Risk factors for homelessness among schizophrenic men: a case-control study

OBJECTIVES: To identify risk factors for homelessness among the severely mentally ill, we conducted a case-control study of 100 indigent schizophrenic men meeting criteria for literal homelessness and 100 such men with no homeless history. METHODS: Subjects were recruited from shelter, clinic, and inpatient psychiatric programs in Upper Manhattan. Clinical interviewers employed standardized research instruments to probe three domains of risk factors: severity of mental illness, family background, and prior mental health service use. RESULTS: Homeless subjects showed significantly higher levels of positive symptoms, higher rates of a concurrent diagnosis of drug abuse, and higher rates of antisocial personality disorder. Homeless subjects experienced greater disorganization in family settings from birth to 18 years and less adequate current family support. Fewer homeless subjects than subjects in the never-homeless comparison group had a long-term therapist. These differences remained when demographic variables were adjusted statistically. CONCLUSIONS: Homeless schizophrenic men differed from their domiciled counterparts in all three domains we investigated; family background, nature of illness, and service use history. Findings are discussed in relation to policy and programs for the severely mentally ill.     

Anthropometric and other risk factors for ovarian cancer in a case-control study

Because it has been suggested that an environmental factor may play a role in the etiology of ovarian cancer, a case-control study was conducted to assess some environmental and other risk factors for ovarian cancer from 1994 to 1996 in northern Kyushu, Japan. We analyzed the data of 89 cases with epithelial ovarian cancer and 323 controls without any cancer or ovarian disorder. After controlling for the effect of potential confounders, the odds ratios of ovarian cancer across increasing quartiles of the heaviest body weight were 1.00, 1.15, 1.71, 2.29 (P = 0.008, test for trend). Significantly increased risks were noted for a history of diabetes mellitus (P < 0.05), and for a family history of ovarian cancer (P < 0.05). Significantly decreased trends for risk were obtained for the number of pregnancies (P < 0.01) and the number of live births (P < 0.001). This study provides additional support for an association between obesity and the risk of ovarian cancer. This relationship may at least partly explain the recent increase in the incidence of ovarian cancer in Japan, although possible contributions of other factors can not be ruled out.     

Nutritional factors and colon carcinoma: a case-control study involving French Canadians in Montréal, Quebec, Canada

BACKGROUND: In a population-based case-control study of colon carcinoma and nutrition involving the francophone community in Greater Montreal, a total of 402 cases (200 males and 202 females) and 668 controls (239 males and 429 females) were interviewed. METHODS: Cases from 1989-1993 were identified through the admission offices of 5 major francophone teaching hospitals in Montreal and were ages 35-79 years. Controls matched by age, place of residence, and language were selected by a modified random digit dialing method. Information on dietary intake was collected with a quantitative food frequency questionnaire. RESULTS: No associations were evident between colon carcinoma and total energy, protein, or carbohydrate consumption, whereas a suggestive inverse association was found with total fat intake, with an odds ratio (OR) of 0.78 (P = 0.0637), and with saturated fat intake as well (OR = 0.71, P = 0.0893). A strongly significant inverse association was found with dietary fiber (OR = 0.50, P = 0.0018). The strongest inverse association concerning fiber was found with fiber from vegetable sources (OR = 0.57, P = 0.0096), and a suggestive (although nonsignificant) inverse association (OR = 0.74, P = 0.0687) was found with fiber from fruits. Calcium was inversely associated with risk (OR = 0.69, P = 0.0411), as was dietary intake of vitamin A (OR = 0.67, P = 0.0162), retinol, (OR = 0.069, P = 0.0409), vitamin E (OR = 0.53, P = 0.0028), and alphatocopherol (OR = 0.63, P = 0.0256). Although there was no association demonstrated between dietary beta-carotene intake and risk, a suggestive (although nonsignificant) inverse association with intake of other types of carotene was observed (OR = 0.76, P = 0.0740). No association was found between intake of other nutrients investigated in this study and risk of colon carcinoma. CONCLUSIONS: There is strong evidence from epidemiologic studies that high intake of fat and meat are risk factors for colorectal carcinoma in humans, whereas high intake of vegetable and fruit are inversely associated with risk of colon carcinoma. The findings from this study are in agreement with this observation.     

