Biomedical subjects

Antonella Zambon

Publications and source records attributed to Antonella Zambon.

11 recordsLinked to original sources

PubMed2006

Exploring the effect of transient exposure on the risk of acute events by means of time-window designs: an application to fluoroquinolone antibacterials and arrhythmia.

PURPOSE: To compare different strategies in allocating time-window at risk and in choosing optimal comparator in the setting of proarrhythmic effects of antibacterial fluoroquinolones. DESIGN: A population-based cohort study. SETTING: Resident population of a Northern Italian Province. PARTICIPANTS: The study cohort comprised 75 226 patients who received at least one prescription for fluoroquinolone from 1997 to 1999. Cohort members who experienced at least an antiarrhythmic drug prescription and/or hospitalisation with diagnosis of arrhythmia during the follow-up were identified. ANALYSIS: Trends in incidence rates of arrhythmia according to different strategies in allocating time-windows at risk were calculated. Standardised incidence ratios were obtained by comparing arrhythmic events experienced by the study cohort during the time-windows at risk with those expected from both external (unexposed target population) and internal (study cohort during reference time-windows) comparators. RESULTS: The rate of arrhythmia was 21.0 per 100 000 person-weeks during the in-treatment period, remained stable during the following week, and progressively decreased until to converge to 7.7 per 100 000 person-weeks from 16th weeks after stop of exposure. Standardised incidence ratios were 2.35 (95%CI: 1.82, 2.99) and 1.86 (1.44, 2.37) according to external and internal comparators respectively. Evidence of linear increasing of proarrhythmic effect with the length of the antibacterial therapy appeared from every approaches, but it was stronger by using internal comparator. CONCLUSIONS: Time-windows designs should be performed by allocating the time-windows at risk and comparing outcome events observed in the cohort during these periods with those experienced by the same cohort during an adequate reference period.

Anti-Bacterial Agents↗

PubMed2006

Evidence of tendinitis provoked by fluoroquinolone treatment: a case-control study.

OBJECTIVE: To investigate the association between the use of fluoroquinolone agents and the risk of tendinitis in a large population-based case-control study. METHODS: The study was performed by linking automated health databases from the Region of Lombardia, Italy. Cases were patients aged > or =18 years who had a hospital discharge diagnosis of non-traumatic tendinitis in 2002-3. For each case, up to five controls were randomly selected among those eligible for inclusion in the study. A conditional logistic regression model was used to estimate the odds ratio of tendinitis associated with the current, recent and past use of fluoroquinolones. Odds ratios were adjusted for exposure to other antibacterials and other drugs. RESULTS: 22,194 cases and 104,906 controls met the inclusion criteria. Current use of fluoroquinolones significantly increased the risk of tendon disorders as a whole (odds ratio [OR] = 1.7; 95% CI 1.4, 2.0), tendon rupture (OR = 1.3; 95% CI 1.0, 1.8) and rupture of the Achilles' tendon (OR = 4.1; 95% CI 1.8, 9.6). Concomitant use of corticosteroids and fluoroquinolones increased the risk of both tendon rupture (OR = 3.1; 95% CI 1.5, 6.3) and rupture of the Achilles' tendon (OR = 43.2; 95% CI 5.5, 341.1). DISCUSSION: Evidence that exposure to fluoroquinolones is associated with the sudden occurrence of tendinitis is supported by this large population-based study. We can estimate that a single case of rupture of the Achilles' tendon would occur for every 5958 persons treated with fluoroquinolones (95% CI 2148, 23,085). The corresponding number needed to harm is 979 (95% CI 122, 9172) for patients who concomitantly use corticosteroids and 1638 (95% CI 351, 8843) for those aged >60 years. CONCLUSION: Clinicians should be aware of this adverse effect, and the increased risk for fluoroquinolone-associated tendinitis in elderly patients with corticosteroid use must be considered when these agents are prescribed.

Achilles Tendon↗

PubMed2005

Estimating dose-response relationship between ethanol and risk of cancer using regression spline models.

Cancers of the upper aero-digestive tract (i.e., oral cavity, pharynx, larynx and oesophagus) are largely attributable to smoking and drinking habits, but the correct estimation of the dose-response relationship between alcohol and cancer risk is challenging. Step functions are widely used to estimate risks and to evaluate trends of continuous exposure. However, results are influenced by the selection of the reference category and cutpoints. More flexible models, like spline regression and fractional polynomial models, may be an attractive alternative for avoiding strict assumptions about the dose-response relationship. Data from a large series of hospital-based case-control studies conducted in Italy and the Swiss Canton of Vaud in the last 2 decades were reassessed to compare findings from logistic regression spline models and standard step function analysis. For all examined cancers, the risk increased to the consumption of 150 grams of ethanol per day (1.5 litre/day of wine), with a possible threshold effect emerging for cancer of the pharynx and larynx (<50 grams of ethanol per day) only. For higher consumptions, the risks flattened. Our study suggests that regression spline models can be useful to estimate the pattern of risk of a continuous exposure variable, such as alcohol consumption, and provide more accurate estimates than categorical analysis when ORs within each interval, especially in the reference category, are not homogeneous.

