
n)

Age group

Montreal CMA

Small towns and rural areas
(%)

0-17 years
(%)

65+ years
(%)

Montreal Island
(%)

Suburbs
(%)

Material

 

1

1,367,798

23.4

10.3

35.3

30.3

 2.3

2

1,367,859

24.1

10.1

21.5

30.7

 8.2

3

1,367,281

23.6

11.2

20.8

25.6

16.9

4

1,367,943

23.4

12.3

23.5

17.9

31.1

5

1,367,081

23.8

13.3

24.6

 7.0

47.8

Social

 

1

1,367,522

28.8

 7.1

10.4

31.0

32.8

2

1,366,503

26.5

 9.3

10.0

26.6

31.6

3

1,368,213

24.0

11.6

19.9

20.7

26.2

4

1,367,708

20.9

14.2

36.9

19.0

12.6

5

1,368,016

18.1

14.9

48.4

14.2

 3.0

Material and social

 

1 and 1

  315,221

29.4

 5.8

28.3

45.3

 1.6

5 and 5

  325,770

20.3

15.0

50.9

 2.9

 2.9

Quebec

6,837,962

23.7

11.4

25.1

22.3

21.3

Source: 1996 Canadian census


   

As Table 3 also shows, this pattern partly reflects the demographic features of the population. The people who were most deprived both materially and socially (quintiles 5 and 5) were slightly older than their more fortunate fellow citizens (quintiles 1 and 1), because of marked differences in their degree of social deprivation, which seemed to increase along with population age.

However, the differences due to age were much less than those associated with the various social indicators in our deprivation index (Table 4). For people aged 65 and over, there were between two and three times as many in quintile 5 for both types of deprivation as in quintile 1 (15% versus 5.8%), but for people living alone (all ages) the corresponding ratio was 9:1 (20.2% versus 2.2%) and for single-parent families it was 5:1 (34.1% versus 6.9%). The discrepancies in education level, employment and income were also quite large and existed beyond any differences in the demographic profiles of the deprivation groups.


TABLE 4
Mean values
a of indicators composing the deprivation index,
by deprivation quintile, Quebec, 1996

Deprivation
quintile

SCOLAR
(%)

EMPLOI
(%)

REVMOY
($)

SEULES
(%)

S_D_V
(%)

F_MONO
(%)

Material

 

1

18.1

66.0

30,045

 8.9

 9.9

13.2

2

28.8

60.8

23,280

 8.7

10.5

14.7

3

36.1

56.8

20,907

 9.7

11.0

15.9

4

43.1

52.7

18,703

10.5

11.5

17.4

5

53.3

43.1

15,624

11.0

12.1

19.0

Social

 

1

35.8

59.6

23,475

 3.5

 6.5

 7.2

2

36.1

57.4

22,792

 5.6

 8.6

10.9

3

35.7

56.3

22,161

 8.1

10.5

14.5

4

35.8

54.9

21,067

12.1

12.8

19.2

5

35.9

51.4

19,068

19.4

16.5

28.4

Material and social

 

1 and 1

17.2

68.2

32,684

 2.2

 6.2

 6.9

5 and 5

51.5

38.7

13,958

20.2

18.3

34.1

Quebec

35.9

55.9

21,712

 9.7

11.0

16.0

a Means for the enumeration areas covered by the deprivation index
Source: 1996 Canadian census

LEGEND
SCOLAR: proportion of persons who have no high-school diploma
EMPLOI: ratio of employment to population
REVMOY: average income
S_D_V: proportion of persons who are separated, divorced or widowed
F_MONO: proportion of single-parent families
SEULES: proportion of people living alone

   

The use of principal component analysis (with Varimax rotation) produced material and social dimensions of deprivation that were relatively independent from a statistical perspective. The correlation was 0.00 between the factor scores for the two principal components and 0.03 between the quintiles established from these factor scores. This is why the variations among quintiles shown in Table 4 were large for some variables and small or non-existent for others. The variations were large when these variables were used to define the component and small when they were not. Low education level, for example, increased with material deprivation but not with social deprivation. This observation is important when interpreting the relations between health and well-being indicators and deprivation.

