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Biomedical subjects

C Hertzman

Publications and source records attributed to C Hertzman.

At least 19 recordsLinked to original sources
PubMed1992

The association of cutaneous malignant melanoma and fluorescent light exposure.

Data are presented from an interview case-control study (583 cases and 608 controls), performed in southern Ontario, Canada, from October 1984 to September 1986, on the association of cutaneous malignant melanoma with exposure to fluorescent light. Males showed a significant trend with cumulative years of occupational exposure and with various indices of exposure to domestic fluorescent light. The risk was more pronounced for lesions on the arms and for superficial spreading melanomas. There was no consistent association in females. These effects were similar when adjusted for other major risk factors for melanoma, including the amount of time spent outdoors occupationally. Comparisons of melanoma cases interviewed before or after diagnosis revealed no evidence of rumination bias. Comparisons of sample data from the same cases and controls by interview and mail questionnaire showed reasonable levels of reliability with no evidence of recall bias. A small sample of subjects was also selected for exposure validation with employers; this revealed very accurate recall of occupational exposure. On the basis of these results, previous epidemiologic studies, and clinical and animal evidence, the authors conclude that fluorescent light exposure remains a potential risk factor for melanoma.

Adult↗
PubMed1992

Recognizing acute health effects of substitute fungicides: are first-aid reports effective?

Recently, many British Columbia sawmills stopped using traditional chlorophenate anti-sapstain fungicides and substituted 2-(thiocyanomethylthio) benzothiazole (TCMTB) and copper-8-quinolinolate (Copper 8). We conducted a cross-sectional study with two aims: to ascertain which acute health effects, if any, were associated with the use of the substitute fungicides; and to determine the effectiveness of first-aid records as a means of detecting acute health outcomes. Workers in five coastal sawmills were asked to complete a self-administered questionnaire about symptoms considered potentially related and unrelated to fungicide exposure, and about injuries commonly reported in sawmills. In addition, we collected first-aid records from the mills, and asked senior workers to estimate the duration of exposure to fungicides for each job. Symptoms found to be consistently elevated in TCMTB mills included dry skin around the eyes, blood-stained mucus from the nose, nose bleed, peeling skin, burning or itching skin, and skin redness or rash. No symptoms were consistently elevated in the Copper 8 mills. Symptoms related to TCMTB exposure were recorded only 12 times in first-aid logs during the study period (versus 335 questionnaire self-reports). This low symptom-recording frequency may be a function of established patterns of first-aid use in which illness symptoms are reported less frequently than injuries.

Acute Disease↗
PubMed1992

On being old and sick: the burden of health care for the elderly in Canada and the United States.

The debate over health care reform in the United States has drawn Canada under the microscope. Canada's health care system is frequently offered as a model for American national health insurance. Curiously absent from this policy discussion is any talk about the relative out-of-pocket costs of alternative models. In this paper, we provide data on these costs for American and Canadian elderly for medical, hospital, and ambulatory pharmaceutical use. Despite the fact that the elderly in America are generally viewed as facing fewer problems with access and out-of-pocket costs than younger Americans, their direct costs far exceed those of their Canadian counterparts. We also present data suggesting that, despite these greater costs, rates of growth in use of these services by American elderly have followed roughly the same pattern as those found in Canada. If Uncle Sam retired north of the border, being old and sick would also mean being wealthier and happier.

Age Factors↗
PubMed1991

Reliability of interviewer and subject assessments of nevus counts in a study of melanoma.

Several types of data are presented concerning the reliability of counting or estimating the density of nevi (moles), a major risk factor for melanoma, using methods typically employed in epidemiologic studies. First, interviewer-derived counts of nevi on the arm produced estimates of inter-observer, inter-subject, temporal and random variability, and their interactions. Second, interviewer-derived arm counts and respondent self-reports of whole body nevus density were compared. Finally, we compared male and female cases and controls with respect to their reported rates of having a relative with a malignant mole. Overall, the intra-observer reliability ranged from 55 to 81%, and was better for observers with more experience. The correlation between the interviewer counts and respondents' self-reported estimates was 0.41. The data on malignant moles in relatives suggest higher reporting rates in male cases and lower reporting in male controls relative to their female counterparts, but there is little difference by sex in the reporting of one's own nevus density.