Adult↗

PubMed2005

Generating signals of drug-adverse effects from prescription databases and application to the risk of arrhythmia associated with antibacterials.

BACKGROUND: Although it is well known that a variety of antibacterials may incidentally cause malignant arrhythmia, the list of drugs causing arrhythmia and the impact of these adverse effects are still uncertain. We investigated on this topic by using a large prescription database with different observational designs. METHODS: Prescription data on all incident users of several antibacterial and antiarrhythmic drugs over the period July 1997 through December 1999 were retrieved from the Drug Prescription Database (DPD) of the Italian Province of Varese. The association between the use of antibacterial and antiarrhythmic drugs was investigated by applying prescription sequence symmetry, cohort and nested case-control designs. RESULTS: Lower proarrhythmic effects were on an average obtained from prescription sequence symmetry approach with respect to both cohort and nested case-control. Evidence of association between exposure to drugs (erythromycin and ciprofloxacin) and the risk of arrhythmia was consistently found by the three approaches. No other signals were generated from the prescription sequence symmetry analysis. Two drugs (clarithromycin and levofloxacin) showed patterns compatible with an arrhythmic effect according to both cohort and nested case-control designs. CONCLUSIONS: Prescription databases are useful tools to explore drug safety through both conventional and emerging observational designs. In spite of its appealing features, prescription sequence symmetry design shows lower sensitivity with respect to conventional designs. Evidence about the association between the use of certain macrolides and fluoroquinolones and the onset of arrhythmia is confirmed by this study.

Adverse Drug Reaction Reporting Systems↗

PubMed2005

Short-acting inhaled beta-2-agonists increased the mortality from chronic obstructive pulmonary disease in observational designs.

OBJECTIVE: The effect of short-acting inhaled beta(2)-agonists on mortality from chronic obstructive pulmonary disease (COPD) is controversial. Different observational designs were used to investigate about this topic. STUDY DESIGN AND SETTING: A population-based case-control design was performed, by linking automated health databases from the Varese Province of Italy. Deaths of COPD generated from the cohort of 135,871 patients for whom at least one prescription for drugs used to treat COPD had been dispensed between 1997 and 1999 entered into the study as cases. Up to 20 controls were randomly selected for each case from the cohort after matching on gender, age, and date of cohort entry. Risk ratios were estimated using the case-control, case-crossover, and case-time-control approaches. RESULTS: A total of 222 cases and 3022 controls met the inclusion criteria. Odds ratios (and corresponding 95% confidence intervals) corresponding to more than 0.5 defined-daily-doses were 2.6 (1.7, 4.0), 1.9 (1.1, 3.3), 2.1 (1.1, 4.0), and 2.3 (1.2, 4.6) by using crude and adjusted case-control, case-crossover, and case-time-control estimates, respectively. CONCLUSION: Evidence that higher doses of short-acting inhaled beta(2)-agonists are associated with higher mortality from COPD was consistently supplied by three observational approaches.

Adrenergic beta-Agonists↗

PubMed2004

Flexible meta-regression functions for modeling aggregate dose-response data, with an application to alcohol and mortality.

In this paper, the authors describe fractional polynomials and cubic splines with which to represent smooth dose-response relations in summarizing meta-analytical aggregate data. Use of these two curve-fitting families can help prevent the problems arising from inappropriate linearity assumptions. These methods are illustrated in the problem of estimating the shape of the dose-response curve between alcohol consumption and all-cause mortality risk. The authors considered aggregate data from 29 cohort studies investigating this issue (1966-2000). J-shaped curves with a nadir at approximately 5-7 g/day of alcohol consumption and a last protective dose of 47-60 g/day were consistently obtained from fractional polynomials and cubic splines. The authors conclude that both of the curve-fitting families are useful tools with which to explore dose-response epidemiologic questions by means of meta-analytical approaches, especially when important nonlinearity is anticipated.

Alcohol Drinking↗

PubMed2004

Genetic risk factor characterizes abdominal aortic aneurysm from arterial occlusive disease in human beings: CCR5 Delta 32 deletion.

