Data Source
The CCHS is a very comprehensive national population survey aimed at describing the health and health services experiences of Canadians. The survey was conducted by Statistics Canada in collaboration with the federal Ministry of Health, the territorial and provincial Ministries of Health, and the Canadian Institute for Health Information. The CCHS survey questionnaire was administered using computer-assisted interviewing in-person, when possible, and by telephone when a face-to-face interview was not feasible [
16].
Based on the available resources and the desire to produce reliable statistics at the health region level, CCHS 2.1 aimed to include 133,700 respondents. The sample was divided among the provinces based on the population and the number of health regions. Each province's sample was then distributed among the health regions proportionally to the square root of the population in each HR. The survey response rate was 80.7%. Individuals that were sampled but did not respond to the survey were accounted for in the survey weights [
16].
Statistics Canada estimates that the survey is representative of approximately 98% of the Canadian population aged 12 and older. The 2% that are not represented include those residing on Indian Reserves or Crown lands, in institutions, in certain remote areas of the territories, or who are full-time members of the Canadian Armed Forces [
16].
This study is based on data collected from adults aged 20 and older and lived in one of the 10 provinces of Canada. The two percent of survey subjects who had their responses given by proxy -- either because they were not available or they were unable to answer because of language or poor health -- were excluded from this study.
Study Variables
The five survey derived outcome variables used in this analysis are:
-
having had an influenza vaccination in the previous two years;
-
having seen a family physician in the previous 12 months;
-
having seen a specialist physician (other than an eye doctor) in the previous 12 months;
-
self-perceived unmet need in the previous 12 months; and
-
having a regular medical doctor.
These outcomes were chosen because they reflect health care access from a broad range of sectors, including primary and secondary care; preventative and therapeutic interventions; and utilization and factors that facilitate utilization. These variables were also expected to show adequate variation across the population.
Having had an influenza vaccination in the last two years is an outcome measure of having received high quality primary health care. The 2002-2003 influenza season National Advisory Committee on Immunization recommendations to Health Canada state that people at risk of influenza-related complications be immunized: people with chronic conditions, residents of nursing homes, people age 65+. They also recommend that people who are in close contact with these at risk groups, such as care givers and health professionals be immunized. Finally, they recommend that healthy people who wish to avoid getting the flu be immunized [
17].
Self-perceived unmet need occurs when an individual feels that they required health care services but for one reason or another they did not receive them. Specifically respondents are asked "During the past 12 months, was there ever a time when you felt that you needed health care but didn't receive it?" The benefit of using this outcome is that it does not rely on respondents seeing a physician. It provides some insight into the health care needs of those who have not seen a physician.
There are two different variables used to assess the use of physician services: having had one or more consultations with a family physician, and having had one or more consultations with a specialist physician. These were based on responses to the following questions.
1.
Not counting when you were an overnight patient, in the past 12 months, how many times have you seen, or talked on the telephone, about your physical, emotional or mental health with: ... a family doctor, or general practitioner?
2.
Not counting when you were an overnight patient, in the past 12 months, how many times have you seen, or talked on the telephone, about your physical, emotional or mental health with: ... any other medical doctor (such as a surgeon, allergist, orthopaedist, gynaecologist or psychiatrist)?
It is estimated that the Canadian National average number of physician visits among those who had a visit in 2003 was 5.2 for family physician visits, and 3.2 for specialist visits [
18].
The final outcome measure was having a regular medical doctor. This measure of health behaviour is also an enabling resource in the health behaviour model. The variable was derived from the response to the questions "Do you have a regular medical doctor?" Often this variable is referred to as usual source of care, however in this case the survey explicitly referred to a medical doctor.
In his previous works Andersen referred to the utilization of health services as realized access and to factors that facilitate the use of services as potential access [
15]. To avoid confusion in this paper if the word access is used it will mean both potential and realized access in general, otherwise the specific component will be referred to directly.
