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Possible Confounding Factors (possible + confounding_factor)
Selected AbstractsThe effect of stopping smoking on perceived stress levelsADDICTION, Issue 8 2010Peter Hajek ABSTRACT Aims Many smokers believe that smoking helps them to cope with stress, and that stopping smoking would deprive them of an effective stress management tool. Changes in stress levels following long-term smoking cessation are not well mapped. This longitudinal project was designed to provide more robust data on post-cessation changes in perceived stress levels by following a cohort of smokers admitted to hospital after myocardial infarction (MI) or for coronary artery bypass (CAB) surgery, as such patients typically achieve higher continuous abstinence rates than other comparable samples. Design A total of 469 smokers hospitalized after MI or CAB surgery and wanting to stop smoking were seen in the hospital and completed 1-year follow-ups. Ratings of helpfulness of smoking in managing stress at baseline, smoking status (validated by salivary cotinine concentration) and ratings of perceived stress at baseline and at 1-year follow-up were collected. Findings Of the patients, 41% (n = 194) maintained abstinence for 1 year. Future abstainers and future smokers did not differ in baseline stress levels or in their perception of coping properties of smoking. However, abstainers recorded a significantly larger decrease in perceived stress than continuing smokers, and the result held when possible confounding factors were controlled for (P < 0.001). Conclusions In highly dependent smokers who report that smoking helps them cope with stress, smoking cessation is associated with lowering of stress. Whatever immediate effects smoking may have on perceived stress, overall it may generate or aggravate negative emotional states. The results provide reassurance to smokers worried that stopping smoking may deprive them of a valuable coping resource. [source] DNA damage in Pakistani pesticide-manufacturing workers assayed using the Comet assayENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 8 2006Javed A. Bhalli Abstract The production and use of chemical pesticides has increased in recent years. Although the increased use of pesticides may benefit agriculture, they are also the potential source of environmental pollution, and exposure to pesticides can have negative consequences for human health. In the present study, we have assessed DNA damage in blood leukocytes from 29 Pakistani pesticide-factory workers and 35 controls of similar age and smoking history. The workers were exposed to various mixtures of organophosphates, carbamates, and pyrethroids. DNA damage was measured with the single cell gel electrophoresis (SCGE) assay or Comet assay, using the mean comet tail length (,m) as the DNA damage metric. Exposed workers had significantly longer comet tail lengths than the controls (mean ± SD 19.98 ± 2.87 vs. 7.38 ± 1.48, P < 0.001). Of the possible confounding factors, smokers had significantly longer mean comet tail lengths than nonsmokers and exsmokers for both the workers (21.48 ± 2.58 vs.18.37 ± 2.28, P < 0.001) and the controls (8.86 ± 0.56 vs. 6.79 ± 1.31, P < 0.001), while age had a minimal effect on DNA damage (P > 0.05 and P < 0.05 for workers and controls, respectively). The results of this study indicate that occupational exposure to pesticides causes DNA damage. Environ. Mol. Mutagen., 2006. © 2006 Wiley-Liss, Inc. [source] Prevalence and characteristics of older community residents with mild cognitive declineGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2 2002Yoshinori Fujiwara Background:, Cognitive impairment is a major health issue, but epidemiological data on mild cognitive decline have been almost absent in Japan. Methods: Of all residents aged 65 years and over living in Yoita town, Niigata Prefecture, Japan in the year 2000 (n = 1673), 1544 participated in the interview survey held at community halls or at home (92.3% response). They underwent the Mini-Mental State Examination (MMSE) for assessment of cognitive function and answered questionnaires comprising socio-demographic, psychological, physical and medical, and social activity items. Higher-level functional capacities were evaluated with the Tokyo Metropolitan Index of Competence (TMIG-Index of Competence). According to subject's age and MMSE score, all subjects were classified into 3 groups: control (MMSE,>,1 SD below age-specific means), mild cognitive decline (MMSE,,,21 and ,,1 SD below age-specific means), and severe cognitive decline (MMSE,,,20), and compared various characteristics among these groups. Results: Mean MMSE score of the subjects showed a linear decline with advancing age. Among the participants, 232 (15.2%) were classified as mild cognitive decline. Compared