Male and female rate differences in carpal tunnel syndrome injuries: personal attributes or job tasks?

Carpal tunnel syndrome (CTS) exacts a significant toll on the health and productivity of American workers. In 1996, 29,937 workers lost time from work due to CTS. Half of these were out for more than 25 days, compared to a median of 5 days for all injuries/illnesses. There are striking gender disparities in CTS rates. Overall, three times more women suffer from CTS than men. While some authors have emphasized the role of gender attributes in this risk disparity, the multifactoral causes of CTS, and the sex segregation of women into jobs with high-risk tasks, may be obscuring the work-related contributions to CTS risk. We argue here that men and women doing the same work tasks will have similar rates of CTS. To examine this premise, we used Bureau of Labor Statistics injury counts (numerator) and census data from the Current Population Survey (denominator) to determine injury rates of CTS for both men and women in six high-risk occupations: (1) assembler, (2) laborer-nonconstruction, (3) packaging and filling machine operators, (4) janitors and cleaners, (5) butchers and meat cutters, and (6) data entry keyers. Variable job tasks exist within five of the six high-risk occupational titles. Among those five, the male to female (M:F) risk rate ratio ranged from 0.29 to 0.50. However, the sixth occupational title, data entry keyers, which requires a single physical task, had a risk rate ratio of 1.06. This suggests that an equal risk between genders exists when the occupational tasks (exposure) are truly similar. Job task analysis unmasks potential biases that may wrongly attribute disproportionate CTS rates to gender attributes. This focus on gender attributes fails all workers because preventive interventions in the workplace are deferred. It fails women disproportionately because they are overrepresented in jobs at high risk for CTS.     

Is there a relationship between influenza vaccinations and risk of melanoma? A population-based case-control study

The aim of the present case-control study was to ascertain whether, in adults, yearly repeated anti-influenza vaccinations (AIV) enhance protection against cutaneous melanoma (CM), as do repeated febrile infections. Ninety-nine new cases of histologically confirmed CM and 104 healthy controls (matched to cases for sex, age, and skin colour) selected from the general population were examined in order to ascertain their skin type, the number of nevi on both arms, and the intensity of freckles on the face and the arms; in these subjects, a structured questionnaire was used to obtain information on age, sex, education, social class, exposure and susceptibility to sunlight, history of febrile infectious diseases, and vaccinations. The odds ratio (OR) and the 95% confidence interval (CI) were estimated by commonly used methods and by fitting models of logistic regression. The risk of CM was reduced in subjects with a history of febrile (temperature above 38.5 °C) infections in the 5 years prior to CM surgery (cases) or interview (controls), but was increased in those with voluntary exposure to sunlight in tropical countries. By holding the above factors constant at logistic regression analysis, it was found that a history of repeated AIV (3–5 times in the last 5 years) halved the risk (OR: 0.43; CI: 0.19–1.00; p < 0.05). With the variable `nevi on arms' included, the protective influence of repeated AIVs was observed in a similar magnitude. The inverse relationship found between melanoma and influenza vaccinations is unlikely to have depended on a bias, even if based on replies in a questionnaire, because neither the interviewers nor the interviewers were informed in advance of the working hypothesis.     

Maternal use of oral contraceptives and risk of hypospadias – a population-based case-control study

The aim of this population-based case-control study was to examine the risk of isolated hypospadias in boys born to mothers who have used oral contraceptives in early pregnancy. The study was based on data from the Hungarian Case-Control Surveillance of Congenital Abnormalities from 1980 to 1996, and included 3,038 boys with hypospadias (cases), 24,799 boys without congenital abnormalities (CA-free controls), and 11,881 boys with abnormalities other than hypospadias. We used unconditional logistic regression to adjust for birth order, maternal age, maternal employment status, maternal diabetes, and pre-eclampsia. When comparing cases with CA-free controls the OR for maternal use of OC was 1.21 (95% CI: 0.67–2.17). When comparing cases with boys with other abnormalities, the OR for maternal use of OC was 0.83 (95% CI: 0.46–1.50). Our data showed that self-reported maternal use of oral contraceptives during pregnancy was not associated with an increased risk of hypospadias in the offspring.     

Paternal occupational exposures and the risk of congenital malformations — A case-control study

Objectives  

This study examined the association between certain paternal occupational exposures during the periconceptional period and the risk of congenital malformations.     

