Many experiments involve subjective measurements or assessments performed by the investigators, as opposed to objective results provided by the experimental system. If the investigator has prior knowledge of the groups to which individuals/samples belong, then investigator bias is a distinct possibility, and this can invalidate any of the findings obtained. In such cases, where the investigator is a factor inherent in the experimental system, it is essential that the investigator is ‘blinded’ to the groups to which individuals or samples belong. Doing so ensures the objectivity of the findings and improves their reliability. Such blinding can refer to treatment in an intervention trial, or to assessment or interpretation of clinical findings in an observational trial. Similarly, the outcome of a treatment could be influenced if a patient knows if they are receiving a placebo or drug; such patient bias should be avoided, by blinding the patient to the nature of the treatment. Being aware of the potential for bias before commencing experimentation can again save the need for time- and resource-consuming repeats.
7.Comply with ethical requirements
There are strict regulations regarding the use of human and animal subjects, and in many countries, regarding the use of stem cells, cell lines and genetically modified materials. Failure to comply with these regulations will prevent publication of your findings and could lead to legal issues; at best, it will limit the range of journals to which you can submit your findings. Make yourself aware of these regulations before you commence your study and ensure that all requirements are complied with so you don’t encounter problems later on. As well as ethical requirements regarding experimentation, there are also strict guidelines provided by most journals regarding the requirements for authorship, and these also need to be complied with. Clinical trials should comply with the Declaration of Helsinki (http://www.wma.net/e/policy/b3.htm) in addition to any local requirements. Informed consent is essential for most trials involving human subjects. Animal studies should comply with local and national regulations, although many journals are now aligning themselves with standards such as the NIH “Guidelines for the Care and Use of Animals” (http://oacu.od.nih.gov/regs/guide/guide.pdf). Finally, many journals require a statement describing who gave ethical approval for the study.
8.Clinical study registration
Many top-tier journals now request that prospective clinical trials involving human participants should be registered online in an accessible database. Many journals will instantly reject studies of this type that have not been registered. More information on this can be found at http://www.icmje.org/faq.pdf. International clinical trial registries include the Chinese Clinical Trials Register (http://www.chictr.org/), the Japanese Primary Registries Network (http://rctportal.niph.go.jp/), The International Standard Randomised Control Trial Number database (http://isrctn.org/) and Clinical Trials.gov (http://www.clinicaltrials.gov/). Registration should be done before the first participant is enrolled, but many of the databases do allow retrospective registration. However, by registering the trial once you receive ethical consent you will save time and overcome a major obstacle to publication.
All studies are different and therefore have different requirements regarding appropriate study design. The points above are just a few of the important considerations that should be made prior to the commencement of experimentation, and the general principles apply to a variety of different study types. It is true that sometimes even peer review fails to detect flaws in study design, as shown, for example, in the following report on randomized controlled clinical trials published in Chinese journals: http://www.trialsjournal.com/content/10/1/46 However, if you want your study to stand the test of time, be published in a top-tier journal and to be widely accepted by the international research community, then planning ahead and designing your study to make it robust and reliable will only serve to save you time, money and heartbreak later on.