Garlic, onion and cereal fibre as protective factors for breast cancer: a French case-control study

The role of diet on breast cancer risk was investigated in a case-control study of 345 patients diagnosed with primary breast carcinoma between 1986 and 1989 in the north-east of France (Lorraine). For each case, one control was matched for age (+/-3 years) and socio-economic status. The dietary history questionnaire consisted of a self-administered food frequency questionnaire, a 6-day food diary and an energy expenditure record. It also elicited personal characteristics and medical history. While taking into account total caloric intake and established risk factors, breast cancer risk was shown to decrease as consumption of fibre (p value for trend = 0.03), and garlic and onions (p value for trend <10(-6)) increased. This study also supports the epidemiologic evidence that saturated fat intake and breast cancer risk are associated in post-menopausal women (p value for trend = 0.03). Conversely, it suggests that unsaturated fat intake could lower the risk in the same subgroup (p value for trend = 0.03). Our findings on protective factors of breast cancer could induce effective preventive measures and warrant further experimental investigations to isolate specific subfractions.     

Risk factors for multiple sclerosis: a case-control study in Israel

This case-control study was aimed at identifying environmental risk factors for multiple-sclerosis (MS). Ninety-three Israeli-born MS patients identified in country-wide studies and 94 age- and sex-matched controls were interviewed. The questionnaire covered a large span of factors at ages 0, 10 and onset of the disease, with particular emphasis on socioeconomic status (SES) and sanitary conditions (SAN). A significantly larger percentage of patients reported frequent respiratory educational levels than controls. The SES and SAN at age 10 were also systematically higher among patients, but significance was reached only when the frequencies of conditions indicating extremely low values of SES or SAN were compared. It is possible that the protective effect of low SES or SAN on risk of MS can be detected only when living conditions are well below average, as is frequent in developing countries.     

Risk factors for rifampin-monoresistant tuberculosis: A case-control study

Rifampin is the cornerstone of short-course chemotherapy for the treatment of tuberculosis (TB). Rifampin monoresistance (RMR) is less common than resistance to isoniazid alone or in combination with other antituberculous medications. We conducted a retrospective case-control study to identify risk factors for RMR-TB. Complete records for 21 of a total of 26 RMR patients from 1990 to 1997 were available for review, and were compared with those of 48 patients with drug-susceptible TB, controlling for year of diagnosis. Cases more frequently had a history of TB than did controls (61% versus 22%, p < 0.01), and were more often human immunodeficiency virus (HIV) positive (81% versus 46%, p = 0.02). With control for HIV status, cases were more likely to have extrapulmonary involvement (47.6% versus 11.6%, p = 0.05). Four cases (19%) and one control (2. 1%) died (p = 0.02) during hospitalization. Cases more often had a history of incarceration (71.4% versus 37.5%, p = 0.09). Among the 13 cases with a history of TB, five had evidence of malabsorption (vomiting and/or diarrhea), versus none of the 11 controls with prior TB. These data support the hypothesis that RMR is seen primarily in individuals with a history of TB and who are HIV positive. Cases were frequently noncompliant with previous treatment for TB, had a history of incarceration, and had poor outcomes.     

Risk factors for prosthetic joint infection: case-control study

Topology-representing neural networks are employed to generate pseudo-atomic structures of large-scale protein assemblies by combining high-resolution data with volumetric data at lower resolution. As an application example, actin monomers and structural subdomains are located in a three-dimensional (3D) image reconstruction from electron micrographs. To test the reliability of the method, the resolution of the atomic model of an actin polymer is lowered to a level typically encountered in electron microscopic reconstructions. The atomic model is restored with a precision nine times the nominal resolution of the corresponding low-resolution density. The presented self-organizing computing method may be used as an information-processing tool for the synthesis of structural data from a variety of biophysical sources.     

