Case Control Study Research Papers (original) (raw)

Clinical data are urgently needed to specify the risk and safety of drug use during pregnancy. For several reasons pregnant women are usually excluded from clinical studies. Therefore, observational data are the main source of knowledge,... more

Clinical data are urgently needed to specify the risk and safety of drug use during pregnancy. For several reasons pregnant women are usually excluded from clinical studies. Therefore, observational data are the main source of knowledge, cohort studies as well as case-control studies. Disadvantages of cohort studies based on observational data have been repeatedly discussed. However, being involved in individual risk characterisation of pregnant women it is the experience of clinical teratologists that even reports on small cohorts should not be disregarded if no other data are available. The recently published "Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement" underlines the value of observational data and provides a checklist regarding the most important inherent methodological problems. Our article describes how Teratology Information Services (TIS) document and evaluate their observations on pregnant women exposed to various drugs and discusses methodological problems and -considering the STROBE statement -how these could be addressed.

ABSTRACT: Study Design. Propensity-matched case control study.Objective. To evaluate the two year clinical outcomes of patients that have undergone instrumented spinal fusions complicated by deep wound infections and compare them to a... more

ABSTRACT: Study Design. Propensity-matched case control study.Objective. To evaluate the two year clinical outcomes of patients that have undergone instrumented spinal fusions complicated by deep wound infections and compare them to a propensity-matched control group who did not have infectionsSummary of Background Data. Postoperative infection following instrumented spinal fusion is a major complication, often resulting in substantial short term morbidity. However, there is little literature reviewing how these patients do in the longer term, after their infection has been managed.Methods. Thirty patients who underwent instrumented lumbar spinal fusion with complete pre-operative and two-year postoperative outcome measures and had acute (≤3 months) postoperative deep wound infections necessitating irrigation and debridement were identified. Outcome measures included the Oswestry Disability Index (ODI), SF-36 Physical (PCS) and Mental (MCS) composite summaries and Numeric rating sca...

OBJECTIVE-To determine the mortality rate after diabetes-related lower-extremity amputation (LEA) in an African-descent Caribbean population. RESEARCH DESIGN AND METHODS-We conducted a prospective case-control study. We recruited case... more

OBJECTIVE-To determine the mortality rate after diabetes-related lower-extremity amputation (LEA) in an African-descent Caribbean population. RESEARCH DESIGN AND METHODS-We conducted a prospective case-control study. We recruited case subjects (with diabetes and LEA) and age-matched control subjects (with diabetes and no LEA) between 1999 and 2001. We followed these groups for 5 years to assess mortality risk and causes. RESULTS-There were 205 amputations (123 minor and 82 major). The 1-year and 5-year survival rates were 69 and 44% among case subjects and 97 and 82% among control subjects (case-control difference, P Ͻ 0.001). The mortality rates (per 1,000 person-years) were 273.9 (95% CI 207.1-362.3) after a major amputation, 113.4 (85.2-150.9) after a minor amputation, and 36.4 (25.6-51.8) among control subjects. Sepsis and cardiac disease were the most common causes of death. CONCLUSIONS-These mortality rates are the highest reported worldwide. Interventions to limit sepsis and complications from cardiac disease offer a huge potential for improving post-LEA survival in this vulnerable group.

The human fatty acid amide hydrolase (FAAH) missense mutation c.385 C!A, which results in conversion of a conserved proline residue to threonine (P129T), has been associated with street drug use and problem drug abuse. Although a link... more

The human fatty acid amide hydrolase (FAAH) missense mutation c.385 C!A, which results in conversion of a conserved proline residue to threonine (P129T), has been associated with street drug use and problem drug abuse. Although a link between the FAAH P129T variant and human drug abuse has been reported, the extent of risk and speciWc types of substance addiction vulnerability remain to be determined. Here, we investigated the relationship of the FAAH P129T variant to a number of linked single nucleotide polymorphisms to establish a haplotyping system, calculate the estimated age and origin of the FAAH 385 C!A mutation and evaluate its association with clinically signiWcant drug addiction in a case control study. The results showed a signiWcant over-representation of the FAAH P129T homozygotes in 249 subjects with documented multiple diVerent drug addictions compared to drug free individuals of the same ethnic backgrounds (P = 0.05) using logistic regression analysis controlling for ethnicity. To increase the logistic regression analysis power by increasing the sample size, the data from our previous study (Sipe et al. in Proc Natl Acad Sci USA 99:8394-8399, 2002) were pooled with the present cohort which increased the signiWcance to P = 0.00003. Investigation of the FAAH chromosomal backgrounds of the P129T variant in both multiple diVerent drug addicted and control subjects revealed a common ancestral haplotype, marked population diVerences in haplotype genetic diversity and an estimated P129T mutation age of 114,425-177,525 years. Collectively, these results show that the P129T mutation is the only common mutation in the FAAH gene and is signiWcantly associated with addictive traits. Moreover, this mutation appears to have arisen early in human evolution and this study validates the previous link between the FAAH P129T variant and vulnerability to addiction of multiple diVerent drugs.

Most studies of mobile phone use are case-control studies that rely on participants' reports of past phone use for their exposure assessment. Differential errors in recalled phone use are a major concern in such studies. INTERPHONE, a... more

Most studies of mobile phone use are case-control studies that rely on participants' reports of past phone use for their exposure assessment. Differential errors in recalled phone use are a major concern in such studies. INTERPHONE, a multinational case-control study of brain tumour risk and mobile phone use, included validation studies to quantify such errors and evaluate the potential for recall bias. Mobile phone records of 212 cases and 296 controls were collected from network operators in three INTERPHONE countries over an average of 2 years, and compared with mobile phone use reported at interview. The ratio of reported to recorded phone use was analysed as measure of agreement. Mean ratios were virtually the same for cases and controls: both underestimated number of calls by a factor of 0.81 and overestimated call duration by a factor of 1.4. For cases, but not controls, ratios increased with increasing time before the interview; however, these trends were based on few subjects with long-term data. Ratios increased by level of use. Random recall errors were large. In conclusion, there was little evidence for differential recall errors overall or in recent time periods. However, apparent overestimation by cases in more distant time periods could cause positive bias in estimates of disease risk associated with mobile phone use.