Life expectancy at birth decreased consistently with material deprivation among both men and women (Table 5), but this pattern did not hold for social deprivation among women. In total, the least deprived men in Quebec (quintiles 1 and 1) can expect to live almost 9 years longer than the most deprived (quintiles 5 and 5). The difference in life expectancy among the corresponding groups of women was slightly less than 3 years. The pattern is similar for general mortality but not at all similar for premature death due to tobacco use (Table 6), which increased continuously with both material and social deprivation among men and women.

The hospitalization rate also increased with material deprivation among both sexes (Table 7). It varied with social deprivation as well but in a different way, first decreasing as people's social deprivation worsened, then increasing steadily, though very slightly. The pattern for hospitalization for mental illness was quite different, increasing continuously with both forms of deprivation among men and women. The same kind of increase was found in fertility rates among teenage girls and birth rates of infants with low birth weight (Table 8).


TABLE 5
Life expectancy at birth by deprivation quintile, Quebec, 1995-1997

Deprivation
quintile

Males
(years)

Females
(years)

TOTAL
(years)

Material

 

1

78.5

84.9

81.9

2

76.4

84.0

80.4

3

75.5

83.7

79.7

4

75.3

83.6

79.5

5

73.7

82.5

77.9

Social

 

1

76.5

82.0

79.0

2

76.7

83.6

80.0

3

76.5

84.6

80.7

4

75.8

84.2

80.2

5

73.4

82.9

78.4

Material and social

 

1 and 1

79.7

83.7

81.8

5 and 5

71.0

81.1

76.0

Quebec

75.8

83.7

79.8

Source: Deaths database, 1995-1997

TABLE 6
Standardized mortality ratios for general mortality and premature mortality due to tobacco use,
a
by sex and deprivation quintile, Quebec, 1995-1997

Deprivation
quintile

General mortality (SMR)b

Tobacco mortality (SMR)b

Males

Females

TOTAL

Males

Females

TOTAL

Material

 

1

0.81

***

0.89

***

0.85

***

0.67

***

0.73

***

0.71

***

2

0.96

***

0.98

 

0.96

***

0.98

 

0.96

 

0.97

 

3

1.03

**

1.00

 

1.01

*

1.02

 

1.00

 

1.01

 

4

1.03

***

1.01

 

1.02

***

1.09

***

1.08

*

1.08

***

5

1.14

***

1.08

***

1.12

***

1.19

***

1.16

***

1.18

***

Social

 

1

0.92

***

1.07

***

1.01

 

0.85

***

0.88

**

0.90

***

2

0.92

***

0.99

 

0.97

***

0.86

***

0.88

**

0.89

***

3

0.94

***

0.93

***

0.94

***

0.96

 

0.88

**

0.94

**

4

1.00

 

0.97

***

0.98

***

1.01

 

1.01

 

0.99

 

5

1.18

***

1.05

***

1.09

***

1.30

***

1.26

***

1.23

***

Material and social

 

1 and 1

0.68

***

0.88

***

0.77

***

0.53

***

0.69

***

0.60

***

5 and 5

1.37

***

1.17

***

1.26

***

1.63

***

1.47

***

1.52

***

Quebec

1.00

 

1.00

 

1.00

 

1.00

 

1.00

 

1.00

 
a See Table 2
b SMR (standardized mortality ratio) differs from the Quebec value (1.00) at p < 0.001***; p <0.01**; p < 0.05*.
Source: Deaths database, 1995-1997

TABLE 7
General hospitalization rates
a and rates of hospitalization for mental illness,b
by sex and deprivation quintile, Quebec, 1997/98

Deprivation
quintile

General hospitalization (%)

Hospitalization for mental illness (%)

Males

Females

TOTAL

Males

Females

TOTAL

Material

 

