Interventional (experimental) studies see if an intervention that purposefully changes some aspect of a subject’s status (e.g. ingesting a drug) affects an outcome (e.g. recovery from disease). To ensure interventional studies are valid, randomization and blinding is often utilised, with randomized control trials (RCTs) being the gold-standard of clinical trials: Random allocation: Subjects are randomly allocated to different treatment groups so that baseline characteristics of … Continue reading Interventional studies

Primary (or empirical) studies are first-hand investigations based on direct observations and can be broadly classed as interventional or observational. They can be performed on animals as well as humans and also include laboratory studies. Observational studies can be subdivided into analytical (analytic) and descriptive studies while all experimental studies are analytical. Continue reading Primary studies

Evidence-based medicine aims to base clinical decisions on sound research findings. Different types of study design can be ranked in a pyramid based on the quality of evidence they provide. At the top, secondary studies, including clinical practice guidelines and meta-analyses provide the highest quality evidence after filtering and synthesizing the results of primary (emprical) studies. Near the bottom, animal and laboratory studies have flaws … Continue reading Study designs