A population-based case-control study was conducted between July 1984 and February 1988 in the Spanish island of Majorca; 286 incident colorectal cancer cases, 295 population controls and 203 hospital controls were interviewed using a... more

A population-based case-control study was conducted between July 1984 and February 1988 in the Spanish island of Majorca; 286 incident colorectal cancer cases, 295 population controls and 203 hospital controls were interviewed using a food frequency questionnaire. In a multivariate analysis, an increased risk of colon cancer was found for high consumption of fresh meats (RR = 2.87) while a high consumption of cruciferous vegetables afforded protection (RR = 0.48). For rectal cancer an increased risk was associated with dairy products (RR = 3.08) while a protection was afforded by consumption of cruciferae (RR = 0.50). For colorectal cancer, the cereal food group also showed an increase in risk (RR = I .92).

Objective. To investigate whether formocresol, in Buckley's original formulation, is mutagenic in vivo to lymphocyte cultures obtained from the peripheral blood of children aged from 5 to 10 years old. These children were recruited from... more

Objective. To investigate whether formocresol, in Buckley's original formulation, is mutagenic in vivo to lymphocyte cultures obtained from the peripheral blood of children aged from 5 to 10 years old. These children were recruited from those attending the dental clinics of Recife City Council and the University of Pernambuco School of Dentistry, Brazil.

To evaluate the difference between pre- and post-menopausal breast cancer regarding menstrual and reproductive risk factors The case-control study was conducted in Mayo Hospital, Lahore, between October 2008 and April 2009. Cases were... more

To evaluate the difference between pre- and post-menopausal breast cancer regarding menstrual and reproductive risk factors The case-control study was conducted in Mayo Hospital, Lahore, between October 2008 and April 2009. Cases were breast cancer patients admitted in the surgical and oncology floors of the hospital. Controls were hospital patients without breast cancer. The study enrolled 150 cases and 300 controls. Menstrual and reproductive history was taken from both the cases and the controls. For every risk factor age-adjusted odds ratio (OR) and 95% confidence interval (CI) was calculated by logistic regression analysis, separate for pre- and post-menopausal women. Among the breast cancer patients, 42.7% were pre-menopausal and 57.3% were post-menopausal. Age at menarche had no association with breast cancer for both pre- and post-menopausal women. Nulliparity was a risk factor for both pre-menopausal (OR 4.1, 95% CI 1.4-12.6) and post-menopausal breast cancer (OR 8.2, 95% C...

A case-control study involving interviews with 1,016 gastric cancer (GC) patients and I, I59 population-based controls in high-and low-risk areas was conducted to evaluate dietary factors and their contribution to the marked geographic... more

A case-control study involving interviews with 1,016 gastric cancer (GC) patients and I, I59 population-based controls in high-and low-risk areas was conducted to evaluate dietary factors and their contribution to the marked geographic variation in mortality from this cancer within Italy. Risks of GC were found to vary significantly with estimated nutrient intake. Risk rose with increasing consumption of nitrites and protein, and decreased in proportion to intake of ascorbic acid, beta-carotene, alpha-tocopherol, and vegetable fat. The associations with nitrite and beta-carotene tended to fade, however, in multivariate analyses adjusting for intake of other nutrients. Ascorbic acid showed the strongest geographic gradient, with highest consumption in low-risk areas. The findings suggest that the protective effects we previously reported for consumption of fresh fruit, fresh vegetables and olive oil may be linked to the vitamins C and E contained in these foods. The findings are consistent with the hypothesis that N-nitroso compounds are involved in GC risks, since elevated risks were apparent for agents (nitrites, protein) that promote nitrosation, while decreased risks were found for nutrients (ascorbic acid and alpha-tocopherol) which inhibit the process.

A case-control study was conducted to understand the risk factors associated with kala-azar in diseaseendemic areas of Bihar, India. A total of 134 kala-azar cases treated at the Rajendra Memorial Research Institute of Medical Sciences in... more

A case-control study was conducted to understand the risk factors associated with kala-azar in diseaseendemic areas of Bihar, India. A total of 134 kala-azar cases treated at the Rajendra Memorial Research Institute of Medical Sciences in Patna and 406 healthy controls selected randomly from the neighborhoods of cases in their native villages were included in the study. Univariate analysis showed that education, a history of other diseases in the previous year, a history of kala-azar in the family, type of walls in houses, presence of a granary inside houses, presence of vegetation around houses, bamboo trees near houses, and irregular spraying around houses with DDT were risk factors. Multivariate analysis showed that a history of other diseases in the previous year (odds ratio [OR] ‫ס‬ 3.6, P ‫ס‬ 0.002), a history of kala-azar in the family (OR ‫ס‬ 1.8, P ‫ס‬ 0.03), mud-plastered walls in houses, (OR ‫ס‬ 2.4, P ‫ס‬ 0.0001], a granary inside houses (OR ‫ס‬ 4.3, P ‫ס‬ 0.0001), presence of bamboo trees around houses (OR ‫ס‬ 2.3, P ‫ס‬ 0.001), and houses not sprayed with DDT in the past six months (OR ‫ס‬ 3.4, P ‫ס‬ 0.0001) were significant risk factors for kala-azar. These results will be useful in developing kala-azar control programs for identifying intervention strategies such as better housing, regular and proper insecticide spraying, and promoting health awareness to the community residing in diseaseendemic areas for reducing transmission and incidence of this disease.

Throughout biomedical research, there is growing interest in the use of ancestry informative markers (AIMs) to deconstruct racial categories into useful variables. Studies on recently admixed populations have shown significant population... more

Throughout biomedical research, there is growing interest in the use of ancestry informative markers (AIMs) to deconstruct racial categories into useful variables. Studies on recently admixed populations have shown significant population substructure due to differences in individual ancestry; however, few studies have examined Caribbean populations. Here we used a panel of 28 AIMs to examine the genetic ancestry of 298 individuals of African descent from the Caribbean islands of Jamaica, St. Thomas and Barbados. Differences in global admixture were observed, with Barbados having the highest level of West African ancestry (89.6% ± 2.0) and the lowest levels of European (10.2% ± 2.2) and Native American ancestry (0.2% ± 2.0), while Jamaica possessed the highest levels of European (12.4% ± 3.5) and Native American ancestry (3.2% ± 3.1). St. Thomas, USVI had ancestry levels quite similar to African Americans in continental U.S. (86.8% ± 2.2 West African, 10.6% ± 2.3 European, and 2.6% ± 2.1 Native American). Significant substructure was observed in the islands of Jamaica and St. Thomas but not Barbados (K=1), indicating that differences in population substructure exist across these three Caribbean islands. These differences likely stem from diverse colonial and historical experiences, and subsequent evolutionary processes. Most importantly, these differences may have significant ramifications for case-control studies of complex disease in Caribbean populations.

