Chapter 1

Introduction


The 1995 Nova Scotia Health Survey (NSHS95) was a population-based survey designed to describe the current health of adult Nova Scotians 18 years of age and older. Selected health-related information was collected from a representative sample of men and women. The survey data provide accurate and up-to-date baseline information on the health and preventive practices of Nova Scotians. This will aid in ongoing efforts to examine and monitor the health status of the population. As well, at a time when the Nova Scotian health system is rapidly changing, the NSHS95 will complement other data used by policy makers to plan effective policies and programs aimed at improving the health of Nova Scotians.

The project was initiated by Heart Health Nova Scotia as a follow-up to the 1986 Nova Scotia Heart Health Survey. Through a partnership with the Nova Scotia Department of Health, and with support from the World Health Organization MONICA project, the Department of Community Health and Epidemiology, the Department of Psychology and the Population Health Research Unit at Dalhousie University, the survey was expanded to estimate health status in specific areas of interest for public health.

Financial support for the project was provided by Health Canada through the National Health Research and Development Program (NHRDP), the Nova Scotia Department of Health, and the Heart and Stroke Foundation.

Goals and Objectives

The NSHS95 had two goals. The first was to provide specific information that describes the health of Nova Scotians. This population-based information is essential to decision-makers engaged in the province's health renewal process, as they redirect resources to identified health needs. The second goal was to replicate key elements of the 1986 Nova Scotia Heart Health Survey to estimate changes in risks for heart disease over the past 10 years.

Four objectives were identified to achieve these two goals:

1. To estimate the prevalence [1] of major health indicators[2] and determinants [3] of health:

Major indicators and determinants are: blood pressure, blood cholesterol, weight, smoking, history of heart disease, family history, physical activity, alcohol consumption, chronic conditions, health practices, awareness of causes of cardiovascular disease, disability and health status, psychosocial indicators, caregiving, and certain demographic variables.

2. To track population changes in these health indicators:

The NSHS95 will serve as a baseline for tracking changes in population indicators and offers the potential for more effective intervention and policy planning.

3. To provide health data for provincial and regional planning:

Survey data will provide information pertinent to prioritizing health objectives.

4. To enable regional health units to gain experience in health research methods:

As a result of involvement with the NSHS95, health regions will gain experience in sampling and surveying techniques which will be applicable in future initiatives to determine the health status of local populations.

This report presents a summary of the current health status and preventive practices of adult Nova Scotians based on selected indicators and will be of interest to the public as well as those in health-related fields throughout the province. Information is reported by age and sex groups. Figures quoted have been converted from sample statistics to population estimates, and therefore, conclusions regarding Nova Scotia's health needs can be based on these findings. Regional comparisons will not be possible using the information in this report, although subsequent documents will provide limited regional analyses.

If numbers total more than 100% in tables and graphs, this is due to computer-based rounding-off procedures within the analysis and is not statistically important. The letter "N' appears in several tables and represents the number of respondents measured or interviewed for the particular data presented. Generally, numbers discussed in the text are highlighted in the tables with white boxes. This is a report of survey highlights, using only age and sex as demographic variables for analysis. Other more technical and in-depth reports will be published as data analyses proceed.

The report is presented in four chapters, the first of which describes survey design issues important for understanding the context and interpreting the results. Chapter 2 outlines how Nova Scotians rate their own health, the extent of activity limitations and caregiving among the population, and reviews data intended to estimate the number of people who may be at risk for depression or in need of treatment. Chapter 3 describes the health of Nova Scotians based on physiological measures such as weight, blood pressure, and blood cholesterol, as well as self-report measures such as physical activity, smoking, alcohol consumption and chronic conditions. In addition, participation in several health screening practices is outlined. Also included in this chapter is a section on cardiovascular health and risk factor levels in 1995 compared to 1986. Finally, Chapter 4 presents some of the implications of the survey findings.