with the controls, the subjects with mild cognitive decline reported poorer subjective health, more depressive moods, more history of stroke, more prevalence of basic activity of daily living (BADL) disability, and lower higher-level functional capacity, even after controlling for possible confounding factors. They also reported a low level of social activities: both participating in group activities and enjoying hobbies were less frequent. Their food intake pattern tended to be monotonous. Conclusions: Older persons with mild cognitive decline comprised a substantial proportion (15.2%) of the community-dwelling older population. In addition to lower cognitive function, they had lower levels of functional capacity and social activity. [source] Cardiovascular Risk Factors in Subjects with Helicobacter pylori InfectionHELICOBACTER, Issue 2 2002Toshiharu Takashima Abstract Background. It has been proposed that Helicobacter pylori infection is related to cardiovascular disease, although this has not been fully investigated. The aim of this study was to investigate whether H. pylori in-fection is associated with cardiovascular risk factors. Subjects and Methods. One thousand six hundred and fifty people undergoing annual medical checks at Shimane Institute of Health Science between September 1998 and August 1999 were enrolled. Gender, age, body mass index, habitual smoking and drinking, systolic and diastolic blood pressure, serum level of total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDLC), blood glucose, leukocyte count and hemoglobin were compared between H. pylori seropositive and seronegative cases. Results. In H. pylori seropositive individuals, HDLC was significantly lower than that in seronegative individuals. After adjustment for possible confounding factors (gender, age, BMI, smoking and drinking habits), mean HDLC in H. pylori -seropositive and seronegative individuals were 56.1 and 58.2 mg/dl, respectively (p < .005). The percentage of the elderly (over 50 years old) individuals with HDLC < 35 mg/dl in H. pylori seropositive and seronegative groups were 7.4% and 4.7%, respectively (p < .001). In addition, the lower HDLC level was accompanied by an increased leukocyte count. Conclusion. Long-term infection with H. pylori may have an important role in decreasing the serum HDLC concentration. [source] Mere presence of distractors: Another determining factor for the attentional blink1JAPANESE PSYCHOLOGICAL RESEARCH, Issue 3 2003Jun-Ichiro Kawahara Abstract: When two visual targets are presented in rapid succession, perception of the second target is deteriorated if the temporal lag between the two targets is short (0,300 ms). This ,attentional blink' (AB) phenomenon has been believed to occur only when the second target is followed by a backward mask or when there is a task switching between two targets. The present study revealed another determining factor for the occurrence of the AB, the presence or absence of a distractor stream. Five experiments examined the effect of possible confounding factors in the extant literature and suggested that the mere presence of a distractor stream affects the processing of targets even when the observers tried to ignore them, resulting in a processing delay. This effect is discussed in a model of AB deficit in terms of decay of the second target's representation. [source] Critical analysis of potential body temperature confounders on neurochemical endpoints caused by direct dosing and maternal separation in neonatal mice: a study of bioallethrin and deltamethrin interactions with temperature on brain muscarinic receptorsJOURNAL OF APPLIED TOXICOLOGY, Issue 1 2003Jürgen Pauluhn Abstract The present investigation was conducted to understand better possible confounding factors caused by direct dosing of neonatal mice during the pre-weaning developmental period. By direct dosing, pups might encounter thermal challenges when temporarily removed from their ,natural habitat'. Typically, this leads to a cold environment and food deprivation (impaired lactation) and modulation of the toxic potency of the substance administered. Growth retardation as a consequence of such behavioural changes in pups makes it increasingly difficult to differentiate specific from non-specific mechanisms. Neonatal NMRI mice were dosed daily by gavage (0.7 mg kg,1 body wt.) from postnatal day (PND) 10,16 with S -bioallethrin, deltamethrin or the vehicle. Then the pups, including their non-treated foster dams, were subjected temporarily for 6 h day to a hypo-, normo- or hyperthermic environment, which was followed by normal housing. The measured temperatures in the environmental chambers were ca. 21, 25 and 30°C, respectively. Thus, temperatures in the hypo- and normothermic groups are comparable to the temperatures commonly present in testing