A case-control study of Alzheimer's disease (AD) was conducted to evaluate the roles of family history of dementing disease and AD, and medical conditions, particularly those related to the viral and immune hypotheses in AD, One hundred... more

A case-control study of Alzheimer's disease (AD) was conducted to evaluate the roles of family history of dementing disease and AD, and medical conditions, particularly those related to the viral and immune hypotheses in AD, One hundred and eighty-three clinically diagnosed patients were identified between 1980 and 1985 through the Geriatric and Family Services clinic at the University of Washington hospital, and 18 patients were identified during the same time period through the Veteran's Administration Medical Center in Seattle, Washington. Telephone interviews were conducted with spouses (87.7%) and children (12.3%) of the patients. Each patient was matched to a friend or nonblood relative of the patient by age, sex, and the relationship between the patient and his or her respondent, for a total of 130 matched pairs. The odds ratio for AD was elevated if a first-degree relative was reported to have a history of dementia (odds ratio, 2.21; 95% confidence interval, 1.17 to 4.18). This risk was especially elevated if a sibling was affected (odds ratio, 4.04; 95% confidence interval, 1.37 to 11.90); the highest risk to the proband was observed if a sibling had presumed AD (odds ratio, 5.92; 95% confidence interval, 1.59 to 21.96). The risk increased with increasing numbers of first-degree family members affected for both a history of dementia and presumed AD. We found little difference between patients and control subjects with respect to the age of the mother or father at the time of the subject's birth. No statistically significant differences were observed between the two groups with regard to conditions that might support the immune and viral hypothesis in AD, smoking, or alcohol problems.

Compounds with dioxin-like toxicity are suspected to adversely affect human reproduction even at current background exposures. Endometriosis, a gynecological disorder often associated with infertility, has been hypothesized to be linked... more

Compounds with dioxin-like toxicity are suspected to adversely affect human reproduction even at current background exposures. Endometriosis, a gynecological disorder often associated with infertility, has been hypothesized to be linked to dioxins and similar chemicals, a hypothesis supported by the outcome of experimental studies on animal models. Endometriosis severity and incidence in Belgium is one of the highest of the world: in this country, the general population exposure to dioxin-like compounds has been, on average, higher than in most industrialized countries. Here we show the results of a pilot case-control study carried out on 22 Italian and 18 Belgian women of reproductive age, with and without endometriosis. No significant differences were found in dioxin-like compound body burdens between cases and controls on a country basis, whereas the body burdens of the Italian women resulted to be significantly lower than that of the Belgian. In particular, total TEQs in Italian and Belgian women without endometriosis were respectively 18 and 45 pg WHO-TE/g lb.

Objective The aim was to examine risk factors for ovarian borderline tumors overall, and according to histological subtype (serous vs. mucinous), in a large Danish population-based case-control study. Methods Ovarian borderline cases and... more

Objective The aim was to examine risk factors for ovarian borderline tumors overall, and according to histological subtype (serous vs. mucinous), in a large Danish population-based case-control study. Methods Ovarian borderline cases and controls were recruited from 1995 to 1999, and personal interviews were conducted. In all, 202 cases and 1,564 randomly selected controls were included. The analysis was performed using multiple logistic regression models. Results The risk of ovarian borderline disease decreased with increasing parity (OR=0.79 per birth, 95% CI: 0.63-0.98) and older age at first birth (OR=0.67 per 5 years, 95% CI: 0.53-0.84). Both a history of breastfeeding and use of oral contraceptives reduced the risk of borderline tumor, the effect being most pronounced for serous tumors. Increasing body mass index (BMI) was associated with elevated risk of serous borderline tumor (OR=1.05 per BMI unit; 95% CI: 1.00-1.10), whereas current smoking was a strong risk factor only for mucinous tumors (OR=2.10; 95% CI: 1.22-3.60). Finally, increasing consumption of milk (all types) was found to increase the risk of borderline disease (OR=1.04 per glass milk per week; 95% CI: 1.02-1.06), and increasing intake of total lactose also increased the risk significantly (OR=1.16 per 50 gram lactose per week; 95% CI: 1.06-1.26). Conclusion The risk profile of ovarian borderline tumors is similar to that of ovarian carcinomas, and we observed significant etiological differences between serous and mucinous borderline tumors.

Background Tobacco use is one of the major avoidable causes of cardiovascular diseases. We aimed to assess the risks associated with tobacco use (both smoking and non-smoking) and second hand tobacco smoke (SHS) worldwide.

Epidemiologic findings suggest that dietary components may contribute to the etiology of Parkinson's disease (PD). This population-based case-control study evaluated PD risk... more

Epidemiologic findings suggest that dietary components may contribute to the etiology of Parkinson's disease (PD). This population-based case-control study evaluated PD risk and dietary intake of fats, cholesterol and iron. Newly diagnosed case (n=420) and age/gender/ethnicity-matched unrelated controls (n=560) were identified between 1992 and 2006 from the Group Health Cooperative health maintenance organization in western Washington State, and the University of Washington Neurology Clinic. In-person interviews elicited data on food frequency habits during most of adult life. Nutritional intakes were calculated and analyzed, with adjustments made for total energy intake (the 'nutrition density' technique). Cholesterol intake in the highest quartile compared with the lowest quartile was associated with a decreased risk of PD in men (odds ratio (OR)=0.53, 95%CI: 0.33, 0.86). The highest versus the lowest quartile of dietary iron increased PD risk in men (OR=1.82, 95%CI: 1.11, 2.99). When the lowest quartile of cholesterol and the highest quartile for iron were compared to the highest quartile of cholesterol and the lowest quartile of iron, no association was seen in women, but for men PD risk was increased (OR=2.70, 95%CI: 1.26, 5.76). Saturated fat intake below the median in combination with iron intake above the median also increased the PD risk (OR=1.50, 95%CI: 1.07, 2.11) in both genders combined. A low intake of cholesterol, particularly in the presence of high iron, may be associated with an increased risk for PD.

