Calendar Time As An Instrumental Variable In Nonexperimental Comparative Effectiveness Research Of Emerging Therapies

Effect of highly active antiretroviral therapy on incident AIDS using calendar period as an instrumental variable.

Human immunodeficiency virus (HIV) researchers often use calendar periods as an imperfect proxy for highly active antiretroviral therapy (HAART) when estimating the effect of HAART on HIV disease progression. The authors report on 614 HIV-positive homosexual men followed from 1984 to 2007 in 4 US cities. During 5,321 person-years, 268 of 614 men incurred acquired immunodeficiency syndrome, 49 d...

comparative analysis of the use of hedges & emphatics in english and persian academic research articles of sociology & psychology

چکیده ندارد.

Propensity Score Estimation to Address Calendar Time-Specific Channeling in Comparative Effectiveness Research of Second Generation Antipsychotics

BACKGROUND Channeling occurs when a medication and its potential comparators are selectively prescribed based on differences in underlying patient characteristics. Drug safety advisories can provide new information regarding the relative safety or effectiveness of a drug product which might increase selective prescribing. In particular, when reported adverse effects vary among drugs within a th...

Nonexperimental Quantitative Research

Mendelian randomization as an instrumental variable approach to causal inference.

In epidemiological research, the causal effect of a modifiable phenotype or exposure on a disease is often of public health interest. Randomized controlled trials to investigate this effect are not always possible and inferences based on observational data can be confounded. However, if we know of a gene closely linked to the phenotype without direct effect on the disease, it can often be reaso...