Sample

The sample of 5,578 people was drawn based on a probability sample designed by Statistics Canada and was representative of the Nova Scotian population by age and sex. The sample consisted of non-institutionalized Nova Scotians age 18 and over whose names were listed in the provincial medical insurance register [4]. All active military personnel, RCMP, and those living on native reserves are not included on the MSI register and, therefore, were not part of the sample. The population was divided by regions (Northern, Western, Central, and Eastern) which were chosen to correspond as closely as possible to the new provincial health regions (Figure 1). These regional groups were then classified by sex (male or female) and by seven age groups [5]. For ease of comparison and statistical analysis, these seven age groups were then collapsed into three groups for presentation in the report (18-34, 35-64, 65+ years). Exceptions are the data on smoking as well as a portion of the data on alcohol, where age groups were not combined in order to present detailed findings on specific younger age categories.

Those who were ineligible due to pregnancy, breastfeeding, ill-health, or disability were screened out. Eligible persons who were contacted and agreed to participate in the survey will hereafter be referred to as "respondents." Although the sampling plan was based on the new health regions, the data presented in this report will be applicable to the province overall.

Data Collection

Provincial Health
Regions

A group of 29 public health nurses took part in a six-day training session to learn the techniques for contacting respondents and collecting data. Data were collected from March through November 1995. Potential survey respondents were sent an introductory letter explaining the survey, and they were then contacted by a public health nurse. Those who agreed to participate were interviewed by the nurses and were assured that their information would remain confidential. The survey questionnaire was a compilation of valid and reliable instruments and consisted of 56 pages, requiring, on average, 1.5 hours to complete. The survey questions were read aloud by the nurses, who then recorded the respondent's answers, and collected two blood pressure readings: one at the beginning and another at the end of the interview. Respondents who completed the interview were asked to attend a clinic session where blood pressure, weight, height, and waist and hip measurements were recorded and a blood sample was drawn for blood cholesterol measurement. During the clinic visit, respondents were asked to take part in a structured videotaped interview to assess behaviour patterns associated with cardiovascular disease (CVD) [6] risk. Results of the structured interviews will be presented in a future report. Completed questionnaires, clinic data sheets, and videotapes were forwarded to the central collection site for data entry, quality assessment, and statistical analysis.

Response

Of the 5,578 people selected at random from the provincial health registry, 83% were located (Table 1). Among those who could not be located, some were deceased, some did not respond to calls or mail despite repeated attempts, and for others the address on the provincial health register was not current and none could be found. Younger people were more difficult to locate, which is not uncommon, as this is an age when people frequently move.

A small percentage (3%) of those located were screened out because they were pregnant or breastfeeding, or not able to participate due to their mental or physical status. Of those remaining, 72% (3,227) completed the home interview, and 59% (2,658) completed the clinic visit. Young males were somewhat less likely than others to participate in both the home interview and the clinic visit.

Data analysis from the 1986 Nova Scotia Heart Health Survey suggests that non- respondents tend to have a less favourable risk profile than respondents (Nova Scotia Department of Health, Department of National Health and Welfare, 1987). Thus, the estimates of prevalence in this report are likely to be underestimates of the true risk profile of Nova Scotians.

Table 1. 
Response

Data Analysis

The means and prevalence estimates were calculated using the SAS statistical package. Estimates of coefficient of variation were calculated and are available on request. For the purposes of this report, cell values were not reported when the unweighted number of respondents contributing to the calculation of an estimate was less than 30. The standard errors of the estimates were calculated using the STATA statistical package, and with a "Jackknife" procedure written in SAS. Selected statistical comparisons, significant at p < 0.05, are quoted in the text.

Ethical Considerations

The survey protocol was submitted to and approved by the Ethics Committee of the Faculty of Medicine, Dalhousie University. All respondents were informed of the benefits and possible risks of participating in the survey prior to signing a series of consent forms. In addition, all physicians in the province were notified of the survey to prepare them for patient inquiries and potential follow-up of elevated blood pressure and cholesterol values. Specific procedures approved by the Dalhousie Ethics Committee were followed by clinic personnel whenever they identified a participant with elevated values. If participants had an elevated blood pressure, they were advised to see their physicians for appropriate intervention. All clinic participants received letters outlining their blood lipid results along with a short explanation of the meaning of these values. Participants found to have blood lipid levels in an unacceptable range were recontacted with an additional letter and phone call from the public health nurse to encourage appropriate action.

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