In order to assess the interaction between alcohol intake, tobacco smoking and coffee consumption in determining the risk of liver cirrhosis we carried out a hospital-based case-control study involving 115 patients at their first... more

In order to assess the interaction between alcohol intake, tobacco smoking and coffee consumption in determining the risk of liver cirrhosis we carried out a hospital-based case-control study involving 115 patients at their first diagnosis of cirrhosis and 167 control patients consecutively enrolled in the General Hospitals of the Province of L'Aquila (Central Italy). The mean life-time daily alcohol intake (as g ethanol consumed daily) was measured by direct patient interviews, whose reproducibility was > 0.80 and similar for cases and controls, as checked by interviewing the relatives of a sample of 50 cases and 73 controls. During the same patient's interview we also measured the mean consumption of coffee (daily number of cups of filtered coffee) and tobacco (life-time daily number of cigarettes smoked). A dose-effect relationship on the risk of cirrhosis was present both for alcohol intake -for which the risk was significantly increased above 100 g of daily intake -and for cigarette consumption. The latter did not however improve the goodness-of-fit of a logistic regression model including alcohol intake as covariate. By contrast, coffee consumption had a protective effect on the risk of cirrhosis and significantly improved the goodness-of-fit of such a model. Abstaining from coffee consumption determined both a significantly increased risk of cirrhosis, even for daily alcohol intake below 100 g, and a multiplicative effect with alcohol intake on this risk. In patients drinking /> 101 g ethanol daily the relative risk increased from 5.5 (95% confidence interval: 1.4-22.0) for coffee consumers to 10.8 (95% confidence interval: 1.3-58.1) for coffee abstainers. We conclude that: (t) tobacco smoking is likely to be a faint risk factor for cirrhosis, and studies on wider patients series should be performed for confirmation; (2) coffee drinking is associated with a reduced risk of cirrhosis. Whether coffee contains some hitherto unknown protective substances, or is just a marker of other life-style or dietary protective factors, deserves further clarification.

The aim of the current study was to investigate from a cross-cultural perspective the hypothesis whether religiosity assessed in two dimensions (religious denomination and subjective religiosity) is a protective factor against attempted... more

The aim of the current study was to investigate from a cross-cultural perspective the hypothesis whether religiosity assessed in two dimensions (religious denomination and subjective religiosity) is a protective factor against attempted suicide. 2819 suicide attempters seen in emergency settings and 5484 controls from community survey in the

Aim. -Diabetic patients defaulting from specialist care have worse metabolic control and complications than those attending regularly. We have compared the clinical characteristics of defaulters and more regular health care attenders on a... more

Aim. -Diabetic patients defaulting from specialist care have worse metabolic control and complications than those attending regularly. We have compared the clinical characteristics of defaulters and more regular health care attenders on a population basis in a multi-ethnic community.

tive analysis of all mechanical trigger factors revealed a significant association of mechanical risk factors as a whole in CAD ! 24 h prior to symptom onset (p = 0.01). Conclusion: Mild mechanical stress, including CMT, plays a role as... more

tive analysis of all mechanical trigger factors revealed a significant association of mechanical risk factors as a whole in CAD ! 24 h prior to symptom onset (p = 0.01). Conclusion: Mild mechanical stress, including CMT, plays a role as possible trigger factor in the pathogenesis of CAD. CMT and recent infections alone failed to reach significance during the present investigation, presumably due to the relatively small sample size of the study cohort.

An inverse association between allergic conditions and glioma risk has been reported previously. In this large population-based case-control study, the authors identified cases diagnosed with glioma or meningioma in Denmark, Norway,... more

An inverse association between allergic conditions and glioma risk has been reported previously. In this large population-based case-control study, the authors identified cases diagnosed with glioma or meningioma in Denmark, Norway, Finland, Sweden, and southeast England between 2000 and. Detailed information on self-reported physician-diagnosed allergic conditions was collected from 1,527 glioma cases, 1,210 meningioma cases, and 3,309 randomly selected controls. Logistic regression showed an odds ratio of 0.70 (95% confidence interval: 0.61, 0.80) for glioma associated with a diagnosis of any of asthma, hay fever, eczema, or other type of allergy. The risk estimates for glioma were around 0.65 for each allergic condition (asthma, eczema, hay fever, and food allergy), and the 95% confidence intervals were equally consistent, at around 0.55, 0.80. The reduced risks of glioma related to eczema, hay fever, and allergy overall, but not asthma, were confined to current rather than past conditions. Meningioma risk was not associated with allergic conditions, except for eczema (odds ratio ¼ 0.74, 95% confidence interval: 0.60, 0.91). Our results show a reduced risk for glioma associated primarily with current allergic conditions. If this is etiologic, it has implications for the understanding of how allergic conditions might reduce the tumor risk.

Sleepiness is related to factors such as the time of day, the time since awakening and the duration of prior sleep. The present study investigated whether actual road crashes could be predicted from a mathematical model based on these... more

Sleepiness is related to factors such as the time of day, the time since awakening and the duration of prior sleep. The present study investigated whether actual road crashes could be predicted from a mathematical model based on these three factors (the Sleep/Wake Predictor-SWP). Data were derived from a population-based case-control study of serious injury crashes. Data on accident time (or control sampling time) and start and end of prior sleep were entered into the model (blind). The predicted sleepiness values were used in logistic regressions. The results showed a highly significant odds ratio (OR) = 1.72 (confidence interval = 1.41-2.09) for each incremental step of sleepiness on the output sleepiness scale (nine steps). There was also a significant interaction with blood alcohol level, showing high OR values for high sleepiness levels and alcohol levels above 50 mg% (0.05 g/dl). It was concluded that the model is a good predictor of road crashes beyond that of alcohol level, and that interaction between the two carries a very high risk.

A tertiary care center-based, case-control study evaluated the status of oxidative stress, enzymes involved in the antioxidant defense and membrane fluidity in platelets of 6 cases with central Eales disease and 5 healthy controls.... more

A tertiary care center-based, case-control study evaluated the status of oxidative stress, enzymes involved in the antioxidant defense and membrane fluidity in platelets of 6 cases with central Eales disease and 5 healthy controls. Significant differences were observed between malonaldialdehyde, superoxide dismutase and catalase levels in the cases and controls. Enhanced oxidative stress, is consistent with an emerging view that antioxidant defenses decline in association with the disease process.

