The phrase "a main study of" is correct and usable in written English.
It can be used when referring to a primary or significant research investigation on a particular topic or subject matter.
Example: "The research paper presents a main study of the effects of climate change on marine biodiversity."
Alternatives: "a primary analysis of" or "a key investigation into".
Individuals with missing information on BMI percentile (n=1,390) or whose BMI percentile was an outlier (n=165) were excluded from analysis, resulting in a main study population of 13,018 children and adolescents.
Arain et al [ 4] recommend the NIHR Evaluation, Trials and Studies Coordinating Centre definitions [ 6] which describe a pilot study as a miniature version of a main study run to test whether components of the main study work together, while feasibility studies are pieces of research done before a main study to answer the question "Can this study be done?".
The detection of abnormalities of Cholesterol inside the body is a main field of study in medical research using bio-medical image processing.
Data were derived from a pilot study and the main study of an intervention designed to promote adherence to antiretroviral medications.
Potential participants were identified from a national sample for the main study of 444,418 type 2 diabetes patients in 559 VA primary care clinics.
In addition to the main study, a satellite study of the change in plasma vit E concentrations through the winter was done at two dairy farms.
This was followed by a presentation of the main study findings and a group discussion of the findings and key questions for an hour (Table 2, & 3).
A Pilot Study is a version of the main study that is run in miniature to test whether the components of the main study can all work together.
The main study is a case study of all the training process of one trainee (John).
