Nova Scotia Health Survey Research Articles

Prospective Study of Skipping Meals to Lose Weight as a Predictor of Incident Type 2 Diabetes With Potential Modification by Cardiometabolic Risk Factors: The Canadian 1995 Nova Scotia Health Survey

BackgroundSkipping meals is an increasingly common practice to lose weight among North American adults. However, the long-term effect of this practice on incident type 2 diabetes mellitus (T2DM) remains unknown. We assessed whether skipping meals to lose weight is associated with T2DM risk and whether this association is modified by cardiometabolic risk factors. MethodsSkipping meals to lose weight was assessed by questionnaire in 2,288 adults from the 1995 Nova Scotia Health Survey and was linked to administrative health databases to determine T2DM incidence in the following 23 years. Multivariable-adjusted Cox proportional hazards models estimated hazard ratios (aHRs) and 95% confidence intervals (CIs) for T2DM. ResultsDuring follow up, 378 T2DM cases were diagnosed. Compared with participants who did not skip meals to lose weight, those who did (2.2%) had a 125% higher risk of T2DM (aHR, 2.25; 95% CI, 1.31 to 3.86). This association was no longer present after further adjustment for baseline body mass index (BMI) (aHR, 1.66; 95% CI, 0.96 to 2.85). Skipping meals to lose weight was associated with T2DM among participants who were men (n=1,135; aHR, 2.09; 95% CI, 1.09 to 4.02) or had a BMI <30 kg/m2 (n=1,676; aHR, 2.64, 95% CI, 1.15 to 6.06), elevated cholesterol (n=1,146; aHR, 2.11; 95% CI, 1.06 to 4.22), high blood pressure (n=1,133; aHR, 2.10; 95% CI, 1.10 to 4.01) and restless sleep (n=1,186; aHR, 2.19; 95% CI, 1.13 to 4.25), but not among women, those with a BMI of ≥30 kg/m2 and those without elevated cholesterol, high blood pressure or restless sleep. ConclusionsSkipping meals to lose weight may be a predictive modifiable risk factor for developing T2DM over time, potentially working in connection with other T2DM risk factors.

Abstract P518: Prospective Study of Skipping Meals to Lose Weight as a Predictor of Incident Type 2 Diabetes and Coronary Heart Disease: The Canadian 1995 Nova Scotia Health Survey

Introduction: Skipping meals is an increasingly common practice to lose weight among North American adults of all bodyweights. However, due to a lack of long-term studies, the long-term effect of skipping meals to lose weight on cardiometabolic health outcomes such as a diagnosis of type 2 diabetes mellitus (T2DM) or incident coronary heart disease (CHD) remains unknown, although previous short-term studies of skipping meals and risk factors for T2DM and CHD have suggested plausible biological pathways for a relationship to exist in either direction, protective or harmful. Hypothesis: We assessed the hypotheses that skipping meals to lose weight was associated with long-term risk of incident T2DM and CHD in the Canadian 1995 Nova Scotia Health Survey (NSHS95), and that these associations were influenced by cardiometabolic risk factors. Methods: Skipping meals to lose weight was assessed via questionnaire in a cohort of 2,898 adults in the NSHS95 and was linked to population-based health care administrative databases to determine incidence of T2DM and/or CHD in the following 23 years. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for T2DM and CHD. Results: During 23 years of follow-up, 430 incident cases of T2DM and 632 incident cases of CHD were diagnosed. Compared to participants who did not skip meals to lose weight, those who did skip meals to lose weight (2.7%) had an 87% higher risk of T2DM (multivariable-adjusted HR=1.87, 95% CI: 1.11-3.17). This association was no longer present after adjustment for baseline body mass index (BMI) (HR=1.42, 0.83-2.42). After stratification by BMI, skipping meals was associated with T2DM among participants who had BMI &lt;25 kg/m 2 (n=1,030; HR=4.42, 1.01-19.30) but not among participants with BMIs of 25-29.9 kg/m 2 (n=1,123; HR=1.07, 0.39-2.96) or 30+ kg/m 2 (n=586; HR=1.21, 0.61-2.39). The multivariable-adjusted (including BMI) association was also present within participants with elevated cholesterol (n=1,450; HR=1.88, 1.00-3.53) and high blood pressure (n=1,363; HR=2.07, 1.11-3.85), but not among those without. No significant association was observed between skipping meals to lose weight and CHD risk before (HR=1.14, 0.67-1.96) or after adjustment for BMI (HR=1.05, 0.61-1.81), or within subgroups. Conclusion: These findings suggest that skipping meals to lose weight may be a predictive modifiable risk factor for developing T2DM over time, especially among people with a BMI &lt;25 kg/m 2 , potentially working in connection or iteration with other T2DM risk factors. With the growing number of popular diets that include skipping meals, future studies are warranted to understand perturbations of potential metabolic consequences.