laboratories, whereas the hyperthermic condition is that temperature typically present in the ,natural habitat' of pups. A deviation from the normal behaviour of both pups and dams was observed in the hypo- and normothermic groups. In these groups the rectal temperatures of pups were markedly decreased, especially in the early phase of the study (PND 10,12). Neonates that received either test substance displayed changes in body weights and brain weights at terminal sacrifice (PND 17) when subjected temporarily to a non-physiological environment. An enormous influence of environmental temperature on the density of muscarinic receptors in the crude synaptosomal fraction of the cerebral cortex was ascertained. In summary, these results demonstrate that the direct dosing of thermolabile neonatal mice by gavage is subject to significant artefacts that render the interpretation of findings from such studies difficult. It appears that if direct dosing of neonatal pups is mandated, and inhalation is a relevant route of exposure, the combined inhalation exposure of dams with their litters is an alternative procedure that does not cause disruption of the ,natural habitat' of pups. However, owing to their higher ventilation, under such conditions the pups may receive dosages at least double those of the dams. Copyright © 2003 John Wiley & Sons, Ltd. [source] Relationship between smoking status and periodontal conditions: findings from national databases in JapanJOURNAL OF PERIODONTAL RESEARCH, Issue 6 2006M. Ojima Background and Objective:, The association between cigarette smoking and periodontitis was examined employing two nationally representative samples of adults in Japan. Material and Methods:, Data were derived from the Survey of Dental Diseases (SDD) and the National Nutrition Survey (NNS) in 1999. In the SDD, periodontal conditions were evaluated by calibrated dentists utilizing the Community Periodontal Index (CPI), whereas in the NNS, participants were interviewed on the basis of smoking status by enumerators. Among 6805 records electronically linked via a household identification code, 4828 records of individuals aged 20 yr or older were analyzed. Results:, The prevalence of periodontal disease varied significantly by smoking status (p < 0.0001): 39.3%, 49.5% and 47.3% (CPI , 3), and 7.9%, 11.7% and 12.4% (a more severe form of periodontitis, CPI = 4), for nonsmokers, former smokers and current smokers, respectively. In adults aged ,,40 yr (n = 3493), logistic regression models revealed greater probabilities (approximately 1.4 times higher) of periodontitis [CPI , 3, odds ratio = 1.38 (1.12,1.71), p = 0.0024] and a more severe form of periodontitis [odds ratio = 1.40 (1.04,1.89), p = 0.0288] in current smokers compared with nonsmokers, following adjustment for possible confounding factors. Conclusion:, Based on the findings of this study and other numerous reports, cigarette smoking leads to deterioration of periodontal conditions in Japanese adults. [source] Detrusor overactivity and urge urinary incontinence following trans obturator versus midurethral slingsNEUROUROLOGY AND URODYNAMICS, Issue 1 2007Sylvia M. Botros Abstract Aims To compare the rates of resolution of detrusor overactivity (DO) and subjective urge urinary incontinence (UUI) as well as de novo DO and UUI between the Monarc, TVT, and SPARC midurethral sling procedures. Methods Two hundred and seventy-six subjects with urodynamic stress or mixed urinary incontinence underwent retropubic midurethral slings (TVT, N,=,99; SPARC, N,=,52) or transobturator slings (Monarc, N,=,125). All evaluable subjects had a routine office evaluation, subjective assessment of UUI, and multichannel urodynamic testing pre- and 3 months postoperatively. Comparisons were made using Student's t -test, ANOVA, McNemar's test, and Chi-Square test where appropriate. Multivariate logistic regression was performed to detect possible confounding factors such as sling type, and differences in concomitant surgical procedures. Results De novo subjective UUI differed significantly between the Monarc and the other two slings (33% TVT vs. 8% Monarc vs. 17% SPARC, P,=,0.04). Fourteen to Sixteen percents of patients with preoperative UUI who underwent TVT or SPARC had worsening of their UUI symptoms while only 6% of the Monarc group did (P,=,0.02). There was no difference in rates of resolution of DO among the three groups (40% vs. 48% vs. 32%, P,=,0.39) or de novo DO (32% vs. 22% vs. 22%, P,=,0.64) at 3 months. Conclusions Patients who undergo transobturator procedures have significantly lower rates of de novo UUI than those who undergo midurethral sling procedures. Rates of resolution of DO, UUI, and de novo DO do not differ between groups. Neurourol. Urodynam. © 2006 Wiley-Liss, Inc. [source] The Effect of Acute Psychological Stress on QT