Sean Hennessy

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Medical message boards are online resources where users with a particular condition exchange information, some of which they might not otherwise share with medical providers. Many of these boards contain a large number of posts and contain patient opinions and experiences that would be potentially useful to clinicians and researchers. We present an approach(More)
The use of propensity scores to adjust for measured confounding factors has become increasingly popular in cohort studies. However, their use in case-control and case-cohort studies has received little attention. The authors present some theory on the estimation and use of propensity scores in case-control and case-cohort studies and present the results of(More)
BACKGROUND Recent studies suggest that proton-pump inhibitors (PPIs) may increase the risk for community-acquired pneumonia (CAP). OBJECTIVE To examine the association between PPI use and CAP in adults followed in general practices in the United Kingdom. DESIGN Nested case-control study. SETTING The General Practice Research Database (1987 to 2002) in(More)
BACKGROUND & AIMS Type 2 diabetes mellitus might increase the risk of colorectal cancer on the basis of chronic hyperinsulinemia and hyperglycemia. However, epidemiologic evidence for this association is inconclusive. We conducted a population-based study to clarify this association. METHODS We conducted a case-control study in the United Kingdom General(More)
OBJECTIVE The authors sought to determine whether use of methylphenidate in adults is associated with elevated rates of serious cardiovascular events compared with rates in nonusers. METHOD This was a cohort study of new users of methylphenidate based on administrative data from a five-state Medicaid database and a 14-state commercial insurance database.(More)
OBJECTIVE To evaluate the risk of gastrointestinal and operative site bleeding associated with the use of parenteral ketorolac tromethamine. DESIGN Postmarketing surveillance inception cohort study. SETTING A total of 35 hospitals throughout the Philadelphia, Pa, region, 1991 to 1993. PATIENTS Patients administered 10,272 courses of parenteral(More)
OBJECTIVE To measure the incidence of cancer in patients with psoriasis, stratified by the severity of their disease. DESIGN A cohort study. SETTING Administrative claims records obtained from Medicaid programs in 3 US states. PARTICIPANTS All individuals in the claims database who qualified for 1 of the 5 following groups: severe psoriasis as defined(More)
OBJECTIVE To examine the rates of cardiac arrest and ventricular arrhythmia in patients with treated schizophrenia and in non-schizophrenic controls. DESIGN Cohort study of outpatients using administrative data. SETTING 3 US Medicaid programmes. PARTICIPANTS Patients with schizophrenia treated with clozapine, haloperidol, risperidone, or thioridazine;(More)
OBJECTIVE This study examined adherence, discontinuation, and switching of rheumatoid arthritis (RA) biologics over a 1-year period after initiation of the biologic treatment in Medicaid patients with RA. METHODS The study sample consisted of Medicaid patients with RA in California, Florida and New York who had newly initiated etanercept (n=1359),(More)
OBJECTIVE Rare but potentially life-threatening cutaneous adverse reactions have been associated with allopurinol, but population-based data on the incidence and mortality of such reactions are scarce. METHODS We conducted a propensity score-matched cohort study to evaluate the incidence rate (IR) and in-hospital mortality of hospitalization for severe(More)