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Andrea Benedetti

Publications and source records attributed to Andrea Benedetti.

6 recordsLinked to original sources
PubMed2006

Consumption of alcoholic beverages and risk of lung cancer: results from two case-control studies in Montreal, Canada.

OBJECTIVE: To investigate the association between consumption of alcoholic beverages and lung cancer risk. METHODS: Data were collected in two population-based case-control studies, conducted in Montreal (Study I--mid-1980s and Study II--mid-1990s). Study I included 699 cases and 507 controls, all males; Study II included 1094 cases and 1468 controls, males and females. In each study group (Study I men, Study II men and Study II women) odds ratios (OR) were estimated for the associations between beer, wine or spirits consumption and lung cancer, while carefully adjusting for smoking and other covariates. The reference category included abstainers and occasional drinkers. RESULTS: For Study I men, lung cancer risk increased with the average number of beers/week consumed (for 1-6 beers/week: OR=1.2, 95% confidence interval (CI): 0.9-1.7; for >or=7 beers/week: OR=1.5, 95% CI: 1.1-2.1). For Study II men, beer consumption appeared harmful only among subjects with low fruit and vegetable consumption. In Study II, wine consumers had low lung cancer risk, particularly those reporting 1-6 glasses/week (women: OR=0.3, 95% CI: 0.2-0.4; men: OR=0.6, 95% CI: 0.4-0.8). CONCLUSIONS: Beer consumption increased lung cancer risk, particularly so among men who had relatively low fruit and vegetable consumption. Moderate wine drinkers had decreased lung cancer risk.

Alcohol Drinking↗
PubMed2006

Sleep-disordered breathing in fatigued postpoliomyelitis clinic patients.

OBJECTIVE: To determine the frequency, predictive factors, and symptoms predictive of sleep-disordered breathing (SDB) in fatigued postpoliomyelitis clinic patients. DESIGN: Cross-sectional, retrospective chart review. SETTING: University-affiliated hospital postpolio clinic. PARTICIPANTS: Postpolio clinic charts (N=590) were reviewed. Ninety-eight patients were included, and 492 patients were not included, primarily because of the lack of a polysomnogram. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The Apnea-Hypopnea Index (AHI) calculated as the total number of sleep-related breathing events/total sleep time. RESULTS: The frequency of SDB defined by an AHI score of 5 or more was 65% and by an AHI score of 10 or more was 50%. Obstructive hypopnea was the predominant form, occurring in 86%. Age, sex, age at acute polio, time since polio, weakness and respiratory difficulties at acute polio, bulbar involvement at acute polio and at evaluation, body mass index, pulmonary function measures, alcohol use, sedative drug use, smoking, fibromyalgia, kyphoscoliosis, and scoliosis and ear-nose-throat surgery were not predictive of SDB (AHI scores > or =5 and > or =10). Snoring was more common in subjects with SDB (AHI score > or =5 and > or =10). Some pulmonary function measures correlated with oxygen saturation during sleep in SDB (AHI scores > or =5). CONCLUSIONS: SDB was very common in fatigued postpoliomyelitis clinic patients referred for sleep evaluation. Obstructive hypopnea was the most frequent type. In this preliminary study, snoring tended to predict SDB.

Cross-Sectional Studies↗
PubMed2004

Using generalized additive models to reduce residual confounding.