Accumulation of Non-Traditional Risk Factors for Coronary Heart Disease Is Associated with Incident Coronary Heart Disease Hospitalization and Death

BackgroundAssessing multiple traditional risk factors improves prediction for late-life diseases, including coronary heart disease (CHD). It appears that non-traditional risk factors can also predict risk. The objective was to investigate contributions of non-traditional risk factors to coronary heart disease risk using a deficit accumulation approach.MethodsCommunity-dwelling adults with no known history of CHD (n = 2195, mean age 46.9±18.7 years, 51.8% women) participated in the 1995 Nova Scotia Health Survey. Three risk factor indices were constructed to quantify the proportion of deficits present in individuals: 1) a 17-item Non-Traditional Risk Factor Index (e.g. sinusitis, arthritis); 2) a 9-item Traditional Risk Factor Index (e.g. hypertension, diabetes); and 3) a frailty index (25 items combined from the other two index measures). Ten-year risks of CHD events (defined as CHD-related hospitalization and CHD-related mortality) were evaluated.ResultsThe Non-Traditional Risk Factor Index, made up of health deficits unrelated to CHD, was independently associated with incident CHD events over 10 years after controlling for age, sex, and the Traditional Risk Factor Index [adjusted {adj.} Hazard Ratio {HR} = 1.31; Confidence Interval {CI} 1.14–1.51]. When all health deficits, both those related and unrelated to CHD, were included in a frailty index the corresponding adjusted hazard ratio was 1.61; CI 1.40–1.85.ConclusionBoth traditional and non-traditional risk factor indices are independently associated with incident CHD events. CHD risk assessment may benefit from consideration of general health information as well as from traditional risk factors.

Comparison of alternate scoring of variables on the performance of the frailty index

BackgroundThe frailty index (FI) is used to measure the health status of ageing individuals. An FI is constructed as the proportion of deficits present in an individual out of the total number of age-related health variables considered. The purpose of this study was to systematically assess whether dichotomizing deficits included in an FI affects the information value of the whole index.MethodsSecondary analysis of three population-based longitudinal studies of community dwelling individuals: Nova Scotia Health Survey (NSHS, n = 3227 aged 18+), Survey of Health, Ageing and Retirement in Europe (SHARE, n = 37546 aged 50+), and Yale Precipitating Events Project (Yale-PEP, n = 754 aged 70+). For each dataset, we constructed two FIs from baseline data using the deficit accumulation approach. In each dataset, both FIs included the same variables (23 in NSHS, 70 in SHARE, 33 in Yale-PEP). One FI was constructed with only dichotomous values (marking presence or absence of a deficit); in the other FI, as many variables as possible were coded as ordinal (graded severity of a deficit). Participants in each study were followed for different durations (NSHS: 10 years, SHARE: 5 years, Yale PEP: 12 years).ResultsWithin each dataset, the difference in mean scores between the ordinal and dichotomous-only FIs ranged from 0 to 1.5 deficits. Their ability to predict mortality was identical; their absolute difference in area under the ROC curve ranged from 0.00 to 0.02, and their absolute difference between Cox Hazard Ratios ranged from 0.001 to 0.009.ConclusionsAnalyses from three diverse datasets suggest that variables included in an FI can be coded either as dichotomous or ordinal, with negligible impact on the performance of the index in predicting mortality.