1

10.3

11.1

10.7

0.60

0.80

0.70

2

12.2

12.8

12.5

0.76

1.01

0.89

3

12.6

13.3

13.0

0.81

1.09

0.95

4

13.1

13.7

13.5

0.93

1.10

1.02

5

14.2

15.1

14.7

1.01

1.29

1.15

Social

 

1

12.2

13.9

13.2

0.62

0.86

0.74

2

11.7

13.2

12.6

0.67

0.88

0.77

3

12.4

12.8

12.6

0.76

0.93

0.85

4

12.8

13.0

12.9

0.91

1.13

1.03

5

13.9

14.2

13.9

1.19

1.46

1.33

Material and social

 

1 and 1

 9.3

11.2

10.4

0.45

0.63

0.55

5 and 5

15.9

16.7

16.2

1.49

1.72

1.61

Quebec

12.5

13.2

12.9

0.82

1.05

0.94

a Rates per 100 population
b See Table 2
Source: Med-Écho database, year 1997/98

TABLE 8
Fertility rates in teenage girls
a and rates of birth of infants with low birth weightb for all women,
by deprivation quintile, Quebec, 1995-1997

Deprivation
quintile

Fertility (%)

Low birth weight (%)

Material

 

1

0.58

5.07

2

1.09

5.35

3

1.53

5.89

4

1.95

6.19

5

2.65

7.12

Social

 

1

0.92

5.22

2

0.94

5.54

3

1.30

5.93

4

1.93

6.28

5

3.11

6.74

Material and social

 

1 and 1

0.26

4.72

5 and 5

4.71

8.19

Quebec

1.56

5.94

a Births to women less than 20 years of age per 100 women aged 15-19
b Births of infants weighing less than 2500 grams, per 100 live births
Source: Births database, 1995-1997

   

Discussion

The size of the inequalities that our deprivation index revealed-especially as regards premature death due to tobacco usage, hospitalization for mental illness, fertility in teenage girls and births of infants with low birth weight-shows that this deprivation index is especially sensitive to the material and social conditions in which people live.

The approach used to develop the index is not totally new. Six-digit postal codes have been used previously in Canada to introduce an income measure into death records,46-48 and some differences in life expectancy and mortality due to several causes have been identified thereby. However, our approach does differ from past efforts in several respects.

First of all, it is based on a clearly established concept of deprivation that comprises two dimensions confirmed by our principal component analysis: material deprivation (including an income measure) and social deprivation. Our results show that within Quebec the two dimensions do not necessarily co-exist: an area can very well be deprived materially but not socially, and vice versa. Our results also show that each of these forms of deprivation can have its own distinct impact on health and that this impact is increased when the two forms are found together. The impact can also vary with sex and with the health and welfare indicator considered. Thus it is useful to distinguish between these two forms of deprivation.

Another difference in our index is that it uses data for enumeration areas rather than census tracts to estimate people's degree of deprivation. Studies done in Quebec49 and elsewhere27,33,34 show that the smaller the reference area, the more likely the population will be homogeneous, the more classification errors will be avoided and the more major discrepancies in health will be revealed. A recent Manitoba study50 shows that average household income for EAs is just as good a predictor of mortality, hospitalization and other health problems as the household income reported in the census. Thus there appears to be an advantage in using EAs as the reference area in this kind of study.

However, some studies51,52 have shown that geographic measures, no matter how small, are not individual measures and that it could be somewhat risky to substitute one for the other. A geographic measure is an aggregate of individual and environmental features, which, separately and jointly, have an impact on the health of a population.53,54 Geographic measures, therefore, provide a general estimate of such an impact without having to disentangle the specific contribution of these individual and environmental features.

A final difference in our approach is that it offers a model of deprivation that covers the vast majority of the territory and population of Quebec rather than just a sample or a part of it and is thus valid everywhere, regardless of area of residence. The model can therefore help to provide a more complete knowledge of inequalities in health and welfare within the population. It can also help to plan programs in a manner consistent with the resources available to the individual communities throughout the jurisdiction concerned. This is a definite advantage for a health and social services system like Quebec's, in which many programs have large regional and local intervention components.