OBJECTIVE: Inflammation is involved in the pathogenesis of atherosclerosis and abdominal aortic aneurysm (AAA), and chemokines are mediators of the inflammatory process. The homozygous Delta 32 deletion mutation of the gene of the chemokine receptor CCR5 is a cause of its lack in inflammatory cells. The purpose of this study was to investigate the relationship between CCR5 Delta 32 deletion mutation and AAA, peripheral arterial occlusive disease (PAOD), and carotid stenosis. METHODS: The CCR5 Delta 32 polymorphism was genotyped in 380 subjects: 70 patients operated on to treat AAA (21 ruptured AAAs, 49 elective repair), 76 patients with PAOD, 62 patients with carotid stenosis, and 172 age-matched and sex-matched healthy control subjects. Risk factors for AAA were considered. Each patient was assessed according to a diagnostic procedure tailored to symptoms at presentation. RESULTS: In patients with AAA the Delta allelic variation was significantly different compared with control subjects (P = .002; odds ratio [OR], 2.7; 95% confidence interval [CI], 1.41-5.15). The increased presence of this allele differentiates AAA from both PAOD (P = .017; OR, 2.77; 95% CI, 1.17-6.52) and carotid stenosis (P = .01; OR, 3.47; 95% CI, 1.31-9.11). The presence in the genotype of patients with AAA of at least 1 Delta 32 allele is more frequent in ruptured AAAs than in electively repaired AAAs (genotype: OR, 4.04; 95% CI, 1.34-12.1; P = .011; allelic frequency: OR, 2.75; 95% CI, 1.07-7.07; P = .035). Among the patients, multiple regression analysis showed that the Delta 32 allele is an independent risk factor for AAA vs PAOD (OR, 3.13; 95% CI, 1.33-7.33; P = .012) and for ruptured AAAs vs electively repaired AAAs (OR, 3.52; 95% CI, 1.01-11.80; P = .045). CONCLUSIONS: CCR5 Delta 32 deletion mutation is significantly more frequent in patients with AAA than in control subjects and in both patients with PAOD and carotid stenosis, and could be a factor that differentiates AAA from PAOD, and ruptured AAAs from AAAs that can be electively repaired. CLINICAL RELEVANCE: The major threat of abdominal aortic aneurysm (AAA) is rupture, accounting for extremely high mortality. This occurrence has been correlated to aneurysm size, but it is a common observation that small AAAs can rupture and large AAAs can remain stable for many years. This study was carried out in an attempt to search for genetic markers of aneurysm rupture. Some single nucleotide polymorphisms are implicated in acceleration of transcription for enzymes involved in the inflammatory process and in extracellular matrix remodeling. An association between single nucleotide polymorphisms and aneurysm rupture could enable better selection for surgical indications in patients with small AAs and in patients at poor risk with large AAAs.

Aged↗

PubMed2004

A meta-analysis of alcohol consumption and the risk of 15 diseases.

BACKGROUND: To compare the strength of evidence provided by the epidemiological literature on the association between alcohol consumption and the risk of 14 major alcohol-related neoplasms and non-neoplastic diseases, plus injuries. METHODS: A search of the epidemiological literature from 1966 to 1998 was performed by several bibliographic databases. Meta-regression models were fitted considering fixed and random effect models and linear and nonlinear effects of alcohol intake. The effects of some characteristics of the studies, including an index of their quality, were considered. RESULTS: Of the 561 initially reviewed studies, 156 were selected for meta-analysis because of their a priori defined higher quality, including a total of 116,702 subjects. Strong trends in risk were observed for cancers of the oral cavity, esophagus and larynx, hypertension, liver cirrhosis, chronic pancreatitis, and injuries and violence. Less strong direct relations were observed for cancers of the colon, rectum, liver, and breast. For all these conditions, significant increased risks were also found for ethanol intake of 25 g per day. Threshold values were observed for ischemic and hemorrhagic strokes. For coronary heart disease, a J-shaped relation was observed with a minimum relative risk of 0.80 at 20 g/day, a significant protective effect up to 72 g/day, and a significant increased risk at 89 g/day. No clear relation was observed for gastroduodenal ulcer. CONCLUSIONS: This meta-analysis shows no evidence of a threshold effect for both neoplasms and several non-neoplastic diseases. J-shaped relations were observed only for coronary heart disease.

Alcohol Drinking↗

PubMed2004

Nutrient intakes, nutritional patterns and the risk of liver cirrhosis: an explorative case-control study.

