Outcomes Research

Outcomes research or clinical epidemiology is the study of treatment effectiveness or the success of treatment in the nonrandomized, real-world setting. It allows researchers to gain knowledge from observational data. Bias and confounding can affect researchers’ interpretation of study data, and an accurate assessment of baseline disease status, comorbidities, treatment given, and outcomes of treatment is critical to sound outcomes research. Outcomes can be evaluated in terms of efficacy or effectiveness. Many types of studies are available to evaluate treatment effectiveness and include the randomized trial, observational study, case-control study, case series, and expert opinions. The concept of evidence-based medicine uses the level of evidence presented in the aforementioned studies to grade diagnostic and treatment recommendations. Meta-analyses can summarize findings across multiple studies and provide important insights into the body of literature. Outcomes in clinical epidemiology can be difficult to quantify, and thus instruments measuring these outcomes must meet criteria of the Classical Test Theory (reliability, validity, responsiveness, and burden) or the Item Response Theory to be considered psychometrically valid. Many outcomes instruments have been created, which assess health-related quality of life. These scales are generic or disease specific, including assessment of head and neck cancer, otologic disease, rhinologic disease, pediatric disease, voice disorders, sleep disorders, and facial plastic surgery outcomes.