We examined familial aggregation and risk of age-related macular degeneration in the Utah population using a population-based case-control study. Over one million unique patient records were searched within the University of Utah Health... more

We examined familial aggregation and risk of age-related macular degeneration in the Utah population using a population-based case-control study. Over one million unique patient records were searched within the University of Utah Health Sciences Center and the Utah Population Database (UPDB), identifying 4764 patients with AMD. Specialized kinship analysis software was used to test for familial aggregation of disease, estimate the magnitude of familial risks, and identify families at high risk for disease. The population-attributable risk (PAR) for AMD was calculated to be 0.34. Recurrence risks in relatives indicate increased relative risks in siblings (2.95), first cousins (1.29), second cousins (1.13), and parents (5.66) of affected cases. There were 16 extended large families with AMD identified for potential use in genetic studies. Each family had five or more living affected members. The familial aggregation of AMD shown in this study exemplifies the merit of the UPDB and supports recent research demonstrating significant genetic contribution to disease development and progression.

Many exposures investigated in epidemiological case-control studies may vary over time. The effects of these exposures are usually estimated using logistic regression, which does not directly account for changes in covariate values over... more

Many exposures investigated in epidemiological case-control studies may vary over time. The effects of these exposures are usually estimated using logistic regression, which does not directly account for changes in covariate values over time within individuals. By contrast, the Cox model with time-dependent covariates directly accounts for these changes over time. However, the over-sampling of cases in case-control studies, relative to controls, requires manipulating the risk sets in the Cox partial likelihood. A previous study showed that simple inclusion or exclusion of future cases in each risk set induces an under-or over-estimation bias in the regression parameters, respectively. We investigate the performance of a weighted Cox model that weights subjects according to age-conditional probabilities of developing the disease of interest in the source population. In a simulation study, the lifetime experience of a source population is first generated and a case-control study is then simulated within each population. Different characteristics of exposure are generated, including time-varying intensity. The results show that the estimates from the weighted Cox model are much less biased than the Cox models that simply include or exclude future cases, and are superior to logistic regression estimates in terms of bias and mean-squared error. An application to frequency-matched population-based case-control data on lung cancer illustrates similar differences in the estimated effects of different smoking variables. The investigated weighted Cox model is a potential alternative method to analyse matched or unmatched population-based case-control studies with time-dependent exposures.

The validity of a 77-item food-frequency questionnaire (FFR) developed for a multicenter case-control study on diet and cancer in Italy was assessed. Trained interviewers administered the same FFQ to 452 volunteers from three b&an... more

The validity of a 77-item food-frequency questionnaire (FFR) developed for a multicenter case-control study on diet and cancer in Italy was assessed. Trained interviewers administered the same FFQ to 452 volunteers from three b&an provinces (Ponfenone, Genoa, and Forli) completed in two different seasons, at an interval of 3 to 10 months. For 395 (130 males, 265 females; median age = 52 years; range = 35 to 69 years) volunteers, two 7-day dietary (7-DD) records were available. Average intake obtained by means of the FFQ was werestimated by approximately 18% in comparison with the corresponding values based on the two 7-DD recora!s (reference method). Pearson partial correlation coefficients, adjusted for total energy intake between the nutrient intakes assessed by the FFQ and reference method, ranged from 0.19 for vegetable fat to 0.64 for sugar (median value r = 0.46). The unadjusted deattenuated coefficients, which took into account the interindividual variability of consumption, estimated by means of the two 7-DD records, ranged from 0.29 for vegetable fat to 0.72 for starch (median value r = 0.54). The proportion of subjects correctly classified within the lowest two quintiles ranged between 59% for vegetable fat and vitamin E, and 94% for alcohol, and those correctly classified within the highest two quintiles ranged between 44% for vegetable fat and 94% for alcohol. The average proportion of subjects correctly classified within one quintile was 73%. These data indicate that this FFQ provides valid estimates of intakes for major nutrients, comparable to those reported from other studies in North America and other European countiies.

In the Netherlands an 18 months case control study into cot death was undertaken as part of the European Concerted Action (ECAS) on sudden infant death syndrome to determine the relative risk of prone sleeping and other sleep practices.... more

In the Netherlands an 18 months case control study into cot death was undertaken as part of the European Concerted Action (ECAS) on sudden infant death syndrome to determine the relative risk of prone sleeping and other sleep practices. Physicians in the Netherlands were asked to report to the study centre all sudden and unexpected deaths of children between 1 week and 2 years of age. Non cot death cases were deleted from further analysis after a consensus was reached by three pathologists, not primarily involved in the post mortem diagnosis. A positive response of families was achieved in 91% of cases registered in the Central Bureau of Statistics. The study comprised 73 cot deaths and 146 controls, two for each case and matched for date of birth. All families were visited at home for completion of a questionnaire. The cot death rate has dropped considerably over the past 10 years after the recommendations on supine sleeping to a low of 0.26 per 1000 live born infants. In addition to the ECAS objective, we wanted to establish whether previously found risk factors are still valid in the present situation or that new factors might have emerged, some of them possibly protective. Conclusion Placing an infant prone or on side on last occasion, secondary prone position (not placed prone but turned to prone), inexperienced prone sleeping and use of a duvet, leading to head and body being covered, were shown to be risk factors. Preventive factors were using a cotton sleeping-sack and a dummy. Even in a low incidence country, such as the Netherlands, there are indications that further prevention is possible.