Adult↗
PubMed1990

Parkinson's disease: a case-control study of occupational and environmental risk factors.

We compared personal histories of 57 cases and 122 age-matched controls to identify possible environmental determinants of Parkinson's disease (PD). Odds ratios (OR) adjusted for sex, age, and smoking were computed using stepwise logistic regression. We found a statistically significant increased risk for working in orchards (OR = 3.69, p = 0.012, 95% CI = 1.34, 10.27) and a marginally significant increased risk associated with working in planer mills (OR = 4.11, p = 0.065, 95% CI = 0.91, 18.50). A Fisher's exact test of the association between PD development and (1) paraquat contact, and (2) postural tremor gave statistically significant probability estimates of 0.01 and 0.03, respectively. The relative risk of PD decreased with smoking, an inverse relationship supported by many studies.

Aged↗
PubMed1990

Flat on your back or back to your flat? Sources of increased hospital services utilization among the elderly in British Columbia.

Between 1969 and 1985, the British Columbia hospital system allocated an increasing proportion of the province's total hospital days to elderly patients who stayed for 60 days or more. By 1985/86, long stay patients accounted for almost 50% of all days. In this paper, we explore the diagnoses which contributed the greatest number of patient days of increase among the elderly as a first step in evaluating the appropriateness of this response to the pressures of an aging population. Patient days of increase were not distributed smoothly across a large number of diagnoses, but could be explained by a small number of chronic conditions. Most important were conditions related to senility and senile dementia, the chronic sequelae of heart disease and stroke, and persons awaiting admission to adequate facilities elsewhere. Eighty percent of the increases were seen in extended care and rehabilitation beds and 20% in acute care beds. Seventy-seven percent of the increased patient days were attributable to females and only 23% to males. Since the major sources of increase in patient days were not related to conditions for which new, effective hospital care modalities are available, they call into question the appropriateness of the system's response to the health care needs of the elderly population.

Aged↗
PubMed1990

The association of cutaneous malignant melanoma with the use of sunbeds and sunlamps.

Data are presented from a large case-control study (583 cases, 608 controls) to estimate the association of melanoma with the use of sunbeds and sunlamps. Odds ratios of 1.88 and 1.45 were found for ever having used a sunbed or sunlamp in males and females, respectively, which was statistically significant in males and of borderline significance in females. These effects persisted when adjustments were made for age and a variety of potential confounders. The effect was slightly stronger for lentigo maligna and for lesions of the face, head, neck, and arms. The risk was greater and significant for both sexes for domestic use of sunbeds/sunlamps, and increased with duration and amount of use. A comparison of 43 cases interviewed before a diagnosis of melanoma had been made with the other 540 cases suggests that recall bias was not responsible for the association. The authors conclude that use of artificial tanning devices appears to be a risk factor for melanoma.

Adult↗
PubMed1990

Acute care hospital utilization under Canadian national health insurance: the British Columbia experience from 1969 to 1988.

This paper uses hospital separation abstracts to assess trends in acute care hospital utilization in British Columbia over the first 18 years of publicly funded health insurance in the province. Between 1969 and fiscal year 1987-88, the overall separation rate decreased by 16%, accompanied by a 23% decrease in average length of stay. For the elderly, the separation rate increased by 14% and three quarter of this increase was for surgical procedures, mostly new high-technology procedures. For the nonelderly, separation rates decreased by 25%. Lengths of stay decreased in both age groups. Over the last two decades overall separation rates in British Columbia were higher than or equal to separation rates in the United States, and lengths of stay were consistently higher in British Columbia. Since access to hospitals by the elderly is similar in the two countries, lower hospital costs in Canada result from factors other than lower overall hospital utilization or decreased access for the elderly.

