David MacLean

Distribution of blood pressure and hypertension in Canada and the United States.

BACKGROUND Two North American population based surveys, the Third National Health and Nutrition Examination Survey (NHANES III) and the Canadian Heart Health Surveys (CHHS) have similar time frames and methods that allow comparisons between these countries in terms of the distribution of systolic (SBP) and diastolic (DBP) blood pressure and the levels of hypertension awareness, treatment, and control. METHODS Cross-sectional population surveys using similar methods conducted home interviews and clinic visits (CHHS), and medical examinations (NHANES III). The CHHS included the ten Canadian provinces (1986-1992) and NHANES III, a representative sample of the United States population (1988-1994). Blood pressure measurements were available for 23,111 Canadians (age 18-74 years), and restricted to the 15,326 US participants in the same age range (age 18-74 years) with both systolic and diastolic mean values. Standardized techniques were used for BP measurements. Mean of all available measurements was used from four measurements for the CHHS and six measurements for NHANES III. A mean SBP/DBP of 140/90 mm Hg or treated with medication defined hypertension. All measures were weighted to represent population values. RESULTS Both surveys showed similar trends in mean BP by age, with slightly higher levels in the CHHS. Hypertension prevalence using the same definitions and the same age range (18-74 years) was NHANES III: 20.1%, CHHS: 21.1%. Although the prevalence of isolated systolic hypertension (ISH) was similar in both studies, around 8% to 9%, the CHHS had higher ISH prevalence than NHANES III in the younger age groups and lower prevalence in the older age groups. Elevated SBP dominated the prevalence figures after the 1950s in both studies. Compared to NHANES III, the CHHS showed a lower proportion (43% v 50%) of individuals with optimal BP (< 120/80 mm Hg) and a very low proportion of hypertensives under control (13% v 25%). About half of diabetic participants were hypertensive (using 140/90 mm Hg) in both countries with a very low level of control in Canada (9%) v the US (36%) for ages 18 to 74 years. CONCLUSIONS The results of these two surveys highlight the importance of SBP, in the later decades of life, an overall low control of hypertension in both countries, and a better overall awareness, treatment, and control of hypertension in the US than in Canada for that period. Dissemination of hypertension guidelines and a more aggressive focus on SBP are urgently needed in Canada, with special attention to diabetics.

Persistence of pertussis in an immunized population: Results of the Nova Scotia Enhanced Pertussis Surveillance Program

An enhanced pertussis surveillance and laboratory diagnosis program was initiated in the Halifax metropolitan area of Nova Scotia to better delineate the epidemiology of pertussis. During the 28 months of the study, 526 cases of pertussis were identified (overall yearly incidence: 74 cases per 100,000 population). Laboratory confirmation was obtained in 168 (32%) cases, including 111 (21%) by culture. Peak incidence occurred among children 2 to 5 years of age; the highest morbidity rate was seen in children less than 1 year of age. Hospitalization was required for 22 (4.2%) patients; 14 (64%) of those hospitalized were less than 1 year of age. Most (91%) patients had received at least three doses of pertussis vaccine; vaccine efficacy was estimated at 45%. The surveillance program demonstrated that the incidence of pertussis in Nova Scotia, although among the highest in North America, is still underestimated. A ninefold increase in cases was identified over the comparable period of the previous year, largely because patients meeting clinical criteria were reported. By supplementing culture techniques with immunofluorescent staining and serologic methods, we increased the rate of laboratory confirmation from 17% to 65%, suggesting that strict clinical criteria accurately reflect accurately reflect incidence. We conclude that pertussis remains a significant health problem in Nova Scotia, despite nearly universal vaccination.

Constructive anger verbal behavior predicts blood pressure in a population-based sample.

The creation of an observational Constructive Anger Behavior-Verbal Style Scale (CAB-V) and its relation to resting blood pressure (BP) in an age- and sex-stratified, population-based sample is examined. Participants (N = 1,862) provided hypertension risk factor information, had resting BP assessed multiple times, and completed a videotaped interview, which was later coded for CAB-V and Hostile Style. High CAB-V scores remained a significant predictor of lower resting BP when controlling for the effects of standard hypertension risk factors (age, sex, body mass index, physical activity, alcohol use, smoking status, parental myocardial infarction history, education, and diabetic status) and psychosocial measures (anxiety, depression, hostility, social support, and Hostile Style). This relation also remained when excluding known hypertensive persons. Results suggest that constructive anger expression may have an independent beneficial association with resting BP.

Facilitators and Challenges to Organizational Capacity Building in Heart Health Promotion

The authors describe the facilitators and challenges to a multisectoral initiative aiming at building organizational capacity for heart health promotion in Nova Scotia, Canada. The research process was guided by participatory action research. The study included 21 organizations from diverse sectors. Participant selection for the data collection was purposive. The authors collected data through organizational reflection logs and one-to-one semistructured interviews and used grounded theory techniques for the data analyses. Factors influencing organizational capacity for heart health promotion varied, depending on the project stage. Nonetheless, leadership, organizational readiness, congruence, research activities, technical supports, and partnerships were essential to capacity-building efforts. Approaches to organizational capacity building should be multileveled, because organizations are influenced by multiple social systems that are not all equally supportive of capacity.