The indicator used to represent communities on the rural-urban continuum is the Statistical Area Classification (SAC) [
19] as recommended by Statistics Canada in the Rural and Small Town Canada Analysis Bulletin [
20]. The basis of this definition is Census Subdivisions which are legislatively determined municipalities or equivalents. According to the definition each Census Subdivision with a population less than 10,000 is categorized as rural or small town. These rural and small towns are further classified into Metropolitan Influence Zones (MIZs) which are determined by the percentage of the community population that commutes to a city or urban centre for employment. Urban municipalities are classified as Census Agglomerations (CAs), small urban centres with between 10,000 and 100,000 people, or Census Metropolitan Areas (CMAs), urban centres with 100,000 people or more [
19,
20]. The Statistical Area Classification is given in Table
1 along with the population of each category [
21,
22].
Table 1
Statistical Area Classification Hierarchy (2001)[
20,
21]
| Census Metropolitan Areas (CMA) | One or more adjacent Census Subdivisions (CSDs) situated around a major urban core (population ≥ 100,000). | 64.3 |
| Census Agglomerations (CA) | One or more adjacent CSDs situated around a major urban core (population ≥ 10,000). | 15.1 |
Rural
| | | |
| Strong Metropolitan Influenced Zone (MIZ) | A CSD where more than 30% of residents commute to work in an urban core (population < 10,000). | 5.1 |
| Moderate MIZ | A CSD where between 5% and 30% of residents commute to work in an urban core (population < 10,000). | 7.6 |
| Weak MIZ | A CSD where between 0% and 5% of residents commute to work in an urban core (population < 10,000). | 6.6 |
| No MIZ | A CSD where forty or fewer residents commute to work in an urban core (population < 10,000). | 1.1 |
Geographic location is assessed at the level of province, health region, and Consolidated Census Subdivision. Health care services are administered provincially in Canada and each province is divided into a number of health regions for administrative purposes. There are 126 health regions in the country and the number of health regions per province varies from one in each of the territories to 37 in the province of Ontario. Consolidated Census Subdivisions (CCSs) are municipalities or adjacent economically dependent communities [
19].
The other independent predictor variables were selected based on Andersen's Health Behaviour Model (HBM) and other research on determinants in Canada [
15]. These predictors were identified as components of: need, predisposing characteristics, and enabling factors.
Two measures of need are used in this study: the presence of chronic conditions and self-rated health status. The measure of chronic conditions indicates whether subjects have zero, one, or two or more chronic conditions. In the questionnaire respondents were given a list of chronic conditions (Table
2) that was preceded by the instruction "Now I'd like to ask about certain chronic health conditions which you may have. We are interested in 'long-term conditions' which are expected to last or have already lasted 6 months or more and that have been diagnosed by a health professional." The number of conditions reported by each person was summed. Self-rated health status is a widely used measure of need and has been shown to be strongly related to utilization of health care services. This measure has the five categories excellent, very good, good, fair, and poor which are rated by survey respondents in response to the question "In general, would you say your health is?"
Table 2
Chronic Conditions
Asthma | Cataracts |
Fibromyalgia | Glaucoma |
Arthritis or rheumatism | Thyroid condition |
High blood pressure | Chronic fatigue syndrome |
Migraine headaches | Multiple chemical sensitivities |
Diabetes | Schizophrenia |
Epilepsy | Mood disorder |
Heart Disease | Anxiety disorder |
Cancer | Other developmental disorder |
Stomach or intestinal ulcers | Eating disorder |
Effects of stroke | Chronic bronchitis |
Bowel disorder/Crohn's or colitis | Emphysema of COPD |
Alzheimer's disease or other dementia | Other long-term health conditions |
Predisposing characteristics describe an individual's propensity to use health care services. They are generally demographic factors that are related to utilisation and are not easily altered. The predisposing variable used in this study were: sex, age, marital status, educational attainment, and ethnic origin.
Enabling resources are the means that individuals have available to them for the use of health care services. These factors are generally more mutable than predisposing characteristics, as they include such things as insurance and availability of physicians. Other enabling factors that are not as easily modified, at least in the short term, are household income, and employment status. The enabling factors used in this study were: having a regular medical doctor, income adequacy, having pharmaceuticals insurance, and occupation class.
Note that the variable "has a regular medical doctor" is included as both an enabling resource (independent variable) and a measure of access (dependent variable). Having a regular medical doctor is a resource that enables the use of care, however having a regular medical doctor to provide care when needed is an indicator of access.
Greater detail on each of the variables can be found in the survey documentation [
16].