Indeed, the deprivation index presented in this paper offers many possibilities for planning and implementing health and social service programs. Here are a few of them.

First of all, we consider it important to conduct an extensive analysis of inequalities in all aspects of the public's health and well-being. Our deprivation index can be used for this purpose, and we have begun a detailed analysis not only of mortality and hospitalization rates but also of malignant tumours, consumption of medical services, consumption of services for young victims of abuse and neglect and for old people living in their own homes. This analysis will allow a preliminary assessment of inequalities in health and well-being associated with deprivation, monitoring of these inequalities and consideration of them when public policies and programs are being developed.

The deprivation index can also be used to support regional and local interventions. Since this index is a geographic measure, based on census data, it can be used to derive a profile of deprived communities at the regional and local levels and determine exactly where such communities are located in Quebec. Because the index can also be entered into client files that record use of services, it can be used to establish deprivation profiles for different target client groups at the regional and local levels. Through comparison of the deprivation profile for the population as a whole with profiles of specific groups of clients, the rate of penetration of health and social services within the deprived population of Quebec can be estimated. We have already started such a project concerning the services provided by CLSCs in the province.

Lastly, our index can simplify the task of measuring population needs in order to allocate resources among regions and local communities. Currently, needs for health and social services are measured in Quebec,55,56 elsewhere in Canada57-59 and elsewhere in the world60,61 according to two parameters: the population's age and its social and health-related characteristics. Two distinct methods are used for this purpose, one for each parameter. Our deprivation index will allow analysts to apply the same method to measure both types of needs, taking a provincial consumption profile and projecting it onto the regional or local level.

In short, the index offers considerable opportunities both for acquiring new information about health and social service needs and for planning policies and programs to meet them. This is true not only in Quebec but also elsewhere in Canada because the tools required to construct the index are available.


References

1. World Health Organization. Global strategy for health for all by the year 2000. Geneva: WHO, 1981.

2. World Health Organization. Regional Office for Europe. Targets for health for all. Copenhagen, 1985.

3. Mhatre SL, Deber RB. From equal access to health care to equitable access to health: a review of Canadian provincial health commissions and reports. Int J Health Serv 1992;22(4):645-68.

4. National Forum on Health. Canada health action: building on the legacy [review articles and reference documents]. Ottawa: Health Canada, 1998.

5. Ministère de la Santé et des Services sociaux. La politique de la santé et du bien-être. Quebec City: MSSS, 1992.

6. Ministère de la Santé et des Services sociaux. Priorités nationales de santé publique 1997-2002. Quebec City: MSSS, 1997.

7. Santé Québec. Et la santé, ça va en 1992-1993. Rapport de l'enquête sociale et de santé 1992-1993, vol. 1 et 2. Montreal: Santé Québec, 1995.

8. Wilkins R. L'inégalité sociale face à la mortalité à Montréal, 1975-1977. Cahiers québécois de démographie 1980;9(2):159-84.

9. Choinière R. Les disparités géographiques de la mortalité dans le Montréal métropolitain, 1984-1988. Cahiers québécois de démographie 1991;20(1):117-46.

10. Loslier L. La mortalité dans les aires sociales de la région métropolitaine de Montréal. Série Les indicateurs de santé. Quebec City: Ministère des Affaires sociales, 1976.

11. Loslier L. La différenciation spatiale et sociale de la mortalité dans la région métropolitaine de Québec. Montreal: Université du Québec à Montréal, 1977.

12. Veillette S, Perron M, Hébert G. La mortalité dans les aires sociales de l'agglomération de Chicoutimi-Jonquière. Jonquière: Groupe Écobes, 1992.

13. Townsend P. Deprivation. J Soc Policy 1987;16(2):125-46.

14. Sullivan RB, Bélanger JP. Le capital social au Québec : revue de littérature et essai d'application à la réalité québécoise. Groupe de recherche sur les aspects sociaux de la santé et de la prévention. Montreal: Université de Montréal, 1998.

