An increased risk of death or near death from asthma was associated with the regular use of inhaled beta 2-agonist bronchodilators, especially fenoterol. Regardless of whether beta-agonists are directly responsible for these adverse effects or are simply a marker for more severe asthma, heavy use of these agents should alert clinicians that it is necessary to reevaluate the patient's condition.

Some authors argue that systematic reviews and meta-analyses of intervention studies should include only randomized controlled trials because the randomized controlled trial is a more valid study design for causal inference compared with the observational study design. However, a review of the principal elements underlying this claim (randomization removes the chance of confounding, and the double-blind process minimizes biases caused by the placebo effect) suggests that both classes of study designs have strengths and weaknesses, and including information from observational studies may improve the inference based on only randomized controlled trials. Furthermore, a review of empirical studies suggests that meta-analyses based on observational studies generally produce estimates of effect similar to those from meta-analyses based on randomized controlled trials. The authors found that the advantages of including both observational studies and randomized studies in a meta-analysis could outweigh the disadvantages in many situations and that observational studies should not be excluded a priori.

Objective. There is increasing evidence in support of an association between systemic lupus erythematosus (SLE) and malignancy, but in earlier studies the association could not be quantified precisely. The present study was undertaken to ascertain the incidence of cancer in SLE patients, compared with that in the general population.Methods. We assembled a multisite (23 centers) international cohort of patients diagnosed as having SLE. Patients at each center were linked to regional tumor registries to determine cancer occurrence. Standardized incidence ratios (SIRs) were calculated as the ratio of observed to expected cancers. Cancers expected were determined by multiplying person-years in the cohort by the geographically matched age, sex, and calendar year-specific cancer rates, and summing over all person-years.Results. The 9,547 patients from 23 centers were observed for a total of 76,948 patient-years, with an average followup of 8 years. Within the observation interval, 431 cancers occurred. The data confirmed an Dr.

Context Many studies have shown a high prevalence of sexually transmitted diseases, human immunodeficiency virus (HIV) infection, viral hepatitis, drug dependence, and mental health problems among street youth. However, data on mortality among these youth are sparse.Objectives To estimate mortality rate among street youth in Montreal and to identify causes of death and factors increasing the risk of death.Design, Setting, and Population From street youth 14 to 25 years of age were recruited in a prospective cohort with semiannual follow-ups. Original study objectives were to determine the incidence and risk factors for HIV infection in that population; however, several participants died during the first months of follow-up, prompting investigators to add mortality to the study objectives. Mortality data were obtained from the coroner's office and the Institut de la Statistique du Qué bec. Main Outcome MeasuresMortality rate among participants and factors increasing the risk of death.Results Twenty-six youth died during follow-up for a mortality rate of 921 per 100000 person-years (95% confidence interval [CI], 602-1350); this represented a standardized mortality ratio of 11.4. The observed causes of death were as follows: suicide (13), overdose (8), unintentional injury (2), fulminant hepatitis A (1), heart disease (1); 1 was unidentified. In multivariate Cox regression analyses, HIV infection (adjusted hazard ratio [AHR]=5.6; 95% CI, 1.9-16.8), daily alcohol use in the last month (AHR=3.2; 95% CI, 1.3-7.7), homelessness in the last 6 months (AHR=3.0; 95% CI, 1.1-7.6), drug injection in the last 6 months (AHR=2.7; 95% CI, 1.2-6.2), and male sex (AHR=2.6; 95% CI, 0.9-7.7) were identified as independent predictors of mortality.Conclusions Current heavy substance use and homelessness were factors associated with death among street youth. HIV infection was also identified as an important predictor of mortality; however, its role remains to be clarified. These findings should be taken into account when developing interventions to prevent mortality among street youth.