PREVENTIVE MEDICINE 12, 191-195 (1983)

The North Karelia Project’

P.PUSKA,J.SALONEN, A. NISSINEN,AND J. TUOMILEHTO

University of Kuopio, Research Institute for Community Health, 70101 Kuopio 10, Finland

A comprehensive community program for control of cardiovascular disease (CVD) was carried out from 1972 to 1977 in the county of North Karelia, Eastern Finland, an area with exceptionally high CVD rates. The primary aim was to reduce CVD mortality and incidence rates among the population through general reduction of smoking rates, serum cholesterol levels (general dietary changes), and elevated blood pressures, and through promoting sec- ondary prevention. The program activities were closely integrated with community organi- zations, and community involvement was emphasized. The aim of the evaluation was to assess the feasibility, effects, process, costs, and other consequences of the program. Rep- resentative population samples were studied at the beginning and end of the period in North Karelia and a matched refcrcncc area. Smoking, serum cholesterol levels, and blood pres- sure levels decreased in North Karelia, even when adjusted for the changes in the reference area. The respective net reduction of estimated coronary heart disease (CHD) risk (based on a logistic model) was 17% for men and 12% for women. Acute myocardial infarction (AMI) and stroke incidence rates as well as CVD and total mortality rates decreased significantly during the program in North Karelia. The changes in mortality, however, were not signifi- cantly different from those in the reference area. A significant net reduction took place in CVD and total disability rates in North Karelia. The program costs were relatively low and several associated positive changes were observed, for example, concerning emotional problems. The overall positive experiences of the project were further supported by the obvious nationwide impact through practical applications and more general influence on national policy decisions. In the meantime, further developments in the community continue to be monitored in order to fully assess the program effects.

INTRODUCTION

Research which ultimately aims at control of cardiovascular diseases (CVD) has proceeded at many levels: pathological studies, animal studies, biochemical and physiological studies, clinical studies, and epidemiological studies. Community studies that seek to determine whether and how existing knowledge can be used to control this modern epidemic form the important link between this research and its large-scale application in the society.

For several decades Finland has been faced with extremely high rates of CVD and especially coronary heart disease (CHD). The highest rates were found in the eastern parts of the country-in North Karelia (NK), a mainly rural area with 180,000 inhabitants. About 10 years ago representatives of that county signed a petition to the Finnish government for urgent action “to reduce the extremely high cardiovascular rates.”

The petition led to the planning, design, and organization of the North Karelia project (3). The project was fortunate to have planning support and assistance

I Presented at the International Symposium on Epidemiology and Prevention of Atherosclerotic Disease, June 24-26, 1981, Anacapri, Italy.

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192 PUSKA ET AL.

from many international experts and WHO; it formed a natural continuation of the epidemiological work started in Finland in the 1950s by Keys, Karvonen, and coworkers (1).

During the planning phase it became obvious that, due to the chronic nature of CVD, the potential for its reduction lay in primary prevention. Despite unan- swered questions about the etiology of CHD and its risk factors, decisions for action had to be based on the best available knowledge. Previous studies and subsequent recommendations had highlighted the importance of three major risk factors: smoking, high serum cholesterol, and high blood pressure. These factors alone and in combination were extremely prevalent in NK. The generally high level of these factors and their close link with community lifestyles, social organi- zation, and even physical environment led to adoption of a community approach strategy.

The primary objective of the NK project was reduction of mortality and mor- bidity, especially of major CVD, among the whole population, but with special reference to middle-aged men. The central intermediate objectives were general reductions in risk factor levels: smoking, changes in dietary habits, and control of high blood pressure. The program was also considered to be a national pilot program to test this approach for nationwide use (3).

After baseline surveys in 1972, a systematic intervention program was started in the area. It was a comprehensive coordinated action where activities were closely integrated with the existing service structure and social organization of the com- munity. The aim was to have a popular community action by mobilizing the community to work for the goals and,to provide a systematic and practical support service structure. The activities included use of mass media, distribution of health education material, arrangements for practical services, training of local person- nel, introduction of environmental changes, and the set-up of a practical informa- tion system for the management of the program.

The underlying information strategies took advantage of the initial health knowledge of the people and emphasized the use of persuasion, e.g., making changes for the sake of North Karelia and the joint action, and teaching practical skills for change. Organization of social and environmental support for mainte- nance of changes was also a central aim (2).

The original project was to evaluate this activity for its first 5-year period. The aim in the evaluation was assessment of: (a) feasibility, (b) effects (risk factors, disease rates), (c) costs, and (d) process and other changes associated with the program (4).

A matched reference area was chosen for the evaluation. At the outset in 1972, a baseline survey of a random population sample of some 11,000 people was carried out in the two areas (men and women ages 25 to 59 years). After 5 years (in 1977) a similar survey was carried out for another cross-sectional sample of the same size. Strictly similar and standardized methods were used each time in the two areas. The participation rates were over 90%. The so called net change, i.e., the ob- served change in NK minus the respective change in the reference area, was calculated to determine the effect attributed to the program. In addition, a number

SYMPOSIUM: ATHEROSCLEROTIC DISEASE 193

TABLE 1 MULTIPLE LOGISTIC FUNCTION ANALYSIS ON RISK FACTORS OF ACUTE MYOCARDIAL INFARCTION

(AMI) IN ~-YEAR FOLLOW-UP OF A POPULATION SAMPLE OF 1,545 MEN,

INITIALLY FREE OF OBVIOUS CVD, IN NORTH KARELIA

Risk factor Standardized coefficient Adjusted risk ratios

Serum cholesterol Smoking Systolic blood pressure All three combined

‘2 P c 0.001. * P s 0.05. c P c 0.01.