15. Sloggett A, Joshi, H. Higher mortality in deprived areas: community or personal disadvantage? BMJ 1994;309:1470-4.

16. Phillimore P, Beattie A, Townsend, P. Widening inequality of health in northern England, 1981-91. BMJ 1994;308:1125-8.

17. Eames M, Ben-Shlomo Y, Marmot MG. Social deprivation and premature mortality: regional comparison across England. BMJ 1993;307:1097-102.

18. Pollock AM, Vickers N. Breast, lung and colorectal cancer incidence and survival in South Thames Region, 1987-1992: the effect of social deprivation. J Public Health Med 1997;19(3):288-94.

19. Huff N, Macleod C, Ebdon D, et al. Inequalities in mortality and illness in Trent NHS Region. J Public Health Med 1999;21(1):81-7.

20. Eachus J, Williams M, Chan P, et al. Deprivation and cause specific morbidity: evidence from the Somerset and Avon survey of health. BMJ 1996;312:287-92.

21. Jones CM, Worthington H. The relationship between water fluoridation and socioeconomic deprivation on tooth decay in 5-year-old children. Br Dent J 1999;186(8):397-400.

22. Tansella M, Bisoffi G, Thornicroft G. Are social deprivation and psychiatric service utilisation associated in neurotic disorders? Soc Psychiatry Psychiatr Epidemiol 1993;28:225-30.

23. Thornicroft G, Margolius O, Jones D. The TAPS project. 6: New long stay psychiatric patients and social deprivation. Br J Psychiatry 1992;161:621-4.

24. Malmström M, Sundquist J, Johansson SE, Johansson LM. The influence of social deprivation as measured by the CNI on psychiatric admissions. Scand J Public Health 1999;27(3):189-95.

25. Koppel S, McGuffin P. Socio-economic factors that predict psychiatric admissions at a local level. Psychol Med 1999;29:1235-41.

26. Kawachi I, Kennedy BP, Wilkinson RG. Crime: social disorganization and relative deprivation. Soc Sci Med 1999;48(6):719-31.

27. Crayford T, Shanks J, Bajekal M, et al. Analysis from inner London of deprivation payments based on enumeration districts rather than wards. BMJ 1995;311:787-8.

28. Bajekal M, Sundquist J, Jarman B. The Swedish UPA score: an administrative tool for identification of underprivileged areas. Scand J Med 1996;24(3):177-84.

29. Carstairs V, Morris R. Deprivation: explaining differences in mortality between Scotland and England and Wales. BMJ 1989;299:886-9.

30. Jarman B. Identification of underprivileged areas. BMJ 1983;286:1705-8.

31. Morris R, Carstairs V. Which deprivation? A comparison of selected deprivation indexes. J Public Health Med 1991;13(4):318-26.

32. Salmon C, Crampton P, Sutton F. NSDep91: a New Zealand index of deprivation. Aust N Z J Public Health 1998;22(7):835-7.

33. Haining R, Wise S, Blake M. Constructing regions for small area analysis: material deprivation and colorectal cancer. J Public Health Med 1994;16(4):429-38.

34. Hyndman JCG, D'Arcy C, Holman J, et al. Misclassification of social disadvantage based on geographical areas: comparison of postcode and collector's district analyses. Int J Epidemiol 1995;24(1):165-76.

35. Statistics Canada. Postal code conversion file. May 1998 postal codes. Ottawa, 1998; Cat 92F0027XDB.

36. Statistics Canada. 1996 census dictionary. Ottawa, 1997; Cat 92-351-XPE.

37. Statistics Canada. Fichier de la pondération de la population par codes postaux, Québec. Codes postaux de mai 1998. Ottawa.

38. Davies WKD, Murdie RA. Measuring the social ecology of cities. In: Bourne LS, Ley DS, editors. The changing social geography of Canadian cities. Montreal: McGill University Press, 1993.

39. Renaud J, Mayer M, Lebeau R. Espace urbain, espace social. Portrait de la population des villes du Québec. Montreal: Éditions Saint-Martin, 1996.

