Biomedical subjects

F E Tan

Publications and source records attributed to F E Tan.

8 recordsLinked to original sources

PubMed2001

Are coffee and tea consumption associated with urinary tract cancer risk? A systematic review and meta-analysis.

BACKGROUND: Narrative reviews have concluded that there is a small association between coffee consumption and an increased risk of urinary tract cancer, possibly due to confounding by smoking. No association for tea consumption has been indicated. This systematic review attempts to summarize and quantify these associations both unadjusted and adjusted for age, smoking and sex. METHOD: Thirty-four case-control and three follow-up studies were included in this systematic review. Summary odds ratios (OR) were calculated by meta-regression analyses. RESULTS: The unadjusted summary OR indicated a small increased risk of urinary tract cancer for current coffee consumers versus non-drinkers. The adjusted summary OR were: 1.26 (95% CI : 1.09-1.46) for studies with only men, 1.08 (95% CI : 0.79-1.46) for studies with only women and 1.18 (95% CI : 1.01-1.38) for studies with men and women combined. Neither unadjusted nor adjusted summary OR provided evidence for a positive association between tea consumption and urinary tract cancer. Even though studies differed in methodology, the results were rather consistent. We did not perform dose-response analyses for coffee and tea consumption due to sparse data. CONCLUSIONS: In accordance with earlier reviews, we found that coffee consumption increases the risk of urinary tract cancer by approximately 20%. The consumption of tea seems not to be related to an increased risk of urinary tract cancer.

Age Factors↗

PubMed2001

Local influence to detect influential data structures for generalized linear mixed models.

This article discusses the generalization of the local influence measures for normally distributed responses to local influence measures for generalized linear models with random effects. For these models, it is shown that the subject-oriented influence measure is a special case of the proposed observation-oriented influence measure. A two-step diagnostic procedure is proposed. The first step is to search for influential subjects. A search for influential observations is proposed as the second step. An illustration of a two-treatment, multiple-period crossover trial demonstrates the practical importance of the detection of influential observations in addition to the detection of influential subjects.

Aspartame↗

PubMed2001

An asymptotically unbiased estimator of exposed versus non-exposed odds ratio from reported dose-response data.

Summary effect measures in meta-analysis of published epidemiological cohort or case control studies are often based on odds ratios reported for several exposure levels with varying arrangements and number of levels across primary studies. Usually only two-way contingency tables together with exposure specific adjusted odds ratios and corresponding standard errors are presented in articles. An asymptotically unbiased estimate of exposed versus non-exposed adjusted odds ratio from reported dose-response data is proposed. This estimate is based on the weighted sum of the exposure specific odds ratios, with the prevalences of the control group as weights. Large sample variance is derived accounting for the dependency between exposure specific adjusted odds ratios. The exposed versus non-exposed adjusted odds ratio could then be used in systematic reviewing.

Case-Control Studies↗

PubMed2000

The impact of characteristics of cigarette smoking on urinary tract cancer risk: a meta-analysis of epidemiologic studies.

BACKGROUND: Although narrative reviews have concluded that there is strong support for an association between cigarette smoking and urinary tract cancer, the association has never been quantified systematically in reviews. The purpose of this systematic review was to summarize and quantify the impact of different smoking characteristics (status, amount, duration, cessation, and age at first exposure) both unadjusted and adjusted for age and gender. METHODS: The authors included 43 epidemiologic studies (8 cohort and 35 case-control) and calculated summary odds ratios (SORs) by meta-regression analyses for different smoking characteristics. They also evaluated changes in summary estimates according to differences in study methodology. RESULTS: Smoking status and increased amount and duration of smoking were associated with a strong increased risk of urinary tract cancer. Smoking cessation and age at first exposure were negatively associated with the risk of urinary tract cancer. The age- and gender-adjusted SORs for current and former cigarette smokers compared with those for nonsmokers were 3.33 (95% confidence interval [CI], 2.63-4.21) and 1.98 (CI, 1.72-2.29), respectively. Even though the component studies differed in methodology, the results were rather consistent. CONCLUSIONS: The results suggest a substantial increase in risk of cancer of the urinary tract for cigarette smokers. Based on the results of this study and previous literature, the authors conclude that current cigarette smokers have an approximately threefold higher risk of urinary tract cancer than nonsmokers. In Europe, approximately half of urinary tract cancer cases among males and one-third of cases among females might be attributable to cigarette smoking.

Adult↗

PubMed1999

Elevated risk of cancer of the urinary tract for alcohol drinkers: a meta-analysis.