The development of venous thromboembolism is influenced by a variety of genetic and environmental risk factors. A few studies have ascertained whether thrombophilic defects are risk factors for venous thromboembolism in Latin American... more

The development of venous thromboembolism is influenced by a variety of genetic and environmental risk factors. A few studies have ascertained whether thrombophilic defects are risk factors for venous thromboembolism in Latin American populations with a variable degree of admixture, such as the Colombian population. To address this issue, we conducted a case-control study involving 100 consecutive patients with deep vein thrombosis and 114 healthy controls from the Hospital Universitario San Vicente de Paú l, Medellín, Colombia. Activated protein C resistance (APC resistance) was detected in 25/99 patients vs. 6/114 controls (OR 5 6.08, 95% CI 5 2.23-17.47). Ten of 100 patients carried the factor V Leiden mutation vs. 1/114 controls (OR 5 12.56, 95% CI 5 1.61-267). APC resistance was associated with the factor V Leiden mutation in only 10/25 patients. The prothrombin G20210A mutation was found in 4/100 patients, but none of the controls (P < 0.05). There was no significant difference in the proportion of homozygous carriers of methylenetetrahydrofolate reductase C677T variant among patients and controls. In conclusion, in our studied population, factor V Leiden, APC resistance, and prothrombin G20210A were associated with an increased risk of deep vein thrombosis. However, the frequencies of these thrombophilic defects and of APC resistance associated with factor V Leiden was lower than the corresponding frequencies previously reported for Caucasian populations. Further study is required to assess the influence of ethnicity on thrombophilia. Am. J. Hematol. 81: [933][934][935][936][937] 2006. V V C 2006 Wiley-Liss, Inc.

The relation between the intake of certain food items thought to be precursors or inhibitors of N-nitroso compounds (NOC) and risk of leukemia was investigated in a case-control study among children from birth to age 10 years in Los... more

The relation between the intake of certain food items thought to be precursors or inhibitors of N-nitroso compounds (NOC) and risk of leukemia was investigated in a case-control study among children from birth to age 10 years in Los Angeles County, California (United States). Cases were ascertained through a population-based tumor registry from 1980 to 1987. Controls were drawn from friends and by random-digit dialing. Interviews were obtained from 232 cases and 232 controls. Food items of principal interest were: breakfast meats (bacon, sausage, ham); luncheon meats (salami, pastrami, lunch meat, corned beef, bologna); hot dogs; oranges and orange juice; and grapefruit and grapefruit juice. We also asked about intake of apples and apple juice, regular and charcoal broiled meats, milk, coffee, and coke or cola drinks. Usual consumption frequencies were determined for both parents and the child. When the risks were adjusted for each other and other risk factors, the only persistent significant associations were for children's intake of hot dogs (odds ratio [OR] = 9.5, 95 percent confidence interval [CI] = 1.6-57.6 for 12 or more hot dogs per month, trend P = 0.01), and fathers' intake of hot dogs (OR = 11.0, CI = 1.2-98.7 for highest intake category, trend P = 0.01). There was no evidence that fruit intake provided protection. While these results are compatible with the experimental animal literature and the hypothesis that human NOC intake is associated with leukemia risk, given potential biases in the data, further study of this hypothesis with more focused and comprehensive epidemiologic studies is warranted. Cancer Causes and Control 1994, 5, 195-202

The purpose of this study was to evaluate active knee flexion range of motion and hamstring strength following hamstring anterior cruciate ligament (ACL) reconstruction. Case control study, consecutive sample. Seventy-four consecutive... more

The purpose of this study was to evaluate active knee flexion range of motion and hamstring strength following hamstring anterior cruciate ligament (ACL) reconstruction. Case control study, consecutive sample. Seventy-four consecutive patients who had undergone hamstring ACL reconstruction underwent isokinetic muscle strength testing at 2 years post surgery. Measurements of the maximum standing active knee flexion angle with the hip extended were also taken. During isokinetic testing, we evaluated flexion torque at 90 degrees of knee flexion, in addition to the peak flexion torque. We further compared these parameters of muscle strength around the knee for the patients in whom only semitendinosus tendon was harvested as a graft source (ST group), and those from whom the semitendinosus tendon and the gracilis tendon were harvested (ST/G group). Isokinetic testing showed that, in both the ST and ST/G groups, the knee flexor strength of the involved leg was less effectively restored at 90 degrees of knee flexion than at the angle at which the peak torque was generated. Conversely, no significant difference was seen in the side-to-side ratio in either the peak flexion torque or the 90 degrees flexion torque between the groups. The side-to-side ratio in mean maximum standing knee flexion angle was significantly lower in the ST/G group than in the ST group. This study suggests that the loss of knee flexor strength following the harvest of the hamstring tendons may be more significant than has been previously estimated. Furthermore, multiple tendon harvest may affect the range of active knee flexion.

In order to examine the associations between sinonasal cancer and occupational exposures other than wood dust and leather dust, the data from 12 case-control studies conducted in seven countries were pooled and reanalyzed. The pooled data... more

In order to examine the associations between sinonasal cancer and occupational exposures other than wood dust and leather dust, the data from 12 case-control studies conducted in seven countries were pooled and reanalyzed. The pooled data set included 195 adenocarcinoma cases (169 men and 26 women), 432 squamous cell carcinomas (330 men and 102 women), and 3136 controls (2349 men and 787 women). Occupational exposures to formaldehyde, silica dust, textile dust, coal dust, flour dust, asbestos, and man-made vitreous fibers were assessed with a job-exposure matrix. Odds ratios (ORs) were adjusted for age, study, wood dust, and leather dust, or other occupational exposures when relevant. 95% confidence intervals (CIs) were estimated by unconditional logistic regression. A significantly increased risk of adenocarcinoma was associated with exposure to formaldehyde. The ORs for the highest level of exposure were 3.0 (Cl = 1.5-5.7) among men and 6.2 (CI=2.0-19.7) among women. An elevated r...

To investigate the incidence, efficacy, and safety of elective induction in a community teaching hospital over 1 year. Methods: This is a retrospective case-control study of rate, safety, and efficacy of all term inductions with vertex... more

To investigate the incidence, efficacy, and safety of elective induction in a community teaching hospital over 1 year. Methods: This is a retrospective case-control study of rate, safety, and efficacy of all term inductions with vertex presentations judged to be elective by chart analysis. Cases were matched one for one for age, parity, and pay status with controls in spontaneous labor. The elective induction women were compared with those in spontaneous labor using 2 Student t test, and Fisher exact test. Potential risk factors for cesarean delivery and neonatal intensive care unit (NICU) admission were then selected and subjected to bivariate analysis. Stepwise logistic regression was applied to control for confounding and to select which risk factors were important for those end points. Results: There were 461 case-control pairs. The elective induction rate was 12.3%. Cesarean delivery was increased by elective induction in bivariate analysis (odds ratio [OR] ‫؍‬ ‫؍‬ ‫؍‬ 1.81, confidence interval [CI] ‫؍‬ ‫؍‬ ‫؍‬ 1.07, 3.08; power ‫؍‬ ‫؍‬ ‫؍‬ .60). The cesarean delivery rate was 8.7% (control 5.0%). In a multiple regression model of potential risk factors for cesarean delivery, nulliparity (