Risk factors for acute myocardial infarction in Indians: a case-control study

BACKGROUND: South Asians who have settled overseas and those in urban India have an increased risk of ischaemic heart disease (IHD). Reasons for this increased risk are unclear. Most studies have been based on migrants to western nations, so their findings may not apply to most south Asians, who live in their own countries. Therefore, we assessed the relative importance of risk factors for IHD among South Asians in Bangalore, India. METHODS: We conducted a prospective hospital-based case-control study of 200 Indian patients with a first acute myocardial infarction (AMI) and 200 age and sex matched controls. We recorded prevalence of the following risk factors for IHD: diet, smoking, alcohol use, socioeconomic status, waist to hip ratio (WHR), blood glucose, serum insulin, oral glucose tolerance test, and lipid profile. FINDINGS: The most important predictor of AMI was current smoking (odds ratio [OR] 3.6, p < 0.001) of cigarettes or beedis (a local form of tobacco), with individuals who currently smoked 10 or more per day having an OR of 6.7 (p < 0.001). History of hypertension and of overt diabetes mellitus were also independent risk factors (OR 2.69 [p = 0.001] and 2.64 [p = 0.004], respectively). Among all individuals, fasting blood glucose was a strong predictor of risk over the entire range, including at values usually regarded as normal (OR adjusted for smoking, hypertension, and WHR 1.62 for 1 SD increase, p < 0.001). Abdominal obesity (as measured by WHR) was also a strong independent predictor across the entire range of measures (OR adjusted for smoking, hypertension, and blood glucose 2.24 for 1 SD increase; p < 0.001). Compared with individuals with no risk factors, individuals with multiple risk factors had greatly increased risk of AMI (eg, OR of 10.6 for the group with smoking and elevated glucose). Lipid profile was not associated with AMI. In univariate analyses, higher socioeconomic (income) status (OR 0.32, p = 0.005 highest vs lowest; OR 0.75 middle vs lowest) and vegetarianism (OR = 0.55, p = 0.006), seemed to be protective. The impact of vegetarianism was closely correlated with blood glucose and WHR. INTERPRETATION: Smoking cessation, treatment of hypertension, and reduction in blood glucose and central obesity (perhaps through dietary modification) may be important in preventing IHD in Asian Indians.     

Risk factors for myocardial infarct: a case-control study in Oporto, Portugal

A case-control study of coronary heart disease (CHD) was conducted in Oporto, Portugal. The cases series consisted of 100 consecutive patients with first time acute myocardial infarction who were admitted to the Coronary and Intermediate Care Units of a major teaching hospital. The community controls were 198 individuals without evidence of CHD by the Rose questionnaire and electrocardiography, selected by random digit dialing, with a participation rate of 70%. Data was collected by trained interviewers using a structured questionnaire and blood samples were obtained for selected laboratory data. The main analysis was made through unconditional logistic regression with calculations of odds ratios (OR). Age, OR: 1.5 (95% CI: 0.8-2.9), male gender, OR: 6.7 (3.6-12.3), family history of premature CHD, OR: 2.4 (1.4-4.3), diabetes, OR: 3.4 (1.6-7.4), antecedents of hypertension, OR:1.9 (1.1-3.1), history of high cholesterol levels, OR: 2.3 (1.4-3.9), high levels of physical activity, OR: 2.0 (0.9-4.1) and tobacco smoking, OR: 8.3 (3.8-18.5) were significant risk factors of acute myocardial infarction. After controlling for demographic variables and for the mutual confounding effects of the risk factors, the investigated factors that remained significantly associated with the risk of developing acute myocardial infarction were male gender, OR: 17.3 (4.8-62.3), family history of CHD, OR: 3.6 (1.4-9.6), diabetes, OR: 4.2 (1.0-18.1), high cholesterol levels OR: 2.7 (1.2-6.1) and smoking habits, OR: 7.7 (1.8-32.4). A negative association with high education levels was significant after controlling for all the variables, OR: 0.01 (0.01-0.5).     