Relation Between Leukocyte Telomere Length and Incident Coronary Heart Disease Events (from the 1995 Canadian Nova Scotia Health Survey)

Leukocyte telomere length has been proposed as a biomarker of cellular aging and atherosclerosis. The aim of this study was to determine whether leukocyte telomere length is independently associated with incident coronary heart disease (CHD) in the general population. Telomere length was measured using a polymerase chain reaction method for participants enrolled in the 1995 Nova Scotia Health Survey (NSHS95; n = 1,917). The primary end point was the first occurrence of a fatal or nonfatal CHD event. During a mean follow-up period of 8.7 years, 164 fatal or nonfatal CHD events occurred. Compared with participants in the longest tertile of telomere length, those in the middle and shortest tertiles had increased incidence of CHD events (6.2, 11.2, and 12.2 per 1,000 person-years, respectively). After adjustment for demographics, traditional risk factors, and inflammatory markers including high-sensitivity C-reactive protein, interleukin-6, and soluble intercellular adhesion molecule-1, those in the middle tertile had significantly elevated risk for incident CHD (hazard ratio 1.63, 95% confidence interval 1.07 to 2.51, p = 0.02) compared with the longest tertile, whereas the risk for those in the shortest tertile was nonsignificantly elevated (hazard ratio 1.25, 95% confidence interval 0.82 to 1.90, p = 0.30). In conclusion, these findings do not support a linear association between leukocyte telomere length and incident CHD risk in the general population.

Depressive Symptoms Are Not Associated with Leukocyte Telomere Length: Findings from the Nova Scotia Health Survey (NSHS95), a Population-Based Study

BackgroundPremature shortening of leukocyte telomere length has been proposed as a novel mechanism by which depression may confer increased risk of adverse cardiovascular events. Prior studies demonstrating associations of depression and depressive symptoms with shorter leukocyte telomere length were small, included selected psychiatric outpatients, were based on convenience samples, and/or adjusted for a limited number of possible confounding factors.Methods and FindingsWe examined the associations of depressive symptoms, probable depressive disorder, and specific depressive symptom clusters, as assessed by the Center for Epidemiological Studies—Depression (CES-D) scale, with leukocyte telomere length, measured by using a real-time PCR method, in 2,225 apparently healthy participants from the 1995 Nova Scotia Health Survey population-based study. The mean age was 48.2±18.9 years; 49.9% of participants were female; and the mean CES-D score was 7.4±7.9. The mean telomere length was 5,301±587 base pairs. In an unadjusted model, depressive symptoms were significantly associated with longer leukocyte telomere length (B = 27.6 base pairs per standard deviation increase in CES-D, 95% confidence interval [CI] = 3.1–52.1, p = 0.027). This association was no longer significant after adjustment for age and sex (B = 9.5, 95% CI = −14.6–33.6, p = 0.44) or after further adjustment for body mass index, Framingham risk score and previous history of ischemic heart disease (all p's≥0.37). Neither probable depressive disorder nor specific depressive symptom clusters were independently associated with leukocyte telomere length.ConclusionsConcurrent depressive symptoms were not associated with leukocyte telomere length in a large, representative, population-based study.

Depressive symptoms are not associated with leukocyte telomere length: findings from the Nova Scotia Health Survey (NSHS95) population-based study

Depressive symptoms are not associated with leukocyte telomere length: findings from the Nova Scotia Health Survey (NSHS95) population-based study

Blood Pressure Reactivity to an Anger Provocation Interview Does Not Predict Incident Cardiovascular Disease Events: The Canadian Nova Scotia Health Survey (NSHS95) Prospective Population Study.

We examined the association between blood pressure (BP) reactivity to an anger provocation interview and 10-year incident CVD events in 1,470 adults from the population-based 1995 Nova Scotia Health Survey (NSHS95). In an unadjusted model, those in the highest decile of systolic BP reactivity were more than twice as likely to have an incident CVD event compared to those in the decile with no reactivity (HR = 2.33, 95% CI = 1.15 – 4.69, P = 0.02). However, after adjusting for age and sex, and then also for Framingham risk score, body mass index, and education, this relationship was attenuated and not statistically significant. Diastolic BP reactivity was not associated with CVD incidence in any model. Individual differences in BP reactivity to a laboratory-induced, structured anger provocation interview may not play a major role in clinical CVD endpoints.