Dispersion in Patients with Coronary Artery DiseasePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2009MUSTAFA HASSAN M.D. Background: An acute psychological stress can precipitate ventricular arrhythmias and sudden cardiac death in patients with coronary artery disease (CAD). However, the physiologic mechanisms by which these effects occur are not entirely clear. Mental stress-induced myocardial ischemia occurs in a significant percentage of the CAD population. It is unknown if the proarrhythmic effects of psychological stress are mediated through the development of myocardial ischemia. Objectives: To examine the effects of psychological stress on QT dispersion (QTd) among CAD patients and whether these effects are mediated via the development of myocardial ischemia. Methods: Psychological stress was induced using a public speaking task. Twelve-lead electrocardiograms (ECG) were recorded at rest, during mental stress, and during recovery. QTd was calculated as the difference between the longest and the shortest QT interval in the 12-lead ECG. Rest-stress myocardial perfusion imaging was also performed to detect mental stress-induced myocardial ischemia. Results: Mental stress induced a significant increase in QTd compared to the resting condition (P < 0.001). This effect persisted beyond the first 10 minutes of recovery (P < 0.001). QTd was significantly associated with the development of mental stress ischemia with ischemic patients having significantly higher QTd during mental stress than nonischemic patients (P = 0.006). This finding remained significant after controlling for possible confounding factors (P = 0.01). Conclusion: An acute psychological stress induces a significant increase in QTd, which persists for more than 10 minutes after the cessation of the stressor. This effect seems to be, at least partially, mediated by the development of mental stress-induced myocardial ischemia. [source] Selective serotonin reuptake inhibitor-induced urinary incontinencePHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 4 2002K. L. L. Movig Abstract Purpose Irrespective of its cause, urinary incontinence is a medical condition seriously affecting quality of life and is increasingly recognized. In this study, we examined the association between the use of selective serotonin reuptake inhibitors (SSRIs) and urinary incontinence. Methods A retrospective follow-up study among starters with an SSRI was performed to estimate the relative and absolute risk for urinary incontinence associated with SSRI use. Data came from the PHARMO database, which includes information on drug dispensing for approximately 450,000 residents living in eight Dutch cities. All patients initially using an SSRI between 1994 and 1998 were selected. The frequency measures for urinary incontinence were estimated by using prescription sequence analysis, where initiation of spasmolytic drugs or absorbent products was used as a measure for urinary incontinence. Besides crude incidence density calculations, Andersen,Gill's model was used in order to control for possible confounding factors and time varying covariates. Results A total of 13,531 were identified as first time users of an SSRI. Compared to non-exposure, the incidence density ratio for urinary incontinence during SSRI exposure was 1.75 (95% CI 1.56,1.97). Overall, compared to baseline, SSRI use caused 14 extra cases of urinary incontinence per 1000 patients treated per year; the elderly were more at risk resulting in 60 extra cases per 1000 patients per year. The adjusted relative risk for urinary incontinence due to SSRI use was 1.61 (95% CI 1.42,1.82); the risk for sertraline users was 2.76; 95% CI 1.47,5.21. Conclusions Exposure to SSRIs is associated with an increased risk for developing urinary incontinence, which can be explaned pharmacologically. Approximately 15 out of 1000 patients treated per year with an SSRI developed urinary incontinence. The elderly and users of sertraline are at the highest risk. Copyright © 2002 John Wiley & Sons, Ltd. [source] Risk factors for suicide following hospital discharge among cancer patientsPSYCHO-ONCOLOGY, Issue 10 2009Herng-Ching Lin Abstract Objectives: This study aims to examine risk factors associated with 3-month post-discharge suicide among cancer patients using Taiwan's nationwide, population-based datasets. Methods: The study cohort comprised all cancer patients discharged from hospitals from 2002 to 2004, inclusive, who committed suicide within 90 days of discharge (n=311). The control group consisted of 1555 cancer patients who did not commit suicide within 90 days of discharge. The dependent variable was whether or not a patient committed suicide within 90 days of discharge, while the independent variables included patient, hospital and physician characteristics at index hospitalization. Cox