Traditionally, confounding by continuous variables is controlled by including a linear or categorical term in a regression model. Residual confounding occurs when the effect of the confounder on the outcome is mis-modelled. A continuous representation of a covariate was previously shown to result in a less biased estimate of the adjusted exposure effect than categorization provided the functional form of the covariate-outcome relationship is correctly specified. However, this is rarely known. In contrast to parametric regression, generalized additive models (GAM) fit a smooth dose-response curve to the data, without requiring a priori knowledge of the functional form. We used simulations to compare parametric multiple logistic regression vs its non-parametric GAM extension in their ability to control for a continuous confounder. We also investigated several issues related to the implementation of GAM in this context, including: (i) selecting the degrees of freedom; and (ii) alternative criteria for inclusion/exclusion of the potential confounder and for choosing between parametric and non-parametric representation of its effect. The impact of the shape and strength of the confounder-disease association, sample size, and the correlation between the confounder and exposure were investigated. Simulations showed that when the confounder has a non-linear association with the outcome, compared to a parametric representation, GAM modelling (i) reduced the mean squared error for the adjusted exposure effect; (ii) avoided inflation of the type I error for testing the exposure effect. When the true confounder-outcome relationship was linear, GAM performed as well as the parametric logistic regression. When modelling a continuous exposure non-parametrically, in the presence of a continuous confounder, our results suggest that assuming a linear effect of the confounder and focussing on the non-linearity of the exposure-outcome relationship leads to spurious findings of non-linearity: joint non-linear modelling is necessary. Overall, our results suggest that the use of GAM to reduce residual confounding offers several improvements over conventional parametric modelling.

Confounding Factors, Epidemiologic↗
PubMed2004

Health-related behavior and the use of hormone replacement therapy.

PURPOSE: To study health-related differences between hormone replacement therapy (HRT) users and nonusers among colorectal cases and women without diagnosed cancer. METHODS: Data from the Saskatchewan Health population-based databases were used to ascertain the use of HRT, oral contraceptives (OCs), cardiovascular system (CVS) drugs, central nervous system (CNS) drugs, prescribed NSAIDs and vitamins among 3338 women diagnosed with colorectal cancer and 13025 women without diagnosed cancer. Physician visits and sigmoidoscopy procedures were also determined. RESULTS: Among women without diagnosed cancer, HRT was associated with CVS drugs (OR = 1.23, 95%CI: 1.10-1.37), CNS drugs (OR = 1.96, 95% CI: 1.72-2.23), other hormones (OR = 1.12, 95% CI: 1.01-1.24), prescribed vitamins (OR = 1.37, 95% CI: 1.22-1.55), NSAIDs (OR = 1.41, 95% CI: 1.18-1.68), having had a sigmoidoscopy 3-5 years prior to index dates (OR = 1.33, 95% CI: 1.12-1.59) and 15 or more visits to physicians during the 5th year prior to assigned index date (OR = 2.0, 95% CI: 1.77-2.35). Similar results were observed among women diagnosed with colorectal cancer, but HRT use was not associated with having had a sigmoidoscopy. CONCLUSIONS: Health-related characteristics of HRT users and nonusers are identified and described. Some of these factors may contribute to selection bias in studies examining the health benefits of HRT.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2004

Defining hormone replacement therapy in longitudinal studies: impact on measures of effect.

Data from a nested case-control study, designed to examine the effect of hormone replacement therapy (HRT) on colorectal cancer risk, were analyzed to determine the effect of exposure definition on the estimation of risk ratios (RR). A prescription drug plan database was used to ascertain HRT prescriptions dispensed prior to index dates to cases (n = 3059) and age-matched controls (n = 12,116). HRT exposure was defined as 'prescription' and 'tablet' counts, 'conjugated estrogen only' and a method based on proportions of minimum exposure to a number of estrogens (SUM-P3 and SUM-P12). The effect of HRT was described with reference to 'ever', <5 and > or = 5 years of HRT use. Conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI). Adjusted ORs for 'ever use' of HRT ranged from 0.72 (95%CI: 0.60-0.88) to 0.86 (95%CI: 0.76-0.99); for <5 years use, from 0.70 (95%CI: 0.56-0.88) to 0.89 (95%CI: 0.78-1.01) and for >5 year of HRT use, from 0.74 (95%CI: 0.59-0.92) to 0.98 (95%CI: 0.42-2.26). Various methods used to define HRT exposure produce a range of estimated ORs that vary in magnitude similar to results reported in the literature from observational studies investigating the association between HRT and colorectal cancer.

Aged↗