Acute Disease↗
PubMed1989

A community survey of Parkinson's disease.

In a rural community of 80,000 people 69 patients were identified as having a diagnosis of Parkinson's disease. After interview and examination we found that 55 met the generally accepted diagnostic criteria for Parkinson's disease, 4 had possible Parkinson's disease, 6 had essential tremor, 2 had dementia and 2 had other conditions. The patients with Parkinson's disease had clinical and epidemiologic characteristics similar to those of patients in previous, mainly hospital-based, studies. These characteristics included mean age at onset (63 years), frequency rate of dementia (20%) and presence of postural tremor (11%). The pattern of treatment varied, some patients receiving more medication than is usual for the severity of their illness, and some patients receiving less than is usual. Parkinson's disease can be difficult to diagnose and manage because of the clinical variation between patients in presentation and response to treatment.

Aged↗
PubMed1989

Trends in use of medical services by the elderly in British Columbia.

We analysed physician fee-for-service use in British Columbia from 1974-75 to 1985-86. Over the study period use increased by 5.3% per year. This can be factored into increases attributable to changes in the age structure of the population (0.4% per year), general population growth (1.8%, for a combined annual "population effect" of 2.2%) and age-specific increases in per-capita use (3% per year). The average annual increase for people aged 75 years or more was 5.5% per capita. The area with the fastest growth in use by the elderly was specialist care, particularly diagnostic services. The average number of specialists seen by people aged 75 years or more doubled over the study period. Our results suggest that increased per-capita use among the elderly that is unrelated to aging of the population should be the main focus of future policy attention. Additional analyses are needed to determine the underlying dynamics of this dramatic increase in rates of use among the elderly.

Adolescent↗
PubMed1989

Potential exposure of cooks to airborne mutagens and carcinogens.

Recent case-control and proportionate mortality studies in Canada, the United States, Britain, and Denmark have shown that cooks and other food-service workers may have elevated risks of cancers of the nasopharynx, buccal cavity, esophagus, lung, and bladder. The purpose of this pilot study was to determine if there might be airborne products of cooking which may be risk factors for these cancers in cooks. Eight air samples were taken in four restaurants and subsequently analyzed for mutagenicity using the Ames assay, and for carcinogens using gas chromatography/mass spectrometry. All four samples taken in the restaurant cooking areas were mutagenic to TA98 without metabolic activation, and two were mutagenic to TA100 also without metabolic activation. Of the four dining area samples, one was mutagenic to TA100 and one to TA98, both without metabolic activation. Compounds tentatively identified by mass spectrometry did not include known carcinogens. The ventilation systems in all four restaurants allow the exposure of cooks to both the air from dining room smoking areas and the volatile products of cooking.

Air Pollutants, Occupational↗
PubMed1989

A comparison of exposure estimates by worker raters and industrial hygienists.

The validity and reliability of nine senior sawmill workers' estimates of frequency, duration, and routes of exposure were compared with individual workers' ratings of their own job titles and industrial hygienists' ratings of all job titles in the plant. The reliability of the senior workers' mean exposure estimates [group intraclass correlation coefficient (ICC) = 0.71] compared favorably with those of three pairs of hygienists (group ICC = 0.57, 0.67, and 0.81). The validity of their ratings was assessed in a comparison with urinary chlorophenate measurements representing 92% of the job titles in the sawmill. The senior workers' ratings [coefficient of determination (R2) = 0.22] resembled those of two pairs of industrial hygienists (R2 = 0.24, 0.22) and was significantly greater than that of the third pair (R2 = 0.08). The validity of the self-reports was also low (R2 = 0.15), but the difference was not statistically significant. Senior workers' exposure ratings appear to be as effective as the other methods tested.

Air Pollutants, Occupational↗
PubMed1989

The long good-bye: the great transformation of the British Columbia hospital system.