0.37” 2.7” 0.256 2.2b 0.29’ 1.5

9.0

of other data sources were available or set up. These mostly consisted of community-based disease registers and of existing data on mortality, hospitaliza- tion, and disability pension awards.

RESULTS

A 5-year prospective follow-up of the baseline survey sample confirmed the important role of the chosen risk factors in the target population (Table 1). The program proved to be feasible; cooperation with the local services and general support by the community were good throughout.

Comparison of results from the baseline and 5year terminal surveys showed that all aspects of health behavior and risk factor changes took place in NK in accordance with the objectives. Similar changes could also be seen in the refer- ence area, although these were smaller than in NK. For the male population, the following net reductions (effects) were observed for the individual risk factors:

TABLE 2 ESTIMATED MEAN CHD RISK SCORES (PERCENTAGE) IN NORTH KARELIA AND THE

REFERENCE AREA IN 1972 AND 1977 ACCORDING TO SEX

Males Females

1972 North Karelia Reference area Difference

1977 North Karelia Reference area Difference

Net reduction in North Karelia Absolute Percentage

4.1 3.7 0.5”

3.4 2.9 3.7 2.9

-0.3” 0.0

0.7” 17.4

3.3 3.0 0.4”

0.4” 11.5

194 PUSKA ET AL.

smoking 10%; serum cholesterol 11 mg/dl or 4%; systolic blood pressure 7 mm Hg or 4%; prevalence of high blood pressure 44%.

To assess the effects on the multiple risk factors simultaneously, a multiple logistic function was applied; a 17% net reduction among men and a 12% net reduction among women was observed in North Karelia in the general risk factor level during the program period (Table 2).

The internal monitoring in North Karelia of morbidity and mortality demon- strated clear reductions during the period. Reduction in acute myocardial infarc- tion (AMI) incidence rates-16%-observed during the program period is shown in Fig. 1. A reduction in total mortality was observed, almost exactly explained by the reduction in CVD rates. When the mortality trends in the two areas were compared, some reduction was also seen in the reference area. Thus within this period no statistically significant difference could be observed, in spite of the clear reduction in North Karelia.

Analyses of national disability data showed that an approximately 15% net reduction in CVD disability occurred in North Karelia during the period. The trends with nonCVD disability cases were very similar. The possible program

MEN

WOMEN

FIG. 1. Age-adjusted annual incidence rates of AM1 in North Karelia in 1973- 1979.

SYMPOSIUM: ATHEROSCLEROTIC DISEASE 195

effects on emotional problems-e.g., concerning anxiety, stress, self reported health and illness days, different symptoms-were assessed. For many factors the development in North Karelia was positive, and in no instance less satisfactory than in the reference area. While a comprehensive index of these reported emo- tional problems was formed, a net reduction of 6% among men and 10% among women was observed.

CONCLUSIONS

The following conclusions were drawn from the North Karelia project: (a) The comprehensive community program was feasible. (b) Cooperation with the local population and health and other local person-

nel was good. (c) The program had clear effects on lifestyles and biological risk factors

(changes in the program area significantly greater than in the reference area). (d) Incidence and mortality rates in the area fell, but due to reduction in the

reference area (probably in the whole country), no significant net effect in mortal- ity could be demonstrated.

(e) A net reduction in CVD and all disability pension rates in the program area took place.

(f) Direct costs of the program were low; for the community the extra costs were small and obvious savings occurred.

(g) An absolute and net reduction in reported emotional problems took place in the program area.

It is felt that 5 years is an adequately long enough period in which to assess permanent lifestyle and risk factor changes. However, only continued follow-up will show the future trends and give a comprehensive picture of possible mortality effects. Thus both the follow-up and most of the other established activities con- tinue in the area. At the same time great national interest and numerous national applications have taken place. It is obvious that the project has contributed to general adoption of the idea that the modern epidemic of CVD can be controlled by systematic action on a number of factors, just as many previous public health problems have been controlled. Associated with the obviously positive develop- ment in North Karelia is the observation that during the last few years the national CHD mortality rate also has started to decrease in Finland.

REFERENCES 1. Keys, A. “Seven Countries, A Multivariate Analysis on Death and Coronary Heart Disease,”

Harvard Univ. Press, Boston, 1980. 2. McAlister, A., Puska, P., Salonen, J. T., Tuomilehto, J., and Koskela, K. Theory and action for

health promotion: Illustrations from the North Karelia project. Amer. J. Pub. Health 72,43-50 (1982).

3. Puska, P. The North Karelia project-An attempt at community prevention of cardiovascular disease. WHO Chron. 27, 55-58 (1973).

4. Puska, P., Tuomilehto, J., Salonen, J., Nissinen, A., Virtamo, J., et al. The North Kareliaproject: Evaluation of a comprehensive community programme for control of cardiovascular diseases in 1972-77 in North Karelia, Finland. WHO Monograph, in press.