proportional hazard regression was carried out to compute the 90-day survival rate, adjusting for possible confounding factors. Results: The mean interval from discharge to suicide was 39.7 days (±95.2) and almost half (46.3%) of the 3-month post-discharge suicides occurred within 14 days after discharge. The adjusted hazard of committing suicide for patients who were not hospitalized in the preceding year was 1.68 (p=0.009), 1.61 (p=0.033), and 2.51 (p<0.001) times greater, respectively, than patients who were hospitalized once, twice and more than twice within the year before index hospitalization. The hazard of committing suicide among patients who were unemployed was 1.71 (p<0.001) times that of their employed counterparts. Conclusions: We conclude that, while our study was limited to suicides among cancer patients within 90 days of discharge, around 60% of deaths occurred within the first month after discharge. The relevant risk factors include the number of hospitalizations within 1 year and employment status. Copyright © 2009 John Wiley & Sons, Ltd. [source] URBAN,RURAL DIFFERENCES IN THE MANAGEMENT OF SCREEN-DETECTED INVASIVE BREAST CANCER AND DUCTAL CARCINOMA IN SITU IN VICTORIAANZ JOURNAL OF SURGERY, Issue 11 2006David L. Kok Background: At least one-third of primary breast cancers in Australia are discovered by population-based mammographic screening. The aim of this study was to determine whether there were any differences in the surgical treatment of women diagnosed with breast cancer by BreastScreen Victoria between urban and rural populations and to investigate temporal changes in their pattern of care. Methods: An analysis of women diagnosed with breast cancer (invasive and non-invasive) by BreastScreen Victoria from 1993 to 2000 was conducted. Descriptive analyses of the proportion of women undergoing each surgical treatment type over time were carried out. Logistic regression was used to assess the effect of urban,rural residence on each treatment outcome while accounting for possible confounding factors. Results: Rural women with invasive breast cancer were less likely to undergo breast-conserving surgery (BCS) compared with urban women (odds ratio, 0.42; 95% confidence interval, 0.35,0.50). The same was also true for rural women with ductal carcinoma in situ (odds ratio, 0.53; 95% confidence interval, 0.29,0.96). This difference was independent of patient and tumour characteristics, including tumour size, surgeon caseload, patient's age and socioeconomic status. It also persisted over time despite a steady overall increase in use of BCS for both invasive and non-invasive cancers over the study period. Conclusions: Among Victorian women with screen-detected breast cancer, urban women consistently had higher rates of BCS compared with rural women despite increased overall adoption of BCS. Reasons for this disparity are still unclear and warrant further investigation. [source] Smoking and pregnancy-related pelvic painBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 8 2010K Biering Please cite this paper as: Biering K, Aagaard Nohr E, Olsen J, Hjollund N, Nybo Andersen A-M, Juhl M. Smoking and pregnancy-related pelvic pain. BJOG 2010;117:1019,1026. Objective, To investigate possible associations between smoking and pregnancy-related pelvic pain. Design, Nested case,control study. Setting, Denmark 2000,2001. Population, The Danish National Birth Cohort. Methods, The women were interviewed twice in pregnancy and twice after childbirth. The first pregnancy interview provided information on smoking and possible confounding factors, whereas the first interview after birth addressed case identification. Cases (n = 2302) were defined on the basis of self-reported pelvic pain, and controls were selected among women who did not report pelvic pain (n = 2692). Logistic regression analysis was used to estimate associations between smoking and pelvic pain. Main outcome mreasue, Pregnancy-related pelvic pain. Results, Compared with non-smokers, women who smoked during pregnancy had an adjusted odds ratio of 1.2 (1.0,1.4) for overall pelvic pain, similar to women who stopped smoking in early pregnancy 1.3 (1.1,1.7). The equivalent adjusted odds ratio for severe pelvic pain was 1.2 (1.0,1.5) for smokers, and 1.5 (1.2,1.9) for women who stopped smoking. Smoking intensity, measured as number of cigarettes smoked per day, was associated with pelvic pain in a dose,response pattern. Information about smoking was collected prospectively, which makes it unlikely that differential recall alone explains the results. Conclusions, Smoking was associated with pregnancy-related pelvic pain, with a dose,response pattern between reported smoking intensity and pelvic pain. These findings suggest a possible new risk factor for a common ailment during pregnancy. [source] | ||||||||||