Much is made of the "threat" an aging population poses to North American health care systems. In this article, we present hospital utilization data from British Columbia over the period 1969-1985, which reinforce our earlier (Barer, Evans, Hertzman, et al. 1987) conclusion: it is not aging per se that poses the threat; rather, it is what we are choosing (through our health care system) to do to and with our elderly. In 1969, British Columbia hospital patients over 65 years of age and staying longer than 60 days accounted for 12.5 percent of all days; by 1985/86, they were accounting for 39 percent. Furthermore, in 1985/86, 1 patient in 200 was using one-quarter of all patient days and dying at the end of the process, and 2 patients in 100 (who stayed over 60 days whether discharged alive or dead) were accounting for almost one-half of all days.

Adolescent↗
PubMed1988

Validity and reliability of a method for retrospective evaluation of chlorophenate exposure in the lumber industry.

This paper describes the validity and reliability of a method to retrospectively assess exposure to antisapstain agents used in sawmills (chlorophenates). The method is based on experienced workers' estimates of exposure for each job title at the sawmill where they work. At a pilot mill, 10 randomly selected workers estimated the frequency and duration of exposures to chlorophenates for all 59 job titles. The reliability of their mean exposure estimates was very high, with an intraclass correlation coefficient for all raters of 0.91 (based on a calculated index of exposure). To assess validity, urinary chlorophenate levels were measured for 86% of the workers at the mill during the summer and/or fall, and compared to experienced workers' estimates of exposure. The correlation between workers' exposure estimates and the urinary chlorophenate levels for each job title were consistently above 0.65 for all analyses and greater than 0.72 when summer and fall urine sample results were averaged. The evidence indicates that the validity and reliability of worker exposure estimates are high enough to justify investigation of the method's generalizability to other sawmills.

Chlorophenols↗
PubMed1987

Aging and health care utilization: new evidence on old fallacies.

The proportion of the population in the older age groups will increase dramatically over the next four decades. Furthermore, current per capita rates of hospital and medical care utilization rise sharply with age beyond the age of about 55. However, demographic trends alone do not imply health care cost increases in excess of what is supportable by normal economic growth. A 'cost crisis' will only occur if per capita rates of utilization among the elderly increase faster than for the general population. In this paper we present some descriptive data from published sources suggesting that this has been the case over the recent past in one Canadian province. The implications for the policy debate over the effects of an aging population are discussed.

Adolescent↗
PubMed1987

Observer perception of skin color in a study of malignant melanoma.

Observer perceptions of skin color with a 15-step skin tone panel were evaluated during an as yet unpublished case-control study of malignant melanoma. Skin color is a risk factor for melanoma, and the skin tone panel was introduced in an effort to reduce its misclassification. Reflectances of the 15 artificial skin tones were measured at four wavelengths with a reflectance spectrophotometer. Six observers each evaluated the skin color of eight study subjects twice under three lighting conditions, and the results were transformed to reflectance values. Components of variance analysis demonstrated that between-subject variability contributed 63% or more of the variance at wave-lengths of 400-600 nm, while observers, light source, observation time, and error contributed 30% or less. At 700 nm, only 25.5% of the variance was due to subjects, indicating lower levels of reliability. Similarly, the correlation of visual and spectrophotometric assessment of skin reflectance was higher at 400-600 nm (r = 0.63-0.71) than at 700 nm (r = 0.41). Thus, the value of the skin tone panel-based assessments depends upon knowledge of which wavelengths most closely relate to the physiologic risk factor. For instance, reflectance at 650-700 nm is a better measure of skin melanin content than reflectance at lower wavelengths. Since the role of melanin as a risk factor remains in doubt, the utility of this technique has yet to be demonstrated. However, data from the case-control study and from this validity and reliability study will allow us to develop an analytic approach that minimizes misclassification of skin color as a confounder.

Analysis of Variance↗