Observed Hostility and the Risk of Incident Ischemic Heart Disease: A Prospective Population Study From the 1995 Canadian Nova Scotia Health Survey

The aim of this study was to examine the relation between hostility and incident ischemic heart disease (IHD) and to determine whether observed hostility is superior to patient-reported hostility for the prediction of IHD in a large, prospective observational study. Some studies have found that hostile patients have an increased risk of incident IHD. However, no studies have compared methods of hostility assessment or considered important psychosocial and cardiovascular risk factors as confounders. Furthermore, it is unknown whether all expressions of hostility carry equal risk or whether certain manifestations are more cardiotoxic. We assessed the independent relationship between baseline observed hostility and 10-year incident IHD in 1,749 adults of the population-based Canadian Nova Scotia Health Survey. There were 149 (8.5%) incident IHD events (140 nonfatal, 9 fatal) during the 15,295 person-years of observation (9.74 events/1,000 person-years). Participants with any observed hostility had a greater risk of incident IHD than those without (p = 0.02); no such relation was found for patient-reported hostility. Those with any observed hostility had a significantly greater risk of incident IHD (hazard ratio: 2.06, 95% confidence interval: 1.04 to 4.08, p = 0.04), after adjusting for cardiovascular (age, sex, Framingham Risk Score) and psychosocial (depression, positive affect, patient-reported hostility, and anger) risk factors. The presence of any observed hostility at baseline was associated with a 2-fold increased risk of incident IHD over 10 years of follow-up. Compared with patient-reported measures, observed hostility is a superior predictor of IHD.

Is vitamin D deficiency a risk factor for ischemic heart disease in patients with established cardiovascular disease? 10-year follow-up of the Nova Scotia Health Survey

Recent studies have reported that low serum vitamin D levels are associated with a variety of diseases, including cardiovascular disease and in particular ischemic heart disease (IHD). Possible mechanisms underlying this association include increased inflammation, renin-angiotensin system upregulation, insulin resistance, altered lipid metabolism, and altered vascular smooth muscle growth and function that lead to hypertension, diabetes, dyslipidemia and atherosclerosis.[1][2]

Don't worry, be happy: positive affect and reduced 10-year incident coronary heart disease: The Canadian Nova Scotia Health Survey

Don't worry, be happy: positive affect and reduced 10-year incident coronary heart disease: The Canadian Nova Scotia Health Survey

Don't worry, be happy: positive affect and reduced 10-year incident coronary heart disease: The Canadian Nova Scotia Health Survey

Positive affect is believed to predict cardiovascular health independent of negative affect. We examined whether higher levels of positive affect are associated with a lower risk of coronary heart disease (CHD) in a large prospective study with 10 years of follow-up. We examined the association between positive affect and cardiovascular events in 1739 adults (862 men and 877 women) in the 1995 Nova Scotia Health Survey. Trained nurses conducted Type A Structured Interviews, and coders rated the degree of outwardly displayed positive affect on a five-point scale. To test that positive affect predicts incident CHD when controlling for depressive symptoms and other negative affects, we used as covariates: Center for Epidemiological Studies Depressive symptoms Scale, the Cook Medley Hostility scale, and the Spielberger Trait Anxiety Inventory. There were 145 (8.3%) acute non-fatal or fatal ischaemic heart disease events during the 14 916 person-years of observation. In a proportional hazards model controlling for age, sex, and cardiovascular risk factors, positive affect predicted CHD (adjusted HR, 0.78; 95% CI 0.63-0.96 per point; P = 0.02), the covariate depressive symptoms continued to predict CHD as had been published previously in the same patients (HR, 1.04; 95% CI 1.01-1.07 per point; P = 0.004) and hostility and anxiety did not (both P > 0.05). In this large, population-based study, increased positive affect was protective against 10-year incident CHD, suggesting that preventive strategies may be enhanced not only by reducing depressive symptoms but also by increasing positive affect.