Several experimental studies have suggested that specific nutrients might play a role on the risk of liver damage. Nevertheless, few epidemiological studies have evaluated the role of diet on the risk of symptomatic liver cirrhosis, giving contradictory results. To evaluate the role of the intake of nutritional factors and dietary patterns on the risk of symptomatic liver cirrhosis and to examine their combined action with alcohol consumption we used data from the Italian Study on Liver Cirrhosis Determinants project. From 1994 to 1998 all the consecutive cirrhotic inpatients admitted to 19 Italian collaborative hospitals for signs of liver decompensation in whom the diagnosis of liver cirrhosis was made for the first time (259 cases) and one or two gender, age and area of residence matched individuals (416 controls) were recruited. Data on lifetime alcohol intake, usual consumption of 191 food items and on markers of hepatitis B and C viral infection were collected. The analysis of principal components identified a nutritional pattern positively correlated with vegetable and fruit intakes and negatively with animal and no-fruit sugar products. With respect to abstainers, relative risks in consumers of use < or = 25 and > or = 51 g/day of alcohol increased from 0.4 [95% confidence interval 0.0, 5.9] to 9.3 [1.3, 69.0] and from 2.1 [1.1, 4.2] to 18.1 [2.8, 118.3] for the lowest and the highest value of this nutritional pattern, respectively. Diet might therefore modulate the damaging effect of alcohol on the liver.

Adult↗

PubMed2004

Lipid lowering drugs prescription and the risk of peripheral neuropathy: an exploratory case-control study using automated databases.

STUDY OBJECTIVE: Although lipid lowering drugs are effective in preventing morbidity and mortality from cardiovascular events, the extent of their adverse effects is not clear. This study explored the association between prescription of lipid lowering drugs and the risk of peripheral neuropathy. DESIGN: A population based case-control study was carried out by linkage of several automated databases. SETTING: Resident population of a northern Italian Province aged 40 years or more. PARTICIPANTS: Cases were patients discharged for peripheral neuropathy in 1998-1999. For each case up to 20 controls were randomly selected among those eligible. Altogether 2040 case patients and 36 041 controls were included in the study. Exposure ascertainment: Prescription drug database was used to assess exposure to lipid lowering drugs at any time in the one year period preceding the index date. ANALYSIS: Conditional logistic regression model for matched data was used to estimate the risk of peripheral neuropathy associated with exposure to statins, fibrates, and other lipid lowering drugs. MAIN RESULTS: Weak but significant effects of lipid lowering drugs as a whole (matched odds ratio: 1.27; 95% confidence intervals: 1.05 to 1.55), statins (1.19; 1.00 to 1.40), and fibrates (1.49; 1.03 to 2.17) were observed. Significant linear trends towards increased risk at increased exposure to both statins and fibrates were observed. CONCLUSIONS: The use of both statins and fibrates was associated with the risk of peripheral neuropathy. The primary purpose of this exploratory study is signal generation. This requires further investigations to evaluate the causal role of lipid lowering drugs on the onset of peripheral neuropathy.

Adult↗

PubMed2002

Alcohol-attributable and alcohol-preventable mortality in Italy. A balance in 1983 and 1996.

BACKGROUND: Since the mid-1970s, a striking reduction in alcohol consumption has been observed in Italy and other developed countries. Alcohol-related mortality in Italy has been estimated for 1983 and 1996. METHODS: Alcohol-attributable and alcohol-preventable deaths were estimated by: i) data on prevalence of drinkers from two Italian surveys; ii) the parameters of meta-regression models investigating the relationship between alcohol intake and the risk of several conditions positively and negatively related to alcohol; and iii) the number of deaths from 21 alcohol-related conditions. RESULTS: About 68,000 and 42,000 deaths were attributed to alcohol consumption in 1983 and in 1996 respectively, mostly from hemorrhagic stroke, liver cirrhosis, cancer, and injuries. About 6,600 deaths from coronary heart disease were prevented by alcohol. Light intake (25 g/day or less) caused about 30% of deaths attributable to any consumption in women. In men, about one-half of the deaths were attributable to the highest category of intake (100 g/day or more), while a lower proportion of deaths was attributed to light intake (almost 7%). In 1996 the number of the deaths caused and those prevented by light intake was approximately the same (5,400 and 5,200 respectively) and did not significantly differ. CONCLUSION: The estimated number of deaths attributable to alcohol consumption in Italy still far exceeds the number prevented for both women and men. Despite the cardiac protective effect, alcohol consumption remains a major public health problem in Italy. Both population and high risk strategies in preventing alcohol-related problems should be implemented.

Alcohol Drinking↗