Risk factors for Trypanosoma cruzi infection among children in central Brazil: a case-control study in vector control settings

This population-based case-control study was conducted in northern Goias State, central Brazil, in rural settings under vector control surveillance. One hundred forty-nine children seropositive for Trypanosoma cruzi antibodies, selected in a cross-sectional survey carried out in village schools, were compared with 298 seronegative classmate controls matched for age, sex, and place of residence. Information on potential environmental, familiar, and social economic risk factors for T. cruzi infection was collected during household visits, and interviews with parents and entomologic inspections of domestic and peridomestic environments were conducted. The presence of triatomines in dwellings or evidence of triatomine colonization was found to be statistically associated with seropositivity in children. The presence of exuviae and a report of triatomines indoors or outdoors by householders in the past were strong predictors of an infected child. Children from seropositive mothers had a 3.9-fold increase in the risk of having anti-T. cruzi antibodies after adjusting for the confounding variables, including triatomine capture, mother's age, and family size in multivariate analysis. Parent's report of vector presence showed a 97.7% sensitivity in identifying a dwelling with at least one seropositive child. The possibility of transplacental T. cruzi transmission and its implication for Chagas' disease control were considered.     

Risk factors for clinically diagnosed Alzheimer's disease: a case-control study of a Greek population

Many efforts have been made to trace the causes of Alzheimer's disease (AD). There are, however, many points of controversy among reports from the same country as well as among reports from different countries. The current study is a case-control study to determine the risk factors in the development of AD in Greece. Sixty-five patients with AD and 69 age-matched controls were examined. All patients with AD fulfilled the DSM-IV criteria for AD and NINCDS-ADRDA criteria for probable AD. Demographic characteristics such as gender, current marital status, who he/she is living with, education, main place of residence in childhood, adulthood, and late life, occupational hazards, patient's medical history (history of diabetes mellitus and hypertension), life habits like alcohol consumption and smoking, and a history of head trauma, heart attack, stroke, parkinsonism, or depression were collected from the subject or from an informant. A family history of selected diseases (hypertension, diabetes mellitus, dementia, Parkinson's disease, Down's syndrome, stroke) was also elicited. Ages of father and mother at birth were also recorded. Chi-square test, Kruskal-Wallis analysis of variance, cluster analysis, and logistic regression analysis were used for statistical analysis. The results (chi-square test) showed a statistically significant difference between patients with dementia of the Alzheimer type and controls as far as marital status (p = .04), the subject's history of major depressive episode (p = .02), and family history of dementia (p = .002) were concerned. Logistic regression analysis results produced a complex model of family aggregation of dementia, with patients with a history of depression and family history of dementia having an up to seven times higher risk of developing AD. These findings, especially a family history of dementia, are consistent with most of the literature.     

Lifestyle factors and prostate cancer risk: a case-control study in Sweden

We examined associations between lifestyle factors and subsequent risk of prostate cancer in a population-based case-control study. Information on smoking and alcohol habits, socioeconomic factors, marital status, family history, and sexual habits were obtained from a questionnaire and a face-to-face interview with 256 (74.6%) eligible patients and 252 (76.6%) selected controls, frequency matched by age and screened for prostate cancer with negative findings. Unconditional logistic regression was used to estimate the odds ratios (ORs). Risk was elevated among current smokers of cigarettes (OR, 1.8) and current users of hard liquor (OR, 1.4); however, the lack of dose-response trend for both of these exposures argues against a causal association. We found tentative evidence that early first intercourse, a larger number of sexual partners, and other indices of high sexual activity are associated with increased risk. Similarly, adult height, an indicator of nutrition during childhood and adolescence, was weakly positively associated with risk, although larger studies are needed to establish this link. Unmarried men had a lower risk than married men (OR, 0.3), and socioeconomic status did not appear to be strongly associated with prostate cancer. Men with a father who had prostate cancer had a more than 2-fold increased risk of prostate cancer, whereas those with a brother affected had about a 5-folk risk.     

A breast cancer case-control study in Girona, Spain. Endocrine, familial and lifestyle factors

This study was designed to explore risk factors for breast cancer with emphasis on the detection of clinical markers of the hormonal imbalance during the perimenarche. Three hundred and thirty women diagnosed with breast cancer and 346 population controls were identified and interviewed in Girona, Spain between 1986 and 89. Cases were more likely than controls to have had long menstrual periods in the first 5 years after menarche [odds ratio (OR) = 3.0], to experience menopause at a late age (OR = 1.5) and to report acne during adolescence (OR = 1.6). Family history of breast cancer was associated with an increased risk (OR = 2.3). Cases reported a lower use of drug treatments for anxiety and sleep disorders than controls. Moderate alcohol drinkers and smokers were at lower risk for breast cancer. No statistically significant association with breast cancer was observed for number of children, age at last pregnancy, oral contraceptive use, hormonal treatment after menopause and weight perception during the teenage years. Hormonal changes in the years following menarche may be relevant to breast cancer risk. The roles of menstrual period length and acne during adolescence should be further explored.     