Prevalence of and risk factors for abdominal aortic aneurysms in a population-based study : The Tromsø Study

In a population-based study of 6,386 men and women aged 25--84 years in Troms?, Norway, in 1994--1995, the authors assessed the age- and sex-specific distribution of the abdominal aortic diameter and the prevalence of and risk factors for abdominal aortic aneurysm. Renal and infrarenal aortic diameters were measured with ultrasound. The mean infrarenal aortic diameter increased with age. The increase was more pronounced in men than in women. The age-related increase in the median diameter was less than that in the mean diameter. An aneurysm was present in 263 (8.9%) men and 74 (2.2%) women (p < 0.001). The prevalence of abdominal aortic aneurysm increased with age. No person aged less than 48 years was found with an abdominal aortic aneurysm. Persons who had smoked for more than 40 years had an odds ratio of 8.0 for abdominal aortic aneurysm (95% confidence interval: 5.0, 12.6) compared with never smokers. Low serum high density lipoprotein cholesterol was associated with an increased risk for abdominal aortic aneurysm. Other factors associated with abdominal aortic aneurysm were a high level of plasma fibrinogen and a low blood platelet count. Antihypertensive medication (ever use) was significantly associated with abdominal aortic aneurysm, but high systolic blood pressure was a risk factor in women only. This study indicates that risk factors for atherosclerosis are also associated with increased risk for abdominal aortic aneurysm.     

An Italian population-based case-control study on the association between farming and cancer: Are pesticides a plausible risk factor?

This population-based case-control study investigated the association between farming (a proxy for pesticide exposure) and cancer in the Vercelli suburban area (northwest Italy). The residents, aged 25 to 79 years, in the above-mentioned area during the period 2002–2009 were considered. Cases were all the first hospital admissions for cancer. Controls were all the subjects not included in the cases and not excluded from the study. Cases and controls were classified according to whether they occupationally resulted farmers or nonfarmers during the period 1965–2009. Cancer odds ratios (ORs) between farmers and nonfarmers were calculated with generalized linear mixed models adjusted by gender and age. Farmers showed higher odds for all cancers (OR=1.459; p < .001), nonmelanoma skin cancer, colorectal cancer, and breast cancer. The results suggest a plausible association between pesticide exposure and cancer occurrence.     

A population-based case-control study on fruit and vegetable intake and lung cancer: a paradox effect?

A population-based case-control study was carried out in Northwest Spain to analyze the effect of fruit and vegetable intake on the appearance of lung cancer. A non-significant protective association was found for overall consumption of leafy green and other vegetables, with consumption once a day or more vs. less than once a week yielding odds ratios of 0.63 [95% confidence interval (CI) = 0.24-1.63] for leafy green vegetables and 0.64 (95% CI = 0.30-1.36) for other vegetables. A significant protective association was found for potato consumption. No protective associations were recorded for fruit, whether overall or singly; instead, fruit consumption once a day or more vs. less than once a week registered a risk of 2.16 (95% CI = 1.02-4.58). Although the possibility that this effect may be due to a phenomenon of reverse causation cannot be ruled out, these results could support other reports and hypotheses which indicate that the protective effect of fruit might not be as pronounced as generally thought.     

Experience with multiple control groups in a large population-based case–control study on genetic and environmental risk factors

We discuss the analytic and practical considerations in a large case–control study that had two control groups; the first control group consisting of partners of patients and the second obtained by random digit dialling (RDD). As an example of the evaluation of a general lifestyle factor, we present body mass index (BMI). Both control groups had lower BMIs than the patients. The distribution in the partner controls was closer to that of the patients, likely due to similar lifestyles. A statistical approach was used to pool the results of both analyses, wherein partners were analyzed with a matched analysis, while RDDs were analyzed without matching. Even with a matched analysis, the odds ratio with partner controls remained closer to unity than with RDD controls, which is probably due to unmeasured confounders in the comparison with the random controls as well as intermediary factors. However, when studying injuries as a risk factor, the odds ratio remained higher with partner control subjects than with RRD control subjects, even after taking the matching into account. Finally we used factor V Leiden as an example of a genetic risk factor. The frequencies of factor V Leiden were identical in both control groups, indicating that for the analyses of this genetic risk factor the two control groups could be combined in a single unmatched analysis. In conclusion, the effect measures with the two control groups were in the same direction, and of the same order of magnitude. Moreover, it was not always the same control group that produced the higher or lower estimates, and a matched analysis did not remedy the differences. Our experience with the intricacies of dealing with two control groups may be useful to others when thinking about an optimal research design or the best statistical approach.     

Ethnic differences in social participation and social capital in Malmö, Sweden: a population-based study

The aim of this study was to investigate ethnic differences in different aspects of social participation in Malm?, Sweden. The public health survey in Malm? 1994 is a cross-sectional study. A total of 5600 randomly chosen individuals aged 20-80 years were asked to complete a postal questionnaire. The participation rate was 71%. The population was divided into categories born in Sweden, Denmark/Norway, other Western countries, former Yugoslavia, Poland, Arabic speaking countries and all other countries. The age-adjusted and multivariate analyses were performed using a logistic regression model in order to investigate the importance of possible confounders (age, education, economic stress and unemployment) on the differences by country of origin in different aspects of social participation. Men and women born in Arabic speaking countries and other countries (Iran, Turkey, Vietnam, Chile and subsaharan Africa) participate to a significantly lower extent in a variety of civic and social activities when compared to the reference population born in Sweden. The differences in participation in these groups compared to the group born in Sweden are observed both for social participation items at the core of the definition of social capital and cultural and other activities unrelated to social capital. This pattern is particularly pronounced for women born in Arabic speaking countries. These women even sharply differ from the participation rates of men born in Arabic speaking countries. The ethnic differences in most cases do not seem to be explained satisfactorily by education, economic stress or possibly unemployment.     