Anger expression and risk of coronary heart disease: Evidence from the Nova Scotia Health Survey

Whereas some studies have found that anger increases the risk of incident coronary heart disease (CHD), others found anger to be protective. Prior studies did not account for different types of anger expression, which may be associated with opposing levels of cardiovascular risk. This study examines whether distinct types of anger expression differentially predict incident CHD. We conducted a population-based, observational prospective study of 785 randomly selected Canadian men and women (50% each) aged 46 to 92 years and free of CHD in 1995. Using videotaped interviews, trained coders rated 3 types of anger expression: constructive anger (discussing anger to resolve the situation), destructive anger justification (blaming others for one's anger), and destructive anger rumination (brooding over an anger-inducing incident). The association between anger expression type per SD and incident CHD was estimated using Cox proportional hazards models adjusted for sex, age, cardiovascular risk factors, depressive symptoms, hostility, and anxiety. Interactions of anger expression type and gender were also tested. There were 115 incident CHD events (14.6%) during 6,584 person-years of follow-up. The association between clinically assessed constructive anger expression and CHD varied by gender (P for interaction = .02); higher levels were associated with a lower risk of incident CHD in men only (hazard ratio 0.58, 95% CI 0.43-0.80, P < .001), whereas higher levels of destructive anger justification was associated with a 31% increased risk of CHD in both sexes (hazard ratio 1.31, 95% CI 1.03-1.67, P = .03) and predicted CHD incidence independent of covariates and depressive symptoms, hostility, and anxiety. Decreased constructive anger in men and increased destructive anger justification in men and women are associated with increased risk of 10-year incident CHD.

Exposure to tricyclic antidepressants is associated with an increased risk of incident CHD events in a population-based study

The purpose of this study was to assess the association between antidepressant use and incident coronary heart disease (CHD) events in a sample of individuals without known baseline heart disease. We studied a group of 970 randomly selected community-dwelling adults in the 1995 Nova Scotia Health Survey, who were followed for up to 10 years. Antidepressant usage was classified according to class. Primary outcomes were acute coronary syndrome hospitalizations or cardiac death, determined by centralized, standardized ratings. During a follow-up period of 10 years, there were 147 incident CHD events (139 acute coronary syndromes and 8 cardiac deaths) during the 8129 person-years of observation (incidence rate = 18.1 events/1000 person-years). In a model controlling for age, sex, Framingham risk score, time to last annual exam, aspirin exposure, and depressive symptoms, an increased risk of CHD events was associated with tricyclic antidepressant exposure (adjusted hazard ratio, 2.10; 95% confidence interval, 1.09-4.06; p = 0.027). In this prospective population-based study, exposure to tricyclic antidepressants was associated with higher risk of first CHD events.

Relation of Inflammation to Depression and Incident Coronary Heart Disease (from the Canadian Nova Scotia Health Survey [NSHS95] Prospective Population Study)

Numerous studies have found that depression was a strong independent risk factor for incident coronary heart disease (CHD), with increasing risk in those with higher levels of depressive symptoms. The association between measures of inflammation (C-reactive protein, interleukin-6, and soluble intracellular adhesion molecule-1), depressive symptoms, and CHD incidence was examined in 1,794 subjects of the population-based Canadian Nova Scotia Health Survey. There were 152 incident CHD events (8.5%; 141 nonfatal, 11 fatal) during the 15,514 person-years of observation (incidence rate 9.8 events/1,000 person-years). Depression and inflammation were correlated at baseline and each significantly predicted CHD in separate models. When both risk factors were in the same model, each remained significant. The association between depressed group by the Center for Epidemiological Studies-Depression scale (score > or =10 vs 0 to 9) and CHD incidence (hazard rate 1.60, 95% confidence interval 1.12 to 2.27) was not reduced by the addition of inflammatory markers to the model (hazard rate 1.59, 95% confidence interval 1.12 to 2.26). Findings were similar after adjustment for aspirin, lipid-lowering medication, or antidepressant use, and the association did not vary by gender, smoking status, age, obesity, cardiovascular medication use, or antidepressant use. In conclusion, increased inflammation explained only a very small proportion of the association between depression and incident CHD.