Objective To evaluate the significance of a new sign in the hysteroscopic incision process of the septate uterus. Design This is a prospective case control study. Design classification II-2. Settings The study was performed in a research... more

Objective To evaluate the significance of a new sign in the hysteroscopic incision process of the septate uterus. Design This is a prospective case control study. Design classification II-2. Settings The study was performed in a research hospital. Patients Fourty-seven consecutive cases were operated for septate uterus. Intervention Septum incision was performed in all cases with a hysteroscopic resectoscope under laparoscopic supervision. Measurements and main results Methylene blue 0.25% was injected through a Rubin canula in all cases for the assessment of tubal patency. Following the methylene blue injection, hysteroscopic septum incision was performed. Conclusion A line (blue line) on the top of the cavity has been observed in 33 of 47 (70.2%) cases. This line (blue line) can be used for determining the midline especially before hysteroscopic incision of uterine septum and can also shorten the operation time.

A case-control study was conducted to understand the risk factors associated with kala-azar in disease- endemic areas of Bihar, India. A total of 134 kala-azar cases treated at the Rajendra Memorial Research Institute of Medical Sciences... more

A case-control study was conducted to understand the risk factors associated with kala-azar in disease- endemic areas of Bihar, India. A total of 134 kala-azar cases treated at the Rajendra Memorial Research Institute of Medical Sciences in Patna and 406 healthy controls selected randomly from the neighborhoods of cases in their native villages were included in the study. Univariate analysis

Large spontaneous portal-systemic shunts have been occasionally described in patients with cirrhosis. This study was undertaken to assess the prevalence of portal-systemic shunts in patients with cirrhosis with recurrent or persistent... more

Large spontaneous portal-systemic shunts have been occasionally described in patients with cirrhosis. This study was undertaken to assess the prevalence of portal-systemic shunts in patients with cirrhosis with recurrent or persistent hepatic encephalopathy (HE) as compared with patients with cirrhosis without HE. Fourteen patients with cirrhosis with recurrent or persistent HE (cases) and 14 patients with cirrhosis without previous or present signs of overt HE matching for age and degree of liver failure (controls) were studied. Each patient underwent neurological assessment and cerebral magnetic resonance (MR) imaging to exclude organic neurological pathological conditions. HE evaluation included psychometric performance (Trail-Making Test A), electroencephalogram (EEG), mental status examination and grading, arterial, venous, and partial pressure of ammonia determination. The presence of portal-systemic shunts was assessed by portal venous phase multidetector-row spiral computed tomography (CT). Large spontaneous portal-systemic shunts were detected in 10 patients with HE and in only 2 patients without HE (71% vs. 14%; chi square ‫؍‬ 9.16; df ‫؍‬ 1.0; P ‫؍‬ .002). The patients with HE presented ascites (P ‫؍‬ .002) and medium/large esophageal varices (P ‫؍‬ .02) less frequently than the control group. In conclusion, our study suggests that large spontaneous shunts may often sustain the chronicity of HE; the presence of large shunts should be sought in patients with cirrhosis with recurrent or persistent HE.

Objective: To evaluate the ability of pre-defined clinical criteria to identify patients who subsequently suffer cardiac arrest, unplanned intensive care unit admission or unexpected death; to determine the ability of modified criteria to... more

Objective: To evaluate the ability of pre-defined clinical criteria to identify patients who subsequently suffer cardiac arrest, unplanned intensive care unit admission or unexpected death; to determine the ability of modified criteria to identify these patients. Design: Nested, matched case-control study. Setting: Seven Australian public hospitals. Patients and participants: Four hundred and fifty cases and 520 controls matched for age, sex, hospital, and hospital ward. Interventions: None. Measurements and results: Highest and lowest respiratory and heart rates, lowest systolic blood pressure, presence of threatened airway, seizures or decrease in Glasgow Coma Scale score of greater than two points and incidence of the three adverse events were measured. Combining a heart rate greater than 140, respiratory rate greater than 36, a systolic blood pressure less than 90 mmHg and a greater than two point reduction in the Glasgow Coma Scale identified adverse events with a sensitivity of 49.1% (44.4-53.8%), specificity of 93.7% (91.2-95.6%), and positive predictive ଝ A Spanish translated version of the summary of this article appears as Appendix in the final online version at The objective medical emergency team activation criteria 63 value of 9.8% (8.7-11.1%). Adding threatened airway, seizures, low respiratory rate and low heart rate did not substantially improve sensitivity (50.4%; 45.7-55.2%). After modifying the cut-off values for respiratory rate, heart rate and systolic blood pressure, the best achievable positive predictive value remained below 16%. Conclusions: In combination, the respiratory rate, heart rate, systolic blood pressure, and level of consciousness identify patients at risk of cardiac arrest, unplanned intensive care admission or unexpected death with high specificity; however the sensitivity and positive predictive value are relatively low, even after modification of the activation criteria cut-off values.

Background In 2002, a poster alerted the French health authorities to the possibility that the risk of childhood leukaemia might be increased by hepatitis B vaccination. Elucidating the role of vaccination in the aetiology of childhood... more

Background In 2002, a poster alerted the French health authorities to the possibility that the risk of childhood leukaemia might be increased by hepatitis B vaccination. Elucidating the role of vaccination in the aetiology of childhood acute leukaemia (AL) was therefore included in the objectives of an ongoing national study. Methods The ESCALE study was a French national population-based case-control

Background: Vertical Banded Gastroplasty (VBG) is one of the most common bariatric operations. It can be performed by open or laparoscopic methods. The purpose of this study was to analyze and compare the 1-year results of 40 patients who... more

Background: Vertical Banded Gastroplasty (VBG) is one of the most common bariatric operations. It can be performed by open or laparoscopic methods. The purpose of this study was to analyze and compare the 1-year results of 40 patients who underwent laparoscopic (20) and open (20).