Building Capacity for Heart Health Promotion: Results of a 5-year Experience in Nova Scotia, Canada

Purpose. To present the outcomes of a capacity-building initiative for heart health promotion. Design. Follow-up study combining quantitative and qualitative methods. Setting. The Western Health Region of Nova Scotia, Canada. Subjects. Twenty organizations, including provincial and municipal agencies and community groups engaged in health, education, and recreation activities. Intervention. Two strategies were used for this study: partnership development and organizational development. Partnership development included the creation of multilevel partnerships in diverse sectors. Organizational development included the provision of technical support, action research, community activation, and organizational consultation. Measures. Quantitative data included number and type of partnerships, learning opportunities, community activation initiatives, and organizational changes. Qualitative data included information on the effectiveness of partnerships, organizational consultation, and organizational changes. Results. Results included the development of 204 intersectoral partnerships, creation of a health promotion clearinghouse, 47 workshops attended by approximately 1400 participants, diverse research products, implementation of 18 community heart health promotion initiatives, and increased organizational capacity for heart health promotion via varied organizational changes, including policy changes, fund reallocations, and enhanced knowledge and practices. Conclusions. Partnership and organizational development were effective mechanisms for building capacity in heart health promotion. This intervention may have implications for large-scale, community-based, chronic-disease prevention projects.

Adaptive defense use and resting blood pressure in a population-based sample.

OBJECTIVES There is an accumulating body of research related to the psychosomatic study of blood pressure. One variable that has received attention is defense use. We examined the relation between defense use and blood pressure in men and women of different ages. METHODS A random sample of 667 participants was selected from a population-based study. Resting blood pressure was obtained, and each participant was rated for defense use by a trained observer using Defense-Q. An Adaptive Defense Profile (ADP) score was calculated for each participant, and this score was related to blood pressure. RESULTS Regression analyses revealed a significant main effect for the ADP score for both diastolic and systolic blood pressure. Those persons with higher ADP scores had lower diastolic and systolic blood pressure. As well, a significant Age x Sex x ADP score interaction was found for diastolic blood pressure. Older women with a less ADP score had higher diastolic blood pressure. CONCLUSIONS These findings suggest the continued investigation of defense use and blood pressure.

Coder gender and potential for hostility ratings.

This study examined the effects of coder gender on Potential for Hostility ratings. Six trained coders (3 men and 3 women) who were unaware of the coder gender effect hypothesis coded 30 male and 30 female undergraduates for Potential for Hostility. Although reliability estimates as calculated by Cronbachs alpha suggested that all coders were consistent, an analysis of variance revealed a significant main effect for coder gender, wherein female coders rated participants as displaying significantly less Potential for Hostility than did male coders. This significant difference was also meaningful, as coder gender accounted for 32% of the variance in Potential for Hostility scores. Thus, future Potential for Hostility investigations need to consider the gender of those coding, as this factor both significantly and substantially influences reported Potential for Hostility ratings.

The Use of Defenses and Physician Health Care Costs: Are Physician Health Care Costs Lower in Persons with More Adaptive Defense Profiles?

Background: The objective of the present study was to determine if persons who use more adaptive defenses have lower physician health care costs compared to those who use less adaptive defenses. Methods: We randomly selected 667 persons from the 1995 population-based Nova Scotia Health Survey who completed a videotaped structured interview. Each interview was rated for typical defense use by the Defense-Q. We obtained physician health care costs for 3 months before and after the interview, as well as medical diagnoses and measures of psychological functioning. Results: A more adaptive defense profile significantly predicted lower future physician health care costs. These results were found when controlling for other psychosocial variables, before and after controlling for previous physician health care costs, and when testing only within a physically healthy subsample. Results of secondary analyses showed that a more adaptive defense profile was positively related to a number of psychosocial variables, such as nurse’s rating of competence, lack of depressive symptoms, and days at work. Conclusions: The adaptiveness of a person’s defense use in managing affect is important in predicting physician health care costs as well as psychosocial functioning.

U-curved relation between total fasting serum cholesterol and hostility: A population-based study

Some researchers have found higher cholesterol levels linearly related to hostility, whereas others have found no relation. Even so, it remains unclear whether research should seek to find a linear relation between hostility and cholesterol levels. We hypothesized that a U-curved association was the proper test of the relation between hostility and cholesterol. Total fasting and low-density lipoprotein (LDL) cholesterol levels were collected from a population-based sample of 2,306 Canadians. Barefoot’s (1989) scoring of the Cook-Medley Hostility Scale was used to assess hostility levels. Both a linear and a U-curved relation among hostility scores, fasting total, and LDL cholesterol levels were significant. Participants with low and high cholesterol levels had significantly higher hostility scores than the normal cholesterol group. A U-curved relation between hostility and serum cholesterol levels may be a more appropriate function to consider given the all-cause mortality findings we seek to explain.

Prevalence of Cardiovascular Risk Factors in Canadians with Diabetes Mellitus

Cardiovascular disease is the leading cause of mortality and morbidity among people with diabetes mellitus. Epidemiological studies have shown that individuals with diabetes are at increased risk of premature coronary heart disease and stroke.1,2,3,4 People with non-insulin dependent diabetes mellitus (NIDDM) have age-specific mortality rates which are about double those of the non-diabetic populations5. Most of the excess mortality is attributable to coronary heart disease.6 Poor glycemic control in people with diabetes has been demonstrated to lead to higher rates of cardiovascular events7,8,9.