Chronic disease risk factors associated with health service use in the elderly

BackgroundTo examine the association between number and combination of chronic disease risk factors on health service use.MethodsData from the 1995 Nova Scotia Health Survey (n = 2,653) was linked to provincial health services administrative databases. Multivariate regression models were developed that included important interactions between risk factors and were stratified by sex and at age 50. Negative-binomial regression models were estimated using generalized estimating equations assuming an autoregressive covariance structure.ResultsAs the number of chronic disease risk factors increased so did the number of annual general practitioner visits, specialist visits and days spent in hospital in people aged 50 and older. This was not seen among individuals under age 50. Comparison of smokers, people with high blood pressure and people with high cholesterol showed no significantly different impact on health service use.ConclusionAs the number of chronic disease risk factors increased so did health service use among individuals over age 50 but risk factor combination had no impact.

The Relation of Body Mass Index to Depressive Symptoms

Data from the 1995 Nova Scotia Health Survey were analyzed to determine the relation between body mass index (BMI) and the risk of depression as measured by the Center for Epidemiological Studies Depression Scale (CES-D). Clinical measures for height and weight and CES-D scores were available for 2,482 subjects from an initial sample of 5,578 Nova Scotians stratified probabilistically to be representative of age, gender and area of residence. BMIs were categorized according to the international standards (BMI 18.5-24.9 acceptable weight; 25-29.9 overweight; > or = 30 obese). More men than women were classified as overweight (43.2% vs. 28.3%) but slightly more women than men were obese (25.6% vs. 23.4%). Based on the summary score of the CES-D, 14.2% were categorized as at risk for depression (> or = 16). Logistic regression indicated that lower education (p < 0.001) and income (p < 0.001), and BMI category (p < 0.05) were all significantly related to an increased risk of depression. The odds ratio for the association between obesity and depression, after controlling for education and income, was 1.41 [95% CI = 1.07-1.86]. More studies are needed to ascertain the mechanism by which obesity and depression could be related and the significance of this relation for the prevention and treatment of both obesity and depression. Given the effects of depression, we suggest that health professionals should assess their obese patients for risk of depression before embarking on a weight management protocol.

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.

Depressive symptoms predict medical care utilization in a population-based sample.

Several examinations have detected a relation between depressive symptoms and medical utilization. However, selection biases have been involved in most previous examinations. We sought to test the association between depressive symptoms and prospective, increased medical care utilization, in a population-based Canadian sample, while controlling for utilization due to medical illness and controlling for selection bias. Data from the Nova Scotia Health Survey 1995, an age- and sex-stratified random sampling of 3227 Nova Scotian adults, included the Center for Epidemiological Studies-Depression scale and items assessing chronic medical conditions and current limitations in daily activities resulting from medical illness. We linked survey data with medical care utilization measures for the year following the survey, including out-patient visits, reimbursement for out-patient services, hospitalizations, and hospitalization days. After controlling for age, sex, count of medical diagnoses and current medical severity, those with a greater level of depressive symptoms were at greater risk of having increased medical care utilization in the following year. These results remained after removing mental health care utilization costs. In a population-based sample, depressive symptoms predicted greater medical care utilization, independent of a number of medical severity measures. Whether depressive symptoms are a risk marker or a causal risk factor for increased medical utilization remains to be explored.

Environmental illness prevalence: A population-based study in Nova Scotia.

OBJECTIVES: Clinic studies demonstrate that people diagnosed with environmental illness experience high levels of disability and health care utilization. Even though the controversial status of this disorder attracts attention, actual prevalence estimates and estimated impact on health care systems are unclear. To address this, we sought both a prevalence estimate and a measure of the degree of health care utilization for those reporting this diagnosis. DESIGN AND METHODS: Point prevalence, as assessed by self-report of professional diagnosis, was established with data from the Nova Scotia Health Survey 1995, a stratified, random sample population survey of 3227 Nova Scotian adults. We compared medical care utilization for the year following the survey, drawn from the provincial medical insurance register, between the 24 cases with no other reported medical conditions and 48 age-, sex-, and education level-matched healthy controls. RESULTS: The adjusted point prevalence of environmental illness was 2.6%. Physician reimbursement costs across the following year were 5.5 times more likely to be above the survey average ($259 CAD) when compared to the healthy control group. CONCLUSIONS: The prevalence of environmental illness diagnoses represents a significant disability and treatment burden, justifying research into case definition and the phenomenology of environmental illness by health psychologists.