40. Perron M, Richard L, Veillette S, Hébert G. Aires sociales et conditions de vie au Saguenay. Un outil de développement régional. CEGEP de Jonquière: Groupes Écobes, 1995.

41. Armitage P. Statistical methods in medical research. London: Blackwell Scientific Publications, 1971.

42. Collishaw NE, Leahy K. Mortality attributable to tobacco use in Canada, 1989. Chronic Dis Can 1991;12(4):46-9.

43. Berendes H, Kessel S, Yaffe S, editors. Advances in the prevention of low birthweight: an international symposium. Washington (DC): National Center for Education in Maternal and Child Health, 1991.

44. Pampalon R, Gauthier D, Raymond G, Beaudry D. La santé à la carte. Une exploration géographique de l'enquête Santé Québec. Quebec City: Les Publications du Québec, 1990.

45. Pampalon R, Loslier L, Raymond G, Provencher P. Les variations géographiques de la santé. Rapport de l'Enquête sociale et de santé 1992-1993. Volume 3. Montreal: Santé Québec, 1995.

46. Wigle DT, Mao Y. Urban mortality in Canada by income level. Ottawa: Health Protection Branch, Health Canada; 1980.

47. Wilkins R, Adams O, Brancker A. Changes in mortality by income in urban Canada from 1971 to 1986. Health Reports 1989;1(2):137-74.

48. Choinière R. Évolution des disparités de la mortalité selon le revenu à Montréal. 67e Congrès de l'ACFAS. Ottawa, 1999.

49. Pampalon R, Raymond G, Caouette L, Côté L. Révision du modèle des aires homogènes utilisé dans les enquêtes générales de Santé Québec. Cahier technique. Montreal: Santé Québec, 1998.

50. Mustard CA, Derksen S, Berthelot JM, Wolfson M. Assessing ecologic proxies for household income: a comparison of household and neighbourhood level income measures in the study of population health status. Health and Place 1999;5:157-71.

51. Geronimus AT, Bound J. Use of census-based aggregate variables to proxy for socioeconomic group: evidence from national samples. Am J Epidemiol 1998;148(5):475-96.

52. Demissie K, Hanley JA, Menzies D, Joseph L, Ernst P. Agreement in measuring socio-economic status: area-based versus individual measures. Chronic Dis Can 2000;21(1):1-7.

53. Macintyre S, Maciver S, Sooman A. Area, class and health: should we be focusing on places or people? J Soc Policy 1993;22(2):213-43.

54. Pampalon R, Duncan C, Subramanian SV, Jones K. Geographies of health perception in Quebec: a multilevel perspective. Soc Sci Med 1999;48:1483-90.

55. Pampalon R, Saucier A, Berthiaume N, et al. The selection of needs indicators for regional resource allocation in the fields of health and social services in Quebec. Soc Sci Med 1996;42(6):909-22.

56. Pampalon R. L'approche québécoise en matière d'indicateurs de besoins pour l'allocation régionale des ressources. Actes du 5e colloque du CREDES. Paris, 1998:3-13.

57. Eyles J, Birch S, Chambers S, et al. A needs-based methodology for allocating health care resources in Ontario, Canada: development and an application. Soc Sci Med 1991;33(4):489-500.

58. Saskatchewan Health. Introduction of needs-based allocation of resources to Saskatchewan district health boards 1994-95; refinements for 1995-96. Regina: Strategic Programs Branch, 1995.

59. Mustard C, Derksen S. A needs-based funding methodology for regional health authorities: a proposed framework. Manitoba Centre for Health Policy and Evaluation, University of Manitoba; 1997.

60. Carr-Hill RA, Hardman G, Martin S, et al. A new formula for distributing hospital funds in England. Interfaces 1997;27:53-70.

61. Lucas-Gabrielli V, Polton D. Réflexions sur les dispositifs actuels d'allocation de ressources en France. Actes du 5e colloque du CREDES. Paris, 1998:14-122.

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