Hormone replacement therapy as a risk factor for epithelial ovarian cancer: results of a case-control study

OBJECTIVE: To evaluate the role of hormone replacement therapy (HRT) as a risk factor for the development of epithelial ovarian cancer. METHODS: A case-control study was performed that used 491 patients with epithelial ovarian cancer frequency matched for age at diagnosis (+/-5 years) with a control population of 741 patients with malignancies of nonestrogen-dependent tissues. The odds ratio (OR) for the development of epithelial ovarian cancer was estimated using logistic regression analysis with adjustment for age at diagnosis, parity, oral contraceptive use, smoking history, family history of epithelial ovarian cancer, age at menarche, menopausal status, income, and education. RESULTS: One hundred of 491 patients (20.4%) in the study population had ever used HRT, and 160 of 741 patients (21.6%) in the control population had ever used HRT (OR 0.85; 95% confidence interval [CI] 0.62, 1.2). A significant association between HRT and specific histologic subtypes of epithelial ovarian cancer was not demonstrable for serous cystadenocarcinoma (OR 1.2, 95% CI 0.8, 1.7), Clear cell carcinoma (OR 1.1, 95% CI 0.4, 3.4), or endometrioid carcinoma (OR 0.4; 95% CI 0.2, 1.2). A significant association between duration of use of HRT and the risk of developing epithelial ovarian cancer was not demonstrable for under 5 years (OR 0.8; 95% CI 0.5, 1.2), 5-9 years (OR 0.6; 95% CI 0.3, 1.1), or 10 or more years (OR 0.6; 95% CI 0.3, 1.4). CONCLUSION: A significant association between the use of HRT and the risk of developing epithelial ovarian cancer, even with prolonged exposure, is not demonstrable.     

Risk factors associated with uterine cervical cancer in Korea: a case-control study with special reference to sexual behavior

We have obtained sediment samples from the world's deepest sea-bottom, the Mariana Trench challenger point at a depth of 10,898 m, using the new unmanned submersible Kaiko. DNA was extracted from the sediment, and DNA fragments encoding several prokaryotic ribosomal RNA small-subunit sequences and pressure-regulated gene clusters, typically identified in deep-sea adapted bacteria, were amplified by the polymerase chain reaction. From the sequencing results, at least two kinds of bacterial 16S rRNAs closely related to those of the genus Pseudomonas and deep-sea adapted marine bacteria, and archaeal 16S rRNAs related to that of a planktonic marine archaeon were identified. The sequences of the amplified pressure-regulated clusters were more similar to those of deep-sea barophilic bacteria than those of barotolerant bacteria. These results suggest that deep-sea adapted barophilic bacteria, planktonic marine archaea, and some of the world's most widespread bacteria (the genus Pseudomonas) coexist on the world's deepest sea-bottom.     

Risk factors for colorectal cancer in a prospective study among U.S. white men

The mRNA expression of presenilin-1 (PS1) and beta-amyloid precursor protein (betaAPP) was investigated in the embryonic day 20 rat olfactory bulb, nasal cavity, and inner ear using in situ hybridization histochemistry. In the olfactory bulb, PS1 mRNA was strongly expressed in both olfactory bulb neuroepithelium and the differentiating olfactory bulb. In contrast, betaAPP mRNA was preferentially expressed in differentiating fields. In the nasal cavity, PS1 mRNA was strongly expressed throughout the olfactory epithelium, while betaAPP mRNA expression was concentrated in the middle part of the epithelium. In the membrane labyrinth of the inner ear, although PS1 mRNA was evenly distributed in both sensory epithelium and supporting cells, betaAPP mRNA was exclusively expressed in the sensory epithelium. These data suggest that PS1 is expressed earlier than betaAPP, and that PS1 and betaAPP co-operatively play pivotal roles in the development of the olfactory and vestibulocochlear systems.     