Objectives: To study potential risk factors for the development of lung cancer in patients with scleroderma and explore the chronological relationship between onset of scleroderma symptoms and subtypes of lung cancer. Method: Linkage of... more

Objectives: To study potential risk factors for the development of lung cancer in patients with scleroderma and explore the chronological relationship between onset of scleroderma symptoms and subtypes of lung cancer. Method: Linkage of two population-based registers to identify lung cancer cases and gender-matched controls with scleroderma, followed by retrospective case note review for clinical details. Results: Patients with scleroderma who smoke are seven times more likely to develop lung cancer than non-smokers (p = 0.008). Smokers with scleroderma and cancer smoke more than smokers with scleroderma without cancer (p = 0.019). Pulmonary fibrosis and anti-topoisomerase antibody do not increase the risk of lung cancer. Peripheral lung tumours occur earlier after the onset of scleroderma symptoms than bronchogenic tumours (p = 0.05).

A case-control study was carried out in Mexico City during 1995–1997 among women with epithelial ovarian cancer (84 cases) and endometrial cancer (85 cases). The control group consisted of 668 healthy women, matched according to age... more

A case-control study was carried out in Mexico City during 1995–1997 among women with epithelial ovarian cancer (84 cases) and endometrial cancer (85 cases). The control group consisted of 668 healthy women, matched according to age categories. In a multivariate analysis, the ...

Bright-or light-colored vehicles are sometimes regarded as safer because they are presumably more visible. We examined the effect of vehicle color on the risk of being passively involved in a collision.

Objective: To examine the socio-economic and lifestyle determinants of cooking oil choice in Costa Rica during the last decade (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004). Design: Cross-sectional study. Subjects... more

Objective: To examine the socio-economic and lifestyle determinants of cooking oil choice in Costa Rica during the last decade (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004). Design: Cross-sectional study. Subjects (total n ¼ 2274) belonged to the control population of a large case-control study; they were recruited yearly. Data about type of oil used for cooking, dietary intake, socio-economic and demographic characteristics were collected. Setting: A dietitian visited all subjects and conducted the interviews at their homes; all subjects lived in the Costa Rican central valley region. Subjects: Adult, free-living, rural and urban Costa Ricans with no history of myocardial infarction and physical or mental disability. Results: The odds of choosing soybean over palm oil increased significantly each year (P , 0.05) and was determined by high socio-economic status (SES) and variables that suggest health awareness (self-reported history of hypertension, high cholesterol, multivitamin use and intake of green leafy vegetables). The odds of choosing other unsaturated oils, namely corn and sunflower, over soybean oil also increased yearly (P , 0.05) and was associated with the same two factors (high SES and health awareness). Palm oil users remained in the lowest SES tertile and were more likely to live in rural areas. Across all SES tertiles, high health awareness determined the odds of choosing other unsaturated oils over palm oil, and soybean oil (P , 0.05). Conclusion: These data show that, in addition to SES, health awareness is associated with selection of unsaturated oils over palm oil in a developing country undergoing transition. These data should be considered when targeting nutrition messages and policies that promote better dietary choices.

Maternal welfare, morbidity and mortality 6-15 years after a pregnancy complicated by alcohol and substance abuse: A register-based case-control follow-up study of 524 women a b s t r a c t Background: A register-based retrospective... more

Maternal welfare, morbidity and mortality 6-15 years after a pregnancy complicated by alcohol and substance abuse: A register-based case-control follow-up study of 524 women a b s t r a c t Background: A register-based retrospective case-control study to investigate the long-term morbidity, mortality, and welfare among women with alcohol and/or substance misuse identified during pregnancy. Methods: Cohort of 524 women followed-up ante-and perinatally 1992-2001 at special out-patient clinics of maternity hospitals in the capital area of Finland. The control group of 1792 women with no evidence of alcohol or substance misuse was matched for maternal age, parity, date of birth and hospital of index delivery. Both groups were followed-up until end of 2007. Results: 7.9% (42/524) of the cases and 0.2% (4/1792) of the controls had died by the end of the median follow-up of 9 years (OR 38, 95% CI 14-108). The cases displayed significant morbidity requiring inpatient care in the areas of mental disorders (AOR 8.8, 95% CI 6.5-11.9), viral (AOR 23.5, 95% CI 8.8-62.7) and bacterial (AOR 6.1, 95% CI 3.5-10.4) infections, skin diseases (AOR 3.9, 95% CI 2.0-7.8) and injury and poisoning (AOR 4.2, 95% CI 3.1-5.6). The cases displayed more out-patient visits (OR 2.7, 95% CI 2.7-2.8). Their mean length of hospital stay was longer compared to controls (10.3 vs. 4.4 days, p < 0.001). The risk of pension granted due to a disorder, disease or disability (OR 8.8, 95% CI 6.0-13.0) and the risk for minimum unemployment benefit were higher compared to controls (OR 2.1, 95% CI 1.8-2.5). Conclusions: These women display significant long-term morbidity, mortality and loss of productivity after delivery. The results emphasize the importance of adequate postnatal follow-up and treatment for misuse. (H. Kahila). , and special multidisciplinary care programs have subsequently been established in Finland . However, the long-term benefits of these interventions and the prognosis of these women are unknown. In an Irish study, the long-term prognosis of opiate-addicted mothers with young infants was poor .

To evaluate the association between human papillomavirus (HPV) and cervical cancer, we performed a population-based case-control study in Colombia and Spain, the former country having an incidence rate of cervical cancer about 8 times... more

To evaluate the association between human papillomavirus (HPV) and cervical cancer, we performed a population-based case-control study in Colombia and Spain, the former country having an incidence rate of cervical cancer about 8 times higher than the latter. It included 436 cases of histologically confirmed invasive cervical cancer and 387 randomly selected population controls. Information on demographic variables, sexual behaviour and other risk factors was obtained by interview. HPV-DNA was measured in cervical-swab specimens with 3 hybridization assays: ViraPap™, Southern hybridization (SH) and polymerase chain reaction (PCR). The presence of HPV-DNA and detection of types 16, 18, 31, 33 and 35 were strongly associated with cervical cancer in each country regardless of the assay used. For both countries combined the adjusted odds ratios and 95% confidence intervals were: ViraPap OR = 25.9 (10.0–66.7); SH OR = 6.8 (3.4–13.4); and PCR OR = 28.8 (15.7–52.6). HPV-16 was the most common type detected in both cases and controls. Our results indicate that there is a very strong association between HPV 16, 18, 31, 33 and 35 and invasive cervical cancer and that this association is probably causal. © 1992 Wiley-Liss, Inc.