Mental health symptoms in relation to socio-economic conditions and lifestyle factors – a population-based study in Sweden

Background  

Poor mental health has large social and economic consequences both for the individual and society. In Sweden, the prevalence of mental health symptoms has increased since the beginning of the 1990s. There is a need for a better understanding of the area for planning preventive activities and health care.     

Myocardial infarction and occupational exposure to motor exhaust: a population-based case–control study in Sweden

There is a well-established association between particulate urban air pollution and cardiovascular disease, but few studies have investigated the risk associated with occupational exposure to particles from motor exhaust. This study investigated the risk of myocardial infarction (MI) after occupational exposure to motor exhaust, using elemental carbon (EC) as a marker of exposure. A population-based case–control study of first-time non-lethal MI was conducted among Swedish citizens in ages 45–70 living in Stockholm County 1992–1994, including 1,643 cases and 2,235 controls. Working histories and data on potential confounders were collected by questionnaire and medical examination. The exposure to EC was assessed through a job-exposure matrix. Odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were estimated by unconditional logistic regression. We investigated various exposure metrics: intensity, cumulative exposure and years since exposure. There was an exposure–response relation between the highest average exposure intensity during the work history and the risk of MI when adjusting for smoking and alcohol drinking (p for trend 0.034), with an OR of 1.30 (95 % CI 0.99–1.71) in the highest tertile of exposure compared to the unexposed. An exposure–response pattern was observed in the analysis of years since exposure cessation among formerly exposed. Additional adjustments for markers of the metabolic syndrome reduced ORs and trends to non-significant levels, although this might be an over-adjustment since the metabolic syndrome may be part of the causal pathway. Occupational exposure to motor exhaust was associated with a moderately increased risk of MI.     

Do cardiovascular risk factors in men depend on their spouses' occupational category?

OBJECTIVE: To analyse the relationships between major cardiovascular risk factors in French men and their spouses' occupational category (OC), taking their own OC into account. DESIGN: A large sample of volunteers working in the French National Electricity and Gas Company (GAZEL). As a check of the robustness, the same analysis was performed in a population-based survey (French multinational MONItoring of trends and determinants in CArdiovascular disease (MONICA) registers). SETTING: Any site of the company in France. Representative sample from the population of the three registers (Lille, Strasbourg, Toulouse). PARTICIPANTS: 9486 and 534 men respectively, in working activity, living in couple and aged 40 to 50 years. MAIN OUTCOME MEASURES: Self-reported arterial hypertension, diabetes, hypercholesterolemia, leisure time sedentary lifestyle, smoking status, body mass index (BMI) and alcohol consumption. RESULTS: In the GAZEL study, diabetes, smoking status, and alcohol consumption in men were associated with their own OC. In contrast, spouses' OC was independently associated with men's hypertension, hypercholesterolemia, sedentary lifestyle, and BMI: men whose spouses were unoccupied or workers have higher risk factors levels. In the MONICA study, the results were mostly comparable, at least for hypercholesterolemia, sedentary lifestyle, smoking status and alcohol consumption. CONCLUSION: Spouses' OC was independently associated with several cardiovascular risk factors in men. These results might indicate that socioeconomic status of the couple, and not only individual characteristics, should be taken into account for a better understanding of cardiovascular risk.     

Prevalence and risk factors for self-reported odour intolerance: the Skövde population-based study

Objectives: The present study was performed to determine the prevalence of odour intolerance in adults with respect to both self-reported general intolerance and affective and behavioural consequences. Furthermore, we aimed to relate odour intolerance to explanatory variables and risk factors. Method: This is a cross-sectional, population-based epidemiological study. A random sample of 1900 inhabitants from the age of 20, stratified for age and gender, were recruited. Subjects were invited for clinical examinations that included questions about general odour intolerance, respiratory symptoms and smoking habits, as well as a smell identification test. The chemical sensitivity scale for sensory hyperreactivity (CSS-SHR) was used to quantify affective and behavioural consequences. Results: In total 1387 volunteers (73% of the sample) were investigated. The overall prevalence of self-reported general odour intolerance was 33% (95% confidence interval (CI): 30–36%), with problems mainly from the upper respiratory tract. The prevalence of affective and behavioural consequences of odour intolerance (CSS-SHR score 43) was 19% (95% CI: 15–22%). The risk for the latter condition was increased in women compared with men (odds ratio = 2.3: 95% CI: 1.5–3.6), but no increased risk was found related to current smoking or impaired sense of smell. Conclusion: This study demonstrates that intolerance to odours is a widespread problem in society, and that it is about twice as common in women than in men.