Lifestyle and gastric cancer: a case-control study

In Hokkaido, Japan, in order to investigate the etiological relation between gastric cancer and lifestyle, a case-control study was conducted, employing 242 cases with this cancer and 484 controls matched for sex, age, and place of residence. Eating meals within a short time, eating until full, irregularity in the time for supper, having dentures, and lack of teeth showed high odds ratios. Putting an excess digestive burden on the stomach by insufficient chewing promotes the development of this cancer. Stress, long working time, irregularity in sleeping time, and gray hair in males showed high odds ratios. A stressful life may be promotive for this cancer through depressed immunoresistance. Logistic regression analysis showed that those who ate meals rapidly, had strong stress and had lost many teeth were at high risk. The linear trend of the dose-response relationship between the number of teeth lost and the odds ratio was highly significant. To avoid stress, to chew foods sufficiently, and to maintain the health of the oral cavity can help to prevent gastric cancer.     

Dietary and nutritional factors and pancreatic cancer: a case-control study based on direct interviews

BACKGROUND: The relationship between diet and pancreatic cancer remains unclear. In this study, we assessed the role of diet and nutrition as risk factors for pancreatic cancer, using data obtained from direct interviews only, rather than data from less reliable interviews with next of kin. We evaluated whether dietary factors could explain the higher incidence of pancreatic cancer experienced by black Americans compared with white Americans. METHODS: We conducted a population-based case-control study of pancreatic cancer diagnosed in Atlanta (GA), Detroit (MI), and 10 New Jersey counties from August 1986 through April 1989. Reliable dietary histories were obtained for 436 patients and 2003 general-population control subjects aged 30-79 years. RESULTS: Obesity was associated with a statistically significant 50%-60% increased risk of pancreatic cancer that was consistent by sex and race. Although the magnitude of risk associated with obesity was identical in blacks and whites, a higher percentage of blacks were obese than were whites (women: 38% versus 16%; men: 27% versus 22%). A statistically significant positive trend in risk was observed with increasing caloric intake, with subjects in the highest quartile of caloric intake experiencing a 70% higher risk than those in the lowest quartile. A statistically significant interaction between body mass index (weight in kg/height in m2 for men and weight in kg/height in m1.5 for women) and total caloric intake was observed that was consistent by sex and race. Subjects in the highest quartile of both body mass index and caloric intake had a statistically significant 180% higher risk than those in the lowest quartile. CONCLUSIONS: Obesity is a risk factor for pancreatic cancer and appears to contribute to the higher risk of this disease among blacks than among whites in the United States, particularly among women. Furthermore, the interaction between body mass index and caloric intake suggests the importance of energy balance in pancreatic carcinogenesis.     

Sources of sporadic Yersinia enterocolitica infections in Norway: a prospective case-control study

Yersinia enterocolitica is a recognized cause of gastroenteritis in northern Europe. During October 1988-January 1990, a prospective case-control study was performed to address risk factors associated with sporadic Y. enterocolitica infections in southeastern Norway. Sixty-seven case-patients (mean age 23.4 years, range 8 months-88 years) and 132 age-, sex- and geographically-matched controls were enrolled in the study. Multivariate analysis of the data showed that persons with Y. enterocolitica infection reported having eaten significantly more pork items (3.79 v. 2.30 meals, P = 0.02) and sausage (2.84 v. 2.20 meals, P = 0.03) in the 2 weeks before illness onset than their matched controls; only one patient had eaten raw pork. Patients were also more likely than controls to report a preference for eating meat prepared raw or rare (47 v. 27%, P = 0.01), and to report drinking untreated water (39 v. 25%, P = 0.01) in the 2 weeks before illness onset. Each of these factors was independently associated with disease, suggesting a link between yersiniosis and consumption of undercooked pork and sausage products and untreated water. Efforts should be directed towards developing techniques to reduce Y. enterocolitica contamination of pork and educating consumers about (1) proper handling and preparation of pork items and (2) the hazards of drinking untreated water.