OBJECTIVES: Recent narrative reviews have concluded that there is no support for an association between alcohol consumption and urinary tract cancer. Many individual studies, however, have reported positive associations, although rarely statistically significant. The purpose of this meta-analysis is to summarize and quantify this relationship with more statistical power and to perform a sensitivity analysis on the study characteristics. METHODS: We included 16 epidemiological studies published up to April 1999 and calculated summary odds ratios (SORs), both upgraded and adjusted for age, sex and smoking by meta-regression analyses. The age- and smoking-adjusted SORs (current alcohol drinking vs. non-drinking) were 1.3 (95% CI 0.9-2.0) for six studies with men and 1.0 (95% CI 0.4-2.6) for four studies with women. RESULTS: The age-, sex- and smoking-adjusted SOR was 1.2 (95% CI 0.9-1.7) for seven studies with men and women combined. CONCLUSION: Even though studies differed in methodology, the results were rather consistent. Subgroup analyses by type or amount of alcohol were not possible due to sparse data. We conclude that the available data suggest a slightly increased risk of urinary tract cancer from alcohol consumption for men. The risk related to alcohol consumption for women and the influence of the amount and type of alcohol remain unclear.

Adult↗

PubMed1999

Multigenerational caregiving and well-being: distress of middle-aged daughters providing assistance to elderly parents.

This article investigates whether being a caregiver of an elderly parent and the caregiver's involvement in multiple roles increases distress in middle-aged women. Previous studies assumed that providing care to frail parents causes distress in women, in particular when they have other social roles as well. Longitudinal data were collected within a cohort of middle-aged women (n = 934; n = 743). The acquisition or loss of the caregiver role did not appear to affect levels of distress of middle-aged women, nor did additional roles of caregivers increase distress levels or caregiver role strain. Most distressed were women not performing any major social role, suggesting that the lack of social roles rather than the multiplicity of roles is associated with distress. The caregiver role might even reduce distress when women have very few other roles. Findings are explained in terms of the role scarcity, the role expansion and role accumulation hypotheses of role theory.

Adult↗

PubMed1995

The endoscope and the radiofrequency unit in DCR surgery.

Endoscopic laser-assisted dacryocystorhinostomy (DCR) offers several advantages over standard external (SE) DCR. The technique eliminates the cutaneous scar and cosmetic blemish of an external dissection and causes less surgical trauma and bleeding than SE-DCR, with shortened postoperative recovery time and lessened postoperative pain. However, the equipment is expensive. We modified this technique using simple instruments such as the curette, Kerrison punch, Freer elevator, Storz endoscope, Ellman Surgitron unit, and the Javate DCR electrodes instead of the laser. Fifty patients with epiphora and nasolacrimal obstruction underwent surgery with our new technique. Fifty age-matched, paired external DCR were performed, and comparisons were made with the endoscopic procedure described. If preoperative epiphora was resolved and nasolacrimal patency was confirmed by lacrimal irrigation 3 months after tube removal, the operation was considered a success. The study attained a 90% success rate for endoscopic radiofrequency-assisted DCR, as compared to a 94% success rate (p > 0.05, not statistically significant) for the SE-DCR.

Adolescent↗

PubMed1987

The reliability of ovulation prediction by a single ultrasonographic follicle measurement.

Since ultrasonographic ovulation detection has been introduced many authors have speculated about the ovulation predictive value of this new technique. Reliable studies in this respect, however, are lacking. The present study describes ultrasonographic data of 158 spontaneously ovulating, infertile patients. Each patient contributed only one cycle to the study. To construct individual follicle growth curves serial follicular measurements were performed. A wide range existed in mean maximum diameters of the preovulatory follicles. Furthermore, the slopes of the follicle growth curves, as well as the durations of the follicle growth phases showed considerable variations. The intrinsic variability in the various characteristics of follicle growth makes a single measurement as accurate as serial measurements in predicting ovulation. A formula has been devised by means of the data of the first 100 women, which correlates follicular diameter with the time interval to ovulation. The formula was developed based on one randomly selected measurement per patient. The validity of the formula has been tested in 58 additional women, also contributing one measurement each. According to this validation the adequacy of the prediction rule was demonstrated. Ultrasound appeared to be a less sensitive method for prediction of ovulation than has been speculated by some investigators. It is, however, an improvement, compared to the prediction of ovulation based upon the length of the previous menstrual cycles. A single follicle measurement may therefore be helpful in timing post-coital tests or artificial inseminations, in addition to being an adjuvant to more reliable methods.

Female↗